Lighting device

Abstract

The utility model provides a lighting device which can effectively reduce the temperature of a light-emitting module and can effectively reduce the temperature of a circuit unit (a circuit substrate). An LED lamp (1), which is an example of a lighting device, is provided with: a light-emitting module (10) that emits light; a metal base plate (20) which is located on the opposite side of the light emitting module (10) from the light irradiation side and supports the light emitting module (10); a circuit board (51) on which a circuit element (52) for lighting the light-emitting module (10) is disposed; and a heat sink (60) which is located on the opposite side of the circuit substrate (51) from the light-emitting module (10) side and supports the circuit substrate (51), the bottom plate (20) is separated from the heat sink (60), and a heat insulating layer (100) is arranged between the bottom plate (20) and the circuit substrate (51).

Description

Technical Field

[0001] The utility model relates to a lighting device, in particular to a lighting device which uses a light emitting diode (LED: Light Emitting Diode) as a light source. Background Art

[0002] Solid-state light-emitting elements such as LEDs are used as light sources for various products because of their small size, high efficiency, and long life. For example, LED lighting using LEDs as light sources has been put into practical use. As LED lighting, lighting fixtures such as downlights, ceiling lights, and spotlights are known.

[0003] In lighting fixtures such as downlights, an LED lamp with a lamp cap is detachably mounted on the fixture body of the lighting fixture. As such an LED lamp, Patent Document 1 discloses a flat lighting device having a GX53 lamp cap. The lighting device disclosed in Patent Document 1 includes an LED, an LED substrate on which the LED is mounted, a light-transmitting cover covering the LED, a lamp cap housing having a GX53 lamp cap, a circuit unit housed in the lamp cap housing, and a metal cover covering the opening of the lamp cap housing. The circuit unit includes a circuit substrate and a plurality of circuit elements mounted on the circuit substrate.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication No. 2010-192337 Utility Model Content

[0007] Problems to be solved by utility models

[0008] In LED lamps, further high beam (high wattage) is required, and research and development of high-output LED lamps are progressing. When the wattage of LED lamps is increased, the heat generated by the LED increases. LED generates heat from the LED itself by emitting light, thereby increasing the temperature of the LED and reducing the light output. In other words, the luminous efficiency of the LED decreases due to the heat generated by the LED itself. Therefore, heat dissipation measures for reducing the temperature of the LED are extremely important. As one of the heat dissipation measures, it can be considered to provide a heat sink to release the heat generated in the LED.

[0009] In this regard, in the lighting device disclosed in Patent Document 1, the heat generated by the LED is conducted to the metal cover and released by attaching the LED substrate to the metal cover. That is, the metal cover is used as a heat sink.

[0010] On the other hand, when the LED emits light, heat is also generated from the circuit unit used to make the LED emit light. Specifically, the circuit elements constituting the lighting circuit of the circuit unit include heat-generating components, and heat is generated from the heat-generating components. In addition, when heat is generated from the circuit element, not only the circuit element but also other circuit elements deteriorate. In particular, there are components with low heat resistance temperatures such as electrolytic capacitors among the circuit elements. Therefore, heat dissipation measures for reducing the temperature of the circuit unit are also important.

[0011] However, in the lighting device disclosed in Patent Document 1, no heat dissipation measures are taken for the circuit unit. Moreover, in the lighting device disclosed in Patent Document 1, a metal cover for releasing heat generated by the LED is arranged near the circuit unit, so the heat generated by the LED is transferred to the circuit unit via the metal cover. Therefore, the circuit elements of the circuit unit are affected not only by the heat generating components but also by the heat generated by the LED.

[0012] The utility model is proposed to solve these problems, and its purpose is to provide a lighting device which can effectively reduce the temperature of the light emitting module and the temperature of the circuit unit (circuit substrate).

[0013] Means used to solve problems

[0014] In order to achieve the above-mentioned purpose, one mode of the lighting device of the utility model comprises: a light-emitting module, which irradiates light; a metal base plate, which is located on the side of the light-emitting module opposite to the light irradiation side and supports the light-emitting module; a circuit substrate, which is configured with circuit elements for lighting the light-emitting module; and a heat sink, which is located on the side of the circuit substrate opposite to the light-emitting module side and supports the circuit substrate, the base plate is separated from the heat sink, and an insulating layer is present between the base plate and the circuit substrate.

[0015] Effect of utility model

[0016] According to the utility model, the temperature of the light emitting module can be effectively reduced, and the temperature of the circuit unit (circuit substrate) can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a perspective view of the LED lamp according to the embodiment as viewed from obliquely above.

[0018] Figure 2 This is a perspective view of the LED lamp according to the embodiment as viewed diagonally from below.

[0019] Figure 3 It is an exploded perspective view of the LED lamp according to the embodiment.

[0020] Figure 4It is a cross-sectional view of the LED lamp according to the embodiment.

[0021] Figure 5 It is a cross-sectional perspective view of the LED lamp according to the embodiment.

[0022] Figure 6 It is a cross-sectional view of the LED lamp according to the embodiment.

[0023] Figure 7 It is a diagram for explaining a heat dissipation path in the LED lamp according to the embodiment.

[0024] Figure 8 This is a graph showing the relationship between the ratio of the thickness of the heat sink to the thickness of the heat insulating layer and the temperature of the circuit element.

[0025] Fig. 9 This is a graph showing the relationship between the ratio of the thickness of the base plate to the thickness of the heat insulating layer, and the temperatures of the LED light emitting portion and the circuit elements.

[0026] Description of Reference Numerals

[0027] 1LED lamp (lighting device)

[0028] 10 light emitting modules

[0029] 20 base plate

[0030] 21Abutment part

[0031] 22 side wall

[0032] 51 Circuit board

[0033] 52 circuit elements

[0034] 60 heat sink

[0035] 70 frame

[0036] 100 Insulation Layer DETAILED DESCRIPTION

[0037] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the embodiments described below all represent a specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, configuration positions and connection methods of the constituent elements shown in the following embodiments are only examples, and the main purpose is not to limit the present invention. Therefore, among the constituent elements of the following embodiments, the constituent elements not recorded in the independent technical solutions representing the highest concept of the present invention will be described as arbitrary constituent elements.

[0038] In addition, each figure is a schematic diagram and is not necessarily a strict illustration. In addition, in each figure, substantially the same structure is marked with the same figure mark, and repeated descriptions are omitted or simplified. In addition, in this specification, the terms "upper" and "lower" do not necessarily refer to the upper direction (vertically above) and the lower direction (vertically below) in absolute space recognition.

[0039] (Implementation Method)

[0040] First, use Figure 1 and Figure 2 The overall structure of the LED lamp 1 according to the present embodiment will be described. Figure 1 This is a perspective view of the LED lamp 1 according to the embodiment as viewed from obliquely above. Figure 2 This is a perspective view of the LED lamp 1 as viewed diagonally from below.

[0041] The LED lamp 1 is an example of a lighting device using an LED as a light source, and irradiates lighting light. Figure 1 and Figure 2 As shown, the overall shape of the LED lamp 1 is cylindrical, and is a flat panel lamp. As an example, the outer dimension of the LED lamp 1 is φ70 mm, but it is not limited thereto.

