Patent Application
20060256199
The present invention relates to a photographing apparatus such as a monitoring camera apparatus or a video camera apparatus, and more particularly, to a pickup device driving apparatus for moving a pickup device in an optical axial direction and a photographing apparatus using the same.
Conventionally, in order to perform flange focus adjustment or focus adjustment, a photographing apparatus for automatically moving a pickup device in an optical axial direction of a lens to obtain a clear image is suggested (for example, Japanese Patent Unexamined Publication No. 2003-274229).
In such a photographing apparatus, heat generated in the vicinity of the pickup device or a driver circuit may have a bad influence on characteristics of the pickup device or components.
In order to solve such a problem, a structure of providing an elastically deformable heat transfer plate such as heat transfer rubber in the vicinity of a pickup device to bring the heat transfer plate into contact with a case in an elastically deformed state such that heat is transferred to the case to radiate the heat is suggested (for example, Japanese Patent Unexamined Publication No. 2001-326840).
According to such a structure, since the heat transfer plate is in contact with the case even when the pickup device is moved in an optical axial direction, it was possible to transfer the heat to the case.
However, in the above-described photographing apparatus, the pickup device is moved in the optical axial direction in a state that the heat transfer plate provided in the vicinity of the photographing device is in contact with the inside of the case. Accordingly, when the pickup device is moved in the optical axial direction, a frictional force is generated between the heat transfer plate and the case. Due to the frictional force, the pickup device need be moved by a larger force. Accordingly, it is difficult to miniaturize a driving motor and to move the pickup device by a small distance.
The present invention has been made in view of the above problem and provides a pickup device driving apparatus which is capable of allowing heat in the vicinity of the pickup device to escape without generating a frictional force even when a pickup device is moved in an optical axial direction, and a photographing apparatus using the same.
According to an aspect of the present invention, there is provided a pickup device driving apparatus including a movable part having a pickup device and capable of moving the pickup device while a direction of a pickup surface is held; and a heat radiation part which is provided in the movable part and allows heat in the vicinity of the pickup device to escape by radiation.
According to this configuration, since it is possible to allow heat in the vicinity of the pickup device to escape by radiation of the heat radiation part, it is possible to allow heat in the vicinity of the pickup device to escape without generating a frictional force even when a pickup device is moved in an optical axial direction.
The heat radiation part may be provided to face a heat sink part provided in a case.
According to this configuration, it is possible to allow heat to escape by radiation from the heat radiation part of the pickup device driving apparatus to the heat sink part provided in the case.
The heat radiation part may be provided on the surface of the movable part.
According to this configuration, it is possible to perform natural convection cooling by rapid radiation.
Convex parts may be provided on a surface of the heat radiation part facing the heat sink part.
According to this configuration, since a heat radiation area increases, it is possible to increase radiation efficiency.
The convex parts of the heat radiation part may be provided to face concave parts of irregularities provided in the heat sink part.
According to this configuration, since a facing area between the heat radiation part and the heat sink part increases, it is possible to increase radiation efficiency.
The convex parts of the heat radiation part may have fin which extend in a movement direction of the pickup device.
According to this configuration, although the pickup device is moved, the heat radiation part is hard to come in contact with the heat sink part and thus radiation efficiency can increase.
The heat radiation part may not be in contact with the heat sink part within a movement range of the pickup device.
According to this configuration, although the pickup device is moved, a frictional force is hard to be generated.
According to another aspect of the present invention, there is provided a photographing apparatus including a lens part; a case; the pickup device driving apparatus of the present invention; and an image signal processing part which performs an image signal process on a signal output from the pickup device of the pickup device driving apparatus.
According to this configuration, since it is possible to allow heat in the vicinity of the pickup device to escape by radiation of the heat radiation part, it is possible to allow heat in the vicinity of the pickup device to escape without generating a frictional force even when a pickup device is moved in an optical axial direction.
A cooling part which cools the heat sink part may be further included.
According to this configuration, it is possible to increase heat sink efficiency.
The cooling part may be a fan motor.
According to this configuration, it is possible to increase heat sink efficiency by a simple configuration.
According to another aspect of the present invention, there is provided a monitoring camera apparatus including the photographing apparatus of the present invention; an illumination-intensity change detecting part which detects change in illumination intensity; a filter part which attaches and detaches an infrared cut filter on an optical axis of the lens part depending on the change in illumination intensity detected by the illumination-intensity change detecting part; and a control part which drives the movable part of the pickup device driving apparatus when the infrared cut filter of the filter part is attached and detached.
