Patent Application
20150234263
1. Field of the Invention
The present invention relates to a projector and a headup display, and more particularly, it relates to a projector and a headup display each including a base portion mounted with a light source portion.
2. Description of the Background Art
A projector or a headup display including a base portion mounted with a light source portion is known in general, as disclosed in International Publication No. 2006-118037, for example.
The aforementioned International Publication No. 2006-118037 discloses an optical pickup including a base mounted with a light source. The optical pickup further includes an adhesive for fixing the base and the light source to each other and a holding portion configured to hold the light source and to fix the same to the base. The holding portion is configured to transfer heat generated by the light source to the base.
However, the optical pickup disclosed in the aforementioned International Publication No. 2006-118037 is so configured that, when a plurality of light sources are mounted on the base, heat generated by all light sources is transferred to the same base portion (base), and hence the light sources may disadvantageously thermally interfere with each other through the base portion. When a first one of the plurality of light sources is cooled, for example, heat generated by a second one may reach the first light source through the base portion, and hence heat generated by the first light source and that reaching the same from the second light source may conceivably exceed the ability for cooling the first light source. In this case, it may conceivably be difficult to control the temperature of the first light source.
The present invention has been proposed in order to solve the aforementioned problem, and an object of the present invention is to provide a projector and a headup display each capable of preventing temperature control of a plurality of light source portions from becoming difficult.
In order to attain the aforementioned object, a projector according to a first aspect of the present invention includes a plurality of light source portions, an optical scanning portion reflecting and scanning light emitted from the light source portions, a base portion mounted with the light source portions and a heat transfer portion that contacts with the light source portions, and the thermal resistance of a first heat transfer path from the light source portions to the base portion is larger than the thermal resistance of a second heat transfer path from the light source portions to the heat transfer portion. In this specification, the term “thermal resistance” denotes a value obtained by multiplying a contact area with a heat source, the length of a heat radiation path (the distance to a next component) and heat conductivity by each other, for example. When a plurality of components are present on a heat transfer path, the thermal resistance is described as a term denoting the sum of values obtained by performing the aforementioned multiplication on the plurality of components.
In the projector according to the first aspect of the present invention, as hereinabove described, the thermal resistance of the first heat transfer path from the light source portions to the base portion is larger than the thermal resistance of the second heat transfer path from the light source portions to the heat transfer portion, whereby the quantity of heat transferred from the light source portions to the base portion is smaller than that of heat transferred from the light source portions to the heat transfer portion. Thus, the light source portions can be prevented from thermally interfering with each other through the base portion. Consequently, temperature control of the plurality of light source portions can be prevented from becoming difficult.
The aforementioned projector according to the first aspect preferably further includes a mounting base portion arranged between the light source portions and the base portion and mounted on the base portion integrally with the light source portions, and the thermal resistance of the mounting base portion is preferably smaller than the thermal resistance of the base portion. According to this structure, the mounting base portion can be made of metal, whereby a press-fitting engaging method can be employed when mounting (fitting) the light source portions on (to) the base portion (the mounting base portion). Consequently, the light source portions can be prevented from misregistration or inclination resulting from thermal expansion of an adhesive due to the press-fitting engaging method, dissimilarly to a method of mounting the light source portions on the base portion (or the mounting base portion) with an adhesive.
The aforementioned projector according to the first aspect preferably further includes a heat radiation portion arranged at a position separated from the base portion, the heat transfer portion preferably includes a first heat transfer portion that contacts with the light source portions and a second heat transfer portion that contacts with the first heat transfer portion and the heat radiation portion, the light source portions are preferably position-aligned and mounted on the base portion, the second heat transfer portion preferably includes a third heat transfer portion including a recess portion in which the first heat transfer portion is at least partially arranged and a fourth heat transfer portion provided to fill up a clearance between the first heat transfer portion and the recess portion and made of a material deformable in response to the clearance, and the recess portion preferably has inner side surfaces opposed to each other in a direction where mounting positions of the light source portions are aligned. According to this structure, the fourth heat transfer portion can reliably transfer heat generated by the light source portions to the heat radiation portion even if the dimension or the shape of the clearance between the light source portions and the first heat transfer portion and the recess portion of the third heat transfer portion changes due to dispersion in the mounting positions of the light source portions (and the first heat transfer portion) with respect to the base portion or the like. Consequently, the mounting positions of the light source portions with respect to the base portion can be aligned when the light source portions are mounted on the base portion, and temperature control of the light source portions can be prevented from becoming difficult.
In this case, the recess portion of the third heat transfer portion is preferably dividable along a direction parallel to the inner side surface arranged on the side of the heat radiation portion. According to this structure, a portion of a second divided portion of the third heat transfer portion constituting the recess portion can be combined after dividing the third heat transfer portion and arranging the first heat transfer portion in a portion of a first divided portion of the third heat transfer portion constituting the recess portion, when arranging the first heat transfer portion in the recess portion of the third heat transfer portion.
In the aforementioned projector including the third heat transfer portion having the recess portion, at least part of the third heat transfer portion and the heat radiation portion are preferably integrally formed. According to this structure, the number of components can be reduced dissimilarly to a case of providing the third heat transfer portion and the heat radiation portion separately from each other, whereby the structure of a light source device can be simplified.
The aforementioned projector according to the first aspect preferably further includes a heat radiation portion arranged at a position separated from the base portion, the heat transfer portion preferably includes a first heat transfer portion that contacts with the light source portions and a second heat transfer portion that contacts with the first heat transfer portion and the heat radiation portion, the light source portions are preferably position-aligned and mounted on the base portion, the first heat transfer portion preferably includes a first side surface in a direction opposite to the direction where the light source portions emit light, the second heat transfer portion preferably includes a second side surface parallel to the first side surface, and the first heat transfer portion and the second heat transfer portion are preferably arranged in a state where the first side surface and the second side surface are in surface contact with each other. According to this structure, the first heat transfer portion and the second heat transfer portion can be easily formed to be relatively movable while a contact area therebetween is increased as compared with a case where the first and second heat transfer portions are in point contact or line contact with each other, whereby heat generated by the light source portions can be efficiently transferred. Further, the first and second side surfaces are parallel to each other, whereby the first and second heat transfer portions can be relatively moved while maintaining the state where the first and second side surfaces are in surface contact with each other. Consequently, the mounting positions of the light source portions with respect to the base portion can be aligned when mounting the light source portions on the base portion, and temperature control of the light source portions can be prevented from becoming difficult. The term “surface contact”, generally indicating that the first and second heat transfer portions are directly in contact with each other on the surfaces thereof, indicates a wider concept also including a case where the first and second heat transfer portions are indirectly in contact with each other through a thin grease layer or the like.
In this case, the first heat transfer portion preferably includes a third side surface which is an outer surface in a direction perpendicular to the optical axes of the light source portions, the second heat transfer portion preferably includes a fourth side surface which is an inner side surface opposed to the third side surface, and a clearance is preferably provided between the third side surface and the fourth side surface. According to this structure, the mounting positions of the light source portions and the first heat transfer portion can be aligned due to the clearance provided between the third side surface and the fourth side surface.
In the aforementioned projector in which the first side surface and the second side surface are arranged in surface contact with each other, the light source portions preferably have columnar stems, the projector preferably further includes a mounting base portion arranged between the light source portions and the base portion and mounted with the light source portions, the mounting base portion preferably includes a first support portion provided at a prescribed angular interval along the outer peripheral surfaces of the stems to be in contact with the outer peripheral surfaces of the stems, and the first heat transfer portion preferably includes a second support portion provided at a prescribed angular interval along the outer peripheral surfaces of the stems to be in contact with portions of the outer peripheral surfaces of the stems not supported by the first support portion. According to this structure, the first support portion of the mounting base portion comes into contact with the outer peripheral surfaces of the stems, whereby the mounting base portion can be precisely mounted with respect to central positions of the stems of the light source portions. Thus, precision in a mounting position of the mounting base portion with respect to the light source portions can be improved. Further, the second support portion of the first heat transfer portion comes into contact with the portions of the outer peripheral surfaces of the stems not supported by the first support portion, whereby contact areas between the light source portions and the first heat transfer portion can be increased as compared with a case where no second support portion is provided. Thus, heat from the light source portions can be efficiently transferred to the first heat transfer portion. Consequently, heat from the light source portions can be efficiently transferred to the first heat transfer portion while improving precision in the mounting position of the mounting base portion with respect to the light source portions.
In this case, the stems preferably have front surfaces on the side where the light source portions emit light and back surfaces on the side opposite to the direction where the light source portions emit light, the mounting base portion preferably includes a front surface support portion coming into contact with and supporting the front surfaces of the stems, and the first heat transfer portion preferably includes a back surface support portion coming into contact with and supporting the back surfaces of the stems. According to this structure, the front surface support portion comes into contact with the front surfaces thereby preventing misregistration of the light source portions with respect to the mounting base portion in a tilting direction, whereby the light source portions can be precisely mounted with respect to the mounting portion. Further, the back surface support portion comes into contact with the base surfaces, whereby heat from the light source portions can be transferred to the first heat transfer portion also from the back surface support portion in addition to the second support portion. Consequently, the contact areas between the light source portions and the first heat transfer portion can be increased, whereby heat from the light source portions can be more efficiently transferred to the first heat transfer portion.
