The present invention relates to light emitting devices and lighting fixtures.
In the past, various kinds of light emitting devices for lighting light emitters have been developed and available commercially (see document 1 [JP 2010-129488 A]). As for the light emitting device disclosed in document 1, a circuit board on which lighting circuit components are mounted is placed on a rear side of an LED substrate on which a light emitting diode (LED) is mounted. Each of the LED substrate and the circuit board is fixed in contact with a heat dissipater.
As mentioned above, the prior light emitting device disclosed in document 1 can dissipate heat generated by the LED and the lighting circuit components. However, the LED and the lighting circuit components are covered by resin only. Hence, to protect the LED and the lighting circuit components, a housing for covering the LED and the lighting circuit components is necessary. Accordingly, the prior light emitting device can not satisfy both of improvement in heat dissipation performance and reduction in the number of parts thereof.
In view of the above insufficiency, the present invention has aimed to propose a light emitting device and a lighting fixture which can satisfy both of improvement in heat dissipation performance and reduction in the number of parts thereof.
The light emitting device of the first aspect in accordance with the present invention includes a light emitter; a lighting circuit unit including a circuit component for lighting the light emitter; and a housing configured to accommodate the light emitter and the lighting circuit unit. The housing is constituted by a substrate on which the light emitter and the lighting circuit unit are placed; and a cover attached to the substrate to cover the light emitter and the lighting circuit unit.
As for the light emitting device of the second aspect in accordance with the present invention, in addition to the first aspect, the light emitter is placed on a first surface of the substrate in a thickness direction of the substrate. The lighting circuit unit is placed on a vicinity of the lighting emitter.
As for the light emitting device of the third aspect in accordance with the present invention, in addition to the first or second aspect, the light emitter and the lighting circuit unit are placed on a first surface of the substrate in a thickness direction of the substrate. The substrate includes a light emitter supporting portion defined as a portion on which the light emitter is placed; a circuit supporting portion defined as a portion on which the lighting circuit unit is placed; and an uneven portion which has a level difference in the thickness direction and is interposed between the light emitter supporting portion and the circuit supporting portion.
As for the light emitting device of the fourth aspect in accordance with the present invention, in addition to the third aspect, the uneven portion is defined by a surface connecting a first surface of the light emitter supporting portion on which the light emitter is placed and a first surface of the circuit supporting portion on which the lighting circuit unit is placed such that the first surface of the light emitter supporting portion on which the light emitter is placed and the first surface of the circuit supporting portion on which the lighting circuit unit is placed are positioned at mutually different positions in the thickness direction.
As for the light emitting device of the fifth aspect in accordance with the present invention, in addition to the third aspect, the uneven portion is defined by a recessed part.
As for the light emitting device of the sixth aspect in accordance with the present invention, in addition to any one of the first to fifth aspects, the circuit component is placed on the substrate.
As for the light emitting device of the seventh aspect in accordance with the present invention, in addition to any one of the first to sixth aspects, the light emitter comprises an LED element.
As for the light emitting device of the eighth aspect in accordance with the present invention, in addition to any one of the first to seventh aspects, the substrate has a first surface and a second surface in a thickness direction of the substrate. The light emitter is placed on the first surface of the substrate. The second surface of the substrate is a flat surface.
As for the light emitting device of the ninth aspect in accordance with the present invention, in addition to any one of the first to seventh aspects, the substrate has a first surface and a second surface in a thickness direction of the substrate. The light emitter is placed on the first surface of the substrate. The substrate is provided at the second surface with a recessed and protruded structure.
As for the light emitting device of the tenth aspect in accordance with the present invention, in addition to any one of the first to ninth aspects, the light emitter is placed on a first surface of the substrate in a thickness direction of the substrate. The cover includes a first part which is placed on the first surface of the substrate to cover the light emitter and is designed to allow light from the light emitter to pass; a second part placed on the first surface of the substrate to not cover the light emitter; and a light reflector which is formed on a surface of the second part and is designed to reflect light from the light emitter.
The lighting fixture of the eleventh aspect in accordance with the present invention, includes a light emitting device according to any one of the first to tenth aspects; and a fixture body configured to support the light emitting device.
With regard to the following first to fourth embodiments, for example, a light emitting device 100 shown in
The following explanations are made to the respective embodiments.
As shown in
The light emitter 2 includes an LED element, a transparent resin member for increasing light extraction efficiency regarding the LED element, and a fluorescent member for converting a wavelength of light from the LED element, which are not shown. Note that, the light emitter 2 may be an LED package in which the LED element and the fluorescent member are formed integrally. In brief, the light emitter 2 may include an LED element.