According to this configuration, since the pickup device can be moved in the optical axial direction of the lens part in a state that the pickup surface is perpendicular to the optical axial direction of the lens part when the infrared cut filter is attached and detached, displacement in a optical path length can be corrected when the infrared cut filter is attached and detached. Accordingly, it is possible to provide a monitoring camera apparatus capable of performing photographing with high precision day and night. Since it is possible to allow heat in the vicinity of the pickup device to escape by radiation of the heat radiation part, it is possible to allow heat in the vicinity of the pickup device to escape without generating a frictional force even when a pickup device is moved in an optical axial direction.
As described above, according to the present invention, it is possible to provide a pickup device driving apparatus which is capable of allowing heat in the vicinity of the pickup device to escape without generating a frictional force even when a pickup device is moved in an optical axial direction, and a photographing apparatus using the same.
Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.
First, a configuration of photographing apparatus 1 according to an embodiment of the present invention will be described.
For simplification of description, in the embodiment of the present invention, an X axis direction, a Y axis direction, and a Z axis direction perpendicular to one another are shown in the drawings. The X axis direction is an optical axial direction of a lens part, and the Y axis and Z axis direction are perpendicular to the optical axis direction. In the embodiment of the present invention, for understanding of description, detailed parts such as screw or the like will be omitted in the drawings.
As shown in
The configuration and operation of pickup device driving apparatus 70 mounted on photographing apparatus 1 according to the embodiment of the present invention will be described.
In the embodiment of the present invention, heat radiation part 120 and heat sink part 140 were obtained by die-casting aluminum and coating black alumite on the surface thereof. Convex parts 121 and 141 which extend in the optical axial direction of lens part 101 and have a width of 1.0 mm and a height of 3.5 mm are provided on the surface facing heat sink part 140 of heat radiation part 120 (upper surface of
As shown in
As shown in
In order to confirm an effect that the temperature is suppressed from rising due to radiation of photographing apparatus 1 according to the embodiment of the present invention, three experiments were performed as follows:
(1) in a case where heat radiation part 120 was provided, heat sink part 140 was not provided, and heat in the vicinity of pickup device 15 was radiated into a case.
(2) in a case where heat radiation part 120 and heat sink part 140 were provided, and heat in the vicinity of pickup device 15 was radiated from heat radiation part 120 to heat sink part 140.
(3) in a case where heat radiation part 120 and heat sink part 140 were provided and the other end of heat sink part 140 is cooled by fan motor 130 such that heat in the vicinity of pickup device 15 is radiated,
maximum values of the temperature in the vicinity of pickup device 15 were measured in a state that a heating value of 452 mW is generated in the vicinity of pickup device 15.
As a result, in the case (1), the temperature rises by about 9.8 degrees at the rear surface of pickup device 15. In the case (2), the temperature rises by about 8.6 degrees. In case (3), the temperature rises by about 5.9 degrees.
That is, it can be seen that, by providing heat sink part 140, heat sink efficiency is improved by about 10% and, by cooling the other end of heat sink part 140 using fan motor 130, heat sink efficiency is improved by about 40%, compared with a configuration without heat sink part 140.
Photographing apparatus 1 according to the embodiment of the present invention is a monitoring camera apparatus which performs photographing while switching filter part 5 according to brightness of an environment day and night. In other words, in a bright environment, the infrared cut filter is disposed on the optical axis and color image photographing is performed in a visible area, and in a dark environment, the infrared cut filter disposed on the optical axis is removed and monochromic image photographing is performed by light beam of a wavelength including light beam in an infrared area. In photographing device 1, the brightness of the environment can be detected by comparing illumination intensity detected by illumination-intensity detecting part (not shown) mounted in a circuit part (not shown) with a predetermined threshold value. When the illumination intensity detected by the illumination-intensity detecting part is changed to exceed the threshold value, it is determined that transition from daytime to nighttime occurs. Thus, the circuit part switches filter part 5. In addition, the switch of filter part 5 can be performed by DC motor part 4 attached to base attaching part 3.
In photographing apparatus 1 according to the embodiment of the present invention, the switch of filter part 5 is performed when the illumination intensity is changed. At this time, since the infrared cut filter is disposed or detached (hereinafter, referred to as attached/detached) on the optical axis or the wavelength of the light beam used for photographing varies, the optical path length is changed and thus an optimal focusing position from lens part 101 to a surface (hereinafter, referred to as pickup surface 83) on which a photoelectric converting element is disposed in pickup device 15 is changed. In order to correct change in optical path length, in photographing device 1 according to the embodiment of the present invention, pickup device driving apparatus 70 for moving pickup device 15 in the optical axial direction (X axis direction) in a state that pickup surface 83 is held in a direction perpendicular to the optical axial direction of lens part 101 (that is, a state that pickup device 15 is located in a plane parallel to a YZ plane in
Now, pickup device driving apparatus 70 mounted on pickup device 1 according to the embodiment of the present invention will be described.
