JP5123862B2 - Two-dimensional lighting device - Google Patents

Description

The present invention comprises a peripheral frame, an irradiation opening, light-emitting diode is associated with a surface lighting device including a light emitting chamber is in the shape of a hollow optical member having a base plate which is at least partially mounted.

  Light-emitting means, called light-emitting diodes or LEDs, give the possibility of producing a flat spotlight that emits uniform light over the entire surface and can be used in relatively large design shapes. The spotlights are used for movie lighting to build light walls, for example in events and stage lighting, in surface lighting devices with the names "soft light", "fill light", or in narrow spaces such as cars and stairwells The shape of the reflective lamp in all areas of professional lighting, such as portrait luminaires located right next to the camera or video camera.

Surface illumination devices having light emitting diodes such as the illumination means have different designs. In the first design, are arranged in a number of light emitting diodes on the base plate of the light emitting chamber is in the shape of a hollow optical element, the light emitting chamber has a diffuse transmission cover and the reflective wall. The light emitting diodes radiate to a hemisphere on the base plate of the light emitting chamber, and the light emitted by them is reflected multiple times to diffuse and emerge from a surface illuminator with a large half-peak diffusion. The light-emitting diodes used here can have different diffusion characteristics such as “uniform diffusion”, “batwing” or “side-illumination” diffusion characteristics, especially when using side-illuminated light-emitting diodes, for example. A surface illumination device with a physically low height can be realized.

In another design, solid optical body surrounding the light emitting diode by a number of light-emitting diode having a lateral illumination of which is arranged on the base plate of the emission chamber, for example by light in acrylic blocks is irradiated , light mixing occurs in the optical body of the solid.

In another design, it is arranged at the inner end of the plurality of light emitting diodes of the housing frame, as a result, light hollow chamber emitted by the light emitting diode, or in particular on the inside to the solid optical body Radiated towards.

  DE 20 2004 016 637 U1 discloses an illuminating device with a fixture, on which a plurality of light emitting diodes and a control device are arranged, and the operating state of the illuminating device is adjusted. In particular, a high-power light-emitting diode that emits white light and has an optical efficiency of at least 20 lm / W, called a “Golden Dragon” light-emitting diode, is used as said light-emitting diode. Drive electronics equipped with an optical sensor that measures the brightness of the surroundings and controls the brightness of the light-emitting diode is used as the control device.

  The use of the illuminating device in a surface illuminating device has the disadvantage that the control device is arranged on the mount together with the light-emitting diode, resulting in a reduction of the light emitting area of the illuminating device.

  In addition, however, the other design described above requires that the control electronics required to operate the light emitting diodes be installed outside the light emitting chamber, and consequently, to keep the light emitting area as small as possible. Because the control electronics need to be placed directly under the light emitting diode, or the light emitting diode needs to be placed in the housing frame to provide a flat design, the relatively large non-lighting end of the surface lighting device In order to provide, it also has the disadvantage that the advantage of producing a surface illumination device with low physical height is limited with the help of light emitting diodes.

  A further problem in the production of surface illuminators with a physically low height and at the same time the largest possible light emitting area is that the heat generated from the light emitting diodes is ensured for a permanent and stable operation. It needs to be emitted. This is especially true in the case of high power light emitting diodes embedded in thermoplastic members including optical light emitting members.

  The object of the present invention includes light emitting diodes having the lowest possible physical height and having as large a light emitting area as possible, enabling the optimum cooling of the light emitting diodes and the control electronics operating the light emitting diodes It is to clarify the surface illuminator that creates the necessary preconditions.

This object is achieved by the features of claim 1.
German Utility Model Registration Gazette No. 20 2004 016 637

  The solution according to the invention provides a surface illuminator with a minimum physical height and a maximum light emitting area, and is suitable for light emitting diodes used as illumination means for surface illuminators and control electronics for operating the light emitting diodes. Is to provide preconditions for proper cooling.

  The solution according to the invention is based on the idea of arranging a number of light emitting diodes on a base plate, the maximum light emission of which is parallel to the base plate, i.e. horizontal, or at an acute angle of eg 20 ° with respect to a horizontal substrate or base plate. Is directed.

Emitting chamber is in the form of a hollow optical member for reflecting diffused, in order to realize a large illumination area as possible to produce results in uniform light distribution, the physical height of the low luminous chamber as possible Even in this case, it is preferable that an optimal light distribution is ensured.