The LED element emits light such as ultraviolet light, purple light, blue light, and green light. This LED element is bonded and fixed to the substrate in a die-bonding manner, and is electrically connected to a wiring layer (not shown) of the substrate 3 via a wire (not shown) such as a bonding wire.
The transparent resin member is formed of silicone, for example. The transparent resin member is provided to a light emission side of the LED element, and increases the light extraction efficiency regarding the LED element.
Note that, the light emitter 2 may be a combination of red, green and blue LED elements. Alternatively, the light emitter 2 may be a combination of a set of the LED element and the fluorescent member and one or more additional LED elements selected from purple, blue, green, yellow, orange, and red LED elements.
The substrate 3 is constituted by a ceramic substrate. The ceramic substrate may be formed of aluminum nitride, alumina, mullite, and cordierite.
The substrate 3 includes a light emitter supporting portion 31 on which the light emitter 2 is mounted and a circuit supporting portion 32 on which the lighting circuit unit 4 is placed. The light emitter supporting portion 31 and the circuit supporting portion 32 are formed integrally with each other. As shown in
The substrate 3 has opposite surfaces in a thickness direction (upward and downward direction in
For example, the substrate 3 has a central part and a vicinity of the central part, the central part used as the light emitter supporting portion 31 and the vicinity used as the circuit supporting portion 32. In the present embodiment, contact positions of the substrate 3 and each of a first cover 6 and a second cover 7 of the cover 5 are on the first surface 321 of the circuit supporting portion 32.
In the substrate 3, a mounting surface for an LED element, that is, the first surface 311, is designed to reflect light from the LED element at high efficiency. Concretely, the reflectance of the first surface 311 for light with a wavelength in a range of 380 nm to 780 nm (visible range) is not less than 85% when the substrate 3 has a thickness of 1 mm.
It is preferred that the second surface 3b (312, 322) of the substrate 3 have a flatness in a range of 0.01 to 0.08. When the flatness of the second surface 3b (312, 322) of the substrate 3 exceeds 0.08, and when the light emitting device 100 is attached to a fixture body 91 (see
It is preferred that the substrate 3 have an average surface roughness (Ra) in a range of 0.3 to 0.8. When the average surface roughness exceeds 0.8, printing performance for the wiring layer formed on the substrate 3 is deteriorated, and it is difficult to form a fine pitch patterned wire. In contrast, when the average surface roughness of the substrate 3 falls below 0.3, junction strength between the substrate 3 and the wiring layer is likely to decrease and thus the wiring layer may be easily detached from the substrate 3. Note that, it is preferred that the substrate 3 be directly fixed to the fixture body 91 (see
Further, to increase the heat dissipation performance (property), it is preferred that the substrate 3 have the thermal emissivity not less than 0.9. Similarly, to increase the heat dissipation performance (property), it is preferred that the substrate 3 have the head conductivity (at 25° C.) not less than 19 W/mK.
The wiring layer (not shown) of the substrate 3 is made of metal (e.g., copper [Cu], silver [Ag], gold [Au], and aluminum [Al]) or conductive material primarily including the metal. The wiring layer (not shown) is formed by means of plating, printing, or deposition.
The lighting circuit unit 4 includes plural circuit components 41, a circuit board 42 on which the plural circuit components 41 are mounted, and plural pillars 43 for supporting the circuit board 42. The lighting circuit unit 4 is placed on a vicinity of the light emitter 2. For example, the lighting circuit unit 4 is provided to the vicinity of the light emitter 2 on the first surface 321 of the substrate 3.
The plural circuit components 41 constitute a lighting circuit for supplying electrical power to the light emitter 2 to light the light emitter 2.
The circuit board 42 is constituted by a ceramic substrate. The ceramic substrate may be formed of aluminum nitride, alumina, mullite, and cordierite. The plural circuit components 41 are mounted on opposite surfaces of the circuit board 42. Some circuit components 41 are located on a second surface (lower surface in
The pillar 43 is a member supporting the circuit board 42 such that the circuit board 42 is away from the substrate 3. The pillars 43 are arranged at plural positions on the circuit board 42. The pillar 43 has one end fixed to the substrate 3 and the other end fixed to the circuit board 42. The pillar 43 is fixed to the substrate 3 by use of adhesive, for example. Thus, the circuit board 42 on which the plural circuit components 41 are mounted is fixed to the substrate 3 by use of the pillars 43. The pillar 43 has a height h1 selected such that the circuit component 41 is not in contact with the substrate 3. Note that, thermally conductive sheet (not shown) with an electrical insulation property may be interposed between the circuit component 41 and the substrate 3.