[0042] In addition, the LED lamp 1 is a replaceable lamp installed in a socket. That is, the LED lamp 1 can be installed in the socket in a detachable manner. By being installed in the socket, the LED lamp 1 is lit by the power supplied through the socket. The socket is installed on an appliance body or a bracket set on a building material such as a ceiling, a wall, and a floor, or is directly set on the building material. By installing the LED lamp 1 in the socket, a lighting fixture such as a downlight, a spotlight, or a ceiling lamp is formed. As an example, the lighting fixture includes an LED lamp 1 and an appliance body, and the appliance body has a socket on which the LED lamp 1 is detachably installed.

[0043] In this embodiment, the LED lamp 1 has a lamp base that can be detachably mounted on a socket. Specifically, the LED lamp 1 has a GX53 lamp base that can be detachably mounted on a GX53 socket. In addition, the lamp base of the LED lamp 1 is not limited to the GX53 lamp base, and may also be other lamp bases such as a GH76p lamp base.

[0044] Next, use Figures 3 to 6 The specific structure of the LED lamp 1 according to the present embodiment will be described. Figure 3 It is an exploded perspective view of the LED lamp 1 according to the embodiment. Figure 4 is a cross-sectional view of the same LED lamp 1 . Figure 5 yes Figure 4 A sectional stereoscopic view of the same LED lamp 1 in the section of FIG. Figure 6 is with Figure 4 The cross-sectional stereoscopic view of the same LED lamp 1 is shown in FIG. Figure 6The cross section is Figure 4 The cross section is a cross section when the LED lamp 1 is rotated 90 degrees around the central axis (optical axis) of the LED lamp 1. Figure 4 In FIG. 5 , the shape, number, etc. of the circuit element 52 in the circuit unit 50 are not accurately illustrated. Figure 3 , Figure 5 and Figure 6 In the figure, the circuit element 52 of the circuit unit 50 is not shown.

[0045] like Figures 3 to 6 As shown, the LED lamp 1 includes a light emitting module 10 , a base plate 20 , a support member 30 , a light-transmitting cover 40 , a circuit unit 50 , a heat sink 60 , a frame 70 , and a base pin 80 .

[0046] In this embodiment, the light-transmitting cover 40 and the frame 70 are outer frame members, and thus the light-transmitting cover 40 and the frame 70 constitute an outer frame of the LED lamp 1 , in which the light-emitting module 10 , the bottom plate 20 , the support 30 , the circuit unit 50 and the heat sink 60 are housed.

[0047] The LED lamp 1 in the present embodiment is a high-power, high-beam type lamp, and the input power to the light emitting module 10 is 9 watts or more. In the present embodiment, the input power to the light emitting module 10 is 9.9 watts.

[0048] The light emitting module 10 is a light source unit that emits light. The light emitting module 10 emits illumination light of a predetermined color. For example, the light emitting module 10 emits white light with a color temperature of 3000K to 7000K as illumination light. The light emitted from the light emitting module 10 passes through the translucent cover 40 and is emitted as illumination light of the LED lamp 1 .

[0049] In the present embodiment, the light emitting module 10 is an LED module composed of LEDs. Specifically, the light emitting module 10 is a COB (Chip On Board) type LED module, which has a substrate 11 and an LED light emitting unit 12 composed of an LED chip directly mounted on the substrate 11. The light emitted from the LED light emitting unit 12 is the light irradiated by the light emitting module 10.

[0050] The substrate 11 is a mounting substrate for mounting the LED chip included in the LED light emitting unit 12. As a base material constituting the substrate 11, a ceramic substrate, a resin substrate, or a metal base substrate is used. In the present embodiment, the planar shape of the substrate 11 is roughly rectangular. Specifically, the planar shape of the substrate 11 is a shape in which a part (corner, etc.) of a square is cut off. In addition, the planar shape of the substrate 11 is not limited to a square or a rectangular rectangle, and may also be a circle, etc.

[0051] A pair of terminals and metal wiring of a prescribed pattern are provided on the substrate 11, the pair of terminals receiving DC power for making the LED chip included in the LED light-emitting unit 12 emit light, and the metal wiring is connected to the pair of terminals and electrically connects the LEDs to each other. As an example, a pair of terminals are electrodes formed on the surface of the substrate 11. A pair of terminals are electrically connected to the circuit unit 50 via a pair of power lines. In addition, the pair of terminals may not be electrodes but connector terminals. In addition, an anti-corrosion coating (resist) composed of an insulating resin material can be formed on the surface of the substrate 11 to cover the metal wiring. Thus, it is possible to ensure insulation withstand voltage while protecting the metal wiring.

[0052] The LED light emitting unit 12 includes an LED chip mounted on the substrate 11 and a sealing member that seals the LED chip. In the present embodiment, a plurality of LED chips are mounted on the substrate 11. Therefore, the sealing member seals the plurality of LED chips.

[0053] The LED chip of the LED light emitting unit 12 is a bare chip that emits monochromatic visible light. The LED chip is, for example, a blue LED chip that emits blue light when powered. For example, a plurality of LED chips are arranged in a matrix on the substrate 11. In addition, at least one LED chip only needs to be arranged.

[0054] The sealing member of the LED light emitting unit 12 is made of a light-transmitting insulating resin material such as silicone resin. The sealing member in this embodiment contains a phosphor as a wavelength conversion material for converting the wavelength of light from the LED chip. The sealing member is, for example, a phosphor-containing resin in which the phosphor is dispersed in silicone resin. That is, the sealing member is a phosphor-containing resin containing a phosphor in a light-transmitting resin, and converts the wavelength of light from the LED chip (color conversion) to a specified wavelength.

[0055] As the phosphor contained in the sealing member, in the case where the LED chip is a blue LED chip that emits blue light, in order to obtain white light, a yellow phosphor of the YAG system, for example, can be used. In this case, the yellow phosphor absorbs a portion of the blue light emitted by the blue LED chip and is excited to emit yellow light. Then, the yellow light is mixed with the blue light not absorbed by the yellow phosphor to form white light, which is emitted from the LED light emitting portion 12. In addition, light diffusion materials such as silica, fillers, etc. can also be dispersed in the sealing member.

[0056] like Figure 3As shown, in this embodiment, the sealing member of the LED light emitting portion 12 is formed into a circular plane shape so that all LED chips are sealed together. The outer shape of the sealing member determines the outer shape of the LED light emitting portion 12. In this case, it is also possible to form an annular convex portion (dam) on the substrate 11 so that when the liquid sealing member is applied to the substrate 11, the liquid sealing member is blocked by the convex portion.

[0057] In addition, the sealing member may seal the LED chips into a shape other than a circle (e.g., a rectangle). In addition, the sealing member may not seal all the LED chips together, but seal the plurality of LED chips into a linear shape in each row, or may seal each LED chip individually.

[0058] like Figures 3 to 6 As shown, the light emitting module 10 is supported by the base plate 20. The base plate 20 is a module plate that supports the light emitting module 10. In the present embodiment, the light emitting module 10 is arranged on the base plate 20 and supported by the base plate 20. The base plate 20 is located on the side opposite to the light irradiation side of the light emitting module 10. That is, the light emitting module 10 is arranged on the base plate 20 in such a manner that the light irradiation side becomes the light-transmitting cover 40 side.

[0059] The bottom plate 20 is a metal member made of a metal material such as aluminum or copper. Therefore, the bottom plate 20 on which the light emitting module 10 is arranged also functions as a heat sink for releasing heat generated in the light emitting module 10. In addition, the bottom plate 20 may be a die-cast metal member or a sheet metal metal member formed into a predetermined shape by stamping a metal plate. In the present embodiment, the bottom plate 20 is a die-cast metal member made of an aluminum alloy.