As shown in
As shown in
Base attaching part 3, base 6, and pickup device holding part 11 may be prepared by a die casting method using aluminum.
As a material of reinforcement plate 27, first reinforcement plate 16, and second reinforcement plate 17, a material having relatively high rigidity such as a SUS material having a thickness of 0.5 mm can be used in order to reinforce the mechanical strength of U-shaped member 80.
In pickup device driving apparatus 70 according to the embodiment of the present invention, first support part 8, second support part 9, movable part 7, and leaf springs 10 are formed by U-shaped integral member 80. First reinforcement plate 16 and second reinforcement 17 are attached to portions of first support part 8 and second support part 9, respectively. Bent parts 74 are provided at the sides of first support part 8 and second support part 9. Thus, rigidity of first support part 8 and second support part 9 is higher than that of leaf springs 10.
Bent parts 76 are also provided at portions of movable part 7 of U-shaped member 80, and reinforcement plate 27 is attached to movable part 7. Thus, rigidity of movable part 7 is higher than that of leaf springs 10.
Bent parts 75 are provided at the ends of attachment surfaces 82 and 85 to be attached to base surface 62 of U-shaped member 80. Thus, rigidity of this portion can increase.
Since portions between movable part 7 of U-shaped member 80 and first support part 8 and second support part 9 are not subjected to a reinforcement process such as a bending process and have widths narrower than those of the other portions, these portions function as leaf springs 10.
Similarly, since portions between attachment surfaces 82 and 85 of U-shaped member 80 and first support part 8 and second support part 9 are not subjected to a reinforcement process such as a bending process and have widths narrower than those of the other portions, these portions also function as leaf springs 10.
In pickup device driving apparatus 70 according to the embodiment of the present invention, attachment surface 82 in which first support part 8 is in contact with base surface 62 and attachment surface 85 in which second support part 9 is in contact with base surface 62 are attached to base surface 62 by screw 71 to be parallel to the Z axis direction perpendicular to the optical axial direction (X axis direction).
Now, a configuration of driving part 100 of pickup device driving apparatus 70 according to the embodiment of the present invention will be described in detail.
As shown in
As shown in
Accordingly, in pickup device driving apparatus 70 according to the embodiment of the present invention, since driving direction changing part 22 for changing an output direction of linear actuator 20 is included in driving part 100, linear actuator 20 need not be the optical axial direction (X axis direction). Accordingly, linear actuator 20 may be arranged in a direction (Z axis direction) perpendicular to the optical axial direction and thus miniaturization of the apparatus can be realized. When the miniaturization is not required, pin 29 may be directly pressed and moved by linear actuator 20 in the optical axial direction (X axis direction) without using driving direction changing part 22.
Now, an operation of pickup device driving apparatus 70 according to the embodiment of the present invention will be described in detail with reference to
In
In pickup device driving apparatus 70 according to the embodiment of the present invention, pickup device holding part 11 including pickup device circuit part 12 having pickup device 15 is disposed on the lower surface of movable part 7. At this time, by attaching pickup surface 83 of pickup device 15 to pickup device holding part 11 to be perpendicular to the surface of movable part 7 of pickup device holding part 11, the pickup surface 83 of pickup device 15 is held perpendicular to the optical axial direction.
In a state shown in
In other words, when pickup device 15 is moved from a state of
In pickup device driving apparatus 70 according to the embodiment of the present invention, contrary to the above, in order to move pickup device 15 to be apart from lens part 101, by increasing the press force of linear actuator 20, the bias force applied to driving direction changing part 22 becomes stronger. Then, as shown in
In pickup device driving apparatus 70 according to the embodiment of the present invention, since movable part 7 is supported by first support part 8 and second support part 9 which have the same height from base surface 62, are parallel to each other, and rotate in the optical axial direction, movable part 7 can be moved in the optical axial direction while being always held parallel to base surface 62. Since pickup device holding part 11 is attached such that pickup surface 83 of pickup device 15 is disposed in the direction perpendicular the movable part 7, pickup device 15 can be moved in the optical axial direction while pickup surface 83 thereof is held perpendicular to the optical axial direction and pickup device 15 can be moved with high precision.