Note that, the lighting circuit unit 4 may be provided with a power supply circuit. In this arrangement, when coupled to an external commercial power source, the lighting circuit unit 4 can light the light emitter 2. It is possible to facilitate power supply to a lighting fixture 9 (see
The cover 5 of the present embodiment is constituted by the first cover 6 designed to entirely cover the first surfaces 311 and 321 of the substrate 3, and the second cover 7 designed to cover the lighting circuit unit 4.
The first cover 6 is defined as a first part which is placed on the first surface 3a of the substrate 3 to cover the light emitter 2 and is configured to allow light from the light emitter 2 to pass. The first cover 6 includes an upper surface part 61 and a side part 62 which are formed integrally with each other. The upper surface part 61 is formed into a circular shape (see
The first cover 6 has a portion which receives light from the light emitter 2, and such a portion is made of transparent or light diffusing glass or synthetic resin with a light transmissive property. The first cover 6 of the present embodiment has light diffusion property to diffuse light. Therefore, the first cover 6 can diffuse light from the light emitter 2, thereby radiating the light to the outside. Hence, color unevenness and a grainy appearance can be reduced. So long as a user ignores the color unevenness and the grainy appearance, the first cover 6 need not necessarily have the light diffusion property. For example, the first cover 6 may be transparent.
Note that, the first cover 6 may contain a fluorescent member converting a wavelength of light from the LED element.
Further, the first cover 6 may be a combination of a flat plate part and a hollow cylindrical part. In this case, the flat plate part may be made of transparent material, and the hollow cylindrical part may be made of opaque material.
The second cover 7 is defined as second part placed on the first surface 3a of the substrate 3 to not cover the light emitter 2. In the present embodiment, the second cover (second part) 7 is placed to cover the lighting circuit unit 4 without covering the light emitter 2. The second cover 7 includes an upper surface part 71, an outer side part 72, and an inner side part 73 which are formed integrally with each other. The upper surface part 71 is formed into a circular ring shape (see
Further, the second cover 7 has a part which receives light from the light emitter 2, and a light reflector (high reflective coating) 74 is formed on such a part. Concretely, the light reflector 74 is formed on outer surfaces of the upper surface part 71 and the inner side part 73. Thus, light from the light emitter 2 can be reflected by the light reflector 74. Hence, it is possible to prevent radiation of light from the light emitter 2 toward the inside of the second cover 7, that is, the lighting circuit unit 4.
In brief, the light reflector 74 is formed on the surface (outer surface) of the second cover (second part) 7 and is designed to reflect light from the light emitter 2.
The first wire 81 from the lighting circuit unit 4 is connected to an external power supply (not shown) via a gap (not shown) formed between the substrate 3 and the cover 5 (the first cover 6 and the second cover 7). Further, the second wire 82 from the lighting circuit unit 4 is electrically connected to the light emitter 2 through the wiring layer (not shown) of the substrate 3. Consequently, the lighting circuit unit 4 can receive power from the external power supply and supply power to the light emitter 2 to light the light emitter 2.
Note that, a connection between the lighting circuit unit 4 and the external power supply may be made by forming an electrode (not shown) for making an electrical connection with the external power supply on the first surface 321 of the substrate 3 and connecting the lighting circuit unit 4 to the substrate 3 via the first wire 81. In this case, the lighting circuit unit 4 and the external power supply can be electrically connected to each other through the wiring layer and the electrode. Alternatively, the electrode may be formed on the second surface 322 of the substrate 3. In this case, the lighting circuit unit 4 and the external power supply may be electrically connected to each other by use of a through-hole electrode (not shown) communicating between the first surface 321 and the second surface 322.
As shown in
For example, the fixture body 91 is made of metal. As shown in
With regard to the fixture body 91, the flat plate part 911 is made of a polished Al die-casting part such that a contact surface to the substrate 3 (i.e., a surface beneath the light emitter 2) has a light reflective property. Alternatively, a high reflective coating may be formed on a surface of the fixture body 91. The high reflective coating may be made of inorganic metal such as silver (Ag) and aluminum (Al) or organic material such as barium sulfate.
Fixing the light emitting device 111 to the flat plate part 911 of the fixture body 91 is made by use of screws 92. Screw holes (attachment holes) 11 for passing the screws 92 are formed in a part of the substrate 3 of the light emitting device 111 which is not covered by the first cover 6. The flat plate part 911 is provided with internal threads for receiving the screws 92. The aforementioned fixing may be made by use of bolts and nuts. Alternatively, the light emitting device 111 may be provided with a base and the fixture body 91 may be provided with a supporting member formed into a socket shape. The light emitting device 111 may be fixed to the fixture body 91 by inserting the base into the supporting member and screwing or fitting one to the other (e.g., a bayonet structure and a catching structure)
The ceiling 93 may be formed into a shape shown in
Alternatively,
The following explanation is made to other examples (modifications) of the light emitting device 110 in accordance with the present embodiment.
