JP2011210719A - Surface light source unit, surface illumination light source device, and surface illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface light source unit in which processing of a light conducting reflecting plate is made easy, a surface illumination light source device, and a surface illumination device inexpensively.SOLUTION: In the surface light source unit 1 having a point light source 5 with high directivity, and the light conducting reflecting plate 2 that opposes to the point light source 5, separately arranged by a prescribed distance, and in which the surface opposing to the point light source 5 is formed at the reflecting face, the light conducting reflecting plate 2 is equipped with: a center reflecting part 3 of high light reflectance and low light transmittance having a size of a prescribed area around a point on the light axis of the point light source 5; and an outer reflecting part 4 in the outer periphery of the center reflecting part 3 in which the light reflectance is reduced according as the distance from the center reflecting part 3 increases while the light transmittance increases. The center reflecting part 3 and the outer reflecting part 4 are formed of different members.

Description

  The present invention relates to a surface light source unit, a surface illumination light source device, and a surface illumination device used in display devices such as LCD backlights, lighting signs, automobiles and vehicles.

  In recent years, as a light source for various display devices and lighting, the use of light emitting diodes (LEDs) instead of incandescent bulbs and fluorescent tubes has been promoted from the viewpoint of long life with less power consumption and heat generation. Since it is a point light source with strong directivity, various devices are required to obtain a uniform light amount distribution over a wide area. This also applies to laser diodes.

  The surface illumination device includes a so-called backlight type in which a light source is disposed behind the illumination surface and a so-called edge light type in which the illumination surface and the light source are orthogonal to each other. The edge light type surface illumination device uses a light guide plate and can be thinned. However, since the light guide plate needs to be provided on the entire illumination surface, the weight increases and the manufacturing cost also increases. On the other hand, some backlight type surface illumination devices do not require a light guide plate, and in that case, it is possible to reduce the weight. Therefore, the backlight type surface illumination device is used in places where the weight reduction is required. . However, although the backlight type surface illumination device is lighter than the edge light type surface illumination device, since the LED is a point light source with strong directivity, light that is strong in the optical axis direction, so-called glare (glare, dazzling) ) Will occur. For this reason, in order to use as illumination, it is necessary to suppress the generation of glare and diffuse light efficiently. Therefore, various devices have been made to use the point light source as a backlight type surface illumination device.

For example, there are the following prior art documents as backlight type surface illumination devices using a point light source.
Japanese Patent Application Laid-Open No. 2004-006317 below discloses a surface light emitting device 101 as shown in FIG. A lens portion 106 of an LED 105, which is a light source attached to the center of the bottom portion 104 of the reflector 103, is covered with a holder portion 109 of a light control means 107 that adjusts the amount of transmitted light, and the disk portion 108 of the light control means 107 is reflected by a reflecting body. The reflection part 111 and the reflection / transmission part 112 are provided, and the reflection main part 111 reduces the transmission amount of the LED 105 and reflects a large amount on the reflector side. The reflection / transmission part 112 has a larger transmission amount than the reflection main part 111. Due to the light transmitted through the reflection / transmission unit 112 and the light diffusely reflected by the reflector 103, the entire diffusion panel 102 covering the upper portion of the reflector 103 has substantially uniform luminance. 110 in the figure is a slit for attaching the holder part 109 to the LED 105.

  Patent Document 2 (Japanese Patent Laid-Open No. 2008-027886) discloses a light guide body having a highly directional light source 202 and a radiation surface 203A in the radiation direction of the light source 202, as shown in FIG. 203 and a casing 204 that surrounds the light-emitting source 202 and closes a surface other than the light-emitting surface of the light guide 203, the surface illumination light source device 201 is provided between the casing 204 and the light guide 203. Increasing the thickness of the LED light source 202 in the radiation direction by providing the inner reflection unit 205 and the radiation side reflection unit 206 that is provided on the radiation surface 203A and reflects the light from the light source 202 at a predetermined ratio. There is disclosed an apparatus capable of obtaining uniform illumination light over a wide area.

  Furthermore, as shown in FIG. 16, the surface illumination light source device 301 disclosed in Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2009-110696) includes a bottom surface portion 311 and a side wall portion 312 provided with a point light source 327 at the center. A casing 313 having an optical reflection plate 314 disposed at a predetermined distance from the bottom surface portion 311. The optical reflector 314 has a concentric non-through hole 316 at the center of the optical reflector, a concentric narrow hole 317 on the outer side, a concentric circular arc hole 319 on the outer side, and a plurality of rounds on the outer side. A technical means is disclosed in which a hole 320 is provided and uniform illumination light is obtained on a surface separated from the radiation surface by a predetermined distance. Reference numeral 315 denotes an opening that collectively refers to the non-through hole 316, the narrow hole 317, the arc hole 319, and the round hole 320.

  17A to 17D are plan views showing the arrangement of the holes in the optical reflector 314 used in the surface illumination light source device of Patent Document 3. The hole 320 provided in the outer part of each optical reflecting plate in FIGS. 17A to 17D has a shape that can be easily processed, and is circular or rectangular. The hole provided in the central part is a narrow arc hole 319 that avoids the central part as shown in FIG. 17A, or a narrow hole 317 as shown in FIG. It is. Further, as shown in FIGS. 17C and 17D, the central portion is not provided with a hole, and is formed as a blank portion. Around the blank portion, a fine through hole 321 having the same shape as the hole provided outside and only the size thereof is changed. And so on.

