JP4701334B2 - Surface illumination light source device and surface illumination device using the same - Google Patents

Description

  The present invention relates to a surface illumination light source device used for a display device such as an LCD backlight, an illumination signboard, an automobile or a vehicle, and a surface illumination device using the same.

  In the surface light source device according to Patent Document 1, at least one primary light source, a light incident end surface on which light emitted from the primary light source is guided and light emitted from the primary light source is incident, and guided light are transmitted. And a plate-shaped light guide having a light exit surface that emits light, and the light guide includes a light exit mechanism on both or one of the light exit surface and the back surface on the opposite side, and the light exit. And / or at least one local lens array forming portion on the front surface and / or the back surface, each of the local lens array forming portions including at least one local lens array, the local lens array being the primary light source. Is formed in a direction different from the direction of the peak light in the luminance distribution at the incident position of the maximum intensity light out of the light incident on the light incident end face, thereby eliminating luminance non-uniformity. Ah .

  The illumination type display device according to Patent Document 2 has an opening formed at one end, a lamp housing having a light source housing part whose inner wall is a light reflecting surface, and an illumination display provided on the back wall of the light source housing part A light-emitting diode that is a light source of the light source, and a display plate that is mounted on the front surface of the opening and has a light-transmitting shape for performing desired display, and the light-emitting diode and the display plate in the light source housing portion And a light guide for scattering incident light into a surface light source to form a contact surface with the inner wall portion of the light source accommodating portion, Processing is performed, and thereby, the illumination of a light source with strong directivity such as an LED is made uniform to improve the visibility of the display shape.

In other words, in Patent Document 2, the light from the light emitting diode is diffusely reflected by the textured inner wall surface and made uniform by the action of a diffusion film or the like.
Further, in Patent Document 3, reflection is repeatedly performed between reflected light from a minute reflecting portion in a diffusion layer formed on a light emission surface and a reflector provided around a light emitting diode (LED). Thus, it is disclosed that uniform light is obtained.

  Further, in Patent Document 4, directional light emitted from an LED (particularly strong light directly above the LED) is reflected to the LED side by a reflection portion formed on the radiation surface. Thus, it is disclosed that the light intensity from the LED is reduced by changing the direction of light to obtain uniform light.

JP 2002-343124 A JP 2003-186427 A JP 2005-284283 A JP 2006-12818 A

  The use of light-emitting diodes (LEDs) as a light source for display devices and lighting is considered from the viewpoint of low power consumption and heat generation. However, because LEDs have strong directivity, in order to obtain a uniform light quantity distribution over a wide area. Conventionally, a device as disclosed in the above-described patent document is required.

  However, in patent document 1, in order to equalize the light with strong directivity by LED, the LED light source is provided laterally with respect to the radiation direction. For this reason, a large space is required.

  In Patent Document 2, a predetermined thickness is required in the radiation direction of the LED. Further, there was no idea that the light scattered by the inner diffusion film was absorbed by the base plate and all the light from the LED was used.

  Moreover, in patent document 3, even if the reflecting plate is provided in the radiation | emission surface and the bottom face around LED, the reflecting plate is not provided in the side surface. For this reason, in a space surrounding the LEDs, it is impossible to obtain uniform illumination light while causing multiple reflections of light and utilizing light from all the LEDs.

  Furthermore, in patent document 4, it is an idea which tries to obtain uniform illumination by controlling the traveling path of the light from LED. That is, the reflection part on the radiation surface is used to change the traveling direction of light. However, this weakens the light intensity, and uniform light cannot be obtained using multiple reflection.

For this reason, the present invention uses a point light source with strong directivity, such as an LED, while using this light with high efficiency, without increasing the thickness in the radial direction of the LED, Surface illumination light source device and surface capable of obtaining uniform illumination light over a wide area without leaving a bright spot on the portion directly above the radiation-side reflecting means to be covered and without darkening the portion directly above The object is to provide a lighting device.