In the aforementioned projector including the first support portion and the second support portion, a region where the second support portion is in contact with the outer peripheral surfaces of the stems is preferably larger than a region where the first support portion is in contact with the outer peripheral surfaces of the stems. According to this structure, the a region where the second support portion is in contact with the outer peripheral surfaces of the stems can be relatively enlarged, whereby the area where the second support portion (the first heat transfer portion) comes into contact with the outer peripheral surfaces (the light source portions) of the stems is enlarged and hence heat from the light source portions can be further efficiently transferred to the first heat transfer portion. Consequently, heat from the light source portions can be further efficiently transferred to the first heat transfer portion through the second support portion having a large contact area while improving precision in the mounting position of the mounting base portion with respect to the light source portions through the first support portion.
In the aforementioned projector including the first support portion and the second support portion, the length of the first support portion and the length of the second support portion are preferably both smaller than the length of the stems in the direction of the optical axes of the light source portions. According to this structure, the first and second support portions can be prevented from interfering with each other in the direction of the optical axes of the light source portions. Thus, the light source portions and the first heat transfer portion can be prevented from formation of clearances therebetween resulting from mutual interference between the first and second support portions, whereby the light source portions and the first heat transfer portion can be prevented from entering noncontact states. Consequently, heat from the heat source portions can be more reliably transferred to the first heat transfer portion.
In the aforementioned projector including the first support portion and the second support portion, the mounting base portion preferably includes a contact surface coming into contact with the base portion, and the mounting base portion and the first heat transfer portion are preferably arranged to parallelize the contact surface of the mounting base portion and the first side surface of the first heat transfer portion to each other. According to this structure, the contact surface and the first and second side surfaces are arranged to be parallel to each other respectively and hence the first side surface of the first heat transfer portion and the second side surface of the second heat transfer portion can be maintained in the surface contact state, also when the mounting base portion is position-aligned with respect to the base portion in a direction parallel to the contact surface.
In the aforementioned projector including the first support portion and the second support portion, the mounting base portion preferably has light transmissivity, and the base portion preferably has a light shielding property. According to this structure, the mounting base portion can be fixed to the base portion by laser welding when the mounting base portion is mounted on the base portion. Consequently, the mounting base portion can be more reliably fixed to the base portion in a state where the mounting base portion is prevented from misregistration with respect to the base portion, as compared with a case of employing an adhesive.
The aforementioned projector including the first support portion and the second support portion preferably further includes an elastic member mounted on the mounting base portion, and the first heat transfer portion is preferably mounted on the mounting base portion by the elastic member. According to this structure, the first heat transfer portion can be mounted on the mounting base portion while preventing application of excess force to the first heat transfer portion and the mounting base portion due to elastic deformation of the elastic member also when the first heat transfer portion and the mounting base portion are position-aligned.
The aforementioned projector according to the first aspect preferably further includes a heat radiation portion arranged at a position separated from the base portion, the heat transfer portion preferably includes a first heat transfer portion that contacts with the light source portions and a second heat transfer portion that contacts with the first heat transfer portion and the heat radiation portion, the heat radiation portion preferably includes an element having a cooling function, and a surface of the first heat transfer portion excluding the boundary surface between the first heat transfer portion and the light source portions or a surface of the second heat transfer portion excluding the boundary surface between the second heat transfer portion and the first heat transfer portion is preferably at least partially covered with a heat shielding member. According to this structure, the element having a cooling function can cool the light source portions also when the external temperature of the light source device is relatively high. When the temperature of the first or second heat transfer portion is lower than the external temperature other than the light source portions due to the element having a cooling function, the first and second heat transfer portions absorb excess heat from the exterior other than the light source portions, and hence the size of the element having a cooling function must be increased. With respect to this point, the surface of the first heat transfer portion excluding the boundary surface between the first heat transfer portion and the light source portions or the surface of the second heat transfer portion excluding the boundary surface between the second heat transfer portion and the first heat transfer portion is at least partially covered with the heat shielding member according to the present invention, whereby the first and second heat transfer portions can be prevented from absorbing excess heat from the exterior other than the light source portions. Thus, the element having a cooling function can be prevented from size increase.
A headup display according to a second aspect of the present invention includes a plurality of light source portions, an optical scanning portion reflecting and scanning light emitted from the light source portions, a base portion mounted with the light source portions and a heat transfer portion that contacts with the light source portions, while the thermal resistance of a first heat transfer path from the light source portions to the base portion is larger than the thermal resistance of a second heat transfer path from the light source portions to the heat transfer portion.
In the headup display according to the second aspect of the present invention, temperature control of the plurality of light source portions can be prevented from becoming difficult also in the headup display, due to the aforementioned structure.
The aforementioned headup display according to the second aspect preferably further includes a mounting base portion arranged between the light source portions and the base portion and mounted on the base portion integrally with the light source portions, and the thermal resistance of the mounting base portion is preferably smaller than the thermal resistance of the base portion. According to this structure, the mounting base portion can be made of metal also in the headup display, whereby a press-fitting engaging method can be employed when mounting (fitting) the light source portions on (to) the base portion (the mounting base portion). Consequently, the light source portions can be prevented from misregistration or inclination resulting from thermal expansion of an adhesive due to the press-fitting engaging method, dissimilarly to a method of mounting the light source portions on the base portion (or the mounting base portion) with an adhesive.
The aforementioned headup display according to the second aspect preferably further includes a heat radiation portion arranged at a position separated from the base portion, the heat transfer portion preferably includes a first heat transfer portion that contacts with the light source portions and a second heat transfer portion that contacts with the first heat transfer portion and the heat radiation portion, the light source portions are preferably position-aligned and mounted on the base portion, the second heat transfer portion preferably includes a third heat transfer portion including a recess portion in which the first heat transfer portion is at least partially arranged and a fourth heat transfer portion provided to fill up a clearance between the first heat transfer portion and the recess portion and made of a material deformable in response to the clearance, and the recess portion preferably has inner side surfaces opposed to each other in a direction where mounting positions of the light source portions are aligned. According to this structure, the fourth heat transfer portion can reliably transfer heat generated by the light source portions to the heat radiation portion even if the dimension or the shape of the clearance between the light source portions and the first heat transfer portion and the recess portion of the third heat transfer portion changes due to dispersion in the mounting positions of the light source portions (and the first heat transfer portion) with respect to the base portion or the like. Consequently, the mounting positions of the light source portions with respect to the base portion can be aligned when the light source portions are mounted on the base portion, and temperature control of the light source portions can be prevented from becoming difficult.
The aforementioned headup display according to the second aspect preferably further includes a heat radiation portion arranged at a position separated from the base portion, the heat transfer portion preferably includes a first heat transfer portion that contacts with the light source portions and a second heat transfer portion that contacts with the first heat transfer portion and the heat radiation portion, the light source portions are preferably position-aligned and mounted on the base portion, the first heat transfer portion preferably includes a first side surface in a direction opposite to the direction where the light source portions emit light, the second heat transfer portion preferably includes a second side surface parallel to the first side surface, and the first heat transfer portion and the second heat transfer portion are preferably arranged in a state where the first side surface and the second side surface are in surface contact with each other. According to this structure, the first and second heat transfer portions can be relatively moved while maintaining the state where the first and second side surfaces are in surface contact with each other also in the headup display. Consequently, the mounting positions of the light source portions with respect to the base portion can be aligned when mounting the light source portions on the base portion, and temperature control of the light source portions can be prevented from becoming difficult.
In this case, the light source portions preferably have columnar stems, the headup display preferably further includes a mounting base portion arranged between the light source portions and the base portion and mounted with the light source portions, the mounting base portion preferably includes a first support portion provided at a prescribed angular interval along the outer peripheral surfaces of the stems to be in contact with the outer peripheral surfaces of the stems, and the first heat transfer portion preferably includes a second support portion provided at a prescribed angular interval along the outer peripheral surfaces of the stems to be in contact with portions of the outer peripheral surfaces of the stems not supported by the first support portion. According to this structure, heat from the light source portions can be efficiently transferred to the first heat transfer portion through the second support portion while improving precision in a mounting position of the mounting base portion with respect to the light source portions through the first support portion also in the headup display.
According to the present invention, as hereinabove described, temperature control of the plurality of light source portions can be prevented from becoming difficult.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Embodiments of the present invention are now described with reference to the drawings.