Japanese Patent Laid-Open No. 2004-006317 JP 2008-027886 A JP 2009-110696 A

  However, in the surface light-emitting device of Patent Document 1, not only the light control means 107 that adjusts the amount of transmitted light but also the diffusion panel 102 is required in order to equalize the highly directional light by the LEDs. The structure of the device was complicated, and the weight was not sufficiently reduced.

  Further, in the surface illumination light source device of Patent Document 2, radiation side reflection means 206 provided on the radiation surface 203A that reflects light from the light emission source 202 at a predetermined ratio is provided, and a concentric opening is formed from the center. I have. However, since the directivity of the LED is extremely strong, if an attempt is made to obtain uniform surface illumination light over the entire radiation surface of the light guide 203, the opening at the center of the radiation side reflection means 206 becomes minute, and the processing is performed. It becomes difficult. Further, the light guide 203 needs to have a predetermined thickness in the radiation direction of the LED, and the light scattered by the radiation side reflection means 206 and the inner reflection means 205 of the casing 204 is absorbed by the light guide 203. There is also a problem.

  Furthermore, in Patent Document 3, the optical reflector 314 is provided with a plurality of openings 315 such as grooves and holes for adjusting the amount of reflection and transmission of light from the point light source 327. The shape of the opening 315 is different between the central portion and the peripheral portion of the optical reflector 314. The central opening surrounding the non-through hole 316 in the central portion is a concentric arc-shaped narrow hole 317, and the outer side is an arc hole. Further, a round hole 320 is formed as a through hole in the peripheral portion. The opening 315 is created by cutting out the optical reflector 314 with a cutting plotter or the like. In this case, the precision of the hole is different between the central part and the peripheral part, and the through hole in the peripheral part can be created by punching, but the non-through hole in the central part has to be created by precisely machining with a cutting plotter. It was. On the other hand, it was difficult to process the peripheral through holes with a cutting plotter. For this reason, a plurality of different processing methods have to be used for manufacturing the optical reflector 314, and there is a problem that it takes time to manufacture, and mass production is difficult and costly.

  As a result of various studies to solve the above problems, the inventor of the present application separately creates a central portion and a peripheral portion having different aperture shapes of the light conducting reflector in the manufacture of the surface light source unit, The manufacturing method suitable for the processing is used for the central part where precise processing is required, and the peripheral part, which can be processed relatively easily, is manufactured using an inexpensive processing method. Thus, the present invention has been completed which can provide a surface light source unit, a surface illumination light source device and a surface illumination device that are easy to mass-produce and inexpensive.

  In other words, the present invention has been made to solve the above-described problems, and by changing the manufacturing method between a central portion that requires precise processing and a peripheral portion that requires simple processing, light emission can be achieved. The manufacturing time of the light conducting reflector used in the surface light source unit that can obtain uniform illumination light on the surface at a predetermined distance from the surface is shortened, the mass production is easy, and the cost is reduced. An object of the present invention is to provide a surface light source unit, a surface illumination light source device, and a surface illumination device.

The present invention employs the following configuration in order to solve the above problems.
That is, according to one aspect of the present invention, a surface light source unit of the present invention includes a surface having a highly directional point light source and a light conducting reflector disposed at a predetermined distance from the point light source. In the light source unit,
The light conducting reflector has a reflective surface at a surface facing the point light source, and has a high light reflectance and a low light transmission with a predetermined area centered on a point on the optical axis of the point light source. A central reflection part of the rate, and an outer reflection part on the outer periphery of the central reflection part, the light reflection ratio is decreased while the light reflection ratio is increased as the distance from the central reflection part increases.
The central reflecting portion and the outward reflecting portion are formed of different members.

  According to a second aspect of the present invention, in the surface light source unit according to the first aspect of the present invention, the central reflecting portion is formed of a central reflecting plate having a predetermined area, and the photoconductive reflecting plate is formed in the central portion. A through hole penetrating the light conducting reflection plate is formed in a region corresponding to the reflection portion, and the central reflection plate is fitted and coupled to the through hole.

  According to a third aspect of the present invention, in the surface light source unit according to the second aspect of the present invention, the photoconductive reflector has a protrusion protruding from the end of the through hole toward the center. In addition, the central reflecting portion has a fitting portion that is fitted to the protruding portion.

  According to a fourth aspect of the present invention, in the surface light source unit according to the first aspect of the present invention, the central reflecting portion is provided with a minute hole smaller than the point light source. .

  According to a fifth aspect of the present invention, in the surface light source unit according to the first aspect of the present invention, a high light reflectivity member is attached to the central reflection portion on the point light source side. To do.

  According to a sixth aspect of the present invention, in the surface light source unit according to the first aspect of the present invention, the light transmitting / reflecting plate is formed with a penetrating opening, and the diffusing member diffuses light in the opening. A microlens or a microprism is attached.

  According to a seventh aspect of the present invention, in the surface light source unit according to the first aspect of the present invention, the height of the central reflecting portion is higher than the height of the outer reflecting portion.

  According to an eighth aspect of the present invention, in the surface light source unit according to any one of the first to seventh aspects of the present invention, the point light source is a single light emitting diode or an assembly of a plurality of light emitting diodes. It is characterized by that.