In pickup device driving apparatus 70 according to the embodiment of the present invention, mechanisms for moving pickup device 15 in the optical axial direction, that is, mechanisms including attachment surface 82 which is in contact with base surface 62, first support part 8, movable part 7, second support part 9, attachment surface 85, and leaf springs 10, can be prepared by performing processes including punching and molding on an integral plate material. Accordingly, friction or saccadic movement is extremely low and thus driving can be performed with high precision even when slight driving is performed.
Now, balance member 220 having weight 210 included in pickup device driving apparatus 70 of photographing apparatus 1 according to the embodiment of the present invention will be described in detail.
That is, in the state shown in
In photographing apparatus 1 according to the embodiment of the present invention, weight increase W1 of heat radiation part 120 is 2.5 g and weight W2 of weight 210 is 1.67 g. Distance L1 from the center of bearing part 18 to pin 29 is 11.0 mm and distance L2 from the center of bearing part 18 to the center of weight 210 is 16.5 mm. W1×L1=W2×L2 is preferably satisfied such that moment F and moment W are in balance.
Although, in the above-described example, the description is given photographing apparatus 1 is disposed such that lens part 101 is disposed at the lower side, photographing apparatus 1 may be advantageously disposed such that lens part 101 is disposed at the upper side in photographing apparatus 1 according to the embodiment of the present invention. This is because moment F and moment W are in balance even when the directions thereof are in the opposite directions.
In photographing apparatus 1 according to the embodiment of the present invention, since weight 210 for adjusting balance is provided, it is possible to realize a configuration in which a load is hard to be applied to linear actuator 20 although lens part 101 is provided in any one of the upper and lower sides in photographing apparatus 1.
Although, in pickup device driving apparatus 70 according to the embodiment of the present invention, leaf springs 10 are formed between movable part 7 and first support part 8, between movable part 7 and second support part 9, between base surface 62 and first support part 8, and between base surface 62 and second support part 9, pickup device driving apparatus according to the present invention is not limited to this configuration.
For example, movable part 7, first support part 8, second support part 9, and base part 6 may be separately provided and a hinge part may be formed between movable part 7 and first support part 8, between movable part 7 and second support part 9, between base surface 62 and first support part 8, and between base surface 62 and second support part 9. According to this configuration, it is possible to realize a configuration with excellent impact resistance in addition to the above-described effect. In such a configuration, an elastic means such as a coil spring for elastically connecting first support part 8 to second support part 9 is preferably provided in order to suppress saccadic movement in the hinge part.
Although, in photographing apparatus 1 according to the embodiment of the present invention, the center position of pickup surface 83 of pickup device 15 is changed in a vertical direction (Y axis direction) of the optical axial direction with the movement of pickup device 15 in the optical axial direction (X axis direction). However, the displacement of pickup device 15 in the direction (Y axis direction) perpendicular to the optical axial direction can be removed in practice by providing a circuit for detecting the displacement thereof using a photo-interrupter or the like, calculating the displacement of pickup device 15 in the direction (Y axis direction) perpendicular to the optical axial direction, and shifting a read area of a signal depending on the displacement to perform correction in the circuit part. When the displacement of pickup device 15 in the optical axial direction (X axis direction) is small, a problem is not caused in practice although the above-described correction process is not performed.
Although, in the embodiment of the present invention, the structure for changing pickup device driving apparatus 70 mounted on photographing device 1 using the rectangular U-shaped member 80 and moving pickup device 15 mounted on pickup device driving apparatus 70 in the optical axial direction in parallel is described, the pickup device driving apparatus and the photographing apparatus according to the present invention is not limited to this embodiment.
Although, in the embodiment of the present invention, fan motor 130 is employed as a cooling part for cooling the other end of heat sink part 140, the pickup device driving apparatus and the photographing apparatus according to the present invention is not limited to this configuration. For example, a known cooling device such as a Peltier device or a liquid cooling mechanism may be used as the cooling part.
Although, examples of mounting the pickup device driving apparatus according to the embodiments of the present invention on the monitoring camera apparatus are described, the use of the photographing apparatus according to the present invention is not limited to the monitoring camera apparatus. For example, the pickup device driving apparatus may be mounted on every known photographing apparatus such as a video camera or a digital camera.
As described above, according to a pickup device driving apparatus and a photographing apparatus using the same according to the present invention, even when a pickup device is moved in an optical axial direction, it is possible to allow heat in the vicinity of the pickup device to escape without generating a frictional force. The present invention is applicable to a photographing apparatus such as a monitoring camera apparatus or a video camera apparatus, and more particularly, to a pickup device driving apparatus for moving a pickup device in an optical axial direction of a lens part and a photographing apparatus using the same.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-140930 | May 2005 | JP | national |