The structure of a headup display 100 according to a first embodiment of the present invention is described with reference to
As shown in
As shown in
The light source device 1 of the headup display 100 includes laser diodes 11a (red (R)), 11b (green (G)) and 11c (blue (B)), collimator lenses 12a to 12c, polarizing prisms 13a to 13c, a beam shaping prism 14, a condensing lens 15, Peltier elements 16a and 16b, temperature sensors 17a and 17b and flexible printed boards 18a to 18c. The laser diodes 11a to 11c are examples of the “light source portions” in the present invention. The Peltier elements 16a and 16b are examples of the “element having a cooling function” or the “heat radiation portion” in the present invention.
As shown in
The Peltier element 16a is configured to be supplied with power from an element driving portion 24 described later thereby lowering the temperature of (absorbing heat from) a first surface side (the side of the laser diode 11a) and making a second surface side (the side of a heat sink 5a described later) generate heat (radiate the heat absorbed on the first surface side). The Peltier element 16b is also configured to lower the temperature of (adsorbs heat from) a first surface side (the side of the laser diode 11b) and to make a second surface side (the side of a heat sink 5b described later) generate heat (radiate the heat adsorbed on the first surface side). In other words, the Peltier elements 16a and 16b have cooling functions with respect to the first surface sides. The Peltier elements 16a and 16b are so configured that the quantities of heat absorption are controllable in response to the magnitude of the power supplied from the element driving portion 24.
The temperature sensor 17a is arranged in the vicinity of the laser diode 11a, and configured to be capable of detecting the temperature of the laser diode 11a. Further, the temperature sensor 17a is connected with a main CPU (Central Processing Unit) 21 described later, and configured to transmit information of the detected temperature to the main CPU 21. Similarly to the temperature sensor 17a, the temperature sensor 17b is configured to be capable of detecting the temperature of the laser diode 11b, and to transmit information of the detected temperature to the main CPU 21.
The flexible printed boards 18a to 18c are provided between an LD (laser diode) driver 23c described later and the respective ones of the laser diodes 11a to 11c, and configured to be capable of supplying power from the LD driver 23c to the respective ones of the laser diodes 11a to 11c.
As shown in
The main CPU 21 is configured to acquire information of the temperatures of the laser diodes 11a and 11b from the temperature sensors 17a and 17b and to control the quantities of heat absorption of the Peltier elements 16a and 16b (the temperatures of the laser diodes 11a and 11b) on the basis of the acquired information of the temperatures. More specifically, the main CPU 21 is configured to control the Peltier element 16a so that the laser diode 11a emitting a red laser beam keeps a temperature of at least 5° C. and not more than 10° C. Further, the main CPU 21 is configured to control the Peltier element 16b so that the laser diode 11b emitting a green laser beam keeps a temperature of about 25° C. On the other hand, the laser diode 11c emitting a blue laser beam is provided with no Peltier element, and configured to naturally radiate heat from the heat sink 5b.
The operation portion 22 is configured to be capable of accepting operations by the user. For example, the operation portion 22 is configured to be capable of accepting an operation of turning on the headup display 100, that of changing a projection angle of an image projected on the screen 201, that of changing the resolution of the image projected on the screen 201 and the like.
As shown in
The image processing portion 23a is configured to output image information to the light source control portion 23b and the mirror control portion 23d on the basis of an externally input image signal. The light source control portion 23b is configured to control application of the laser beams from the laser diodes 11a to 11c by controlling the LD driver 23b on the basis of the image information received from the image processing portion 23a.
The mirror control portion 23d is configured to control the mirror driver 23e by transmitting a prescribed control signal thereto. The mirror driver 23e is configured to drive MEMS (Micro Electro Mechanical Systems) mirrors 31 and 32 described later by supplying power thereto on the basis of the control signal received from the mirror control portion 23d.
As shown in
The optical scanning portion 3 of the headup display 100 is provided with the MEMS mirrors 31 and 32, as shown in
According to the first embodiment, the light source device 1 is provided with a case body portion 4a made of resin or the like and provided therein with a housing portion 7 (base portion) described later and the like, a case upper surface portion 4b and a case light-emitting portion 4c made of resin or the like, heat sinks 5a and 5b made of metal such as aluminum, a heat transfer member 6a made of metal such as aluminum (or resin higher in heat conductivity than general resin) and the Peltier element 16a, as shown in
The heat sinks 5a and 5b are arranged to be adjacent to each other in plan view (as viewed along arrow Z1), as shown in
As shown in
According to the first embodiment, the laser diode 11a emitting the red laser beam is mounted on a first side surface (the side surface along arrow Y2) of the housing portion 7 to emit the laser beam in the inner direction (the direction along arrow Y1) of the housing portion 7, as shown in
According to the first embodiment, LD (laser diode) plates 8a to 8c made of metal such as aluminum (or resin higher in heat conductivity than general resin) are arranged on back surface sides (in directions opposite to the directions where the laser diodes 11a to 11c emit the laser beams) of the laser diodes 11a to 11c respectively, and provided to be capable of transferring heat from the back surfaces of the laser diodes 11a to 11c to the side of the heat sinks 5a and 5b (the side along arrow Z2 in
More specifically, the laser diode 11a and the LD plate 8a are fixed to each other with an adhesive or the like in a state where the side of the back surface (the side along arrow Y2) of the laser diode 11a and the LD plate 8a are in surface contact with each other before the laser diode 11a is mounted on the housing portion 7, as shown in
As shown in
The mounting positions of the laser diodes 11a to 11c are so aligned in the aforementioned manner that the optical axes of the laser beams emitted from the laser diodes 11a to 11c through a light-emitting portion 72 provided on the front surface side (the side along arrow X2) of the housing portion 7 are coaxially superposed with each other through the collimator lenses 12a to 12c and the polarizing prisms 13a to 13c provided in the aforementioned housing portion 7, as shown in
According to the first embodiment, the laser diode 11a includes three electrodes 19 provided to project from the laser diode 11a toward the back surface side (the side along arrow Y2) thereof, as shown in
L3>L4 (1)
According to the first embodiment, the light source device 1 includes the flexible printed board 18a capable of supplying power to the laser diode 11a, as shown in
According to the first embodiment, the heat transfer member 6a is arranged between the LD plate 8a and the heat sink 5a and provided to be capable of transferring heat from the LD plate 8a to the Peltier element 16a (the heat sink 5a), as shown in
As shown in
According to the first embodiment, the LD plate 8a includes an outer side surface 83 in a direction orthogonal to the direction where the laser diode 11a emits the laser beam, as shown in
The Peltier element 16a is arranged on a side (the side along arrow Z2) of the lower heat transfer portion 62a closer to the heat sink 5a, while the lower heat transfer portion 62a and a heat-absorbably constituted first side (the upper surface) of the Peltier element 16a are configured to be fixed to each other in a state in surface contact with each other. Thus, the headup display 100 is so configured that the Peltier element 16a absorbs heat transferred to the lower heat transfer portion 62a.
As shown in
As shown in
As shown in
As shown in
According to the first embodiment, the heat transfer member 6a is configured to be capable of transferring heat from the laser diode 11a and the LD plate 8a whose mounting positions have been aligned to the Peltier element 16b (the heat sink 5a) on any position in the range where the mounting positions of the laser diode 11a and the LD plate 8a are aligned in the direction parallel to the back surface of the laser diode 11a, as shown in
More specifically, the upper heat transfer portion 61a has a height h1 (in the direction along arrow Z) and a width W1 (in the direction along arrow X) from the upper end portion of the lower heat transfer portion 62a, as shown in
h1≧L2 (2)
W1≧L1 (3)
According to the first embodiment, the heat transfer member 6a and the LD plate 8a are configured not to be fixed to each other. In other words, the heat transfer member 6a and the LD plate 8a are configured to be relatively movable.
Transfer paths of heat (heat transfer paths) in the headup display 100 according to the first embodiment are now described with reference to
According to the first embodiment, the thermal resistance of a first heat transfer path from the laser diode 11a (11b or 11c) to the housing portion 7 (base portion) is larger than the thermal resistance of a second heat transfer path from the laser diode 11a (11b or 11c) to the heat sink 5a or 5b. In this specification, the term “thermal resistance” denotes a value obtained by multiplying a contact area with a heat source, the length of a heat radiation path (the distance to a next component) and heat conductivity by each other. When a plurality of components are present on the heat transfer path, the thermal resistance is described as a term denoting the sum of values obtained by performing the aforementioned multiplication on the plurality of components.