[0060] The bottom plate 20 has a base portion 21 for supporting the light emitting module 10, and a side wall portion 22 erected on the base portion 21. In the present embodiment, the base portion 21 is in the shape of a flat plate, and the side wall portion 22 is in the shape of a cylinder. Specifically, the bottom plate 20 is a cylindrical member with a low height. Therefore, the base portion 21 is in the shape of a circular plate, and the side wall portion 22 is in the shape of a cylinder. The base portion 21 and the side wall portion 22 of the bottom plate 20 are integrally formed, but are not limited thereto. For example, the bottom plate 20 may also be obtained by joining the base portion 21 and the side wall portion 22 manufactured separately.

[0061] like Figures 4 to 6 As shown, the base 21 has a mounting surface for mounting the substrate 11 of the light emitting module 10. A heat conducting sheet or grease may be sandwiched between the mounting surface of the base 21 and the substrate 11. Thus, the heat generated in the light emitting module 10 can be efficiently conducted to the bottom plate 20.

[0062] The side wall portion 22 is erected from the end of the base portion 21. The side wall portion 22 extends from the base portion 21 toward the circuit unit 50 side (circuit substrate 51 side). In the present embodiment, the height of the side wall portion 22 is fixed, but is not limited to this. For example, the height of the side wall portion 22 may be partially increased or decreased. In addition, the wall thickness of the side wall portion 22 is thinner than the thickness of the base portion 21, but is not limited to this. That is, the wall thickness of the side wall portion 22 may be the same as the thickness of the base portion 21, or may be thicker than the thickness of the base portion 21.

[0063] The bottom plate 20 is close to the inner surface of the frame 70. Specifically, Figures 4 to 6 As shown, the lateral end surface of the base portion 21 of the bottom plate 20 and the wall surface of the side wall portion 22 are close to the inner surface of the frame 70. Therefore, the outer diameter of the base portion 21, the outer diameter of the side wall portion 22 and the inner diameter of the frame 70 are substantially the same. Since the bottom plate 20 is close to the inner surface of the frame 70, the heat of the light-emitting module 10 that has been transferred to the bottom plate 20 can be efficiently released to the outside of the LED lamp 1 through the frame 70.

[0064] In addition, the transverse end surface of the base portion 21 and the wall surface of the side wall portion 22 may be in contact with the inner surface of the frame 70, or there may be a small gap between the transverse end surface of the base portion 21 and the wall surface of the side wall portion 22 and the inner surface of the frame 70 with only the degree of dimensional tolerance. Since the wall surface of the side wall portion 22 is longer than the transverse end surface of the base portion 21, as shown in FIG. Figures 4 to 6 As shown, at least the wall surface of the side wall portion 21 is in contact with the inner surface of the frame body 70. Thus, the heat conducted to the bottom plate 20 can be efficiently conducted to the frame body 70.

[0065] The bottom plate 20 is fixed to the frame 70. Specifically, the bottom plate 20 is fixed to the inner surface of the upper side of the side wall portion 71 of the frame 70. In this case, a locking structure (e.g., a concave-convex structure) such as a locking claw and a locking hole is provided on the inner surface of the bottom plate 20 and the frame 70, and the bottom plate 20 can be fixed to the frame 70 by snap-in locking the locking structure of the bottom plate 20 to the locking structure of the frame 70. Alternatively, a thread groove can be provided on the inner surface of the bottom plate 20 and the frame 70, respectively, and the bottom plate 20 can be screwed into and fixed to the inner surface of the frame 70 by rotating it.

[0066] In addition, since the bottom plate 20 in the present embodiment is a bottomed cylindrical shape, the portion surrounded by the flat plate-shaped base portion 21 and the cylindrical side wall portion 22 is a space region, but the present invention is not limited thereto. For example, the bottom plate 20 may be a flat plate-shaped metal member consisting only of the base portion 21 without the side wall portion 22, or may be a thick-walled flat plate-shaped metal member having a columnar shape instead of a cylindrical shape.

[0067] The light emitting module 10 disposed on the bottom plate 20 is fixed to the bottom plate 20. The holder 30 is a module holder (light source holder) that holds the light emitting module 10. The holder 30 is made of an insulating resin material such as polybutylene terephthalate (PBT).

[0068] In this embodiment, the light emitting module 10 is fixed to the base portion 21 in a state where the substrate 11 is pressed against the base portion 21 of the bottom plate 20 by the holder 30. Figure 4 As shown, with the end of the substrate 11 of the light emitting module 10 sandwiched between a portion of the holder 30 and the base portion 21, a screw 91 is inserted through the insertion hole 31 of the holder 30 (see Figure 3 ), the screw 91 is screwed into the threaded hole 23 of the bottom plate 20, so that the holder 30, the substrate 11 and the bottom plate 20 are fastened together by the screw 91. Thus, the light emitting module 10 is fixed to the bottom plate 20 while being pressed by the holder 30.

[0069] In addition, if Figure 3 As shown, three screws 91 are used to fix the light emitting module 10 to the bottom plate 20, but the number of screws 91 is not limited to three. Figure 3 As shown in the figure, the screw hole 23 of the bottom plate 20 is provided at the peripheral edge of the mounting surface of the base portion 21, but the present invention is not limited thereto.

[0070] like Figures 4 to 6 As shown, the light emitting module 10 is covered by a light-transmitting cover 40. The light-transmitting cover 40 is a light-transmitting cover member that covers the light emitting module 10. The light-transmitting cover 40 is made of a light-transmitting material. For example, the light-transmitting cover 40 is made of a transparent resin material such as acrylic or polycarbonate, or a transparent material such as a glass material.

[0071] The light-transmitting cover 40 is mounted on the opening end of the opening of the frame 70. In this case, when a locking structure (e.g., a concave-convex structure) such as a locking claw and a locking hole is provided at the opening ends of the light-transmitting cover 40 and the frame 70, the light-transmitting cover 40 can be fixed to the frame 70 by locking the locking structure of the light-transmitting cover 40 with the locking structure of the frame 70. Alternatively, thread grooves may be provided at the opening ends of the light-transmitting cover 40 and the frame 70, respectively, and the light-transmitting cover 40 may be rotated and screwed into the frame 70 to be fixed. In addition, an annular pad member made of an elastic body or the like may be inserted into the joint portion of the light-transmitting cover 40 and the frame 70.

[0072] The light-transmitting cover 40 allows light emitted from the light-emitting module 10 to pass therethrough. That is, the light emitted from the light-emitting module 10 enters the light-transmitting cover 40 , passes through the light-transmitting cover 40 , and is emitted to the outside of the light-transmitting cover 40 .

[0073] The light-transmitting cover 40 may be an optical member that provides an optical effect to the light emitted from the light-emitting module 10. For example, the light-transmitting cover 40 may have a light distribution control function that controls the light distribution of the light emitted from the light-emitting module 10.

[0074] In the present embodiment, the light-transmitting cover 40 has a lens function of converging the light emitted from the light-emitting module 10. That is, the light-transmitting cover 40 has an optical function of narrowing the light distribution angle of the light emitted from the light-emitting module 10. Specifically, the light-transmitting cover 40 has a Fresnel lens, that is, a lens portion 41. The lens portion 41 has a central protrusion formed on the inner surface (light incident surface) of the light-transmitting cover 40 and a plurality of annular protrusions concentrically surrounding the central protrusion. The central protrusion and the plurality of annular protrusions constitute an annular zone of the Fresnel lens.

