JP2016129090A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device which achieves excellent heat radiation performance despite having a thin form.SOLUTION: A lighting device 1 includes: a light source 3 which emits light to the front side; a reflector 4 covering the front outer side of the light source 3; an optical member 5 disposed at the front side of the reflector 4; and heat radiation fins 41b provided at an outer periphery part of the reflector 4. The reflector 4 has: a heat sink part 41 provided with the heat radiation fins 41b; and a holder part 42 holding the optical member 5. The holder part 42 is molded using a material having heat conductivity smaller than that of the heat sink part 41.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lighting device.

  Conventionally, an illumination device including a reflector has been proposed (for example, Patent Document 1 and Patent Document 2). Patent Document 1 discloses an illumination device in which a flat lens is arranged in an opening on the front side of a reflector surrounding a light source. Patent Document 2 discloses an illumination device in which a reflector is disposed in front of a light source and a heat sink is disposed behind the light source. Here, by arranging the heat sink of Patent Document 2 behind the light source of Patent Document 1, it is possible to realize an illumination device that can control the orientation and has excellent heat dissipation.

JP 2011-151218 A JP 2013-30599 A

  However, when the heat sink is arranged behind the light source, the lighting device becomes thick, which causes a problem that the thinning of the lighting device is hindered.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an illumination device that is thin and excellent in heat dissipation.

In order to solve the above problems, (1) the present invention is an illumination device, which is a light source that emits light forward, a reflector that covers a front outer side of the light source, and an optical that is disposed on the front side of the reflector. A radiating fin provided on an outer peripheral portion of the reflector.
(2) In the above (1), the reflector has a heat sink portion in which the heat radiating fin is provided and a holder portion for holding the optical member, and the holder portion is more thermally conductive than the heat sink portion. It is molded using a material with low properties.
(3) The material constituting the heat sink portion is a metal material, and the material constituting the holder portion is a resin material.
(4) In the above (2) or (3), the heat radiating fins of the heat sink portion are formed to extend in the front-rear direction.
(5) In any one of the above (1) to (4), a part of the reflector is in contact with the front surface of the substrate included in the light source.
(6) In the above (5), the light source is preferably a COB type LED.
(7) The present invention is an illumination device, comprising: a light source that emits light forward; a reflector that covers a front outer side of the light source; and an optical member that is disposed on the front side of the reflector, and the light source Has a substrate on which a light emitting diode is mounted at the center, and a part of the reflector is in contact with the front surface of the substrate of the light source.

It is sectional drawing of the illuminating device which concerns on embodiment of this invention. It is a perspective view in the state where a lighting device concerning an embodiment of the present invention was partially broken. It is a disassembled perspective view of the illuminating device which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.

  FIG. 1 is a cross-sectional view of a lighting device according to an embodiment of the present invention. FIG. 2 is a perspective view of the lighting device according to the embodiment of the present invention in a partially broken state. FIG. 3 is an exploded perspective view of the lighting device according to the embodiment of the present invention.

  As shown in FIGS. 1 to 3, the lighting device 1 according to the embodiment of the present invention is arranged from the rear (lower side in the drawing) to the base 2 (sheet metal in the drawing) and the center of the front surface of the base 2. A light source (LED (Light Emitting Diode) base substrate 31 and LED light emitting unit 32) 3 and a reflector (a heat sink unit 41 and a holder unit 42) disposed on the front surface of the base 2 to surround the light source 3 from the outside (enclose the front outside of the light source). ) 4 and an optical member (lens) 5 disposed in the opening on the front side of the reflector 4. Note that heat conductive sheets (or greases) 6 and 7 are appropriately disposed between the base 2 and the light source 3 and between the light source 3 and the reflector 4.

The base 2 is formed in a disk shape using, for example, a sheet metal having excellent heat dissipation.
The light source 3 is a COB (Chip on Board) type LED, and has a rectangular (other shape, for example, circular) LED base substrate 31 and a central portion of the front surface of the LED base substrate 31. A light emitting diode is mounted, and the LED light emitting unit 32 is formed in a circular shape. The LED light emitting unit 32 includes a plurality of LED chips and a sealing resin that contains a phosphor and covers the plurality of LED chips. The LED light emitting unit 32 emits light forward (upward in the figure).

  The reflector 4 is formed in a low-profile cylindrical shape that covers the front outer side of the light source 3 and has an outer diameter substantially equal to the outer diameter of the base 2. On the inner side (optical axis side) rear of the reflector 4, a circular first opening 41a that exposes the LED light emitting unit 32 of the light source 3, and an inclined surface 42a that expands toward the front and functions as a light reflecting surface. And a circular second opening 42b formed on the front end side of the inclined surface 42a. Note that a stepped portion 42c that holds the outer peripheral portion of the optical member 5 is formed in the second opening 42b. Further, in the present embodiment, the reflector 4 is located on the rear side and functions as a heat radiating portion, and the heat sink portion 41 provided with the heat radiating fins 41b is located in front of the heat sink portion 41 and functions as a reflector and an optical member. And a holder portion 42 having a function of holding the lens.