The first cover 6 of
In a similar manner as the first cover 6 of
With regard to the first cover 6 of
In the light emitting devices 112 and 113 of
Further, in the light emitting device 113 of
Alternatively, instead of the fluorescent layer 66, a fluorescent sheet may be located on the part of the first cover 6 which passes light from the light emitter 2 to the outside. In this case, with arbitrarily changing fluorescent material contained in the fluorescent layer 66 or the fluorescent sheet, it is possible to convert a wavelength of light form the light emitter 2 into a desired wavelength.
In the light emitting device 110 (111 to 115) of the present embodiment explained above, part of the substrate 3 on which the light emitter 2 and the lighting circuit unit 4 are mounted constitutes part of the housing 8. Hence, heat can be dissipated to the outside via the substrate 3 without using a heat dissipater. Consequently, in contrast to a configuration where a substrate does not constitute a housing, the light emitting device 110 (111 to 115) of the present embodiment can have the improved heat dissipation performance for heat from the light emitter 2 and the lighting circuit unit 4.
Further, according to the light emitting device 110 (111 to 115) of the present embodiment, the housing 8 can be constituted by the substrate 3 and the cover 5. Hence, a housing separate from the substrate 3 and the cover 5 is unnecessary.
Accordingly, the light emitting device 110 (111 to 115) of the present embodiment can satisfy improvement in heat dissipation performance and reduction in the number of parts thereof.
As mentioned above, the light emitting device 100 (110) of the present embodiment includes the following first to fifth features. Note that, the second to fifth features are optional.
As for the first feature, the light emitting device 110 includes the light emitter 2; the substrate 3 having the first surface 3a on which the light emitter 2 is placed; the lighting circuit unit 4 which includes the circuit component 41 for lighting the light emitter 2 and is placed on the substrate 3; and the cover 5 configured to cover the light emitter 2 and the lighting circuit unit 4. The substrate 3 has a part which constitutes part of the housing 8.
In other words, the light emitting device 110 includes the light emitter 2; the lighting circuit unit 4 including the circuit component 41 for lighting the light emitter 2; and the housing 8 configured to accommodate the light emitter 2 and the lighting circuit unit 4. The housing 8 is constituted by: the substrate 3 on which the light emitter 2 and the lighting circuit unit 4 are placed; and the cover 5 attached to the substrate 3 to cover the light emitter 2 and the lighting circuit unit 4.
As for the second feature, in the first feature, the lighting circuit unit 4 is placed on a vicinity of an area of the substrate 3 on which the light emitter 2 is placed, and is placed on a space between the cover 5 and the substrate 3. In other words, the light emitter 2 is placed on the first surface 3a of the substrate 3 in the thickness direction of the substrate 3. The lighting circuit unit 4 is placed on the vicinity of the light emitter 2.
As for the third feature, in the first or second feature, the light emitter 2 includes an LED element.
As for the fourth feature, in any one of the first to third features, the substrate 3 has the first surface 3a and the second surface 3b in the thickness direction of the substrate 3. The light emitter 2 is placed on the first surface 3a of the substrate 3. The second surface 3b of the substrate 3 is a flat surface.
As for the fifth feature, in any one of the first to fourth features, the light emitter 2 is placed on the first surface 3a of the substrate 3 in the thickness direction of the substrate 3. The cover 5 includes: the first part which is placed on the first surface 3a of the substrate 3 to cover the light emitter 2 and is designed to allow light from the light emitter 2 to pass; the second part placed on the first surface 3a of the substrate 3 to not cover the light emitter 2; and the light reflector which is formed on the surface of the second part and is designed to reflect light from the light emitter 2.
Further, the lighting fixture 9 in accordance with the present embodiment includes the light emitting device 100 (110), and the fixture body 91 configured to support the light emitting device 110.
In the lighting fixture 9 of the present embodiment, part of the substrate 3 on which the light emitter 2 and the lighting circuit unit 4 are mounted constitutes part of the housing 8. Hence, heat can be dissipated to the outside via the substrate 3 without using heat dissipating means. Consequently, in contrast to a configuration where a substrate does not constitute a housing, the lighting fixture 9 of the present embodiment can have the improved heat dissipation performance for heat from the light emitter 2 and the lighting circuit unit 4.
Further, according to the lighting fixture 9 of the present embodiment, the housing 8 can be constituted by the substrate 3 and the cover 5. Hence, a housing separate from the substrate 3 and the cover 5 is unnecessary.
Accordingly, the lighting fixture 9 of the present embodiment can satisfy improvement in heat dissipation performance and reduction in the number of parts thereof.