  In a preferred embodiment of the invention, the maximum light emission is horizontal, i.e. oriented parallel to the base plate as a result of their shape, or the side inclined at an acute angle to the horizontal substrate or base plate. Partially illuminated LEDs are used as light emitting diodes.

  In addition, the inclined surface, whose slope and curvature is set to be the result of a very good light and color distribution, despite the reduction in the size of the reflective area of the light emitting chamber, It can be disposed between the base plate of the light emitting chamber.

  In particular, the use of light emitting diodes that emit horizontally with an inclined surface disposed in the light emitting chamber results in a very good light and color distribution.

  In order to achieve an improved light distribution, the inclined surface can be bent or convex and / or waved or pleated.

  The design shape of the light emitting chamber of the surface lighting device according to the present invention with an inclined surface arranged between the peripheral frame and the base plate allows the control electronics for operating the light emitting diode to be directly below the inclined surface, and in particular the inclined surface. Can be placed in the cavity formed by the base plate and the peripheral frame, and as a result, the area used for light emission or light reflection is not blocked, and therefore no non-light emitting area is created. In addition, the prerequisites for optimal cooling of the control electronics and the light-emitting diode are thereby ensured.

  In particular, the cooling of the light emitting diode is realized by mounting the light emitting diode on a highly heat conductive substrate such as a metal core or a ceramic substrate, and the substrate is directly fixed to the heat sink.

  Alternatively, a light emitting diode is mounted on a substrate made of any desired printed wiring board material, and there is an opening or hole below it, and the heat sink part that is in the shape of a finger passes directly to the base plate or the cooling surface of the light emitting diode. Or connected to the cooling surface of the base plate or the light emitting diode with high thermal conductivity.

  This mounting of light emitting diodes in the light emitting chamber ensures optimal cooling even for high power light emitting diodes, and consequently allows even the highest possible mounting density for maximum luminous efficiency. .

  Another alternative that provides further advantages with respect to cost-effective manufacturing and the possibility of simple electrical insulation of the cooling surface of the light-emitting diode is that a recess is provided in the surface of the heat sink, said surface being on the light-emitting diode. The bolt is inserted into the recess and is thermally conductively connected to the base plate or the cooling surface of the light emitting diode, the bolt is pressed against the recess of the heat sink, and the metal, preferably copper It is characterized by having a metal with higher thermal conductivity than aluminum, which is

  When electrical insulation is required, especially in the case of conductive connections between the cooling surface of the light emitting diode and the anode or cathode, this is done by an electrically insulating layer, but the highly thermally conductive material is used between the substrate and the heat sink. Or between the light emitting diode and the substrate, in particular between the cooling surface of the light emitting diode and the part of the heat sink protruding through the opening, or the bolt. These layers may be sprayed, e.g. varnished, or printed protective layers, or so-called "thermally conductive pads" or "thermally conductive adhesives".

  In the case of a connection between the cooling surface of the base plate or the light emitting diode and the bolt inserted in the recess of the heat sink, a bolt with a very high thermal conductivity and an electrically insulating ceramic can be used.

  In order to protect the light emitting chamber, in particular the light emitting diode, and to make the emitted light more uniform, the irradiation opening is provided with a light transmissive covering, for example in the form of a transparent covering, frosted glass, or lens. Can be provided.

  The subject matter of the invention and further features and advantages of the surface illumination device according to the invention will be explained with reference to exemplary embodiments.

Schematic perspective view, a plan view, and a surface illumination device illustrated in FIGS. 1 to 3 as a longitudinal cross-sectional view includes a light emitting chamber 1 is in the shape of a hollow optical member, predeterminable in emission chamber 1 And a plurality of light emitting diodes 2 arranged based on a distribution pattern that can be. The light emitting chamber 1 includes a peripheral frame 11 and a base plate 12, and a substrate 3 having a light emitting diode 2 is disposed on the base plate, and an irradiation opening 10 of the light emitting chamber 1 is disposed together with the light emitting optical members. Has been. The end of the base plate 12 and the area of the peripheral frame 11 adjacent to the base plate 12 are bridged by the inclined surface 13, so that the cavity 14 is between the lower part of the peripheral frame 11, the end of the base plate 12 and the inclined surface 13. Is formed.