As shown in
Then, the heat received by the LD plate 8a is transferred to the heat sink 5a through the heat transfer member 6a and the Peltier element 16a in surface contact with each other (through the second heat transfer path). Then, the heat generated by the laser diode 11a and transferred to the heat sink 5a is radiated from the light source device 1 through the fins (see
The flexible printed board 18a supplies power to the laser diode 11b, which in turn emits a laser beam and generates heat similarly to the laser diode 11a. The heat generated by the laser diode 11b is mainly transferred to the LD plate 8b. Then, the heat received by the LD plate 8b is transferred to the heat sink 5b through the heat transfer member 6b and the Peltier element 16b (through the second heat transfer path). The heat generated by the laser diode 11b and transferred to the heat sink 5b is radiated from the light source device 1 through the fins (see
The flexible printed board 18c supplies power to the laser diode 11c, which in turn emits a laser beam and generates heat. The heat generated by the laser diode 11c is mainly transferred to the LD plate 8c. Then, the heat received by the LD plate 8c is transferred to the heat sink 5b through the heat transfer member 6c (through the second heat transfer path). The heat generated by the laser diode 11c and transferred to the heat sink 5 is radiated from the light source device 1 through the fins (see
According to the first embodiment, the following effects can be attained:
According to the first embodiment, as hereinabove described, the LD plates 8a to 8c are arranged on the back surface sides of the respective ones of the laser diodes 11a to 11c, while the heat transfer members 6a to 6c are arranged between the LD plates 8a to 8c and the heat sinks 5a and 5b respectively. Thus, the mounting position of the laser diode 11a with respect to the housing portion 7 can be aligned and the heat generated by the laser diode 11a can be transferred to the heat sink 5a through the LD plate 8a and the heat transfer member 6a in the case where the heat transfer member 6a is arranged after the mounting positions of the laser diode 11a and the LD plate 8a are aligned with respect to the housing portion 7 when the laser diode 11a is mounted on the housing portion 7.
According to the first embodiment, as hereinabove described, the heat sinks 5a and 5b are arranged to be separated from the housing portion 7 (arranged on positions exposed with respect to the housing portion 7), the LD plates 8a to 8c are provided to be capable of transferring heat from the back surfaces of the laser diodes 11a to 11c to the sides of the heat sinks 5a and 5b respectively, and the heat transfer members 6a to 6c are provided to be capable of transferring heat from the LD plates 8a to 8c to the heat sinks 5a and 5b respectively. Thus, the heat generated by the laser diodes 11a to 11c can be radiated from the heat sinks 5a and 5b having high heat radiation properties, dissimilarly to a case of transferring heat from the laser diodes 11a to 11c to the housing portion 7. Consequently, the mounting positions of the laser diodes 11a to 11c with respect to the housing portion 7 can be aligned, and temperature control of the laser diodes 11a to 11c can be prevented from becoming difficult when the laser diodes 11a to 11c are mounted on the housing portion 7.
According to the first embodiment, as hereinabove described, the laser diodes 11a to 11c are so configured that the mounting positions thereof are aligned in the directions perpendicular to the optical axes of the laser diodes 11a to 11c (directions parallel to the back surfaces of the laser diodes 11a to 11c) when the laser diodes 11a to 11c are mounted on the housing portion 7, while the LD plates 8a to 8c or the heat transfer members 6a to 6c are configured to be capable of transferring heat generated by the position-aligned laser diodes 11a to 11c to the sides of the heat sinks 5a and 5b on any positions in the range where the mounting positions of the laser diodes 11a to 11c are aligned in the directions parallel to the back surfaces of the laser diodes 11a to 11c. Thus, heat generated by the laser diodes 11a to 11c can be transferred to the heat sinks 5a and 5b regardless of the mounting positions of the laser diodes 11a to 11c, whereby temperature control of the respective ones of the laser diodes 11a to 11c can be reliably prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the laser diodes 11a to 11c and the LD plates 8a to 8c are provided to be fixed to each other in heat-transferable states respectively. Further, the LD plates 8a to 8c and the heat transfer members 6a to 6c are configured to be capable of transferring heat in states relatively movable in the directions perpendicular to the optical axes of the laser diodes 11a to 11c (in the directions along the back surfaces of the laser diodes 11a to 11c) respectively. In addition, the heat transfer members 6a to 6c are configured to be capable of transferring heat from the laser diodes 11a to 11c and the LD plates 8a to 8c whose mounting positions have been aligned to the heat sinks 5a and 5b on any positions in the range where the mounting positions of the laser diodes 11a to 11c and the LD plates 8a to 8c are aligned in the directions perpendicular to the optical axes of the laser diodes 11a to 11c (in the directions parallel to the back surfaces of the laser diodes 11a to 11c). Thus, the LD plates 8a to 8c and the heat transfer members 6a to 6c can transfer heat in the states relatively movable in the directions along the back surfaces of the laser diodes 11a to 11c, whereby heat generated by the laser diodes 11a to 11c can be transferred to the heat sinks 5a and 5b regardless of the mounting positions of the laser diodes 11a to 11c and the LD plates 8a to 8c. Consequently, temperature control of the laser diodes 11a to 11c can be more reliably prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the LD plates 8a to 8c (surfaces 82) and the heat transfer members 6a to 6c (side surfaces 161a) are arranged in surface contact states in the directions along the back surfaces of the laser diodes 11a to 11c. Thus, the LD plates 8a to 8c and the heat transfer members 6a to 6c can be easily configured to be relatively movable, while the contact areas are enlarged as compared with a case where the LD plates 8a to 8c and the heat transfer members 6a to 6c are in point or line contact with each other, whereby heat generated by the laser diodes 11a to 11c can be efficiently transferred. Further, the LD plate 8a and the heat transfer member 6a can be relatively moved while maintaining the state where the surface 82 and the side surface 161a are in contact with each other.
According to the first embodiment, as hereinabove described, the laser diodes 11a to 11c include the electrodes 19 provided to project from the laser diodes 11a to 11c to the back surface sides thereof, and the length L4 of the LD plates 8a to 8c is larger than the length L3 of the electrodes in the directions parallel to the extensional directions of the electrodes 19. Thus, the electrodes 19 can be prevented from projecting beyond the LD plates 8a to 8c, whereby no structures corresponding to the projecting electrodes 19 (electrodes relieving electrodes) may be provided on the heat transfer members 6a to 6c when the heat transfer members 6a to 6c are provided in the extensional directions of the electrodes 19. Therefore, the contact areas of the LD plates 8a to 8c and the heat transfer members 6a to 6c can be prevented from reduction resulting from provision of structures for relieving the electrodes on the heat transfer members 6a to 6c.
According to the first embodiment, as hereinabove described, the laser diodes 11a to 11c include the electrodes 19 provided to project from the laser diodes 11a to 11c toward the back surface sides thereof. The light source device 1 further includes the flexible printed boards 18a to 18c capable of supplying power to the laser diodes 11a to 11c. Further, the LD plates 8a to 8c are provided with the openings 81 on the sides opposite to the heat sinks 5a and 5b, and the flexible printed boards 18a to 18c are connected to the electrodes 19 through the openings 81 of the LD plates 8a to 8c and configured to supply power to the laser diodes 11a to 11c. Thus, the flexible printed boards 18a to 18c can easily supply power to the laser diodes 11a to 11c, and the quantities of heat transferred by the LD plates 8a to 8c can be prevented from reduction resulting from provision of the openings 81, dissimilarly to a case of providing the openings 81 on the sides of the LD plates 8a to 8c closer to the heat sinks 5a and 5b.
According to the first embodiment, as hereinabove described, the housing portion 7 is so configured that the plurality of laser diodes 11a to 11c can be mounted thereon, while the LD plates 8a to 8c are arranged on the back surface sides of the laser diodes 11a to 11c to be capable of transferring heat from the back surfaces of the laser diodes 11a to 11c to the sides of the heat sinks 5a and 5b. When the housing portion 7 is provided with a plurality of laser diodes (the laser diodes 11a to 11c) in general, the laser diodes may thermally interfere with each other through the housing portion 7. In this point, the headup display 100 according to the first embodiment is so configured that heat generated by the laser diodes 11a to 11c can be transferred to the heat sinks 5a and 5b set to be separated from the housing portion 7 as hereinabove described, whereby the LD plates 8a to 8c and the heat transfer members 6a to 6c transfer heat generated by the laser diodes 11a to 11c to the heat sinks 5a and 5b set to be separated from the housing 7. Consequently, the laser diodes 11a to 11c can be prevented from thermally interfering with each other through the housing portion 7, dissimilarly to a case where heat generated by the laser diodes 11a to 11c are transferred to the same housing portion 7. Further, temperature control (heat radiation or the like) of the respective ones of the laser diodes 11a to 11c can be prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the LD plates 8a to 8c are arranged to be in contact with the laser diodes 11a to 11c respectively, while the heat transfer members 6a to 6c are arranged to be in contact with the LD plates 8a to 8c and the heat sinks 5a and 5b respectively. Thus, the mounting positions of the laser diodes 11a to 11c with respect to the housing portion 7 can be aligned and heat generated by the laser diodes 11a to 11c can be transferred to the heat sinks 5a and 5b through the LD plates 8a to 8c and the heat transfer members 6a to 6c in the case where the heat transfer members 6a to 6c are arranged after the mounting positions of the laser diodes 11a to 11c and the LD plates 8a to 8c are aligned with respect to the housing portion 7 when the laser diodes 11a to 11c are mounted on the housing portion 7, for example.