[0075] In addition, a plurality of grooves (recesses) are formed on the outer surface of the light-transmitting cover 40. The plurality of grooves are formed to cover the entire outer surface of the light-transmitting cover 40. Thus, the light-transmitting cover 40 can have a light diffusion function, so that the light emitted from the light-emitting module 10 can be uniformed, and the graininess (brightness difference) caused by the plurality of LED chips can be suppressed.

[0076] In addition, the outer surface of the light-transmitting cover 40 may be further subjected to a corrugation process. That is, both a plurality of grooves and a micro-concave-convex structure generated by the corrugation process may be formed on the outer surface of the light-transmitting cover 40. Thus, the light emitted from the light-emitting module 10 can be further uniformed. In addition, the process of forming the micro-concave-convex structure is not limited to the corrugation process. The micro-concave-convex structure may also be formed on the outer surface of the light-transmitting cover 40 by applying an etching process or a sandblasting process. In addition, the micro-concave-convex structure may be formed not only on the outer surface of the light-transmitting cover 40, but also on the inner surface of the light-transmitting cover 40.

[0077] like Figure 1 and Figure 3 As shown, a pair of protrusions 42 are provided on the outer surface of the light-transmitting cover 40. The pair of protrusions 42 function as hooks for the user's fingers to hook when the LED lamp 1 is rotated and installed on the lighting fixture. By providing the pair of protrusions 42, the LED lamp 1 can be easily rotated, so that the LED lamp 1 can be easily installed on the fixture body of the lighting fixture or easily removed from the fixture body.

[0078] The light emitting module 10 emits light by the power supplied from the circuit unit 50. The circuit unit 50 generates power for causing the light emitting module 10 to emit light, and supplies the generated power to the light emitting module 10. Specifically, the circuit unit 50 supplies a direct current to the light emitting module 10. The light emitting module 10 emits light by the direct current supplied from the circuit unit 50.

[0079] The light emitting module 10 and the circuit unit 50 are electrically connected through a pair of power lines. Since the bottom plate 20 exists between the light emitting module 10 and the circuit unit 50, Figure 3 As shown in FIG. 1 , the bottom plate 20 is provided with through holes 24 for inserting a pair of power lines. The through holes 24 are provided in the base portion 21 of the bottom plate 20 .

[0080] The circuit unit 50 constitutes a lighting circuit (power supply circuit) for lighting and extinguishing the light emitting module 10. Specifically, the lighting circuit of the circuit unit 50 converts AC power supplied from the base pins 80 into DC power. The lighting circuit includes, for example, a constant current circuit.

[0081] In addition, the circuit unit 50 includes not only a lighting circuit but also a lighting control circuit. For example, the circuit unit 50 may include a dimming circuit or a color adjustment circuit as a lighting control circuit. In this case, the lighting control circuit controls the lighting circuit according to a lighting control signal (dimming control signal or color adjustment control signal, etc.) input from the outside of the LED lamp 1, and dims or adjusts the color of the light emitted from the light emitting module 10. In addition, when the color of the light emitted from the light emitting module 10 is adjusted, the light emitting module 10 may have a plurality of LED light sources with different color temperatures. In addition, the circuit unit 50 may also have other control circuits such as a wireless communication circuit for wireless communication with an external device.

[0082] like Figure 4 As shown, the circuit unit 50 includes a circuit substrate 51 and a plurality of circuit elements 52 disposed on the circuit substrate 51. The circuit unit 50 is accommodated in a frame 70. In addition, the circuit unit 50 is disposed between the base plate 20 and the heat sink 60. Specifically, the circuit substrate 51 of the circuit unit 50 is disposed between the base plate 20 and the heat sink 60.

[0083] The circuit substrate 51 is a printed circuit substrate (PCB) formed with metal wiring such as copper foil. The circuit substrate 51 may be a single-sided substrate with metal wiring formed on only one surface, or a double-sided substrate with metal wiring formed on both surfaces. A plurality of circuit elements 52 mounted on the circuit substrate 51 are electrically connected to each other via metal wiring formed on the circuit substrate 51. The circuit substrate 51 is, for example, a plate-shaped substrate with a portion of a circular plate cut away.

[0084] A pair of output terminals and a pair of input terminals are provided on the circuit substrate 51. The pair of output terminals are electrically connected to the light emitting module 10 via a pair of power lines, and the pair of input terminals are electrically connected to a pair of base pins 80 via a pair of power lines.

[0085] The circuit element 52 is an electronic component for lighting the light emitting module 10. The circuit element 52 is mounted on the circuit substrate 51 by soldering or the like. A plurality of circuit elements 52 are mounted on the circuit substrate 51. The plurality of circuit elements 52 are, for example, capacitance elements such as electrolytic capacitors or ceramic capacitors, coil elements (inductors) such as choke coils or choke transformers, resistance elements such as resistors, transistor elements such as FETs, noise filters, diodes, or IC packages.

[0086] The plurality of circuit elements 52 include a specific circuit element 52 with a low heat resistance. As the specific circuit element 52 with a low heat resistance, an electrolytic capacitor can be cited. The specific circuit element 52 with a low heat resistance is arranged on the surface of the circuit substrate 51 on the side opposite to the light emitting module 10 side (the bottom plate 20 side). That is, the specific circuit element 52 with a low heat resistance is mounted on the surface of the circuit substrate 51 on the heat sink 60 side, that is, the first surface. In addition, as Figure 4 As shown, the circuit elements 52 with leads among the plurality of circuit elements 52 are mounted on the first surface on the heat sink 60 side of the circuit substrate 51. In addition, most of the surface-mounted circuit elements 52 among the plurality of circuit elements 52 are mounted by soldering on the second surface of the circuit substrate 51 on the light emitting module 10 side (bottom plate 20 side).

[0087] like Figures 4 to 6 As shown in FIG. 1 , the circuit substrate 51 is arranged in a posture (horizontally) with the main surface being substantially orthogonal to the cylindrical axis of the frame 70. In this embodiment, the cylindrical axis of the frame 70 is the same as the optical axis of the LED lamp 1 (the optical axis of the light emitting module 10). In addition, the circuit substrate 51 is placed on the surface of the heat sink 60 on the light emitting module 10 side. Specifically, as Figure 6 As shown, the circuit board 51 is placed on the end surface ( Figure 6 upper end surface).

[0088] The circuit unit 50 thus constructed is disposed between the bottom plate 20 and the heat sink 60. Specifically, the circuit substrate 51 of the circuit unit 50 is disposed between the bottom plate 20 and the heat sink 60. Specifically, the circuit substrate 51 is covered by the bottom plate 20. In this embodiment, the circuit substrate 51 is not in contact with the bottom plate 20. Figure 4 and Figure 6 As shown in FIG. 1 , there is a heat insulating layer 100 between the bottom plate 20 and the circuit substrate 51. That is, the bottom plate 20 and the circuit substrate 51 are separated at least by the heat insulating layer 100. In this embodiment, the heat insulating layer 100 is an air layer as a space region. In addition, although the heat insulating layer 100 is an air layer, Figure 4 and Figure 6 In order to make the heat insulation layer 100 easier to understand, dotted shadows are applied to the heat insulation layer 100 for convenience.