  The heat sink portion 41 is formed using a member having excellent heat conductivity (for example, a metal material, aluminum in the present embodiment), and has a disk-like base portion 41c having an opening that forms the first opening portion 41a in the center portion. And a plurality of radiating fins 41b provided on the outer peripheral portion of the reflector 4 on the outer peripheral side of the base portion 41c. Each of the radiation fins 41b is provided so as to extend inward from the outer peripheral surface and extend in the front-rear direction (optical axis direction), that is, provided on the outer peripheral side of the base 41c so as to extend forward from the front surface of the base 41c. It has been. Each of the heat radiation fins 41b is provided so as to be orthogonal to the four sides of the LED base substrate 31 of the light source 3 in a portion outside the LED base substrate 31 of the light source 3 in plan view. Furthermore, an inclined surface (no symbol) is formed in the front portion on the inner peripheral side of each heat radiating fin 41 b corresponding to the shape of the reflecting surface of the reflector 4.

  Further, the heat sink portion 41 is formed with a step portion 41d on the rear surface (back surface) thereof where the outer portion of the LED base substrate 31 of the light source 3 (the portion where the LED light emitting portion 32 is not disposed) is disposed (cross section) (See diagram). Thereby, a part of the heat sink part 41 can be brought into contact with the front surface of the LED base substrate 31 of the light source 3, and heat generated in the LED light emitting part 32 of the light source 3 can be efficiently released to the heat sink part 41. In the present embodiment, as described above, the heat conductive sheet (or grease) 7 is interposed on the contact surface between the heat sink 41 and the light source 3 in order to further improve the heat dissipation to the heat sink 41.

  The heat sink portion 41 is provided with cutouts 41e at two rotationally symmetrical positions, which are connected to connection terminals (not shown) formed on the LED base substrate 31 of the light source 3. Is not essential to the present invention.

  Next, the holder part 42 is formed using a member having poor heat conductivity as compared with the heat sink part 41. That is, the holder portion 42 is formed using a material having a smaller thermal conductivity than the heat sink portion 41. For example, in the present embodiment, the material constituting the holder portion 42 is a resin material such as white polycarbonate, and the material constituting the heat sink portion 41 is a metal. Thereby, the heat transmitted from the light source 3 to the heat sink part 41 can be made difficult to be transmitted to the optical member 5 via the holder part 42. That is, the deterioration of the optical member 5 due to heat can be suppressed. In particular, in this embodiment, since the heat sink 41 is provided with a plurality of heat radiation fins 41b extending in the front-rear direction, the contact area between the holder 42 and the heat sink 41 can be reduced. Thereby, it becomes difficult to transmit heat from the heat sink part 41 to the holder part 42, and deterioration of the optical member 5 due to heat can be further suppressed.

  The optical member 5 is preferably a Fresnel lens that controls the orientation of light emitted from the light source.

  It has been clarified by thermal analysis that the lighting device 1 of the above embodiment can suppress the temperature rise of the light source by about 10 ° C. as compared with the case of using a reflector made of a resin material.

  Next, a modified example of the lighting device according to the embodiment of the present invention will be described. In the above embodiment, a part of the reflector (heat sink part) 4 is brought into contact with the front surface of the LED base substrate 31 of the light source 3, but in the present invention, when the heat dissipation effect of the reflector 4 is sufficiently obtained, It is not always necessary to make contact.

  In addition, when a material having excellent thermal conductivity is used for the reflector 4 and a part of the reflector 4 is brought into contact with the front surface of the LED base substrate 31 of the light source 3, a sufficient heat radiation effect can be obtained. It is not necessary to provide the heat radiation fin 41b. In this case, the reflectors (the heat sink part 41 and the holder part 42) 4 may be integrally formed using the same member.

  In the said embodiment, although the reflector 4 is formed in the cylindrical shape, each invention can be applied to the reflector of an arbitrary shape. The optical member 5 is not limited to a Fresnel lens, and may be a member having diffusibility, for example. In the said embodiment, although the base 2 is comprised with the sheet metal, the heat sink which provided the radiation fin in back (back surface) or the outer peripheral direction of a cylinder may be sufficient, for example.

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the description of the scope of claims that embodiments with such changes or improvements can also be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Base 3 Light source 31 LED base board 32 LED light emission part 4 Reflector 41 Heat sink part 41a 1st opening part 41b Radiation fin 41c Base part 41d Step part 41e Notch part 42 Holder part 42a Inclined surface 5 Optical member 6, 7 Heat Conductive sheet

Claims (7)

A lighting device,
A light source that emits light forward;
A reflector covering the front outside of the light source;
An optical member disposed on the front side of the reflector,
An illuminating device comprising a heat dissipating fin provided on an outer peripheral portion of the reflector. The reflector has a heat sink part provided with the radiation fins, and a holder part for holding the optical member,
The lighting device according to claim 1, wherein the holder portion is formed using a material having a smaller thermal conductivity than the heat sink portion. The material constituting the heat sink is a metal material,
The lighting device according to claim 2, wherein a material constituting the holder portion is a resin material.   The lighting device according to claim 2, wherein the heat radiation fin of the heat sink portion is formed to extend in the front-rear direction.   5. The lighting device according to claim 1, wherein a part of the reflector is in contact with a front surface of a substrate included in the light source.   The lighting device according to claim 5, wherein the light source is a COB type LED. A lighting device,
A light source that emits light forward;
A reflector covering the front outside of the light source;
An optical member disposed on the front side of the reflector,
The light source has a substrate on which a light emitting diode is mounted in the center,
A lighting device, wherein a part of the reflector is brought into contact with a front surface of a substrate of the light source.