According to the first embodiment, as hereinabove described, the heat sinks 5a and 5b are arranged to be separated from the housing portion 7 (arranged on the positions exposed with respect to the housing portion 7), the LD plates 8a to 8c are arranged to come into contact with the laser diodes 11a to 11c respectively, and the heat transfer members 6a to 6c are arranged to come into contact with the LD plates 8a to 8c and the heat sinks 5a to 5b. Thus, heat generated by the laser diodes 11a to 11c is transferred to the heat sinks 5a and 5b arranged to be separated from the housing portion 7 (arranged on the positions exposed with respect to the housing portion 7), whereby the laser diodes 11a to 11c can be prevented from thermally interfering with each other through the housing portion 7, dissimilarly to a case where heat generated by the laser diodes 11a to 11c is transferred to the same housing portion 7. Consequently, temperature control of the laser diodes 11a to 11c can be prevented from becoming difficult. Thus, the mounting positions of the laser diodes 11a to 11c with respect to the housing portion 7 can be aligned when the laser diodes 11a to 11c are mounted on the housing portion 7, while temperature control of the laser diodes 11a to 11c can be prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the headup display 100 is so configured that the thermal resistance of the first heat transfer path from the laser diode 11a (11b or 11c) to the housing portion 7 (base portion) is larger than the thermal resistance of the second heat transfer path from the laser diode 11a (11b or 11c) to the heat sink 5a or 5b (the LD plates 8a to 8c or the heat transfer members 6a to 6c) so that the quantity of heat transferred from the laser diode 11a (11b or 11c) to the housing portion 7 is smaller than the quantity of heat transferred from the laser diode 11a (11b or 11c) to the heat sink 5a or 5b, whereby the laser diodes 11a to 11c can be prevented from thermally interfering with each other through the housing portion 7. Thus, temperature control of the laser diodes 11a to 11c can be further prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the headup display 100 is provided with the LD plate 8a arranged in contact with the laser diode 11a and the heat transfer member 6a arranged in contact with the LD plate 8 and the heat sink 5a, and the housing portion 7 is so configured that the laser diode 11a is position-aligned and mounted thereon. The LD plate 8a includes the outer side surface 83, the heat transfer member 6a includes the side surface 16a, and the clearance 63a is provided between the outer surface 83 and the side surface 162a. Thus, the mounting positions of the laser diode 11a and the LD plate 8a can be moved without moving the arrangement position of the heat transfer member 6a, due to the clearance 63a provided between the outer surface 83 and the side surface 162a. Consequently, the mounting position of the laser diode 11a with respect to the housing portion 7 can be aligned when the laser diode 11a is mounted on the housing portion 7, while temperature control of the laser diode 11a can be prevented from becoming difficult.
According to the first embodiment, as hereinabove described, the Peltier elements 16a and 16b are provided between the heat transfer member 6a (the heat transfer members 6a and 6c) and the heat sink 5a (as well as the heat sink 5b). Thus, the Peltier elements 16a and 16b can cool the laser diodes 11a to 11c, even if the temperature outside the light source device 1 is relatively high. Thus, temperature control of the laser diodes 11a to 11c can be prevented from becoming difficult also when the temperature outside the light source device 1 is relatively high.
The structure of a headup display 101 according to a second embodiment of the present invention is now described with reference to
As shown in
As shown in
According to the second embodiment, the first heat transfer member 64a is arranged to partially cover the upper surface side (the side along arrow Z1) of the housing portion 7a, which is provided with engaging portions 73 and 74 configured to be engageable with the first heat transfer member 64a including engaging portions 64c and 64d configured to be engageable with the engaging portions 73 and 74 provided on the housing portion 7a, as shown in
More specifically, the housing portion 7a is provided with the engaging portions 73 and 74 having convex shapes of a length L5, as shown in
D1>L5 (4)
Thus, the laser diode 11a is configured to be capable of being position-aligned in a direction (along arrow Y) perpendicular to the back surface thereof also when the position (in the direction along arrow Y) where the first heat transfer member 64a and the LD plate 8a are in surface contact with each other is dispersed, since the depth D1 of the engaging portions 64c and 64d is larger than the length L5 of the engaging portions 73 and 74. The remaining structures of the headup display 101 according to the second embodiment are similar to those of the headup display 100 according to the first embodiment.
According to the second embodiment, the following effect can be attained:
According to the second embodiment, as hereinabove described, the housing portion 7a is provided with the engaging portions 73 and 74 configured to be engageable with the first heat transfer member 64a, which in turn includes the engaging portions 64c and 64d configured to be engageable with the engaging portions 73 and 74 provided on the housing portion 7a, and the engaging portions 73, 74, 64c and 64d are configured to engage with each other to be capable of being position-aligned in the direction perpendicular to the back surface of the laser diode 11a. Further, the depth D1 of the engaging portions 64c and 64d is larger than the length L5 of the engaging portions 73 and 74. Thus, the housing portion 7a and the first heat transfer member 64a can be fixed to each other also when the arrangement position of the laser diode 11a or the LD plate 8a provided between the housing portion 7a and the first heat transfer member 64a is dispersed. The remaining effects of the headup display 101 according to the second embodiment are similar to those of the headup display 100 according to the first embodiment.
The structure of a headup display 102 according to a third embodiment of the present invention is now described with reference to
As shown in
As shown in
According to the third embodiment, surfaces (S1, S2 and S3) of the LD plate 8d excluding the boundary surface between the same and the laser diode 11a and a surface (S4) of the heat transfer member 6e excluding the boundary surface between the same and the LD plate 8d are covered by insulation coating. More specifically, insulation coating with heat conductivity of at least 0.1 W/m·K and less than 0.22 W/m·K is applied to the upper surface (S1), the back surface (S2) and a side end surface (S3) of the LD plate 8d and the overall side surface (S4) of the heat transfer member 6e.
The heat conductivity of the insulation coating is smaller than the heat conductivity (about 100 W/m·K) of an aluminum alloy. Thus, the quantity of heat transferred from an inner portion E of the case body portion 4e to the LD plate 8d or the heat transfer member 6e can be reduced when the temperature of the inner portion E of the case body portion 4e is higher than that of the LD plate 8d or the heat transfer member 6e. In this case, a main CPU 21 and the Peltier element 16a control the laser diode 11a to keep a temperature of at least 5° C. and not more than 10° C. as hereinabove described, whereby necessity of increasing cooling performance of the Peltier element 16a is suppressed also when the temperature of the inner portion E of the case body 4e exceeds 10° C. The remaining structures of the headup display 102 according to the third embodiment are similar to those of the headup display 100 according to the first embodiment.
According to the third embodiment, the following effect can be attained:
According to the third embodiment, as hereinabove described, the headup display 102 is provided with the LD plate 8d arranged in contact with the laser diode 11a, the heat transfer member 6e arranged in contact with the LD plate 8d and the Peltier element 16a, while the surfaces (S1, S2 and S3) of the LD plate 8d excluding the boundary surface between the same and the laser diode 11a and the surface (S4) of the heat transfer member 6e excluding the boundary surface between the same and the LD plate 8d are covered by the insulation coating. When the temperature of the LD plate 8d or the heat transfer member 6e is lower than that of the outside of the laser diode 11a (the inner portion E of the case body portion 4e) due to the Peltier element 16a, the LD plate 8d and the heat transfer member 6e absorb excess heat from the outside of the laser diode 11a (the inner portion E of the case body portion 4e), and hence the Peltier element 16a must be increased in size. In this point, the headup display 102 according to the third embodiment includes the Peltier element 16a while the surfaces (S1, S2 and S3) of the LD plate 8d excluding the boundary surface between the same and the laser diode 11a and the surface (S4) of the heat transfer member 6e excluding the boundary surface between the same and the LD plate 8d are covered by the insulation coating so that the LD plate 8d and the heat transfer member 6e can absorb excess heat from the outside of the laser diode 11a (the inner portion E of the case body portion 4e), whereby size increase of the Peltier element 16a can be prevented. The remaining effects of the headup display 102 according to the third embodiment are similar to those of the headup display 100 according to the first embodiment.
The structure of a headup display 301 according to a fourth embodiment of the present invention is now described with reference to
As shown in
According to the fourth embodiment, the light source device 301a includes a housing portion 306 (base portion) made of resin or the like, heat sinks 307 and 308 made of metal such as aluminum, heat transfer members 309a to 309c made of metal and Peltier elements 310a and 310b, as shown in
According to the fourth embodiment, the Peltier elements 310a and 310b are arranged on the upper surface (the surface in the direction along arrow Z1 in
According to the fourth embodiment, the heat transfer member 309c is arranged on the upper surface (the surface along arrow Z1 in
As shown in
As shown in
As shown in
According to the fourth embodiment, an LD plate 312a made of metal or the like is provided on the rear surface side (the side along arrow Y2 in
According to the fourth embodiment, the laser diodes 311a to 311c are configured to be movable so that mounting positions thereof are aligned when the laser diodes 311a to 311c are mounted on the housing portion 306, as shown in
According to the fourth embodiment, the heat transfer member 309a has a recess portion 309d in which the laser diode 311a and the LD plate 312a are arrangeable, as shown in
According to the fourth embodiment, the width W11 and the height H11 of the recess portion 309d of the heat transfer member 309a in the directions (along arrows X and Z in
L13<L11
L14<L12
More specifically, the recess portion 309d of the heat transfer member 309a is rectangularly formed as viewed from the front side, and has the width W11 (in the direction along arrow X in
W11≧L11 (5)
H11≧L12 (6)
D11≧t10 (7)
Transfer paths of heat (heat transfer paths) in the headup display 301 according to the fourth embodiment are now described with reference to
First, the laser diode 311a is supplied with power, thereby emitting a laser beam and generating heat, as shown in
As shown in
The laser diode 311b is supplied with power thereby emitting a laser beam and generating heat, similarly to the laser diode 311a. The heat generated by the laser diode 311b is mainly transferred to the LD plate 312a and the grease member 315. In other words, the quantity of heat generated by the laser diode 311b and transferred to the housing portion 306 is small.
