JP2006278309A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system which can be used for lighting by reducing brightness variations in a light radiation surface. <P>SOLUTION: The lighting system of claim 1 is composed of a substrate 2; an insulator 4 provided on the substrate, circuit patterns 5a and 5b provided on the substrate through the insulator; a plurality of light emitting elements 6 arranged in a matrix shape through the circuit patterns; a reflection body 9 provided on the substrate and reflecting light radiated from the plurality of the light emitting elements; a phosphor layer 12 converting light from the light emitting element; and a dimming body 23 provided with a radiation surface radiating light incident from the light emitting element, a periphery region projecting a part of light traveling toward a part of the radiation surface opposite to each light emitting element from a periphery region not opposite to the light emitting element out side of a opposing part, and a constitution such that a ratio of a minimum brightness to a maximum brightness is 0.01 or more and 1 or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting device using a light emitting element as a light source.

  2. Description of the Related Art Conventionally, in a light emitting device using a light emitting diode as a light source as a light emitting element, for example, a light emitting diode is mounted on a substrate and a lens for controlling light emitted from the light emitting diode is disposed. On the front side of such a lens, a planar emission surface from which light from the light emitting diode is emitted toward the optical axis direction is formed, and light directed from the light emitting diode to the side is parallel to the optical axis direction on the back side. A reflection surface is formed that is reflected and emitted from the peripheral area of the emission surface.

And among the light radiated from the light emitting diode, the light directed to the opposed area opposite to the light emitting diode on the emission surface is totally transmitted and emitted, and the light directed to the reflection surface is emitted from the peripheral area of the emission surface ( For example, see Patent Document 1.)
JP 2001-237463 A (page 4-5, FIG. 1-3)

  As a result, the brightness of the facing area, which is the exit surface facing the light emitting diode, is high, and the light toward the facing area of the exit surface is totally transmitted and emitted, so the brightness of the facing area is higher than that of the peripheral area. There is a problem that the brightness becomes uneven in the opposed area of the exit surface and the peripheral area.

  An object of this invention is to provide the illuminating device which can be used for illumination, reducing the brightness nonuniformity of an output surface.

  The invention described in claim 1 includes: a substrate; an insulator disposed on the substrate; a circuit pattern disposed on the substrate via the insulator; and a plurality of elements disposed in a matrix via the circuit pattern. A light-emitting element; a reflector disposed on the substrate and reflecting light emitted from the plurality of light-emitting elements; a phosphor layer converting light from the light-emitting element; and incident from each of the light-emitting elements A periphery having an emission surface for emitting light, and a portion of the emission surface that is directed to a facing area that faces each light emitting element, and is emitted from a peripheral area that does not face each light emitting element outside the facing area. And a light control body configured to have a ratio between a maximum luminance and a minimum luminance of 0.01 or more and less than 1.

  The material of the substrate is glass epoxy resin, aluminum, aluminum nitride, or the like, but a substrate containing aluminum has good heat dissipation and suppresses a temperature increase of the light emitting element, thereby suppressing a decrease in luminous efficiency and element deterioration. The insulator is necessary when a metal material is selected as the material of the substrate, but is not necessary in the case of a glass epoxy resin substrate. The circuit pattern is formed of a copper pattern, and, for example, light emitting diodes as a plurality of light emitting elements are electrically connected between the positive electrode and the negative electrode. A plurality of light emitting elements are arranged in a matrix on the substrate to form a surface light source. The reflector is formed of a white resin and has a reflecting surface so as to surround the periphery of the light emitting element.

  The emitted light of the light emitting element is reflected by the reflecting surface. The phosphor layer is obtained by mixing a phosphor into a silicone resin or the like, and converts it into visible light by light from the light emitting element. Alternatively, the light emitting element may be covered with a diffusing material, and a phosphor layer may be disposed on the diffusing material. This configuration diffuses the light emitted from the phosphor layer by the diffusing material, suppresses the increase in the brightness of the opposed area of the light control body, and brings the brightness ratio with the brightness of the peripheral area close to 1. It works to let you.

  The light control body is formed of an acrylic resin or the like, and is optically designed for each light emitting element. The opposed area mainly refers to an area facing the light emitting element, and the peripheral area is a portion that exists around the opposed area and has a lower luminance than the luminance of the opposed area. The ratio between the highest luminance and the lowest luminance is configured to be 0.01 or more and less than 1. When the luminance ratio is less than 0.01, it becomes worse than the luminance ratio in the lighting device for existing facilities, and thus cannot be put into practical use as a lighting device. When the luminance ratio is 1, it is necessary to increase the diffusibility of the light control body, but on the other hand, the transmittance of light from the light emitting element is lowered, so that the efficiency of the appliance is deteriorated, so that it can be put into practical use as a lighting device. Absent.