As shown in
The protrusion part 34 is formed into a circular shape in a plane normal to the thickness direction of the substrate 3. Hence, a surface area (heat dissipation area) and a volume of the outer side of the substrate 3 are increased. In brief, the light emitting device 121 includes the protrusion part 34 as the recessed and protruded structure.
Further, as for the light emitting devices 123 and 124 of
The second cover 7a includes a lower surface part 75 and a side part 76 which are formed integrally with each other. The lower surface part 75 is formed into a circular ring shape. The side part 76 is formed into a hollow cylindrical shape and extends upward from an outer periphery of the lower surface part 75. The second cover 7a is attached to the substrate 3 by fitting an inner periphery of the lower surface part 75 into the fitting part 341. Thus, it can be easy to attach the second cover 7a to the substrate 3.
In the light emitting device 123 of
Accordingly, the light emitting device 120 (121 to 124) of the present embodiment can increase at least one of the surface are (heat dissipation area) of the outer side of the substrate 3 and the volume (heat capacity) of the substrate 3. Hence, the heat dissipation performance can be more improved.
In brief, the light emitting device 120 of the present embodiment includes the following sixth feature in addition to the first feature. As for the sixth feature, the substrate 3 has the first surface 3a and the second surface 3b in the thickness direction of the substrate 3. The light emitter 2 is placed on the first surface 3a of the substrate 3. The substrate 3 is provided at the second surface 3b with the recessed and protruded structure.
Note that, the light emitting device 120 of the present embodiment may include the second, third, and fifth features selectively.
As shown in
The side part 33 is formed into a hollow cylindrical shape, and is provided at its apex with a fitting part 331 designed to catch the first cover 6. Accordingly, the substrate 3 constitutes not only the bottom surface of the housing 8 but also the side surface of the housing 8. Note that, explanations are not made to the functions same as those of the substrate 3 (see
The cover 5 of the present embodiment does not include the second cover 7 but includes the first cover 6 only. The first cover 6 of the present embodiment is devoid of the side part 62, and includes the upper surface part 61 and the protrusion part 63 which are formed integrally with each other. The first cover 6 is fixed to the substrate 3 by fitting the outer periphery of the upper surface part 61 into the fitting part 331 of the side part 33. Note that, explanations are not made to the functions same as those of the first cover 6 (see
Further, as for the light emitting device 132 of
The second cover 7a of the light emitting device 132 is constituted by the lower surface part 75 only, and is formed into a circular ring shape. The second cover 7a is fixed to the substrate 3 by fitting the outer periphery and the inner periphery of the second cover 7a into a fitting part 332 of the side part 33 and the fitting part 341 of the protrusion part 34 respectively. Thus, it can be easy to attach the second cover 7a to the substrate 3.
Accordingly, the light emitting device 130 (131, 132) of the present embodiment can increase the surface are (heat dissipation area) of the outer side of the substrate 3. Hence, the heat dissipation performance can be more improved. Note that, the light emitting device 130 of the present embodiment includes the first feature in a similar manner as the first embodiment. Besides, the light emitting device 130 of the present embodiment may include the second to sixth features selectively.
As shown in
The substrate 3 of the present embodiment includes the side part 33 formed integrally with the light emitter supporting portion 31 and the circuit supporting portion 32. The side part 33 extends upward from the outer periphery of circuit supporting portion 32. The side part 33 is formed into a hollow cylindrical shape, and is provided at its apex with the fitting part 331 designed to catch the first cover 6. Accordingly, the substrate 3 constitutes not only the bottom surface of the housing 8 but also the side surface of the housing 8. Note that, explanations are not made to the functions same as those of the substrate 3 (see
The first cover 6 of the present embodiment is devoid of the side part 62. The first cover 6 of the present embodiment is fixed to the substrate 3 by fitting the outer periphery of the upper surface part 61 into the fitting part 331 of the side part 33. Note that, explanations are not made to the functions same as those of the first cover 6 (see
The side part 33 is formed into a hollow cylindrical shape. The 33 is provided at its upper end with the fitting part 331 designed to catch the first cover 6 and at its lower end with the fitting part 332 designed to catch the second cover 7a.
Further, as for the light emitting device 142 of
The second cover 7a is constituted by the lower surface part 75 only, and is formed into a circular ring shape. The second cover 7a is fixed to the substrate 3 by fitting the outer periphery and the inner periphery of the second cover 7a into the fitting part 332 of the side part 33 and the fitting part 341 of the protrusion part 34 respectively. Thus, it can be easy to attach the second cover 7a to the substrate 3.
In brief, the light emitting device 140 of the present embodiment includes the following seventh feature in addition to the first feature. As for the seventh feature, the circuit component 41 is mounted (placed) on the substrate 3.
Note that, the light emitting device 140 of the present embodiment may include the second to sixth features selectively.