Therefore, the surface illumination light source device of the present invention has a casing having a bottom surface and a side surface with a predetermined area and an opening, an inner reflection means provided therein, and a point light source having strong directivity disposed at the center of the bottom surface,
A radiation-side reflecting means that covers the opening at a predetermined distance from the point light source and transmits and reflects light;
The inner reflection means and the radiation side reflection means have a reference line passing through the shortest distance between the point light source and the radiation side reflection means as a symmetry axis, and at least one of the reflection means is relative to the symmetry axis. It is formed with a flat or polyhedral reflector ,
The radiation-side reflecting means is opposed to the radiation side of the first radiation-side reflecting means with a certain distance from the first radiation-side reflecting means that transmits and reflects part of the light from the point light source. A second radiation-side reflecting means that is arranged and reflects and transmits a part of the light that has passed through the first radiation-side reflecting means,
The first radiation side reflection means includes a first reflection surface that reflects a part of the light from the point light source into the casing, and a first reflection surface that is opposite to the first reflection surface and reflects the light. The second radiation side reflection means reflects the light that has passed through the first radiation side reflection means and causes multiple reflection between the second reflection surface and the second reflection surface. And a reflective surface
The first reflecting surface of the first radiation side reflecting means has a predetermined area centered on the specific point and an outside of the central reflective portion when the intersection with the front reference line is called a specific point. An outer reflecting portion around the outer reflecting portion, and the outer reflecting portion is made of a reflecting member that transmits and reflects a part of light and has a predetermined reflectivity, and the central reflecting portion is a portion of the outer reflecting portion. It is characterized by being formed of a light transmissive reflecting portion having a reflectance higher than the reflectance .
In addition, at least one of the first and second radiation side reflecting means may be formed of a flat or polyhedral reflector with respect to the symmetry axis.
According to this configuration, even when a point light source with strong directivity such as an LED is used, the point light source is covered without increasing the thickness in the radiation direction of the LED while using this light with high efficiency. Uniform illumination light can be obtained over a wide area without leaving a bright spot in the portion directly above the radiation side reflection portion and conversely without darkening the portion directly above. In particular, by providing the first radiation side reflection means, the thickness of the surface illumination light source device in the radiation direction can be reduced. Further, the first radiation side reflection means and the second radiation side reflection means can convert the light of the point light source into a beam having a predetermined width and output a light beam having a predetermined width by the lens effect.

  Moreover, the surface illumination light source device of this invention WHEREIN: The said center reflection part shall be formed in the shape similar to the opening shape of the said casing.

  Further, in the surface illumination light source device according to the present invention, the outward reflecting portion is provided with a plurality of strip-like reflectors having a narrow width as the distance from the central reflecting portion of the shape increases with a predetermined gap. can do. According to this embodiment, uniform illumination light can be obtained at the outward reflecting portion.

  Further, in the surface illumination light source device according to the present invention, the central reflecting portion is formed in a circular or rectangular shape centered on the specific point, and the outer reflecting portion has a width as the distance from the central reflecting portion of the shape increases. A plurality of annular reflectors having a narrow length may be provided with a predetermined gap. According to this embodiment, uniform illumination light can be obtained at the outward reflecting portion.

  Moreover, the surface illumination light source device of this invention WHEREIN: The said gap | interval shall be formed so that the gap | interval width | variety becomes wide as it distances from the said center reflection part. According to this embodiment, uniform illumination light can be obtained at the outward reflecting portion.

  In the surface illumination light source device of the present invention, the central reflecting portion may be provided with a slit or an opening in a part thereof, or may be formed thin. According to this embodiment, a spot is not left in the central reflecting portion, and the central reflecting portion is not darkened.

  Further, in the surface illumination light source device of the present invention, each of the central reflection portion and the outer reflection portion is formed of a reflection dot, and the density distribution of the reflection dots of the central reflection portion is determined by the density of the reflection dots of the outer reflection portion. It can be higher than the distribution.

  Moreover, the surface illumination light source device of this invention WHEREIN: The said inner side and side surface reflection part shall be an ultrafine foaming light reflection member, and the said radiation | emission side reflection part shall be an ultrafine foaming light reflection member. According to this embodiment, even when a highly directional point light source such as an LED is used, the light emitted from the point light source can be used with a high efficiency of 94%, for example.

  Further, in the surface illumination light source device of the present invention, the inner and side reflecting portions are ultrafine foamed light reflecting members, and the radiation side reflecting portion is a coating film containing fine particles of titanium white or polytetrafluoroethylene. can do. According to this embodiment, light emitted from a highly directional point light source such as an LED can be used with a high efficiency of 93%, for example.

  Also, in the surface illumination light source device of the present invention, the inner and side reflecting portions are coating films containing fine particles of titanium white or polytetrafluoroethylene, and the radiation-side reflecting portions are coating films containing fine particles of polytetrafluoroethylene. It can be assumed that According to this embodiment, light emitted from a highly directional point light source such as an LED can be used with high efficiency of, for example, 90% or more.