  According to a ninth aspect of the present invention, in the surface light source unit according to any one of the first to eighth aspects of the present invention, the photoconductive reflector is formed of an ultrafine foaming resin, The reflectance is 95 to 99.8%, and the light transmittance is 0.2 to 5%.

According to the aspect of claim 10 of the present invention, the surface illumination light source device of the present invention is a surface illumination light source device having the surface light source unit according to any one of claims 1 to 9 and a casing,
One surface light source unit is arranged in the casing.

  According to an aspect of an eleventh aspect of the present invention, in the surface illumination light source device according to the tenth aspect of the present invention, the casing is perpendicular to a bottom surface portion to which the point light source is attached and an end portion of the bottom surface portion. A standing side wall and an opening facing the bottom are provided, and the opening is closed by the photoconductive reflector.

According to the aspect of claim 12 of the present invention, in the surface illumination light source device of the present invention, the surface illumination light source device having the surface light source unit according to any one of claims 1 to 9 and a casing,
A plurality of the surface light source units are arranged in the casing.

  According to a thirteenth aspect of the present invention, in the surface illumination light source device according to the twelfth aspect of the present invention, the casing includes a bottom surface portion to which a plurality of the point light sources are attached, and an end portion of the bottom surface portion. A vertically standing side wall and an opening facing the bottom surface are provided, and the opening is closed by the photoconductive reflector.

  According to a fourteenth aspect of the present invention, in the surface illumination light source device according to the twelfth or thirteenth aspect of the present invention, all the light conducting reflectors attached to the surface illumination light source device are connected. It is characterized by

  According to a fifteenth aspect of the present invention, in the surface illumination light source device according to any one of the twelfth to fourteenth aspects of the present invention, the casing is erected vertically from the bottom surface portion. It has the partition plate which partitions off between light sources, It is characterized by the above-mentioned.

  According to an aspect of the sixteenth aspect of the present invention, in the surface illumination light source device according to any one of the twelfth to fourteenth aspects of the present invention, the casing is provided with the light standing upright from the bottom surface portion. It has the supporting member which supports a conduction | electrical_connection reflecting plate, It is characterized by the above-mentioned.

  According to an aspect of claim 17 of the present invention, in the surface illumination light source device according to any one of claims 10 to 16 of the present invention, the casing is formed of an ultra-fine foaming resin, and the reflectance of the member Is 95 to 99.8%, and light transmittance is 0.2 to 5%.

According to an aspect of claim 18 of the present invention, in the surface illumination device of the present invention, the surface illumination light source device according to any one of claims 9 to 17, a housing, and the surface illumination light source device are opposed to each other. A surface illumination device having a diffuser plate arranged at a predetermined interval,
One or a plurality of the surface illumination light source devices are arranged in the housing.

  According to the present invention, in the surface light source unit, the light conducting reflection portion is composed of two members, that is, the central reflection portion and the outward reflection portion, so that the processing method can be selected according to the type of the hole in the manufacture. Therefore, manufacturing time can be shortened, mass production is easy, and it can be manufactured at low cost. Therefore, a surface light source unit and surface illumination that can obtain uniform illumination light on a surface that is a predetermined distance away from the radiation surface without increasing the thickness of the light in the radiation direction while using light from the light source with high efficiency A light source device and a surface illumination device can be provided at low cost.

  According to one aspect of the present invention, in addition to the above-described effect, in the surface light source unit according to claim 1, the central reflection portion is fixed to the optical conductive reflector by fitting and coupling, so that the optical conductive reflector is Since there is no deformation or alteration, substantially uniform illumination light can be obtained over the entire surface.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to claim 2, the central reflection portion and the outer reflection portion formed of different members are fitted to the protrusion portion. Since they are coupled with each other, the coupling method is simple and easy to create.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to claim 1, since light passing through the photoconductive reflector is reduced, the spectrum of light is not changed, The color temperature of the illumination light can be made uniform.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to claim 1, the light passing through the photoconductive reflector is further reduced, so that the light spectrum does not change. The color temperature of the illumination light can be made uniform.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to claim 1, the change in the light spectrum becomes uniform, and the color temperature of the illumination light can be made uniform. become. Also, the illuminance is made uniform.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to claim 1, since light passing through the photoconductive reflector is reduced, the spectrum of light is not changed, The color temperature of the illumination light can be made uniform.

  According to one aspect of the present invention, in addition to the above effect, in the surface light source unit according to any one of claims 1 to 6, the point light source is a single light emitting diode or an assembly of a plurality of light emitting diodes. It is preferable to achieve the desired effect.

  According to one aspect of the present invention, in addition to the above effect, in the surface illumination light source device according to any one of claims 1 to 7, the central reflecting portion is formed of an ultrafine foamed resin, The light reflectance is preferably 95 to 99.8% and the light transmittance is preferably 0.2 to 5% in order to achieve the desired effect.

  According to one aspect of the present invention, it is possible to provide a surface illumination light source device that can obtain illumination light with substantially uniform brightness over the entire surface using the surface light source unit. Moreover, the surface illumination light source device which can illuminate a wide range can be provided by using two or more point light sources.

  According to one aspect of the present invention, in addition to the above effect, in the surface illumination light source device according to claim 9 or 11, the illumination range can be clarified by providing the casing with the bottom plate portion and the side plate portion. Thus, it is possible to provide a surface illumination light source device that can obtain illumination light with more uniform luminance.