The heat received by the LD plate 312b is transferred to the grease member 315 in contact therewith. The heat received by the grease member 315 is transferred to the heat transfer member 309b. The heat received by the heat transfer member 309b is transferred to the Peltier element 310b. The heat received by the Peltier element 310b is transferred to the heat sink 307. In other words, the heat generated by the laser diodes 311a and 311b is transferred to the heat sink 307 in common. Then, the heat generated by the laser diode 311b and transferred to the heat sink 307 is radiated from the light source device 301a through the fins (see
The laser diode 311c is supplied with power, thereby emitting a laser beam and generating heat. The heat generated by the laser diode 311c is mainly transferred to the LD plate 312c and the grease member 315. In other words, the quantity of heat generated by the laser diode 311c and transferred to the housing portion 306 is small.
Then, the heat received by the LD plate 312c is transferred to the grease member 315 in contact therewith. The heat received by the grease member 315 is transferred to the heat transfer member 309c. The heat received by the heat transfer member 309c is transferred to the heat sink 308 arranged directly in contact with the heat transfer member 309c. Then, the heat generated by the laser diode 311c and transferred to the heat sink 308 is radiated from the light source device 301a through the fins (see
According to the fourth embodiment, the following effects can be attained:
According to the fourth embodiment, as hereinabove described, the LD plates 312a to 312c and the grease members 315 are provided between the laser diodes 311a to 311c and the housing portion 306 respectively to be in contact with the laser diodes 311a to 311c so that heat generated by the laser diodes 311a to 311c can be transferred to the heat sinks 307 and 308 arranged to be separated from the housing portion 306 (arranged on positions exposed with respect to the housing portion 306), whereby heat generated by at least one of the laser diodes 311a to 311c is transferred to the heat sinks 307 and 308 arranged to be separated from the housing portion 306 (arranged on the positions exposed with respect to the housing portion 306) through the LD plates 312a to 312c and the grease members 315. Therefore, the laser diodes 311a to 311c can be prevented from thermally interfering with each other through the housing portion 306, dissimilarly to a case where heat generated by the laser diodes 311a to 311c is transferred to the same housing portion 306. Consequently, temperature control (heat radiation or the like) of the laser diodes 311a to 311c can be prevented from becoming difficult.
According to the fourth embodiment, as hereinabove described, the LD plates 312a to 312c and the grease members 315 are provided to be in contact with the laser diodes 311a to 311c respectively, and so configured that heat generated by the laser diodes 311a to 311c can be transferred to the heat sinks 307 and 308 through the LD plates 312a to 312c and the grease members 315 in contact with the laser diodes 311a to 311c respectively. Thus, heat generated by the laser diodes 311a to 311c can be transferred to the heat sinks 307 and 308, whereby temperature control (heat radiation or the like) of the laser diodes 311a to 311c can be effectively performed.
According to the fourth embodiment, as hereinabove described, the headup display 301 is provided with the LD plate 312a arranged in contact with the laser diode 311a and the heat transfer member 309a arranged in contact with the LD plate 312a and the heat sink 307, and the housing portion 306 is so configured that the laser diode 311a is position-aligned and mounted thereon. Further, the headup display 301 includes the heat transfer member 309a including the recess portion 309d in which the laser diode 311a is arranged and the grease member 315 provided to fill up the clearance between the laser diode 311a and the recess portion 309d of the heat transfer member 309a and made of a material deformable in response to the clearance, while the recess portion 309d includes the opposed inner side surfaces 319a and 319b (opposed to each other in the direction along arrow Z) and the opposed inner side surfaces 319c and 319d (opposed to each other in the direction along arrow X) in the direction (along arrow X or Z) where the mounting position of the laser diode 311a is aligned. Thus, heat generated by the laser diode 311a can be reliably transferred to the heat sinks 307 and 308 through the grease member 315 even if the dimension or the shape of the clearance between the laser diode 311a and the recess portion 309d of the heat transfer member 309a changes due to dispersion in the mounting position of the laser diode 311a with respect to the housing portion 306 or the like. Consequently, the mounting position of the laser diode 311a with respect to the housing portion 306 can be aligned when mounting the laser diode 311a on the housing portion 306, and temperature control of the laser diode 311a can be prevented from becoming difficult.
According to the fourth embodiment, as hereinabove described, the light source device 301a further includes the LD plate 312a (the LD plates 312b and 312c) provided between the laser diode 311a and the grease member 315 and configured to be capable of transferring heat generated by the laser diode 311a (the laser diodes 311b and 311c) to the grease member 315. Thus, heat generated by the laser diode 311a can be transferred to the grease member 315 through the LD plate 312a, whereby heat generated by the laser diode 311a can be effectively transferred to the heat sinks 307 and 308.
According to the fourth embodiment, as hereinabove described, the laser diode 311a is configured to be movable so that the mounting position thereof is aligned when the laser diode 311a is mounted on the housing portion 306, while the width W11 and the height H11 (see
According to the fourth embodiment, as hereinabove described, the light source device 301a includes the heat sink 307 provided in common to the heat transfer members 309a and 309b for radiating heat generated by the laser diodes 311a and 311b, and further includes the two Peltier elements 310a and 310b, having cooling functions, provided between the respective ones of the heat transfer members 309a and 309b and the heat sink 307 correspondingly to the heat transfer members 309a and 309b. Thus, the Peltier elements 310a and 310b having cooling functions can individually cool the laser diodes 311a and 311b also when the heat sink 307 common to the heat transfer members 309a and 309b is employed, whereby the laser diodes 311a and 311b can be prevented from thermally interfering with each other through the heat sink 307.
According to the fourth embodiment, as hereinabove described, the light source device 301a is configured to further include the heat sink 308 provided to be directly in contact with the heat transfer member 309c for radiating heat generated by the single laser diode 311c. Thus, no thermal interference is caused through the heat sink 308 when the single heat transfer member 309c is provided thereon, whereby no Peltier element may be provided. Consequently, the structure of the light source device 301a can be simplified.
The structure of a headup display 302 according to a fifth embodiment of the present invention is now described with reference to
As shown in
As shown in
As shown in
W12≧L11 (8)
H12≧L12 (9)
D12≧t10 (10)
As shown in
Thus, the laser diode 311a (and the LD plate 312a) can be arranged in the recess portion by dividing the first and second heat transfer members 316a and 316b as hereinabove described, dissimilarly to the case of moving the laser diode 311a (and the LD plate 312a) in a plane direction (the direction of an X-Y plane in
According to the fifth embodiment, the following effect can be attained:
According to the fifth embodiment, as hereinabove described, the recess portion formed by the first and second heat transfer members 316a and 316b has the inner side surface 329 arranged on the side (in the direction along arrow Z2) closer to the heat sink 307 and is configured to be dividable along the direction (the opening direction (along arrow Y1 in
The structure of a headup display 303 according to a sixth embodiment of the present invention is now described with reference to
As shown in
As shown in
As shown in
According to the sixth embodiment, the following effect can be attained:
According to the sixth embodiment, as hereinabove described, the second heat transfer member 316b and the heat sink 307 are integrally formed. Thus, the number of components can be reduced dissimilarly to a case of providing the second heat transfer member 316b and the heat sink 307 (see
The structure of a headup display 400 according to a seventh embodiment of the present invention is now described with reference to
According to the seventh embodiment, the headup display 400 includes a light source device 401, as shown in
The LD plate 408a and the heat transfer member 406a are so arranged that a surface 482 of the LD plate 408a on a side along arrow Y2 (a side opposite to a direction where a laser diode 11a emits a laser beam) and a surface 461a of the heat transfer member 406a on a side along arrow Y1 are parallel to each other. The surfaces 482 and 461a are in surface contact with each other. The surface 482 is an example of the “first side surface” in the present invention. The surface 461a is an example of the “second side surface” in the present invention.
The LD plate 408a includes an outer side surface 483 in a direction along arrow Z2 (a direction perpendicular to the optical axis of the laser diode 11a). The heat transfer member 406a includes a side surface 462a opposed to the outer side surface 483 of the LD plate 408a. A clearance 463a is provided between the outer side surface 483 of the LD plate 408a and the side surface 462a of the heat transfer member 406a. The outer side surface 483 is an example of the “third side surface” in the present invention. The side surface 462a is an example of the “fourth side surface” in the present invention.