  According to a second aspect of the present invention, in the illumination device according to the first aspect, the light control body reflects the light directed laterally from the light emitting element toward the peripheral region outside the opposed region of the emission surface. It has a reflective surface.

  The main reflecting surface reflects a part of the light radiated to the opposing area to the peripheral area, and accordingly reduces the luminance of the opposing area and increases the luminance of the peripheral area.

  According to a third aspect of the present invention, in the illuminating device according to the second aspect, the light control portion of the emission surface is formed with a depression that is recessed from the emission surface around the optical axis of the light emitting element. The ring-shaped exit surface part that emits light from the opposed area and the annular reflection surface part that reflects light to the peripheral area are alternately formed around the optical axis, and the area of the exit surface part approaches the center of the recessed part. It is characterized by being small.

  According to a fourth aspect of the present invention, in a lighting device configured to have a predetermined average luminance by a plurality of light emitting elements arranged in a matrix, a luminance ratio between the luminance of each of the light emitting elements and the luminance of the peripheral portion is set. It is characterized by being configured to be 0.01 or more and less than 1.

  For example, when the illumination device is installed at a mounting height h = 1800 mm (distance from the installation height of the illumination device to the eye height of the subject), the ratio Lb between the luminance Lp of the light emitting element and the luminance Lb of the peripheral portion. / Lp is defined as the luminance ratio. Note that Lb = 50 cd / m @ 2 (square meter). There are two types of visual line positions of the subject: the center of the lighting device (direct view) and 10 ° below the lighting device (periphery).

  When the subject looks at the lighting device under the above conditions, the average luminance of the lighting device when performing an unpleasant glare evaluation from “being worried about glare” to “beginning to feel uncomfortable” (average of the entire lighting device) FIG. 7 shows the relationship between the luminance ratio and the BCD average luminance.

  In FIG. 7, the horizontal axis represents the luminance ratio in logarithmic log, and the vertical axis represents the BCD average luminance ratio in logarithmic log. As a result, it can be seen that when the luminance ratio increases, the average luminance increases and unpleasant glare is reduced. In addition, when the lighting device has a BCD average luminance of 7000 to 10000 cd / m 2 (square meter) or more, the luminance ratio is 0.01, and it has been found that the glare does not matter.

  According to the illuminating device according to any one of claims 1 to 3, in order to emit a part of the light directed to the opposed area facing the light emitting element, from the peripheral area outside the opposed area, of the emission surface of the light control body. The brightness unevenness on the exit surface can be reduced.

  According to the illumination device of the fourth aspect, since the luminance ratio between the luminance of each of the light emitting elements and the luminance of the peripheral portion is 0.01 or more and less than 1, it is difficult to sense luminance unevenness and glare.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a lighting device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. As shown in the figure, the lighting device 1 has a plurality of light emitting devices 3, 3... Arranged on a substrate 2 in a matrix of, for example, 3 rows and 3 columns, and are integrally connected. The substrate 2 is made of a flat plate made of aluminum (Al), Ni, glass epoxy or the like having heat dissipation and rigidity, and a lead frame 5 is disposed on the substrate 2 via an electrical insulator 4.

  As shown in FIG. 3, the lead frame 5 has cathode and anode circuit patterns (wiring patterns) 5a and 5b formed of an alloy of Cu and Ni, Au, or the like for each LED device 3, and this lead frame. 5, a blue light emitting LED chip 6 as a light emitting element is mounted for each light emitting device 3. Each blue light emitting LED chip 6 is made of, for example, a gallium nitride (GaN) semiconductor that emits blue light. Each blue light emitting LED chip 6 has its bottom electrode placed on one of the circuit patterns 5a and 5b to be electrically connected, while its top electrode is connected to the other of the circuit patterns 5a and 5b by a bonding wire 7. Yes.

  And on the board | substrate 2, the circumference | surroundings of each blue light emission LED chip 6 are surrounded at a required space | interval, and the reflective surface which spreads gradually toward the other side (FIG. 2, FIG. 3 upper direction) of the board | substrate 2 is comprised. Each of the LED devices 3 is formed with a reflector 9 having conical conical recesses 8 formed concentrically, and these are integrally formed. The reflector 9 is made of, for example, a synthetic resin such as PBT (polybutylene terephthalate), PPA (polyphthalamide), PC (polycarbonate), and each recess 8 has an opening 8a that opens to the outside.