  According to one aspect of the present invention, in addition to the above-described effect, in the surface illumination light source device according to claim 11 or 12, the light conducting reflector is attached to the casing by connecting all the light conducting reflectors. Can be made easier.

  According to 1 aspect of this invention, in addition to said effect, in the surface illumination light source device of any one of Claims 11-13, the range which each point light source illuminates is clear by providing a partition plate. Therefore, it is easy to make the illuminance uniform. Further, when the photoconductive reflector is connected, the photoconductive reflector is supported by the partition plate.

  According to 1 aspect of this invention, in addition to said effect, in the surface illumination light source device of any one of Claims 11-13, by supporting the connected photoconductive reflecting plate, photoconductive reflection is carried out. A board becomes easy to make surface illumination light with uniform illuminance.

  According to one aspect of the present invention, in addition to the above effect, in the surface illumination light source device according to any one of claims 9 to 15, the casing is formed of an ultrafine foaming resin, and the light reflection of the member In order to achieve the desired effect, it is preferable that the rate is 95 to 99.8% and the light transmittance is 0.2 to 5%.

  According to one aspect of the present invention, it is possible to provide a surface illumination device that can obtain illumination light with substantially uniform brightness over the entire surface using the surface illumination light source device.

It is a perspective view of the surface light source unit which concerns on Example 1 of this invention. It is a disassembled perspective view of the surface light source unit which concerns on Example 1 of this invention. It is sectional drawing in the III-III line in FIG. FIG. 4A is a plan view of the central reflecting portion of the photoconductive reflector, and FIG. 4B is a side sectional view of the central reflector of the photoconductive reflector. 5A to 5C are a plan view and a side sectional view according to a modification of the central reflection portion of the light conducting reflection plate. It is sectional drawing in the modification of the surface light source unit which concerns on embodiment of this invention. It is a perspective view of the surface illumination light source device which concerns on Example 2 of this invention. It is a disassembled perspective view of the surface illumination light source device which concerns on Example 2 of this invention. It is sectional drawing of the surface light source unit which concerns on Example 3 of this invention. It is a perspective view of the surface illumination light source device which concerns on Example 4 of this invention. It is a disassembled perspective view of the surface illumination light source device which concerns on Example 4 of this invention. It is a disassembled perspective view of the modification of the surface illumination light source device which concerns on Example 4 of this invention. It is a disassembled perspective view of the surface lighting apparatus which concerns on Example 5 of this invention. It is a perspective view of the surface illumination apparatus of the 1st prior art example. It is a sectional side view of the surface illumination apparatus of the 2nd prior art example. It is a sectional side view of the surface illumination light source device of the 3rd prior art example. It is a top view which shows arrangement | positioning of the hole of the optical reflecting plate used for the surface illumination light source device of the 3rd prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a surface light source unit, a surface illumination light source device, and a surface illumination device for embodying the technical idea of the present invention. It is not intended to be specific to the light source device and the surface illumination device, but can be equally applied to other embodiments included in the claims.

  Hereinafter, an embodiment of the present invention will be described with reference to Example 1 of the present invention. 1 is a perspective view of the surface light source unit according to the first embodiment of the present invention, FIG. 2 is an exploded perspective view of the surface light source unit according to the first embodiment, and FIG. 3 is a sectional view taken along line III-III in FIG. It is.

  According to one embodiment of the present invention, the surface light source unit 1 of the present invention includes a highly directional point light source 5 and a light conducting reflector 2 arranged at a predetermined distance h from the point light source 5. . The light conducting reflection plate 2 includes a central reflecting portion 3 having a predetermined area centered on the center 30 on the optical axis of the point light source 5 and an outer reflecting portion 4 provided on the outer periphery of the central reflecting portion 3. And. In the surface light source unit 1 according to the present invention, the light conducting reflection plate 2 is composed of two members, a central reflection portion 3 and an outward reflection portion 4.

  The point light source 5 is not only an element that emits light itself, such as an LED or a laser diode, which is a point light source with strong directivity, but may also be light guided by a light guide wire or the like. Further, the point light source 5 includes not only a single light emitting element but also a case where a plurality of light emitting elements are arranged close to each other. Furthermore, for example, the case where red, blue, and green light emitting elements, which are the three primary colors of light, are arranged close to each other is included.

  For the light conducting reflection plate 2, a member is used in which the surface facing the point light source 5 is formed of a reflection surface having high light reflectance and low light transmittance. As this member, an ultrafine foaming resin, for example, an ultrafine foamed light reflecting plate, an emulsion of fine particles of titanium white, a fine particle of polytetrafluoroethylene, or a combination thereof Is preferably used. The reflectance of the member is preferably 95 to 99.8%, and the light transmittance is preferably 0.2 to 5%.

  The center of the light conducting reflection plate 2 faces the point light source 5, and the light conducting reflection plate 2 has a plurality of non-through holes 31 or arc-shaped through holes 32 formed in a groove shape near the center 30. And a plurality of circular through holes 41 are formed on the outer side. The non-through hole 31, the arc-shaped through hole 32, and the circular through-hole 41 are moved away from the center 30 of the photoconductive reflector 2, and the non-through hole 31, the arc-shaped through-hole 32, and the circular through-hole The area 41 has a larger ratio of the area of the non-through hole 31, the arc-shaped through hole 32, and the circular through hole 41 in the predetermined area of the photoconductive reflector 2 to a predetermined area. Thus, the luminance of the light conducting reflection plate 2 is set to be uniform over the entire surface.