As mentioned above, the prior light emitting device disclosed in document 1 has a structure where the lighting circuit unit (the lighting circuit component, the circuit board) is mounted on the rear side of the LED substrate. Hence, a dimension (height) of the light emitting device in the thickness direction of the LED substrate is likely to be increased. In other words, as for the prior light emitting device, to reduce the height of the entire device is difficult.
Further, a decrease in a distance between the LED and the lighting circuit component is likely to cause a problem that heat from the LED may be transferred to the lighting circuit component and heat from the lighting circuit component may be transferred to the LED.
Accordingly, it is desirable that the light emitting device and the lighting fixture can satisfy both of improvement in heat dissipation performance and reduction in height.
With regard to the following fifth to eighth embodiments, for example, the light emitting device 100 (150) shown in
The level difference between the light emitter supporting portion 31 and the circuit supporting portion 32 is, for example, a height difference between the light emitter supporting portion 31 and the circuit supporting portion 32, a recessed portion with a bottom interposed between the light emitter supporting portion 31 and the circuit supporting portion 32, or a combination of the height difference and the recessed portion.
According to the light emitting device 100 (150), in contrast to a structure where the light emitter 2 and the lighting circuit unit 4 are placed on mutually different surfaces, the height of the whole device in the thickness direction of the substrate 3 can be lowered. Further, according to the light emitting device 100 (150), in contrast to a structure where no level difference is formed between the light emitter 2 and the lighting circuit unit 4, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Hence, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
The following explanations are made to the respective embodiments.
In the substrate 3, the level difference is provided between the first surface 311 of the light emitter supporting portion 31 and the first surface 321 of the circuit supporting portion 32. In the substrate 3 of the present embodiment, as shown in
The light emitter supporting portion 31 of the present embodiment is formed into a tapered shape, and a side surface 313 thereof is closer to the outside toward a bottom of the light emitter supporting portion 31 than at the first surface 311. In the present embodiment, the side surface 313 defines an uneven portion which has a level difference in the thickness direction and is interposed between the light emitter supporting portion 31 and the circuit supporting portion 32. In other words, the uneven portion is defined by a surface (side surface 313) connecting the first surface (mounting surface) 311 of the light emitter supporting portion 31 on which the light emitter 2 is placed and the first surface (supporting surface) 321 of the circuit supporting portion 32 on which the lighting circuit unit 4 is placed such that the first surface (mounting surface) 311 of the light emitter supporting portion 31 on which the light emitter 2 is placed and the first surface (supporting surface) 321 of the circuit supporting portion 32 on which the lighting circuit unit 4 is placed are positioned at mutually different positions in the thickness direction.
Further, in the present embodiment, contact positions of the substrate 3 and each of the first cover 6 and the second cover 7 of the cover 5 are on the first surface 321 of the circuit supporting portion 32. Thus, the contact positions are below the first surface 311 of the light emitter supporting portion 31.
Furthermore, in the instance shown in
As shown in
As shown in
Alternatively,
The following explanation is made to other examples (modifications) of the light emitting device 150 in accordance with the present embodiment.
The first cover 6 of
Further, the light reflector (high reflective coating) 64 is formed on a part covering the lighting circuit unit 4 of the inner surface of the first cover 6. For example, the light reflector 64 is formed on an inner surface of part of the upper surface part 61, an inner surface of the side part 62, and an outer surface of the protrusion part 63. Hence, it is possible to reflect light from the light emitter 2 by the light reflector 64.
In the light emitting device 152 of
The light emitter supporting portion 31 of the substrate 3 of
In the substrate 3 of
In the light emitting device 150 (151 to 154) of the present embodiment explained above, the light emitter 2 and the lighting circuit unit 4 are placed while fixed on the same surface 3a (311, 312) of the substrate 3. According to the light emitting device 150 of the present embodiment, in contrast to a structure where the light emitter and the lighting circuit unit are placed while fixed on mutually different surfaces, the height of the whole device in the thickness direction of the substrate 3 can be lowered.
Further, in the light emitting device 154 of
Furthermore, in the light emitting device 150 of the present embodiment, while the lighting circuit unit 4 is placed in the vicinity of the light emitter 2, the level difference is formed between the light emitter supporting portion 31 and the circuit supporting portion 32. For example, the light emitting device 150 of the present embodiment has the height difference (height h3) between the light emitter supporting portion 31 and the circuit supporting portion 32 in the thickness direction of the substrate 3. According to the light emitting device 150 of the present embodiment, in contrast to a structure where no level difference is formed, that is, the light emitter supporting portion 31 and the circuit supporting portion 32 are flush with each other, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Consequently, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
Consequently, the light emitting device 150 of the present embodiment can satisfy both of improvement in heat dissipation performance and reduction in height.