  Each recess 8 is filled with a thermosetting transparent resin such as translucent silicone rubber or epoxy resin as a sealing resin 10. The sealing resin 10 is formed in two layers: a diffusion layer 11 on the blue light emitting LED chip 6 side and a yellow light emitting phosphor layer 12 as a phosphor layer on the concave opening 8a side.

The diffusion layer 11 is a blue light emitting sealing resin obtained by adding 3 to 5 mass% (mass%) of a diffusing agent such as alumina (Al ₂ O ₃ ), Ti, Ca, Si, Al, or Y in the recess 8. It is formed by injecting to a position higher than the LED chip 6 and thermosetting, and the boundary surface 11a with the phosphor layer 12 is formed in a curved surface recessed to the blue light emitting LED chip 6 side (lower surface side in FIG. 3). Yes. The curved boundary surface 11a is preferably 1 μm to 5 μm, for example, between the upper end and the lower end of the curve.

  Moreover, since the addition amount of the diffusing agent added to the sealing resin 10 of the diffusion layer 11 is 3 to 5% by mass, it is possible to reduce the color unevenness of white light without reducing the luminous flux. Table 1 below shows changes in luminous flux depending on the amount of diffusing agent added. In addition, when the addition amount of the diffusing agent is zero, that is, when the addition amount of the diffusing agent is 100%, when the addition amount of the diffusing agent exceeds 5% by mass, the light flux is decreased and the addition amount is 3 When the content was less than mass%, the effect of reducing color unevenness decreased.

  The yellow light-emitting phosphor layer 12 is sealed by adding the required mass% of a yellow light-emitting phosphor that receives blue light from the LED chip 6 and fluoresces yellow after the thermosetting formation of the diffusion layer 11. It is configured by injecting resin and thermosetting.

  FIG. 4 is a front view of the light control body. The light control body 23 is configured by integrating nine portions corresponding to the LED chip 6, and is disposed and fixed on the reflector 9. FIG. 5 is an enlarged plan view of a part of the light control body. 6 is a cross-sectional view in the diagonal direction of the enlarged plan view of FIG.

  The illuminating device has LED chips 6 mounted on the surface side of the reflector 9 arranged at equal intervals in the vertical and horizontal directions, and a light control body 23 arranged on the surface side of the reflector 9. The light control body 23 is a plurality of light control body portions which are prisms or lenses which are integrally formed of transparent resin or glass having light guide properties and are arranged at equal intervals in the vertical and horizontal directions corresponding to the respective LED chips 6. Has 24.

  On the back side of each light control body portion 24, a housing portion 25 which is a concave portion having a cylindrical cross section for housing the LED chip 6 is formed, and an incident surface on which light from the LED chip 6 enters the inner surface of the housing portion 25 26 is formed, and a reflection surface 27 is formed that spreads toward the surface side around the accommodating portion 25 and reflects light to the surface side, and is incident on the surface side of each light control body portion 24 A square-shaped emission surface 28 that constitutes the light emitting surface 15 from which light is emitted is formed.

  As the incident surface 26, an opposing incident surface 29 is formed so as to be opposed to the front surface of the light emitting surface of the LED chip 6, and a side incident surface 30 positioned beside the light emitting surface of the LED chip 6 is formed. ing. The opposite incident surface 29 is formed on a convex lens portion 31 protruding into the housing portion 25, and the light incident by the lens portion 31 is directed in a direction substantially parallel to the optical axis S perpendicular to the light emitting surface of the LED chip 6. Refract.

  As the reflecting surface 27, the light that has spread around the housing portion 25 toward the emission surface 28 side and is incident from the side surface incidence surface 30 is outside the facing region 28 a that faces the LED chip 6 in the emission surface 28. A main reflection surface 32 that reflects toward the peripheral area 28b is formed, and the opposite area 28a of the emission surface 28 on the back side of the corners 28c of the four corners that are part of the peripheral area 28b of the emission surface 28 A peripheral reflection surface 33 is formed to emit light from the side toward the corner portion 28c of the peripheral area 28b from the corner portion 28c of the peripheral area 28b. The direction in which the light reflected by the main reflection surface 32 and the peripheral reflection surface 33 is emitted from the emission surface 28 is configured to be a direction that spreads mainly outward with respect to the central optical axis S.