As shown in
Therefore, heat generated by the laser diode 11a is transferred to the heat sink 405a also through a path along arrow H3, in addition to a path along arrows H1 and H2 (identical to the second heat transfer path in the headup display 100 according to the first embodiment). Thus, the thermal resistance of a second heat transfer path in the headup display 400 according to the seventh embodiment is further smaller than the thermal resistance of the second heat transfer path in the headup display 100 according to the first embodiment.
The remaining structures of the headup display 400 according to the seventh embodiment are similar to those of the headup display 100 according to the first embodiment.
According to the seventh embodiment, the following effect can be attained:
According to the seventh embodiment, as hereinabove described, the heat transfer member 406a and the heat sink 405a are integrally formed. Thus, the number of components can be reduced dissimilarly to a case of providing the heat transfer member 406a and the heat sink 405a separately from each other, whereby the structure of the light source device 401 can be simplified. The remaining effects of the headup display 400 according to the seventh embodiment are similar to those of the headup display 100 according to the first embodiment.
The structure of a headup display 800 according to an eighth embodiment of the present invention is now described with reference to
As shown in
The base portion 807a includes a base portion-side base portion 807a. The base portion-side base portion 807a and the lens portion 812a are mounted on the base portion 807.
As shown in
The light-emitting portion 811c is provided in the form of a column having a diameter D22 and a length L22, with the optical axis G serving as a central axis thereof. The diameter D21 is larger than the diameter D22 (D21>D22). The three electrodes 819 (
According to the eighth embodiment, the stem 811b has a front surface 811d on the side (along arrow Y1) where the laser diode 811a emits a laser beam and a back surface 811e on a side (along arrow Y2) opposite to the direction where the laser diode 811a emits a laser beam. The stem 811b (particularly the front surface 811d) is a surface serving as the standard on dimensional accuracy of the laser diode 811a.
According to the eighth embodiment, the mounting base portion 871a includes three positioning portions 871b provided along an outer peripheral surface 811f of the stem 811b at a prescribed angular interval (of 120°, for example) to be in contact with the outer peripheral surface 811f of the stem 811b, as shown in
As shown in
As shown in
According to the eighth embodiment, the mounting base portion 871a includes a contact surface 871a coming into contact with the base portion 870, and the contact surface 871a is arranged to be parallel to a plane (X-Z plane) on which a mounting position is aligned. The mounting base portion 871a further includes a front surface support surface 871b coming into contact with and supporting the front surface 811d of the stem 811b. Thus, the front surface 811d of the laser diode 811a and the front surface support surface 871b of the mounting base portion 871a come into contact with each other, whereby a position of the laser diode 811a with respect to a tilting direction (along arrow F1) is determined. The front surface support surface 871b is an example of the “front surface support portion” in the present invention.
As shown in
Four protrusions 871i are provided on regions of the front surface support surface 871f not in contact with the front surface 811d. According to the eighth embodiment, the mounting base portion 871a is made of a light-transmitting material (resin) with respect to a laser beam for welding, while the base portion 807 is made of a light-shielding material (resin) with respect to the laser beam for welding. The laser beam for welding is so applied to the four protrusions 871i that the base portion 807 and the mounting base portion 871a are partially welded to each other and the mounting base portion 871a is fixed to the base portion 807.
According to the eighth embodiment, the LD plate 808a includes three pawl portions 808b provided along the outer peripheral surface 811f of the stem 811b at a prescribed angular interval (of 120°, for example) to be in contact with portions (see
As shown in
More specifically, the area S11 of the regions where the three pawl portions 808b come into contact with the outer peripheral surface 811f of the stem 811b is expressed as follows, assuming that θ11, θ12 and θ13 represent angles of outer peripheries where the three pawl portions 808b come into contact with the outer peripheral surface 811f of the stem 811b, as shown in
π×D21×(θ11+θ12+θ13)/360°×L25
On the other hand, the area S12 of the regions where the three positioning portions 871b come into contact with the outer peripheral surface 811f of the stem 811b is expressed as follows, assuming that θ21, θ22 and θ23 represent angles of outer peripheries where the three positioning portions 871b come into contact with the outer peripheral surface 811f of the stem 811b:
π×D21×(θ21+θ22+θ23)/360°×L23
As shown in
(θ11+θ12+θ13)>(θ21+θ22+θ23)
Therefore, the area S11 is larger than the area S12 (S11>S12) when the lengths L23 and L25 are substantially equal to each other. In this case, it follows that the pawl portions 808b are configured to be larger than the positioning portions 871b in the outer peripheral direction of the stem 811b, whereby the pawl portions 808b are larger in strength than the positioning portions 871b.
According to the eighth embodiment, the LD plate 808a includes a back surface support surface 808c coming into contact with and supporting the back surface 811e of the stem 811b, as shown in
According to the eighth embodiment, the lengths L23 and L25 of the positioning portions 871b and the pawl portions 808b are smaller than the length L21 of the stem 811b in the direction of the optical axis G, as shown in
According to the eighth embodiment, the mounting base portion 871a and the LD plate 808a are so arranged that the contact surface 871e of the mounting base portion 871a and a side surface 808e of the LD plate 808a are parallel to each other. The LD plate 808a and the heat transfer member 806a are so arranged that the side surface 808e of the LD plate 808a and a side surface 806b of the heat transfer member 806a are parallel to each other.
According to the eighth embodiment, the LD plate 808a is configured to be mounted on the mounting base portion 871a with the elastic member 820, as shown in
As shown in
The remaining structures of the headup display 800 according to the eighth embodiment are similar to those of the headup display 100 according to the first embodiment.
A method of assembling the light source device 801 is now described with reference to
The base portion-side base portion 807a and the lens portion 812a are previously mounted on the base portion 807. The stem 811b of the laser diode 811a is press-fitted into a recess portion (see
According to the eighth embodiment, the following effects can be attained:
According to the eighth embodiment, as hereinabove described, the laser diode 811a is provided with the columnar stem 811b. The light source device 801 includes the mounting base portion 871a arranged between the laser diode 811a and the base portion 807 so that the laser diode 811a is mounted thereon. The mounting base portion 871a includes the positioning portions 871b provided along the outer peripheral surface 811f of the stem 811b at the prescribed angular interval (of 120°) to be in contact with the outer peripheral surface 811f of the stem 811b. The LD plate 808a includes the pawl portions 808b provided along the outer peripheral surface 811f of the stem 811b at the prescribed angular interval (of 120°) to be in contact with the portions of the outer peripheral surface 811f of the stem 811b not supported by the positioning portions 871b. Thus, the positioning portions 871b come into contact with the outer peripheral surface 811f of the stem 811b, whereby the mounting base portion 871a can be precisely mounted with respect to a central position of the stem 811b of the laser diode 811a. Consequently, the precision of the mounting position of the mounting base portion 871a with respect to the laser diode 811a can be improved. The pawl portions 808b come into contact with the portions of the outer peripheral surface 811f of the stem 811b not supported by the positioning portions 871b, whereby a contact area between the laser diode 811a and the LD plate 808a can be increased as compared with a case where no pawl portions 808b are provided. Thus heat generated by the laser diode 811a can be efficiently transferred to the LD plate 808a. Consequently, heat generated by the laser diode 811a can be efficiently transferred to the LD plate 808a through the pawl portions 808b while improving the precision of the mounting position of the mounting base portion 871a with respect to the laser diode 811a with the positioning portions 871b.
According to the eighth embodiment, as hereinabove described, the stem 811b is provided with the front surface 811d on the side where the laser diode 811a emits a laser beam and the back surface 811e on the side opposite thereto, the mounting base portion 871a is provided with the front surface support surface 871f coming into contact with and supporting the front surface 811d of the stem 811b, and the LD plate 808a is provided with the back surface support surface 808c coming into contact with and supporting the back surface 811e of the stem 811b. Thus, the front surface support surface 871f so comes into contact with the front surface 811d as to prevent misregistration of the laser diode 811a with respect to the mounting base portion 871a in the tilting direction, whereby the laser diode 811a can be precisely mounted with respect to the mounting base portion 871a. Further, the back surface support surface 808c so comes into contact with the back surface 811e that heat generated by the laser diode 811a can be transferred to the LD plate 808a also from the back surface support surface 808c in addition to the pawl portions 808b. Consequently, the contact area between the laser diode 811a and the LD plate 808a can be increased, whereby heat generated by the laser diode 811a can be more efficiently transferred to the LD plate 808a.