The circular through holes 41 are arranged in a matrix on the light conducting reflection plate 2 and are provided so that the opening area gradually increases from the periphery of the central reflecting portion 3 toward the outer peripheral portion. The size and number of the through holes are formed such that the ratio of the area of the predetermined area to the area (reference area) of the predetermined area (opening) = (opening ratio) is constant. That is, the openings such as the arc-shaped through hole 32 and the circular through hole 41 are formed so that the opening ratio A satisfies the following relational expression. In the following equation, A is the aperture ratio, x is the distance from the center 30 of the light conducting reflector 2, and a and b are constants.
A = ax ² + b

  As shown in FIG. 1, the aperture ratio A increases in proportion to the square of the distance of the light conducting reflector 2 as it moves away from the center 30 of the light conducting reflector 2 facing the point light source 5. Yes. A uniform brightness can be obtained by reducing the aperture ratio of the central reflecting portion 3 close to the light source and having strong light, and increasing the aperture ratio of the outer portion having low light. According to this embodiment, since the aperture ratio A is increased according to the distance from the center of the light conducting reflector 2 facing the point light source 5, a predetermined distance from the surface of the light conducting reflector 2 in the light emission direction. Uniform illumination light could be obtained on surfaces separated by (for example, 5 mm) or more.

  The circular through-holes 41 may be arranged not only in an orthogonal lattice shape, but in a staggered manner in a plan view, for example. Moreover, the circular through-hole 41 adjacent to the arc-shaped through-hole 32 may be arranged so that the outline is a hexagon. In this case, it is desirable that the arc-shaped through hole 32 farthest from the center 30 of the light conducting reflection plate 2 is disposed on a straight line connecting the center and the circular through hole corresponding to the apex of the hexagon. Thus, the arrangement of each through hole can be variously selected.

  In the present embodiment, the central reflection portion 3 is a disk-shaped member having a diameter r with the center 30 of the light conducting reflection plate 2 as the center. This diameter is determined by the luminance of the point light source 5. In the case of the present embodiment, the diameter of the central reflecting portion 3 is 3 cm. A predetermined range from the center 30 of the light conducting reflection plate 2 is not processed, or a non-through hole (half cut hole) 31 is provided. This is because, if it is a through hole, direct light from the point light source 5 enters the eyes and so-called glare occurs. The non-through hole 31 is a groove having a V-shaped or U-shaped cross section dug to a depth of about half the thickness of the central reflecting portion 3. The non-through hole 31 is provided in order to obtain uniform illumination light over the entire illumination surface, with the brightness not being lower than that in the vicinity when the hole is not formed in the central reflecting portion 3. This is because when the light conducting reflection plate 2 is incorporated in the surface light source unit 1, the amount of light transmitted from the point light source 5 of the surface light source unit 1 is adjusted to obtain uniform illumination light. A plurality of concentric, annular non-through holes 31 from the center 30 are formed near the center 30 of the central reflecting portion 3.

  A plurality of concentric and discontinuous narrow arc-shaped through holes 32 are formed outside the non-through holes 31. As shown in FIG. 4, the narrow arc-shaped through-hole 32 is formed in a discontinuous annular shape, that is, in a plurality of arc shapes by the connecting portion 33. The reason why the arc shape is discontinuous is that if it is a continuous annular shape, the opening portion sandwiched between the annular through-holes is detached.

The outer reflection portion 4 is formed of a square plate having a side length of 10 cm having a fitting hole 20 into which the central reflection portion 3 can be fitted, with a portion corresponding to the central reflection portion 3 being hollowed out. Is. A large number of circular through holes 41 are formed in the outer reflection portion 4. In FIG. 2, a large number of circular through holes 41 ₁ , 41 ₂ , 41 ₃ ,..., 41 _n are arranged in a matrix.

  A conventional optical reflector is provided with a plurality of openings such as grooves and holes for adjusting the amount of reflection and transmission of light from the light source. As described above, the shape of the opening is different between the central portion and the outer portion of the optical reflector, and the opening in the central portion that surrounds the non-through hole in the central portion is a narrow hole by a concentric arc-shaped half cut, and the outer shape is annular. And a circular through hole is formed on the outer side. The opening was created by cutting out the optical reflector with a cutting plotter or the like. In this case, the precision of the hole is different between the central part and the outer part of the optical reflector, and the circular through hole in the outer part can be created by punching, but the non-through hole in the central part is precisely machined with a cutting plotter. Had to be created. As described above, in manufacturing the conventional optical reflector, it is necessary to use a plurality of different processing methods for manufacturing the same substrate, which takes time, makes mass production difficult, and increases the cost.

  According to this embodiment, since the photoconductive reflecting plate 2 is composed of two members, that is, the central reflecting portion 3 and the outer reflecting portion 4, each member is processed separately by a necessary processing method, thereby producing the same. In this case, the manufacturing time of the member can be shortened, mass production is easy, and it can be manufactured at low cost.

  As shown in FIG. 3, the central reflecting portion 3 and the outer reflecting portion 4 are provided below the hollow portion of the outer reflecting portion 4 and the protrusion 3 a that extends over the entire circumference on the upper side surface of the central reflecting portion 3. The protrusions 4a are joined by fitting. FIG. 4 shows a plan view 4A and a side sectional view 4B of the central reflecting portion 3 of FIG.