  A part of the light traveling toward the facing area 28a is surrounded by a central area around the optical axis S of the emission surface 28 and facing the LED chip 6 around the outside of the facing area 28a. A light control part 34 that reflects toward the area 28b is formed. The light control portion 34 is formed with a hollow portion 35 that is recessed in a pyramidal shape from the light exit surface 28 with the optical axis S as a center. The light recess portion 35 has a light exit surface 28 for emitting light from the opposed region 28a. Parallel quadrangular annular emission surface portions 36 and quadrangular annular reflection surface portions 37 inclined by approximately 90 ° with respect to the emission surface 28 that reflects light to the peripheral region 28b are alternately formed around the optical axis S. Each side of the emission surface portion 36 and the reflection surface portion 37 is formed so as to face each corner portion 28c of the emission surface 28, and the area of the emission surface portion 37 is smaller as it is closer to the center of the recess portion 35 and larger as it is closer to the outside. .

  In the light emitting device 3 configured as described above, when the LED chip 6 is turned on, the light incident on the opposing incident surface 29 from the LED chip 6 is emitted as light parallel to the optical axis S through the lens unit 31. To the opposite area 28a of the surface 28. Of the light traveling toward the facing area 28a, the light that has reached the exit surface 36 of the facing area 28a is emitted through the exit surface 36, and the light that has reached the reflecting surface 37 is not transmitted through the reflecting surface 37 but is reflected by the reflecting surface 37. The light is reflected toward the peripheral area 28b at 37, and the light traveling toward the peripheral area 28b is reflected again by the peripheral reflection surface 33 and emitted from the corner portion 28c of the peripheral area 28b of the emission surface 28.

  As shown in FIG. 6, the light incident on the side incident surface 30 from the LED chip 6 is reflected by the main reflecting surface 32 and is emitted from the peripheral region 28 b outside the opposed region 28 a of the emitting surface 28. In this way, a part of the light that enters from the opposing incident surface 30 of the light control body 23 and travels toward the opposing region 28a of the exit surface 28 is reflected toward the peripheral region 28b, and is reflected from the opposing region 28a to the peripheral region. Since the light toward 28b is emitted from the peripheral region 28b of the emission surface 28 by the peripheral reflection surface 33, the luminance of the opposed region 28a of the emission surface 28 is lowered and the luminance of the peripheral region 28b is increased, and the emission surface 28 is opposed to The luminance unevenness between the area 28a and the peripheral area 28b can be reduced, and the luminance of the emission surface 28 can be made uniform.

  In the present embodiment, the maximum luminance is 200 cd / m 2 (square meter), the minimum luminance is 50 cd / m 2 (square meter), and the luminance ratio is 0.250. This is considered to be due to a synergistic effect with the diffusion layer 11. This has a sufficient effect when the luminance ratio between the maximum luminance of 1200 cd / m 2 (square meter) and the minimum luminance of 1 cd / m 2 (square meter) in the absence of the light control member is 0.001. In addition, in the existing general fluorescent lamp lighting fixture for facilities, the maximum luminance is 8000 cd / m 2 (square meter), the minimum luminance is 1800 cd / m 2 (square meter), the luminance ratio is 0.225, and the luminance ratio of this embodiment is excellent. I found out.

  Furthermore, since the light incident from the side incident surface 30 of the light control body 23 is reflected by the main reflection surface 32 toward the peripheral region 28b outside the opposed region 28a, the luminance of the peripheral region 28b can be improved.

  In addition, a recess 35 that is recessed from the exit surface 28 with the optical axis S as the center is formed in the opposite area 28 a of the exit surface 28, and the exit surface 36 and the reflection surface 37 are centered around the optical axis S in the recess 35. Since they are formed alternately, the light traveling toward the opposed area 28a of the emission surface 28 can be distributed into the direction of emission through the emission surface section 36 and the direction of reflection to the peripheral area 28b.

  Since the area of the emission surface portion 36 is set smaller as it approaches the center of the hollow portion 35, the light emitted through the emission surface portion 36 can be suppressed as it approaches the center.

  The exit surface 28 is formed in a square shape, and the exit surface portion 36 and the reflection surface portion 37 of the recess 35 are formed in a square shape so that each side of the exit surface portion 36 and the reflection surface portion 37 faces each corner portion 28c of the exit surface 28. In addition, the luminance of the corner portion 28c of the emission surface 28 can be improved. The emission surface portion 36 and the reflection surface portion 37 may have an annular shape.