  As shown in FIGS. 4 and 5, it has an LED 20 and a side irradiation optical member 21 having a lens holder made of transparent polycarbonate for accurate placement of the LED 20 and the lens, and has an optimum mechanical strength. Any desired LED having a cooling surface 22 for dissipating heat that guarantees, but preferably a side-illuminated LED, can be used as the light emitting diode 2. Such side-illuminated LEDs are sold, for example, under the name “Golden Dragon LED” by OSRAM. The side illumination LEDs are made with different illumination angles, i.e. the maximum light emission of the side illumination LEDs is horizontal or directed at an illumination angle of, for example, a maximum of 35 ° relative to the horizontal. The high efficiency of such side-illuminated LEDs, which represents up to 85% of the total luminous flux of the LEDs, can be replaced with common incandescent and halogen light sources from the point of view of their light emission design, especially for use in flat illumination Suitable for

  In the case of this application, a horizontal light-emitting side-illuminated LED that is a side-illuminated LED that emits light in parallel to the base plate, and a side that emits light at an acute angle with respect to the horizontal, for example, at an irradiation angle of about 20 ° with respect to the horizontal. Irradiation LEDs can be used. In particular, a very good light and color distribution of the light emission of the surface illuminator is realized by the side-illuminated LED that emits exactly horizontal light with the inclined surface 13 arranged in the light emitting chamber 1.

In order to optimize the light distribution in the light emitting chamber 1 is in the shape of a hollow optical member, the inclined surface 13 is concavely curved or convexly instead of plane, or is alternatively or additionally wavy or pleated Can have a surface, resulting in optimal light diffusion. The inclination or curvature of the inclined surface 13 associated with the base plate 12 seems to provide a very good light and color distribution in this case setting despite the reduced size of the reflective area of the light emitting chamber 1. It has become.

One or more control electronics unit for operating a light-emitting diode 2, the peripheral frame 11, it is preferable to be disposed in a cavity 14 formed by the base plate 12 and the inclined surface 13, as a result, a hollow optical member, A partition is provided between the control or power supply of the light emitting diode 2, and neither the light emitting surface nor the reflecting surface of the light emitting chamber 1 is disturbed by these additional devices. At the same time, in this way, a compact design of the surface lighting device is ensured and its housing is determined solely by the peripheral frame 11 and the base plate 12. In order to further optimize the light diffusion and / or protect the light emitting diode 2 arranged in the light emitting chamber 1, the illumination opening 10 is transparent or translucent, for example safety glass, frosted glass or lenses. Can be covered with a cover.

  The cooling required for the light-emitting diode 2 used in the light-emitting chamber 1 of the surface illumination device according to the present invention, in particular in the shape of a side-illuminated LED, can be performed as shown in the schematic diagrams of FIGS. .

  FIG. 4 shows a general solution, in which a light emitting diode 2 having an LED 20, a side illumination optical member 21 and a cooling surface 22 is arranged on a substrate 3 in the form of a metal core printed wiring board, The wires running on the metal core printed wiring board 3 are connected to the wires 23 and 24. The cooling surface 22 of the LED 20 is connected to the heat sink 5 having the cooling rib 50 on the side facing the light emitting diode 2 and is in high thermal conductivity contact with the metal core printed wiring board 3 which is also high thermal conductivity. As a result, the heat generated by the LED 20 is dissipated through the cooling surface 22 to the heat sink 5 and the metal core printed wiring board 3 having high thermal conductivity, and is dissipated through the cooling rib 50 of the heat sink.

  The general solution shown in FIG. 4 allows multiple light emitting diodes 2 to be placed directly adjacent to each other or at any desired spacing and in the desired shape on the metal core printed wiring board 3. By doing so, a desired light emission pattern can be realized.

  FIG. 5 shows that the light emitting diodes 2 are arranged on any desired printed wiring board or substrate 4, and similarly run on the LED 20, the side optical member 21, the cooling surface 22 and the printed wiring board 4. A deformation body having connecting wires 23 and 24 connected to the wires is illustrated. The printed wiring board 4 has an opening directly below the LED 20 of the light emitting diode 2, and the finger 61 of the heat sink 6 disposed on the side of the printed wiring board 4 facing the light emitting diode protrudes therethrough. And thermally connected to the cooling surface 22 of the light emitting diode 2. Accordingly, the heat generated by the LED 20 is transferred to the cooling rib 60 via the cooling surface 22 and the finger 61 of the heat sink 6, and the cooling rib dissipates the heat generated by the light emitting diode 2 to the surrounding environment.