  The coupling by fitting is not limited to the example of FIG. 4, but as shown in FIG. 5A, the side surfaces 3Aa of the central reflecting portion 3A and the hollow portion 4Aa of the outer reflecting portion 4A are used as the inclined surfaces, and both slopes are matched. Further, as shown in FIGS. 5B and 5C, the central reflecting portions 3B and 3C are rotated on the side surfaces of the central reflecting portions 3B and 3C and the hollow portions of the outer reflecting portions 4B and 4C, respectively, so that they are not detached. You may make it couple | bond by providing protrusion 3Ba and 3Ca and the notch part 4Ba and 4Ca which respond | correspond to this, and fitting and fixing so that it may regulate. In FIG. 5, details such as non-through holes are omitted. Furthermore, although not shown, the outer surface of the central reflecting portion 3 and the inner surface of the outer reflecting portion 4 may be screwed and screwed so that both are screwed.

  Further, FIG. 6 shows that the central reflecting portion 3 and the outer reflecting portion 4 are fitted with the corresponding notches 39 provided on the outer edge of the central reflecting portion 3 with the hook-like protrusions 49 provided on the inner edge of the outer reflecting portion 4. It is an example fixed by.

  In addition, the center reflection part 3 and the outward reflection part 4 can also adhere to a contact part using an adhesive agent, or can also be heat-welded. However, since there is a possibility that the illuminance may become non-uniform due to changes in the reflectance and light transmittance of the bonded portion and the heat-welded portion, the central reflecting portion 3 and the outer reflecting portion 4 are fixed by fitting and coupling. Is preferred.

  As described above, in the surface light source unit 1, the central reflection portion 3 is fitted into the outer reflection portion 4 and fixed by coupling so that the light conducting reflection plate 2 is not deformed or deteriorated. A substantially uniform illumination light can be obtained on the entire surface.

  The surface illumination light source device according to the second embodiment of the present invention will be described with reference to FIGS. Components having the same configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. 7 is a perspective view of the surface illumination light source device according to the second embodiment of the present invention, and FIG. 8 is an exploded perspective view of the surface illumination light source device according to the second embodiment.

  The surface illumination light source device 10 of the present invention has a configuration in which a casing is added to the surface light source unit of the first embodiment. That is, the surface illumination light source device 10 of the present invention is erected from the bottom surface portion 6e in which the light source mounting hole 60 for arranging the highly directional point light source 5 is formed at the center and the end portion of the bottom surface portion 6e. A box-shaped casing 6 having side walls 6a to 6d and having an opening 6f facing the bottom surface 6e, and a light that is opposed to the bottom surface 6e at a predetermined distance by closing the opening 6f. A conductive reflector 2 and a point light source 5 are provided. On the upper sides of the side wall portions 6 a to 6 d of the casing 6, a plurality of claws 6 g for coupling the light conducting reflection plate 2 is provided.

  That is, the surface illumination light source device 10 has a box shape as a whole. As an example of the size of the surface illumination light source device 10, a rectangular parallelepiped having a width of 10 cm, a depth of 10 cm, and a thickness of 1.5 cm is employed. However, the size of the surface illumination light source device 10 is not limited to this. The inner surfaces of the side wall portions 6a, 6b, 6c, 6d and the bottom surface portion 6e of the casing are formed by reflecting surfaces and have a function of reflecting light. Further, a reflection surface is also formed on the inner surface of the light conducting reflection plate 2 disposed to face the bottom surface portion 6 e of the casing 6.

  The member of the casing 4 includes a member having high light reflectivity and low light transmittance, such as an ultrafine foamed light reflecting plate, an emulsion of fine particles of titanium white, and fine particles of polytetrafluoroethylene (polyfluorocarbon). Any one or a combination thereof is used. The reflectance of the member is preferably 95 to 99.8%, and the light transmittance is preferably 0.2 to 5%.

  According to the second embodiment, by using the surface light source unit, a surface illumination light source device capable of obtaining illumination light having substantially uniform luminance on the entire surface can be provided with a simple manufacturing process and at a low cost.

  Next, with reference to FIG. 9, the surface illumination light source device in Example 3 of this invention is demonstrated. Components having the same configurations as those of the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. In addition, FIG. 9 is sectional drawing of the surface illumination light source device which concerns on Example 3 of this invention. The surface light source device used in the surface illumination device according to the third embodiment of the present invention is obtained by partially changing the configuration of the surface light source device according to the second embodiment of the present invention. In the following description, components that are common to the surface illumination light source device 10 are denoted by the same reference numerals, overlapping descriptions are omitted, and different configurations are described.

  When the surface illumination light source device is thinned and the side plate portion has a height of about 3 to 5 mm, there is a problem that the color immediately above the point light source is different from the peripheral portion. This is because the illumination light near the point light source is mainly light that has passed through the photoconductive reflector, and the illumination light in the periphery is mainly light that has passed through the opening provided in the photoconductive reflector. This is considered to be because there is.

  In the surface illumination light source device 10A of the present embodiment, as shown in FIG. 9A, a fine hole 34 having a diameter of 60 microns to 100 microns is formed in the central reflecting portion 3. Since the light from the point light source 5 comes out without passing through the light conducting reflection plate, the spectrum of the light emitted from the central reflecting portion 3 is not changed, and the entire color temperature can be made uniform. .