  In addition, out of the emission surface 28 that emits the light incident on the light control body 23 from each LED chip 6 arranged in a matrix, a part of the light directed to the opposed area 28a that faces each LED chip 6 is opposed to that. Since the light is emitted from the peripheral region 28b that does not oppose each LED chip 6 outside the region 28a, it is possible to improve the occurrence of a dark portion on the emission surface 28.

  FIG. 7 shows a relationship diagram between the luminance ratio and the average luminance of the illumination device according to another embodiment. That is, in the present embodiment, in the lighting device configured to have a predetermined average luminance of 7000 to 10000 cd / m 2 (square meters) or more by a plurality of light emitting elements arranged in a matrix as in the above-described embodiment, The luminance ratio between the luminance of each light emitting element and the luminance of the peripheral portion is configured to be 0.01 or more and less than 1.

  When the illumination device is installed at a mounting height h = 1800 mm (distance from the installation height of the illumination device to the eye height of the subject), the ratio Lb / Lp between the luminance Lp of the light emitting element and the luminance Lb of the peripheral portion. Was defined as the luminance ratio. Note that Lb = 50 cd / m @ 2 (square meter). The subject's line of sight has two types, the center of the lighting device (direct view) and 10 ° below the lighting device (peripheral vision), both of which show the same tendency.

  When the subject looks at the lighting device under the above conditions, the average luminance of the lighting device when performing an unpleasant glare evaluation from “being worried about glare” to “beginning to feel uncomfortable” (average of the entire lighting device) Brightness and BCD average brightness) were calculated and determined to be 7000 to 10000 cd / m @ 2 (square meter) or more.

  Next, when the luminance ratio is changed in the lighting device having the BCD average luminance with the luminance ratio Lb / Lp between the luminance Lp of each light emitting element and the luminance Lb of the peripheral portion as the luminance ratio, Whether or not to evaluate discomfort glare was determined from the luminance ratio, and the results are summarized in FIG.

  In FIG. 7, the horizontal axis represents the luminance ratio in logarithmic log, and the vertical axis represents the BCD average luminance ratio in logarithmic log. As a result, it can be seen that when the luminance ratio increases, the average luminance increases and unpleasant glare is reduced.

  In addition, when the lighting device has a BCD average luminance of 7000 to 10000 cd / m 2 (square meter) or more, the luminance ratio is 0.01, and it has been found that the glare does not matter.

The top view of the illuminating device which shows one embodiment of this invention. Similarly, the II-II sectional view taken on the line of FIG. Similarly, the III part enlarged view of FIG. Similarly, the front view of a light control body. Similarly, the one part enlarged plan view of a light control object. Similarly, sectional drawing of the diagonal direction of the enlarged plan view of FIG. The relationship figure of the luminance ratio and average luminance of the illuminating device in other embodiment.

Explanation of symbols

  2 substrate, 4 insulator, 5a, 5b circuit pattern, 6 light emitting element, 9 reflector, 12 phosphor layer, 23 light control body.

Claims (4)

A substrate;
An insulator disposed on the substrate;
A circuit pattern disposed on the substrate via an insulator;
A plurality of light emitting elements arranged in a matrix through a circuit pattern;
A reflector disposed on the substrate and reflecting light emitted from the plurality of light emitting elements;
A phosphor layer for converting light from the light emitting element;
A light emitting surface that emits light incident from each of the light emitting elements, and a part of the light that is directed to the facing area that faces each light emitting element of the emitting surface is not opposed to each light emitting element outside the facing area; A light control body having a peripheral area that is emitted from the peripheral area and configured such that a ratio of the highest luminance to the lowest luminance is 0.01 or more and less than 1;
An illumination device comprising:   The lighting device according to claim 1, wherein the light control member has a main reflection surface that reflects light directed from the light emitting element to the side toward a peripheral region outside the opposed region of the emission surface.   The light control portion of the light emission surface is formed with a hollow portion that is recessed from the light emission surface with the optical axis of the light emitting element as the center, and this hollow portion is formed into an annular light emission surface portion that emits light from the opposed region and a peripheral region. 3. The illumination device according to claim 2, wherein annular reflecting surface portions that reflect light are alternately formed with the optical axis as a center, and the area of the exit surface portion is provided smaller as it approaches the center of the recessed portion.   In a lighting device configured to have a predetermined average luminance by a plurality of light emitting elements arranged in a matrix, a luminance ratio between the luminance of each of the light emitting elements and the luminance of the peripheral portion is 0.01 or more and less than 1. It is comprised in the lighting apparatus characterized by the above-mentioned.

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