[0089] The circuit unit 50 is fixed to the heat sink 60. Specifically, the circuit substrate 51 of the circuit unit 50 is fixed to the heat sink 60. More specifically, the circuit substrate 51 is fixed to the heat sink 60 by tightening the circuit substrate 51 to the heat sink 60 with screws 92. In this case, the circuit substrate 51 is placed on the side wall portion 61 of the heat sink 60, and the screws 92 are inserted through the cutout portion 51a (see Figure 3 ), and screw the screw 92 into the threaded hole 63 provided on the heat sink 60 (refer to Figure 3 ), thereby fixing the circuit substrate 51 to the heat sink 60. Figure 3 As shown, two screws 92 are used to fix the circuit substrate 51 to the heat sink 60, but the number of screws 92 is not limited to two. In addition, the fixing mechanism for fixing the circuit substrate 51 and the heat sink 60 is not limited to screws. For example, a locking structure can be provided on the circuit substrate 51 and the heat sink 60 respectively, and the circuit substrate 51 and the heat sink 60 can be fixed by locking the locking structures with each other.

[0090] The heat sink 60 is a heat dissipation member that releases heat generated in the circuit unit 50. The heat sink 60 is a metal member made of a metal material such as aluminum or copper. The heat sink 60 may be a die-cast metal member or a sheet metal metal member formed into a predetermined shape by stamping a metal plate. In the present embodiment, the heat sink 60 is a die-cast metal member made of an aluminum alloy, similarly to the base plate 20.

[0091] The heat sink 60 is annular. Figure 3 As shown in the figure, in this embodiment, the heat sink 60 is annular as a whole, and has a substantially cylindrical side wall portion 61 and an annular brim portion 62 protruding from the inner surface of the lower end of the side wall portion 61. Although the heat sink 60 is formed by the side wall portion 61 and the brim portion 62 as a whole, it is not limited to this. For example, the heat sink 60 can be formed by joining the side wall portion 61 and the brim portion 62 made separately.

[0092] like Figures 4 to 6As shown, the side wall portion 61 extends in the cylindrical axis direction of the frame body 70. Among the multiple circuit elements 52 of the circuit unit 50, there is one or more circuit elements 52 surrounded by the heat sink 60. Specifically, the roughly cylindrical side wall portion 61 of the heat sink 60 surrounds the circuit elements 52 (mainly the circuit elements 52 with leads) installed on the first surface of the heat sink 60 side of the circuit substrate 51 among the multiple circuit elements 52 installed on the circuit substrate 51. That is, the circuit elements 52 installed on the first surface of the heat sink 60 side of the circuit substrate 51 are accommodated in the side wall portion 61. As a result, the heat around the circuit elements 52 installed on the first surface of the circuit substrate 51 can be efficiently conducted to the heat sink 60. In addition, the circuit elements 52 surrounded by the side wall portion 61 include specific circuit elements 52 (electrolytic capacitors, etc.) with low heat resistance temperatures.

[0093] The heat sink 60 is located on the side of the circuit board 51 opposite to the light emitting module 10 side. Specifically, the heat sink 60 is located between the circuit board 51 and the bottom 72 of the frame 70. In the present embodiment, the heat sink 60 is placed on the bottom 72 of the frame 70.

[0094] The heat sink 60 also functions as a supporting member for supporting the circuit substrate 51. Specifically, the side wall portion 61 of the heat sink 60 supports the outer peripheral end portion of the circuit substrate 51. Figure 6 As shown, the circuit board 51 is placed on the end surface of the side wall portion 61 on the light emitting module 10 side. Thus, in this embodiment, the circuit board 51 is not in contact with the bottom plate 20 but in contact with the heat sink 60.

[0095] In addition, if Figures 4 to 6 As shown, the heat sink 60 is close to the inner surface of the frame 70. Specifically, the wall surface of the side wall portion 61 of the heat sink 60 is close to the inner surface of the frame 70. Therefore, the outer diameter of the side wall portion 61 is substantially the same as the inner diameter of the frame 70. The heat sink 60 is close to the inner surface of the frame 70, so that the heat conducted to the heat sink 60 can be efficiently released to the outside of the LED lamp 1 through the frame 70.

[0096] In addition, the wall surface of the side wall portion 61 and the inner surface of the frame body 70 may be in contact, or there may be a small gap between the wall surface of the side wall portion 61 and the inner surface of the frame body 70 with only a small gap of the degree of dimensional tolerance, but the wall surface of the side wall portion 61 and the inner surface of the frame body 70 are in contact. In this way, the heat conducted to the heat sink 60 can be efficiently conducted to the frame body 70.

[0097] The heat sink 60 is fixed to the frame 70. In this embodiment, Figure 5 and 6As shown, the heat sink 60 is fixed to the frame 70 by tightening with screws 93. In this case, the heat sink 60 is placed on the bottom 72 of the frame 70, and the screws 93 are inserted into the insertion holes 64 formed on the heat sink 60 (see Figure 6 ), the screw 93 is screwed into the threaded hole 73 provided at the bottom 72 of the frame 70 (refer to Figure 6 ), so that the heat sink 60 can be fixed on the frame 70. In addition, Figure 3 As shown, three screws 93 are used to fix the heat sink 60 to the frame 70, but the number of screws 93 is not limited to three. In addition, the fixing mechanism for fixing the heat sink 60 and the frame 70 is not limited to screws. For example, a locking structure may be provided on the heat sink 60 and the frame 70, respectively, and the heat sink 60 and the frame 70 may be fixed by locking the locking structures with each other.

[0098] like Figures 4 to 6 As shown, the frame 70 is a housing for housing the bottom plate 20, the circuit unit 50 and the heat sink 60. Figure 3 As shown, the frame body 70 is substantially in the shape of a bottomed cylinder having an opening, and includes a side wall portion 71 and a bottom portion 72 .

[0099] like Figures 4 to 6 As shown, the opening of the frame 70 is closed by the bottom plate 20. In addition, the opening of the frame 70 is covered by the light-transmitting cover 40. The side wall 71 of the frame 70 is cylindrical and is vertically provided at the bottom 72.

[0100] like Figure 2 and Figure 4 As shown in FIG. 1 , the bottom 72 of the frame body 70 is formed to have a step. Specifically, a protrusion is formed in the center of the bottom 72 so as to protrude outward in a cylindrical shape. Figures 4 to 6 As shown, a heat sink 60 is placed on the bottom 72. Figure 4 As shown, the base pin 80 passes through the bottom 72. In this embodiment, the base pin 80 is fixed to the bottom 72 by insert molding. The base of the LED lamp 1 is formed by the protruding portion at the center of the bottom 72 and the base pin 80.

[0101] The frame 70 is made of a resin material such as polybutylene terephthalate (PBT) or a metal material such as aluminum. In the present embodiment, the frame 70 is an insulating frame made of PBT.

[0102] The lamp cap pin 80 is a conductive lamp pin, and has a function of receiving power from the outside of the LED lamp 1 for making the light-emitting module 10 emit light. For example, an AC power (for example, an AC power from a commercial power supply of AC100V) is received from a socket of a lighting fixture through a pair of lamp cap pins 80. The pair of lamp cap pins 80 are electrically connected to the circuit unit 50, and the power received by the pair of lamp cap pins 80 is supplied to the circuit unit 50. The pair of lamp cap pins 80 are arranged at opposite positions of the bottom 72 with the cylindrical axis of the frame 70 as the center. That is, the pair of lamp cap pins 80 are arranged at intervals of 180 degrees in the circumferential direction.