  Moreover, as shown in FIG. 9B, a high light reflectance member 35 may be attached to the point light source 5 side in the central reflecting portion 3. By attaching the high light reflectivity member 35, there is no more light passing through the central reflecting portion 3, and the color temperature of the illumination light can be made uniform. Examples of the high light reflecting member include aluminum and a pure silver coating film. Moreover, you may attach the light absorption member which absorbs a specific wavelength instead of a high light reflection member. In the case of the present embodiment, since the color changes to yellow, the color temperature of the illumination light can be made uniform by attaching a light absorbing member that absorbs a yellow wavelength.

  Further, as shown in FIG. 9C, a plurality of convex reflection members 35a may be formed instead of the high light reflectance member. 9D, the diffusion member 35b, the microlens 35c, or the microprism 35d may be attached to the openings provided in the central reflecting portion 3 and the outward reflecting portion 4. Further, as shown in FIG. 9E, two high-light-reflecting members 35 may be sandwiched between two light-conducting reflecting plates, and the same opening as the light-conducting reflecting plate may be sandwiched therebetween.

  Further, as shown in FIG. 9F, the height of the central reflecting portion 3 may be made higher than that of the outer reflecting portion 4. By increasing the height of the central reflecting portion 3, the amount of light that passes through the central reflecting portion 3 is further reduced, and the color temperature of the entire surface illumination light source device can be made uniform. Further, as shown in FIG. 9G, the height of the central reflecting portion 3 is lowered as it goes away from the center of the central reflecting portion 3 to the outer periphery, and the outer reflecting portion 4 and the outer reflecting portion 4 are connected to the outer reflecting portion 4. A convex lens shape having the same height may be used. By setting the central reflecting portion 3 to the same height as the outer reflecting portion 4 at the connecting portion with the outer reflecting portion 4, it becomes easy to control the illuminance around the connecting portion.

  Next, a surface illumination light source device according to a fourth embodiment of the present invention will be described with reference to FIGS. Components having the same configurations as those of the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. 10 is a perspective view of a surface illumination light source device according to a fourth embodiment of the present invention, FIG. 11 is an exploded perspective view of the surface illumination light source device according to the third embodiment, and FIG. 12 is a surface illumination according to the third embodiment. It is a disassembled perspective view of the modification of a light source device. In FIG. 11 and FIG. 12, details such as the non-through holes of the light conducting reflection plate 2A are omitted.

  In the second embodiment, the case where there is only one point light source 5 has been described. However, as shown in FIG. A light conducting reflection plate 2A corresponding to the plate 2 may be used.

In the surface illumination light source device 10B, as shown in FIG. 10 and FIG. 11, four light source mounting holes 60 are provided in a rectangular lattice pattern on the bottom surface portion 6e of the casing 6A. Light sources 51-54 are attached. The casing 6B is a rectangular parallelepiped having a size equivalent to that of four casings 6 arranged in an orthogonal lattice, that is, a length of one side of the bottom surface portion 6e is 20 cm and a height is 1.5 cm. The light conducting reflection plate 2B is attached to the opening 6f of the casing 6B so as to close the opening 6f. The light conducting reflection plate 2B is obtained by connecting four light conducting reflection plates 2 ₁₁ , 2 ₁₂ , 2 ₂₁ , and 2 ₂₂ arranged in an orthogonal lattice shape. In FIG. 11, details such as the non-through holes of the light conducting reflection plate 2B are omitted.
Partitioning each light source between the point light sources 8 _{11-8 22,} the partition plate 61 for supporting the light conducting reflection plate 2B which closes the opening 6f of the casing 6, erected vertically from the bottom portion 6e Has been.
By providing the partition plate 61, the range illuminated by each of the point light sources 81 to 84 becomes clear, and it becomes easy to obtain illumination with uniform illuminance as a whole.

When the partition plate 61 is provided, the range illuminated by each point light source becomes clear, but the periphery of the partition plate 61 becomes dark, and a dark shadow may occur on the illumination surface. Therefore, so that does not occur shadows in the illumination plane, without providing the partition plate between the point light sources 8 _{11-8 22} As shown in FIG. 12, the center portion of the casing 6B, a support for supporting the light conducting reflection plate 2B The part 7 may be erected vertically.
By not providing the partition plate 61, there are few things which block light in a casing, ie, the shadow which arises in the illumination surface of a partition plate periphery is lose | eliminated, and it becomes easy to obtain the illumination of uniform illumination intensity as a whole. Moreover, the member which comprises a casing can be decreased.

  Next, a surface illumination device according to Embodiment 5 of the present invention will be described with reference to FIG. Components having the same configurations as those of the first to third embodiments are denoted by the same reference numerals and description thereof is omitted. FIG. 13 is an exploded perspective view of the surface illumination device according to the fifth embodiment of the present invention.

According to the fifth embodiment of the present invention, the surface illumination device 100 of the present invention includes a housing 8, a plurality of surface illumination light source devices 10 ₁₁ to 10 ₃₃ arranged in a matrix in the housing 8, and a light conducting reflector. 2 and a diffusing plate 9 arranged at a predetermined interval. The surface illumination device 100 can configure a surface illumination device of a desired size by changing the number of surface illumination light source devices 10 to be used. In the present embodiment, the surface illumination device 100 is configured by using a total of nine 3 × 3 surface illumination light source devices 10, and a surface illumination device of 30 cm × 30 cm = 900 cm ² is obtained. Moreover, you may comprise the surface illumination apparatus 100 using the surface illumination light source device 10A in Example 3. FIG. In this case, the surface illumination light source device 10B has nine point light sources arranged in a matrix on the bottom plate portion.