According to the eighth embodiment, as hereinabove described, the regions where the pawl portions 808b come into contact with the outer peripheral surface 811f of the stem 811b are larger than the regions where the positioning portions 871b come into contact with the outer peripheral surface 811f of the stem 811b. Thus, the regions where the pawl portions 808b come into contact with the outer peripheral surface 811f of the stem 811b can be relatively enlarged, whereby the area S11 of the regions where the pawl portions 808b (the LD plate 808a) come into contact with the outer peripheral surface 811f (the laser diode 811a) of the stem 811b is so increased that heat generated by the laser diode 811a can be further efficiently transferred to the LD plate 808a. Consequently, heat generated by the laser diode 811a can be further efficiently transferred to the LD plate 808a through the pawl portions 808b having large contact areas while improving the precision of the mounting position of the mounting base portion 871a with respect to the laser diode 811a with the positioning portions 871b.
According to the eighth embodiment, as hereinabove described, the lengths L23 and L25 of the positioning portions 871b and the pawl portions 808b are smaller than the length L21 of the stem 811b in the direction of the optical axis G of the laser diode 811a. Thus, the positioning portions 871b and the pawl portions 808b can be prevented from interfering with each other in the direction of the optical axis G of the laser diode 811a. Consequently, the laser diode 811a and the LD plate 808a can be prevented from formation of a clearance therebetween resulting from interference between the positioning portions 871b and the pawl portions 808b, whereby the laser diode 811a and the LD plate 808a can be prevented from entering a noncontact state. Thus, heat generated by the laser diode 811a can be more reliably transferred to the LD plate 808a.
According to the eighth embodiment, as hereinabove described, the mounting base portion 871a is provided with the contact surface 871e coming into contact with the base portion 807, while the mounting base portion 871a and the LD plate 808a are so arranged that the contact surface 871e of the mounting base portion 871a and the side surface 808e of the LD plate 808a are parallel to each other. Thus, the contact surface 871e and the side surfaces 806b and 808e are arranged to be parallel to each other also when the mounting base portion 871a is position-aligned with respect to the base portion 807 in a direction parallel to the contact surface 871e, whereby the state where the side surface 808e of the LD plate 808a and the side surface 806b of the heat transfer member 806a are in surface contact with each other can be maintained.
According to the eighth embodiment, as hereinabove described, the mounting base portion 871a has light transmissivity, and the base portion 806 has a light shielding property. Thus, the mounting base portion 871a can be fixed to the base portion 807 by laser welding when mounting the mounting base portion 871a on the base portion 807. Consequently, the mounting base portion 871a can be more reliably fixed to the base portion 807 in a state where the mounting base portion 871a is prevented from misregistration with respect to the base portion 807.
According to the eighth embodiment, as hereinabove described, the light source device 801 is provided with the elastic member 820 mounted on the mounting base portion 871a, and the LD plate 808a is configured to be mounted on the mounting base portion 871a with the elastic member 820. Thus, the LD plate 808a can be mounted on the mounting base portion 871a while preventing application of excess force to the LD plate 808a and the mounting base portion 871a due to elastic deformation of the elastic member 820, also when the LD plate 808a and the mounting base portion 871a are position-aligned.
The remaining effects of the headup display 800 according to the eighth embodiment are similar to those of the headup display 100 according to the first embodiment.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
For example, while the headup display is employed as the projector according to the present invention in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, a device other than the headup display may alternatively be employed as the projector. For example, a projector projecting a laser beam on a screen different from a windshield may be employed.
While the laser diodes are employed as the light source portions according to the present invention in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, devices other than the laser diodes may alternatively be employed as the light source portions. For example, light-emitting diodes (LEDs) may be employed.
While three laser diodes are employed as the plurality of light source portions according to the present invention in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, laser diodes of a number other than three may alternatively be employed. For example, two or at least four laser diodes may be employed.
While the LD plate(s) and the heat transfer member(s) are configured to be capable of being position-aligned in the direction (along arrow X or Z) parallel to the back surface(s) of the laser diode(s) in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, a side surface on a back-surface side (along arrow Y2 in
A light source device 1c according to the first modification includes the LD plate 8e, as shown in
While the surface of the LD plate in surface contact with the heat transfer member is provided in the U-shaped manner in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the surface of the LD plate in surface contact with the heat transfer member may alternatively be provided in a shape other than the U shape. For example, the surface of the LD plate in surface contact with the heat transfer member may be provided in an O-shaped manner.
While the contact surface between the laser diode and the LD plate and that between the LD plate and the heat transfer member are directly brought into surface contact with each other in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the contact surface between the laser diode and the LD plate and that between the LD plate and the heat transfer member may alternatively be indirectly brought into surface contact with each other through thin grease layers or the like, for example.
While the surfaces of the LD plate and the heat transfer member are partially subjected to insulation coating as the heat-shielding member according to the present invention in the aforementioned third embodiment, the present invention is not restricted to this. According to the present invention, the surfaces of the LD plate and the heat transfer member may alternatively be covered with a heat-shielding member other than the insulation coating. For example, the surfaces of the LD plate and the heat transfer member may be partially subjected to surface treatment with fluororesin.
While the three laser diodes are provided with the heat transfer members respectively in each of the aforementioned first to third embodiments, the present invention is not restricted to this. According to the present invention, the three laser diodes may not be provided with heat transfer members respectively. For example, the headup display may be configured to transfer heat generated by one of the three laser diodes to the housing portion, so that the remaining two laser diodes are provided with heat transfer members and heat generated by the remaining two laser diodes is transferred to an external device other than the housing portion.
While the recess portion of each heat transfer member is rectangularly formed as viewed from the opening direction in each of the aforementioned fourth to sixth embodiments, the present invention is not restricted to this. According to the present invention, the recess portion of the heat transfer member may alternatively be provided in a shape other than that of a rectangular parallelepiped. For example, the recess portion of the heat transfer member may be provided in a circular shape (columnar shape) as viewed from the opening direction.
While each grease member is employed as the fourth heat transfer portion according to the present invention in each of the aforementioned fourth to sixth embodiments, the present invention is not restricted to this. According to the present invention, a heat-transferable member other than the grease member may alternatively be employed as the fourth heat transfer portion. For example, heat-conductive resin or heat-conductive powdery substance may be employed.
While the heat sink having the fins is employed as the heat radiation portion in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, a component other than the heat sink having the fins may alternatively be employed as the heat radiation portion. For example, a cooling plate having a water-cooled tube may be employed as the heat radiation portion.
While the element having a cooling function is employed in the case of employing the heat radiation portion provided in common to the plurality of heat transfer portions according to the present invention in each of the aforementioned fourth to sixth embodiments, the present invention is not restricted to this. According to the present invention, the element having a cooling function may alternatively be employed in a case other than that of employing the heat radiation portion provided in common to the plurality of heat transfer portions. For example, the element having a cooling function may be employed in a case of employing a heat radiation portion provided with respect to one heat transfer portion. Also in the case of employing the heat radiation portion provided in common to the plurality of heat transfer portions, no element having a cooling function may be employed if the heat transfer portions do not thermally interfere with each other.
While the heat transfer member is configured to be dividable into two portions along the opening direction of the recess portion in each of the aforementioned fifth and sixth embodiments, the present invention is not restricted to this. According to the present invention, the heat transfer member may alternatively be configured to be dividable into a number other than two. For example, the heat transfer member may be configured to be dividable into at least three portions.
While the mounting base portion is made of resin in each of the aforementioned first to eighth embodiments, the present invention is not restricted to this. According to the present invention, a mounting base portion 771a may alternatively be made of a material such as metal higher in heat conductivity than general resin, as in a second modification of the present invention shown in
As shown in
According to the second modification, the mounting base portions 771a to 771c are configured to be higher in heat conductivity than the housing portion 7 (the mounting base portions 771a to 771c are made of metal, for example), whereby a press-fitting engaging method can be employed when mounting (fixing) the laser diode 11a on (to) the housing portion 7 (the mounting base portions 771a to 771c). Consequently, the laser diode 11a can be prevented from misregistration or inclination resulting from thermal expansion since the press-fitting engaging method results in a smaller thermal expansion coefficient as compared with a method of mounting the laser diode 11a on the housing portion 7 (or the mounting base portions 771a to 771c) with an adhesive.
While the first heat transfer portion is mounted on the mounting base portion with the elastic member in the aforementioned eighth embodiment, the present invention is not restricted to this. According to the present invention, the first heat transfer portion may alternatively be mounted on the mounting base portion with a member other than the elastic member. For example, the first heat transfer portion may be mounted on the mounting base portion with an adhesive. However, the adhesive may change over time, and hence the elastic member hardly changing over time is preferably employed, as in the eighth embodiment.
While the elastic member is fixed to the mounting base portion with the screws while pressing the first heat transfer portion thereby fixing the first heat transfer portion to the mounting base portion in the aforementioned eighth embodiment, the present invention is not restricted to this. According to the present invention, the elastic member may alternatively be fixed to the first heat transfer portion with screws while pressing the mounting base portion, thereby fixing the first heat transfer portion to the mounting base portion.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-026903 | Feb 2014 | JP | national |
| 2014-069783 | Mar 2014 | JP | national |
| 2015-003595 | Jan 2015 | JP | national |