[0103] A pair of lamp cap pins 80 penetrates the bottom 72. One end of each lamp cap pin 80 is located inside the frame 70 and is electrically connected to the circuit unit 50. In addition, the other end of each lamp cap pin 80 is exposed outside the frame 70, and is electrically and mechanically connected to the conductive part of the socket when the LED lamp 1 is installed in the socket of the lighting fixture. Therefore, the pair of lamp cap pins 80 also function as a mounting portion for mounting the LED lamp 1 on the lighting fixture. By mounting the pair of lamp cap pins 80 on the socket of the lighting fixture, the LED lamp 1 is held in the lighting fixture, and AC power is supplied to the LED lamp 1.

[0104] Next, use Figure 7 The effects of the LED lamp 1 according to the present embodiment will be described. Figure 7 1 is a diagram for explaining a heat dissipation path in the LED lamp 1 according to the embodiment. Figure 7 Corresponds to Figure 4 In addition, Figure 7 In, with Figure 4 Likewise, the thermal insulation layer 100 is hatched for convenience.

[0105] When the light emitting module 10 is turned on, illumination light is irradiated from the LED lamp 1. In this case, heat is generated from the light emitting module 10 by the light emitting module 10 being turned on. Specifically, heat is generated from the LED light emitting portion 12 of the light emitting module 10. For example, when the light emitting module 10 is turned on and heat is generated from the light emitting module 10, the temperature of the light emitting module 10 becomes 100° C. or more. In particular, since the LED lamp 1 in the present embodiment is a high beam, the temperature of the light emitting module 10 rises to nearly 120° C.

[0106] At this time, since the light emitting module 10 is supported by the metal bottom plate 20 (first heat sink), the heat generated in the light emitting module 10 is conducted to the bottom plate 20 .

[0107] On the other hand, when the light emitting module 10 is turned on, the heat generating components included in the plurality of circuit elements 52 in the circuit unit 50 generate heat, and the temperature of the circuit unit 50 also rises. Examples of the heat generating components included in the circuit elements 52 include semiconductor elements such as FETs and ICs, resistor elements, or coil elements.

[0108] At this time, since the circuit substrate 51 of the circuit unit 50 is supported by the metal heat sink 60 (second heat sink), the heat around the circuit unit 50 is conducted to the heat sink 60 .

[0109] Thus, when the light emitting module 10 is turned on, heat is generated in the light emitting module 10 in the LED lamp 1, and the temperature of the light emitting module 10 rises, and heat is also generated in the circuit unit 50 (circuit substrate 51), and the temperature of the circuit unit 50 rises. That is, since the light emitting module 10 is turned on, there are two heat sources in the LED lamp 1.

[0110] Therefore, assuming that the bottom plate 20 is connected to the heat sink 60 or the circuit substrate 51, the heat generated in the light emitting module 10 and the heat generated in the circuit unit 50 may interfere with each other. For example, since the heat generated in the light emitting module 10 is higher than the heat generated in the circuit unit 50, the heat generated in the light emitting module 10 is transferred to the circuit unit 50, and the circuit element 52 in the circuit unit 50 may be degraded. In addition, the heat generated in the circuit unit 50 is conducted to the light emitting module 10, and the heat dissipation performance of the heat generated in the light emitting module 10 may be reduced.

[0111] In contrast, in the LED lamp 1 of the present embodiment, the bottom plate 20 supporting the light emitting module 10 and the heat sink 60 supporting the circuit unit 50 are separated, and a heat insulating layer 100 is present between the bottom plate 20 and the circuit substrate 51. Therefore, since the heat generated in the light emitting module 10 is insulated by the heat insulating layer 100, it is not easily transferred to the circuit unit 50.

[0112] In particular, in this embodiment, the heat insulating layer 100 is an air layer with a thermal conductivity much lower than that of the base plate 20 , so the heat generated in the light emitting module 10 is conducted through the base plate 20 and is not easily transferred to the circuit unit 50 via the heat insulating layer 100 .

[0113] Therefore, the heat generated in the light emitting module 10 is Figure 7 Specifically, the heat generated in the light emitting module 10 is conducted in the order of the light emitting module 10 → the bottom plate 20 → the frame 70, and is released to the outside of the LED lamp 1. That is, the heat generated in the light emitting module 10 is basically not transferred to the circuit unit 50, but is released to the outside of the LED lamp 1.

[0114] In addition, the bottom plate 20 in the present embodiment includes not only the base portion 21 but also the side wall portion 22 erected on the base portion 21. The side wall portion 22 is in contact with the frame body 70.

[0115] According to this structure, the heat of the light emitting module 10 conducted to the base portion 21 is facilitated to be conducted to the side wall portion 22 of the bottom plate 20 , and can be efficiently released from the side wall portion 22 to the outside of the LED lamp 1 through the frame 70 .

[0116] Furthermore, the bottom plate 20 in the present embodiment includes a base portion 21 and a cylindrical side wall portion 22 , and the side wall portion 22 extends toward the circuit board 51 side.

[0117] According to this structure, a space region is formed in the portion surrounded by the base portion 21 and the cylindrical side wall portion 22 on the circuit substrate 51 side of the bottom plate 20. Moreover, this space region also functions as a heat insulating layer of the air layer. That is, in the LED lamp 1 of this embodiment, a double heat insulating structure is formed by the heat insulating layer 100 between the bottom plate 20 and the circuit substrate 51, and the heat insulating layer of the portion surrounded by the base portion 21 and the side wall portion 22. As a result, it is possible to further suppress the heat of the light emitting module 10 conducted to the bottom plate 20 from being transferred to the circuit unit 50.

[0118] In the present embodiment, the plurality of circuit elements 52 in the circuit unit 50 include specific circuit elements (electrolytic capacitors, etc.) with a low heat resistance temperature, and the specific circuit elements are arranged on the surface of the circuit substrate 51 opposite to the light emitting module 10 side.

[0119] According to this structure, even if the heat generated in the light emitting module 10 is conducted to the circuit unit 50, the heat is insulated by the circuit substrate 51, so that the temperature rise of the specific circuit element 52 with a low heat resistance temperature can be suppressed. Thus, the specific circuit element 52 with a low heat resistance temperature can be suppressed from thermal degradation.

[0120] Furthermore, since the specific circuit element 52 with a low heat resistance temperature is surrounded by the heat sink 60, it is possible to further suppress the temperature rise of the specific circuit element 52 with a low heat resistance temperature. Furthermore, it is possible to suppress the temperature rise of not only the specific circuit element 52 with a low heat resistance temperature but also the circuit element 52 surrounded by the heat sink 60. In this way, by surrounding the circuit element 52 with the heat sink 60, thermal degradation of the circuit element 52 can be suppressed.

[0121] In addition, since the heat insulating layer 100 is present between the bottom plate 20 and the circuit substrate 51 , the heat generated in the circuit unit 50 is also insulated by the heat insulating layer 100 , and the heat generated in the circuit unit 50 is difficult to be transferred to the light emitting module 10 .

[0122] Therefore, the heat generated in the circuit unit 50 is Figure 7Specifically, the heat generated in the circuit unit 50 is conducted in the order of circuit unit 50 → heat sink 60 → frame 70, and released to the outside of the LED lamp 1. In other words, the heat generated in the circuit unit 50 is basically not transferred to the light emitting module 10, but is released to the outside of the LED lamp 1.