Further, according to the light emitting device 150 of the present embodiment, in a process of attaching the second cover 7 for covering the lighting circuit unit 4, it is possible to facilitate positioning of the second cover 7 by use of the height difference between the light emitter supporting portion 31 and the circuit supporting portion 32.
As mentioned above, the light emitting device 150 of the present embodiment includes the following eighth and ninth features in addition to the first feature.
As for the eighth feature, the light emitting device 150 includes the light emitter 2; the substrate 3 having the first surface 3a on which the light emitter 2 is placed; and the lighting circuit unit 4 which includes the circuit component 41 for lighting the light emitter 2 and is placed on the substrate 3. The lighting circuit unit 4 is placed in the vicinity of the light emitter 2 while fixed on the first surface 3a of the substrate 3. The substrate 3 is formed to have the level difference at least in the first surface 3a between the light emitter supporting portion 31 on which the light emitter 2 is placed and the circuit supporting portion 32 on which the lighting circuit unit 4 is placed. Additionally, the light emitting device 150 includes the cover 5 designed to cover the lighting circuit unit 4.
In other words, the light emitter 2 and the lighting circuit unit 4 are placed on the first surface 3a of the substrate 3 in the thickness direction of the substrate 3. The substrate 3 includes the light emitter supporting portion 31 defined as a portion on which the light emitter 2 is placed; the circuit supporting portion 32 defined as a portion on which the lighting circuit unit 4 is placed; and the uneven portion which has the level difference in the thickness direction and is interposed between the light emitter supporting portion 31 and the circuit supporting portion 32.
As for the ninth feature, in the eighth feature, the substrate 3 has the height difference between the light emitter supporting portion 31 and the circuit supporting portion 32 in the thickness direction.
In other words, the uneven portion is defined by the surface (side surface 313) connecting the first surface 311 of the light emitter supporting portion 31 on which the light emitter 2 is placed and the first surface 321 of the circuit supporting portion 32 on which the lighting circuit unit 4 is placed such that the first surface 311 of the light emitter supporting portion 31 on which the light emitter 2 is placed and the first surface 321 of the circuit supporting portion 32 on which the lighting circuit unit 4 is placed are positioned at mutually different positions in the thickness direction.
Note that, the light emitting device 150 of the present embodiment may include the second to seventh features selectively.
Further, the lighting fixture 9 in accordance with the present embodiment includes the light emitting device 100 (150), and the fixture body 91 configured to support the light emitting device 110.
In this lighting fixture 9, the light emitter 2 and the lighting circuit unit 4 are placed while fixed on the same surface 3a of the substrate 3. According to the lighting fixture 9, in contrast to a structure where the light emitter 2 and the lighting circuit unit 4 are placed while fixed on mutually different surfaces, the height of the whole device in the thickness direction of the substrate 3 can be lowered.
Furthermore, in the lighting fixture 9, while the lighting circuit unit 4 is placed in the vicinity of the light emitter 2, the level difference is formed between the light emitter supporting portion 31 and the circuit supporting portion 32. According to the lighting fixture 9, in contrast to a structure where no level difference is formed, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Consequently, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
Consequently, the lighting fixture 9 of the present embodiment can satisfy both of improvement in heat dissipation performance and reduction in height.
As shown in
Further, the second cover 7 of the present embodiment is fixed such that the apex of the inner side part 73 is fitted into the groove 36. Note that, explanations are not made to the functions same as those of the second cover 7 (see
In the light emitting device 160 (161 to 164) of the present embodiment explained above, the recess (groove 36, 371, 372) is formed between the light emitter supporting portion 31 and the circuit supporting portion 32. According to the light emitting device 160 (161 to 164) of the present embodiment, in contrast to a configuration where no recess is formed between the light emitter supporting portion 31 and the circuit supporting portion 32, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Hence, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
Specifically, the light emitting device 162 of
Further, in the light emitting device 160 (161 to 164) of the present embodiment, formed between the light emitter supporting portion 31 and the circuit supporting portion 32 is the recess. Hence, in contrast to a structure where a through hole is formed between the light emitter supporting portion and the circuit supporting portion, it is possible to prevent a decrease in strength of the substrate 3.
Furthermore, in the light emitting device 160 (161 to 164) of the present embodiment, it is possible to facilitate positioning of the second cover 7 by use of the recess of the substrate 3.
As mentioned above, the light emitting device 160 of the present embodiment includes the following tenth feature in addition to the first and eighth feature. In the tenth feature, the substrate 3 is provided with the recess (groove 36, 371, 372) between the light emitter supporting portion 31 and the circuit supporting portion 32. In other words, uneven portion is defined by the recess (groove 36, 371, 372). Note that, the light emitting device 160 of the present embodiment may include the second to seventh features selectively.