  In FIG. 6, the light emitting diode 2 is similarly arranged on a desired printed wiring board or substrate 4, and the LED 20, the side irradiation optical member 21, the cooling surface 22, and the printed wiring board or substrate 4 are overlaid. Fig. 4 illustrates a further variant with connecting lines 23, 24 connected to the running wires. An opening 40 is provided in the printed wiring board or substrate 4 directly below the LED 20 of the light emitting diode 2, and a bolt 8 protrudes therethrough and is connected to the cooling surface 22 of the light emitting diode 2 with high thermal conductivity. Yes. The bolt 8 is pressed against a recess 72 formed in the surface 71 of the heat sink 7 facing the printed wiring board 4. In the first embodiment, the bolt 8 comprises a metal, in particular a metal having a higher thermal conductivity than aluminum, usually copper, to optimally dissipate heat from the LED 20 and pass it to the heat sink 7. From there, heat is transferred to the cooling ribs 70 of the heat sink 7 and radiated to the surrounding environment.

  When electrical insulation is required, especially in the case of a conductive connection between the cooling surface of the light-emitting diode and the anode or cathode, this is achieved by means of a layer 9 made of an electrically insulating material, which is a highly thermally conductive material. Is inserted between the substrate 3 and the heat sink 5 or between the light emitting diode and the substrate, in particular between the cooling surface of the light emitting diode 2 and the part 61 of the heat sink 6 protruding through the opening, or the bolt 8. Yes. The insulating layer 9 can have a thermal spray, vapor deposition or print protection layer, such as a varnish or an insulating thermal conductive adhesive, or a so-called “thermal conductive pad”.

  Instead of placing the insulating layer 9 between the bolt 8 and the cooling surface 22 of the light emitting diode 2, the bolt is pressed into the recess 72 of the heat sink 7, and the bolt has a very high thermal conductivity electrically insulating ceramic.

  In the case of a large number of light-emitting diodes 2 arranged based on any predetermined pattern, a large number of openings 40 corresponding to the number of light-emitting diodes are provided in the printed wiring board 4, and the correspondence is made through the openings. A large number of fingers 61 or bolts 8 of the heat sink 6 protrude from the light-emitting diode 2 and are connected to the cooling surface 22 of the light-emitting diode 2 in a highly heat-conductive manner and possibly in an electrically insulating manner.

  In the first specific embodiment, a number of light emitting diodes 2 shown in FIGS. 1 to 3 are arranged on the substrate 3 or 4 on the base plate 12 of the light emitting chamber 1 and the openings of the base plate 12 or substrate 4 are arranged. The heat sink 6 that engages with a large number of fingers 61 corresponding to the number of the light-emitting diodes 2 and having excellent thermal contact with the cooling surface 22 of the light-emitting diodes 2 is fixed to the outside of the base plate 12. Therefore, the cooling rib 60 of the heat sink 6 protrudes outward from the bottom surface of the light emitting chamber 1, and as a result, the optimal release of heat to the environment around the surface lighting device is ensured.

  In the second specific embodiment, the multiple light emitting diodes 2 shown in FIGS. 1 to 3 are arranged on a substrate or printed wiring board 4 on the base plate 12 of the light emitting chamber 1, and the heat sink 7 is outside the substrate 4. The heat sink surface 71 facing the substrate 4 is provided with a recess or recess 72, and a copper bolt 8 is pressed into the recess or recess 72 and emitted from the light emitting diode 2. Heat is dissipated to the heat sink 7 via the bolt, and heat generated by the light-emitting diode 2 is dissipated to the surrounding environment of the surface lighting device. For the purpose of electrical insulation, an electrical insulation layer 9 is provided between the bolt 8 and the cooling surface 22 of the light emitting diode 2.

In an alternative form, a bolt made of highly thermally conductive and electrically insulating ceramic is provided in place of the copper bolt 8 and is pressed against the recess 72 of the heat sink 7.
Here, among the inventions described in the embodiments, the inventions not described in the claims are listed below.
(1) The light emitting diode (2) is designed so that the maximum light emitted from the light emitting diode (2) is directed parallel to the base plate (12) or is irradiated at an acute angle to the base plate (12). And / or a surface illumination device arranged on the base plate (12).
(2) The surface illumination device in which the base plate (12) has the printed wiring board (4) and the opening (40) is disposed directly below the light emitting diode (2).
(3) The portion (61) of the heat sink (6) thermally connected to the cooling surface (22) of the base plate or light emitting diode (2) protrudes through the opening (40) (2) Surface lighting device.
(4) A recess (72) is provided in the surface (71) of the heat sink (7) facing the light emitting diode (2), and the bolt (8) is inserted into the recess (72) and the base plate or the light emitting diode. The assertion illumination device according to (3), which is thermally conductively connected to the cooling surface (22) of (2).
(5) The bolt (8) is pressed against the recess (72) of the heat sink (7) and has a metal, preferably a metal having a higher thermal conductivity than aluminum, in particular copper, or has a thermal conductivity (4) The surface illumination device having the electrically insulating ceramic.