[0123] Thus, according to the LED lamp 1 of the present embodiment, since the heat insulating layer 100 is present between the bottom plate 20 and the circuit substrate 51, the heat generated in the light emitting module 10 and the heat generated in the circuit unit 50 are released to the outside of the LED lamp 1 through their respective heat dissipation paths without interference. Therefore, the temperature of the light emitting module 10 can be effectively reduced, and the temperature of the circuit unit 50 (circuit substrate 51) can also be effectively reduced.

[0124] Next, an experiment was conducted on the effect of the thickness of the heat insulating layer 100 and the thickness of the heat sink 60 on the temperature reduction effect of the circuit unit 50. Figure 8 Describe the results of the experiment. Figure 8 1 is a graph showing the relationship between the ratio of the thickness of the heat sink 60 to the thickness of the heat insulating layer 100 and the temperature of the circuit element 52 .

[0125] In this experiment, if Figure 4 and Figure 6 As shown, when the thickness of the heat sink 60 in the axial direction of the frame 70 (i.e., the direction orthogonal to the main surface of the circuit substrate 51) is set to X and the thickness of the thermal insulation layer 100 in the axial direction of the frame 70 is set to Y, the temperature of the circuit element 52 is measured when the ratio (X / Y) of the thickness (X) of the heat sink 60 to the thickness (Y) of the thermal insulation layer 100 changes. Figure 8 The measurement results are shown. In addition, the circuit element 52 is an electrolytic capacitor, and the temperature of the electrolytic capacitor is measured. In this experiment, the height (A) of the frame 70 and the thickness (Z) of the bottom plate 20 are fixed values.

[0126] Here, it is preferred that the temperature of the electrolytic capacitor be 95°C or less. Figure 8 The results shown indicate that the ratio of the thickness (X) of the heat sink 60 to the thickness (Y) of the heat insulating layer 100 preferably satisfies the relationship of 1≤X / Y≤5.

[0127] This is because, when X / Y<1, it can be considered that the volume of the heat sink 60 becomes small, the heat of the circuit unit 50 cannot be efficiently released, and the temperature of the circuit element 52 cannot be efficiently reduced. On the other hand, when X / Y>5, although the volume of the heat sink 60 becomes large, the thickness (Y) of the heat insulating layer 100 becomes small, and the temperature of the circuit element 52 is affected by the heat of the light emitting module 10 and rises. In addition, when X / Y>5, the volume of the heat sink 60 becomes uselessly large, and the weight and cost of the LED lamp 1 also increase.

[0128] In addition, an experiment was conducted on the influence of the thickness of the heat insulating layer 100 and the thickness of the bottom plate 20 on the temperature reduction effect of the light emitting module 10 and the temperature reduction effect of the circuit unit 50. Fig. 9 Describe the results of this experiment. Fig. 9 The graph shows the relationship between the ratio of the thickness of the base plate 20 to the thickness of the heat insulating layer 100 , and the temperature of the LED light emitting unit 12 of the light emitting module 10 and the temperature of the circuit element 52 .

[0129] In this experiment, if Figure 4 and Figure 6 As shown, when the thickness of the base plate 20 in the axial direction of the frame 70 (i.e., the direction orthogonal to the main surface of the circuit substrate 51) is set to Z and the thickness of the thermal insulation layer 100 in the axial direction of the frame 70 is set to Y, the respective temperatures of the LED light-emitting portion 12 and the circuit element 52 are measured when the ratio (Z / Y) of the thickness (Z) of the base plate 20 to the thickness (Y) of the thermal insulation layer 100 changes. Fig. 9 The measurement results are shown in FIG. Fig. 9 In the experiment, the circuit element 52 is an electrolytic capacitor, and the temperature of the electrolytic capacitor is measured for the circuit element 52. In addition, in this experiment, the height (A) of the frame 70 and the thickness (X) of the heat sink 60 are fixed values.

[0130] Here, the temperature of the LED light emitting unit 12 is preferably below 110°C, and the temperature of the electrolytic capacitor is preferably below 95°C. Fig. 9 The results shown indicate that the ratio of the thickness (Z) of the bottom plate 20 to the thickness (Y) of the heat insulating layer 100 preferably satisfies the relationship of 1≤Z / Y≤5.

[0131] This is because, when Z / Y<1, it can be considered that the volume of the bottom plate 20 becomes small, the heat in the light emitting module 10 cannot be efficiently released, and the temperature of the LED light emitting portion 12 cannot be reduced. On the other hand, when Z / Y>5, although the volume of the bottom plate 20 becomes large, the thickness (Y) of the heat insulating layer 100 becomes small, and the temperature of the circuit element 52 is affected by the heat of the light emitting module 10 and rises. In addition, when Z / Y>5, the volume of the bottom plate 20 becomes uselessly large, and the weight and cost of the LED lamp 1 also increase.

[0132] Next, the preferred ranges and ratios of the thickness of the bottom plate 20 , the thickness of the heat sink 60 , the thickness of the heat insulating layer 100 , and the height of the frame 70 were studied, and the results of the study will be described.

[0133] First, if Figure 4 and Figure 6 As shown, when the height of the frame in the cylindrical axis direction of the frame 70 is A and the thickness of the heat insulating layer 100 in the cylindrical axis direction of the frame 70 is Y, it is better to satisfy the relationship of 2≤A / Y≤35.

[0134] This is because, when A / Y<2, it can be considered that the height of the frame 70 becomes low, and it is impossible to ensure sufficient space for configuring the circuit element 52 with leads and the light-emitting module 10. On the other hand, when A / Y>35, the base plate 20 and the heat sink 60 will be close to each other, and the heat conducted to the base plate 20 and the heat conducted to the heat sink 60 will interfere with each other, or the insulation distance between the base plate 20 and the heat sink 60 cannot be sufficiently ensured.

[0135] In addition, in the LED lamp 1 of the present embodiment, the thickness (X) of the heat sink 60 is preferably greater than (X≥Y) the thickness (Y) of the heat insulating layer 100. Thus, since the envelope volume of the heat sink 60 can be increased, the heat of the circuit unit 50 conducted to the heat sink 60 can be efficiently released without being conducted to the light emitting module 10.

[0136] As an example, the thickness (X) of the heat sink 60 is preferably greater than 10 mm and less than 25 mm. When the thickness of the heat sink 60 is less than 10 mm, the heat sink 60 cannot be used to accommodate a tall circuit component 52 such as a circuit component with leads 52. On the other hand, when the thickness of the heat sink 60 exceeds 25 mm, the volume of the heat sink 60 becomes unnecessarily large, and the weight and cost of the LED lamp 1 also increase.

[0137] In addition, in the LED lamp 1 of the present embodiment, the thickness (Z) of the bottom plate 20 may be greater than the thickness (Y) of the heat insulating layer 100 (Z ≥ Y). Thus, since the envelope volume of the bottom plate 20 can be increased, the heat of the light emitting module 10 conducted to the heat sink 60 can be efficiently released without being conducted to the circuit unit 50.