As shown in
In the lighting circuit unit 4 of the present embodiment, the plural circuit components 41 are not placed on the substrate 3 by use of the pillars 43, but are directly placed on the substrate 3. Note that, in the light emitting device 171 of
The second cover 7 of the present embodiment is fixed to the first surface 311 of the light emitter supporting portion 31 at the apex of the inner side part 73. In the second cover 7, a space in which the lighting circuit unit 4 is placed is filled with insulating resin 44. Note that, explanations are not made to the functions same as those of the second cover 7 (see
The side part 33 is formed into a hollow cylindrical shape. The 33 is provided at its upper end with the fitting part 331 designed to catch the first cover 6 and at its lower end with the fitting part 332 designed to catch the second cover 7a.
The first cover 6 of
Further, as for the light emitting devices 172 of
The second cover 7a is formed into a circular ring shape. The second cover 7a is fixed to the substrate 3 by fitting the outer periphery and the inner periphery of the second cover 7a into the fitting part 332 of the side part 33 and the fitting part 375 of the intermediate portion 37 respectively.
Thus, it can be easy to attach the second cover 7a to the substrate 3. Note that, a space between the second cover 7a and the second surface 322 of the circuit supporting portion 32 may be filled with resin. Alternatively, such a space may be filled with resin while the second cover 7a is not provided.
In addition,
Moreover,
In the light emitting device 170 (171 to 177) of the present embodiment explained above, like the sixth embodiment, the recess (groove 36, 371, 372) is formed between the light emitter supporting portion 31 and the circuit supporting portion 32. According to the light emitting device 170 (171 to 177) of the present embodiment, in contrast to a configuration where no recess is formed between the light emitter supporting portion 31 and the circuit supporting portion 32, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Hence, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
Specifically, the light emitting device 172 of
As mentioned above, the light emitting device 170 of the present embodiment includes the tenth feature in addition to the first and eighth features like the light emitting device 160 of the sixth embodiment. Note that, the light emitting device 170 of the present embodiment includes the second to seventh features selectively.
As shown in
Further, the recessed part 323 in the form of a circular ring shape is formed in the second surface 322 of the circuit supporting portion 32. Some circuit components 41 are accommodated in the recessed part 323. The recessed part 323 has the depth d1 which is selected such that the circuit component 41 is housed in the recessed part 323 without protruding from the recessed part 323.
In the light emitting device 180 (181 and 182) of the present embodiment explained above, like the light emitting device 150 of the fifth embodiment, the light emitter 2 and the lighting circuit unit 4 are placed while fixed on the same surface 3a (311, 312) of the substrate 3. According to the light emitting device 180 (181 and 182) of the present embodiment, in contrast to a structure where the light emitter and the lighting circuit unit are placed while fixed on mutually different surfaces, the height of the whole device in the thickness direction of the substrate 3 can be lowered.
Further, in the light emitting device 180 (181 and 182) of the present embodiment, like the light emitting device 150 of the fifth embodiment, while the lighting circuit unit 4 is placed in the vicinity of the light emitter 2, the level difference is formed between the light emitter supporting portion 31 and the circuit supporting portion 32. According to the light emitting device 180 (181 and 182) of the present embodiment, in contrast to a structure where no level difference is formed, a heat transfer path between the light emitter 2 and the lighting circuit unit 4 can be lengthened. Consequently, heat transfer between the light emitter 2 and the lighting circuit unit 4 can be reduced.
Accordingly, the light emitting device 181 of the present embodiment includes the following ninth feature in addition to the first and eighth features, like the light emitting device 150 of the fifth embodiment.
Meanwhile, the light emitting device 182 of
Accordingly, the light emitting device 182 of the present embodiment includes the following tenth feature in addition to the first and eighth features, like the light emitting device 160 of the sixth embodiment.
Consequently, the light emitting device 180 (181 and 182) of the present embodiment can satisfy both of improvement in heat dissipation performance and reduction in height, like the light emitting device 150 of the fifth embodiment. Note that, the light emitting device 180 (181 and 182) of the present embodiment may include the second to seventh features selectively.
Note that, each of the light emitting devices 100 (110, 120, 130, 140, 150, 160, 170, and 180) of the respective embodiments can be attached to the fixture body 91 shown in
Besides, an electrical connection between the fixture body 91 and the light emitting device 100 may be made by providing a power cable to the light emitting device 100 and connecting the power cable to the fixture body 91, or by providing a power terminal (e.g., a pin) to the light emitting device 100 and connecting the power terminal to the fixture body 91.
Number | Date | Country | Kind |
---|---|---|---|
2012-133804 | Jun 2012 | JP | national |
2012-133806 | Jun 2012 | JP | national |