  According to the fifth embodiment, it is possible to provide a surface illumination device capable of obtaining illumination light having substantially uniform luminance on the entire surface using the surface light source unit with a simple manufacturing process and at low cost.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can take various configurations without departing from the gist of the present invention. .
For example, the shape of the through hole of the light conducting reflection plate can be selected from a circular shape, an elliptical shape, a polygonal shape such as a triangular shape, a rectangular shape, a hexagonal shape, a narrow shape such as an arc shape or a zigzag shape. Various arrangements such as a matrix or a pile can be selected as necessary. Whether the central opening is set as a non-through hole, an arc-shaped through hole, a circular through hole, or other through holes may be selected and set according to the light reflectivity of the light conducting reflector.
In addition, the surface illumination device has been described as an example in which the shape of the casing is a square plane, but other polygons such as a triangle and a hexagon may be used, and a shape arranged in a matrix without a gap is preferable.

One surface light source unit 2 light conducting reflection plate 20 fitting hole 3 the central reflector portion 31 non-through holes 32 arc-shaped through hole 33 connecting portion 34 micropores 4 outer reflection section 41 circular holes 5,5 _{11-5 22} points source 10 Surface illumination light source device 6 Casing 60 Light source mounting hole 6a to 6d Side wall portion 6e Bottom surface portion 6f Opening portion 6g Claw 61 Partition plate 7 Support portion 100 Surface illumination device 8 Housing 9 Diffusion plate

Claims (18)

In a surface light source unit having a highly directional point light source and a light conducting reflection plate that is opposed to the point light source and arranged at a predetermined distance, and a surface facing the point light source is formed by a reflective surface.
The light conducting reflector is a high light reflectance and low light transmittance central reflecting portion having a predetermined area size centered on a point on the optical axis of the point light source, and an outer periphery of the central reflecting portion. With the outer reflection part in which the light transmittance is increased while decreasing the light reflectivity with increasing distance from the central reflection part,
The surface light source unit, wherein the central reflection portion and the outward reflection portion are formed of different members.   The central reflecting portion is formed of a central reflecting plate having a predetermined area, and the light conducting reflecting plate is formed with a fitting hole penetrating the light conducting reflecting plate in a region corresponding to the central reflecting portion. The surface light source unit according to claim 1, wherein the central reflector is fitted and coupled.   The light conducting reflection plate has a protrusion that protrudes from the end of the through-hole toward the center, and the central reflection portion has a fitting portion that is fitted to the protrusion. The surface light source unit according to claim 2.   The surface light source unit according to claim 1, wherein the central reflecting portion is provided with a fine hole smaller than the point light source.   The surface light source unit according to claim 1, wherein a high light reflectance member is attached to the central reflection portion on the point light source side.   2. The surface light source unit according to claim 1, wherein an opening penetrating the light conducting reflection plate is formed, and a diffusion member, a microlens, or a microprism for diffusing light is attached to the opening.   The surface light source unit according to claim 1, wherein a height of the central reflecting portion is higher than a height of the outer reflecting portion.   The surface light source unit according to claim 1, wherein the point light source is a single light emitting diode or an assembly of a plurality of light emitting diodes.   The light conducting reflector is formed of an ultrafine foaming resin, and the reflectance of the member is 95 to 99.8% and the light transmittance is 0.2 to 5%. The surface light source unit according to any one of the above. A surface illumination light source device comprising the surface light source unit according to any one of claims 1 to 9 and a casing,
One surface light source unit is disposed in the casing.   The casing includes a bottom surface portion to which the point light source is attached, a side wall portion erected vertically from an end portion of the bottom surface portion, and an opening portion facing the bottom surface portion, and the opening portion is the light conducting portion. The surface illumination light source device according to claim 10, wherein the surface illumination light source device is blocked by a reflecting plate. A surface illumination light source device comprising the surface light source unit according to any one of claims 1 to 9 and a casing,
A surface illumination light source device, wherein a plurality of the surface light source units are arranged in the casing.   The casing includes a bottom surface portion to which a plurality of the point light sources are attached, a side wall portion standing vertically from an end portion of the bottom surface portion, and an opening portion facing the bottom surface portion, The surface illumination light source device according to claim 12, wherein the surface illumination light source device is blocked by a light conducting reflection plate.   14. The surface illumination light source device according to claim 12, wherein all of the light conducting reflection plates attached to the surface illumination light source device are connected.   The surface illumination light source device according to any one of claims 12 to 14, wherein the casing includes a partition plate that stands vertically from the bottom surface part and partitions the point light sources.   The surface illumination light source according to any one of claims 12 to 14, wherein the casing includes a support member that is erected vertically from the bottom surface portion and supports the photoconductive reflector. apparatus.   The casing is formed of an ultrafine foaming resin, and the reflectance of the member is 95 to 99.8%, and the light transmittance is 0.2 to 5%. 2. The surface illumination light source device according to 1. A surface illumination device comprising the surface illumination light source device according to any one of claims 10 to 17, a housing, and a diffuser plate facing the surface illumination light source device and disposed at a predetermined interval. ,
One or more surface illumination light source devices are disposed in the housing.

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