[0138] As an example, the thickness (Z) of the bottom plate 20 is preferably greater than 2 mm and less than 25 mm. When the thickness of the bottom plate 20 is less than 2 mm, the heat generated in the light emitting module 10 cannot be efficiently conducted to the bottom plate 20. That is, the temperature of the light emitting module 10 may not be efficiently reduced. On the other hand, when the thickness of the bottom plate 20 exceeds 25 mm, the volume of the bottom plate 20 becomes unnecessarily large, and the weight and cost of the LED lamp 1 increase.

[0139] In addition, in the LED lamp 1 of the present embodiment, the height (A) of the frame 70 is preferably greater than 30 mm and less than 70 mm. When the height of the frame 70 is less than 30 mm, sufficient space for configuring the circuit unit 50 and the light-emitting module 10 may not be ensured. On the other hand, when the height of the frame 70 exceeds 70 mm, the total height of the LED lamp 1 becomes high, and when the LED lamp 1 is mounted on the fixture body, the LED lamp 1 may be exposed from the fixture body. As a result, the appearance of the lighting fixture is damaged and the aesthetics of the lighting fixture is reduced.

[0140] In addition, in the LED lamp 1 of the present embodiment, the thickness (Y) of the heat insulating layer 100 is preferably not less than 2 mm and not more than 15 mm. When the thickness of the heat insulating layer 100 is less than 2 mm, sufficient insulation between the circuit unit 50 and the bottom plate 20 may not be ensured. On the other hand, when the thickness of the heat insulating layer 100 exceeds 15 mm, sufficient space for arranging the circuit unit 50 and the light emitting module 10 may not be ensured.

[0141] (Variation Example)

[0142] As mentioned above, although the lighting device etc. of this invention were demonstrated based on embodiment, this invention is not limited to the said embodiment.

[0143] For example, in the above embodiment, the heat insulating layer 100 between the bottom plate 20 and the circuit substrate 51 is an air layer, but the invention is not limited thereto. Specifically, the heat insulating layer 100 may be an insulating member made of a heat insulating material with low thermal conductivity.

[0144] In addition, in the above embodiment, the light-transmitting cover 40 has an optical function of converging the light of the light-emitting module 10, but is not limited thereto. For example, the light-transmitting cover 40 may have an optical function of diffusing the light of the light-emitting module 10. In addition, the light-transmitting cover 40 may not have a lens function.

[0145] In addition, in the above-mentioned embodiment, the light emitting module 10 is a COB type LED module, but is not limited to this. For example, the light emitting module 10 may be an SMD (Surface Mount Device) type LED module. In this case, the light emitting module 10 has a substrate and one or more LED packages arranged on the substrate as an LED light emitting portion. The LED package is a surface mounted LED light source obtained by encapsulating an LED chip as a bare chip, and has a container (package), an LED chip mounted in the container, and a sealing member that seals the LED chip. In the case where the LED chip is a blue LED chip, in order to obtain white light, the sealing member is a phosphor-containing resin containing a yellow phosphor. In addition, the LED lamp may have a COB type LED module and an SMD type LED module.

[0146] In addition, in the above-mentioned embodiment, the LED light emitting unit 12 is configured to emit white light through a blue LED chip and a phosphor-containing resin containing a yellow phosphor, but is not limited to this. For example, a phosphor-containing resin containing a red phosphor and a green phosphor may be used, and it may be configured to emit white light by combining it with a blue LED chip. Furthermore, in order to improve the color rendering, a red phosphor or a green phosphor may be mixed in addition to the yellow phosphor. Furthermore, an LED chip that emits light of a color other than blue may be used. For example, an ultraviolet LED chip that emits ultraviolet light having a wavelength shorter than that of the blue light emitted by the blue LED chip may be used, and white light may be emitted by a blue phosphor, a green phosphor, and a red phosphor that are mainly excited by ultraviolet light to emit blue light, red light, and green light.

[0147] In addition, in the above-mentioned embodiment, the base of the LED lamp 1 has a base pin 80, but it is not limited thereto. For example, the base of the LED lamp 1 may be a screw-in Edison type (E type) base. As the Edison type base, for example, an E26 type or an E17 type base can be used. In this case, the LED lamp 1 is a bulb-shaped LED lamp.

[0148] Furthermore, in the above-described embodiment, an LED lamp having a base is exemplified as the lighting device, but the present invention is not limited thereto. For example, the present invention can also be applied to a lighting device not having a base.

[0149] In addition, the above-mentioned embodiments are implemented with various modifications that can be thought of by those skilled in the art, and the embodiments are realized by arbitrarily combining the constituent elements and functions in the embodiments within the scope that does not deviate from the main purpose of the present invention. In addition, the technical solutions obtained by arbitrarily combining two or more technical solutions within the scope that is not technically contradictory from the multiple technical solutions recorded in the claims when submitting this application are also included in the present utility model. For example, when the subordinate form technical solutions recorded in the claims when submitting this application are cited in a manner that all the upper technical solutions are cited within the scope that is not technically contradictory, or when multiple citations are made to multiple technical solutions, the combination of all technical solutions included in the technical solutions cited in multiple or multiple citations are also included in the present utility model.

Claims

1. A lighting device, wherein: have: A light emitting module for irradiating light; A metal bottom plate, located on the side of the light emitting module opposite to the light irradiation side, and supporting the light emitting module; A circuit substrate, configured with circuit elements for lighting the light-emitting module; as well as a heat sink, located on a side of the circuit substrate opposite to the light emitting module side, and supporting the circuit substrate, The bottom plate is separated from the heat sink, and a heat insulation layer is present between the bottom plate and the circuit substrate.

2. The lighting device according to claim 1, wherein: The circuit elements are multiple, The plurality of circuit elements include specific circuit elements having a low heat resistance temperature, The specific circuit element is arranged on a surface of the circuit substrate on a side opposite to the light emitting module side.

3. The lighting device according to claim 2, wherein: The heat sink is annular. Among the plurality of circuit elements, there is more than one circuit element surrounded by the heat sink.

4. The lighting device according to claim 3, wherein: The specific circuit element is one of the circuit elements surrounded by the heat sink.

5. The lighting device according to any one of claims 1 to 4, wherein: The heat insulating layer is an air layer.

6. The lighting device according to claim 5, wherein: The bottom plate includes a base portion and a cylindrical side wall portion erected on the base portion. The side wall portion extends toward the circuit substrate.

7. The lighting device according to any one of claims 1 to 4, wherein: The thickness of the bottom plate is greater than the thickness of the heat insulation layer.

8. The lighting device according to any one of claims 1 to 4, wherein: The thickness of the heat sink is greater than the thickness of the heat insulation layer.

9. The lighting device according to any one of claims 1 to 4, wherein: A frame housing the bottom plate and the heat sink is also provided.

10. The lighting device according to claim 9, wherein: When the height of the frame is A and the thickness of the heat insulation layer is Y, the relationship 2≤A / Y≤35 is satisfied.

11. The lighting device according to any one of claims 1 to 4, wherein: When the thickness of the heat sink is X and the thickness of the heat insulation layer is Y, the relationship of 1≤X / Y≤5 is satisfied.

12. The lighting device according to any one of claims 1 to 4, wherein: When the thickness of the bottom plate is Z and the thickness of the heat insulation layer is Y, the relationship 1≤Z / Y≤5 is satisfied.

13. The lighting device according to any one of claims 1 to 4, wherein: The input power to the light emitting module is above 9 watts.

14. The lighting device according to any one of claims 1 to 4, wherein: The invention also comprises a lamp base which is detachably mounted on the socket.

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