Schematic perspective view of a surface illumination device having a plurality of light emitting diodes arranged on a base plate and a light emitting chamber having a peripheral frame and an inclined surface Plan view of the surface illumination device of FIG. AA line sectional view of the surface illumination device shown in FIG. Longitudinal cross section through the arrangement of light emitting diodes with side illuminated optical members on a metal core printed wiring board connected to a heat sink Longitudinal cross-sectional view through the arrangement of light emitting diodes with side illumination optical members on a printed wiring board with openings for contacting the cooling surface of the base plate or light emitting diodes and with heat sink fingers passing through the openings Longitudinal length through an array of light emitting diodes with side illumination optics on a printed wiring board with openings for contacting the cooling surface of the base plate or light emitting diodes and with thermally conductive bolts inserted into the recesses of the heat sink Sectional view

Explanation of symbols

1 Light emitting chamber 2 Light emitting diode 3 Substrate (metal core printed wiring board)
4 Printed wiring board or substrate 5, 6, 7 Heat sink 8 Bolt 9 Insulating layer 10 Irradiation opening 11 Peripheral frame 12 Base plate 13 Inclined surface 14 Cavity 20 LED
21 Side irradiation optical member 22 Cooling surface 23, 24 Connecting line 40 Opening 50 Cooling rib 60 Cooling rib 61 Finger 70 Cooling rib 71 Surface 72 Recess, depression

Claims (12)

1. A peripheral frame (11), irradiating openings (10), a plurality of light emitting diodes (2) has a base plate (12) that is at least partially mounted, the light emitting chamber is in the form of a hollow optical element A surface illumination device having (1),
   Emission chamber (1) is reflected to diffuse in the form of a hollow optical member, and the base plate (12) and a plurality of end regions of the base plate corresponding plurality of peripheral frame (11) adjacent to (12) A plurality of inclined surfaces (13) bridging the region over the periphery, the inclined surface (13) includes a lower region of the peripheral frame (11), an end region of the base plate (12), A surface illumination device that forms a plurality of cavities (14) with an inclined surface (13).
2.   The surface illumination device according to claim 1, wherein the inclined surface is a flat surface.
3.   The surface illumination device according to claim 1, wherein the inclined surface (13) is curved in a concave shape or a convex shape.
4.   The surface illumination device according to any one of claims 1 to 3, wherein the inclined surface (13) is corrugated or pleated.
5.   2. The surface illumination device according to claim 1, wherein control electronics for driving the light emitting diode (2) are arranged in the cavity (14).
6.   The surface illumination device according to claim 1 or 2, wherein the light emitting diode (2) has a side-illuminated LED.
7.   The surface illumination device according to any one of claims 1 to 6, wherein the base plate (12) has a thermally conductive substrate (3) or is connected to the thermally conductive substrate (3).
8.   8. The surface illumination device according to claim 7, wherein the thermally conductive substrate (3) is at least thermally coupled to the heat sink (5) and has a metal core or ceramic substrate (3).
9.   The surface illumination device according to any one of claims 1 to 8, wherein the base plate (12) has a printed wiring board (4), and the opening (40) is arranged directly below the light emitting diode (2).
10.   The number of bolts (8) or one or more heat sink (6) portions (61) matching the number of light emitting diodes (2) protrude through the opening (40). Surface lighting device.
11.   An electrically insulating high thermal conductive layer (9) is provided between the substrate (3) and the heat sink (5) or between the cooling surface (22) of the light emitting diode (2) and the printed wiring board (4) opening (40). 11. A surface illumination device according to claim 9 or 10, which is arranged between a part (61) or a bolt (8) of a heat sink (6) projecting therethrough.
12.   The surface illumination device according to any one of claims 1 to 11, wherein a light-transmitting cover is provided in the irradiation opening (10).

Images