  In the surface illumination light source device of the present invention, the second radiation-side reflecting means may have a plurality of fine holes having a diameter of 10 μm or more and 100 μm or less dispersed therein.

  In the surface illumination light source device of the present invention, the second radiation side reflecting means may be constituted by a half mirror.

  In the surface illumination light source device according to the present invention, the second radiation side reflection means may be a light diffusing plate.

  In the surface illumination light source device of the present invention, the second radiation side reflecting means may be formed of a light diffraction structure.

  Further, in the surface illumination light source device of the present invention, the casing is provided with a plurality of the point light sources, and the radiation-side reflecting means according to claim 1 is provided directly above each of the point light sources. Can be. According to this embodiment, it is possible to configure a surface illumination light source device that generates uniform illumination light by arranging a plurality of point light sources.

According to the invention relating to these surface illumination light source devices, even if a point light source with strong directivity is used, this light is used with high efficiency, and without increasing the thickness in the radial direction of the point light source, Uniform illumination light can be obtained over a wide area without leaving a bright spot in the portion directly above the radiation-side reflecting portion covering the point light source, and conversely, without darkening the portion directly above. In particular, by providing the first radiation side reflection means, the thickness of the surface illumination light source device in the radiation direction can be reduced. Further, the first radiation side reflection means and the second radiation side reflection means can convert the light of the point light source into a beam having a predetermined width and output a light beam having a predetermined width by the lens effect. Furthermore, it is possible to configure a surface illumination device that generates uniform illumination light by arranging a plurality of surface illumination light source devices.

It is a schematic block diagram of the surface illumination light source device of this invention. It is a schematic explanatory drawing which shows the structure of the radiation | emission side reflection part of 1st Embodiment. It is a schematic explanatory drawing which shows the structure of the radiation | emission side reflection part of 1st Embodiment. It is a figure which shows the relationship between the reflectance of a radiation side reflection part, and illumination intensity. It is a figure which shows the relationship between the reflectance of a radiation side reflection part, and illumination intensity. It is a figure which shows the relationship between the light quantity and the reflectance of the transmitted light in A point same as the above. It is a figure which shows embodiment which provided the center light transmissive part in the radiation | emission side reflection part. (A), (b), (c) is the schematic explanatory drawing which showed the structure of the radiation | emission side reflection part of 2nd Embodiment, respectively. (A), (b) is the schematic explanatory drawing which showed the structure of the radiation | emission side reflection part of 3rd Embodiment, respectively. It is the schematic explanatory drawing which showed the structure of the radiation | emission side reflection part of 4th Embodiment. It is the schematic explanatory drawing which showed the structure of the radiation | emission side reflection part of 5th Embodiment. (A) shows 6th Embodiment, The schematic plan view which showed the structure of the surface illuminating device, (b) is the front view. It is the schematic explanatory drawing which showed the structure of the surface lighting apparatus of 7th Embodiment. It is a longitudinal cross-sectional view of the surface illumination light source device of 8th Embodiment. (A) is the Example top view of the strip | belt-shaped surface illumination light source device of 9th Embodiment, (b) is the longitudinal cross-sectional view. It is the schematic of what curved the strip | belt-shaped surface illumination light source device of 10th Embodiment. It is the schematic of what curved the strip | belt-shaped surface illumination light source device of 11th Embodiment in S shape. (A) is a perspective view of what applied the strip | belt-shaped surface illumination light source device of 12th Embodiment, (b) is the cross-sectional side view, (c) is the front view. (A) is a top view of the polygonal surface illumination light source device of 13th Embodiment, (b) is a top view of other embodiment of a surface illumination light source device, (c) is a surface illumination light source device. Furthermore, the cross-sectional top view of other embodiment, (d) is the top view. It is a top view of the film which has a slit of 14th Embodiment. (A) is a sectional plan view of a surface illumination light source device having a plurality of light sources, (b) is a QQ sectional view thereof, (c) is a plan view thereof, and (d) is a QQ line. It is a figure which shows the light intensity of. (A) is the longitudinal cross-sectional view of the polygonal surface illumination light source device of 14th Embodiment, (b) is the top view. It is a longitudinal cross-sectional view which shows the surface illumination light source device of 17th Embodiment. (A) is a top view of the 2nd radiation | emission side reflection means, (b) is a longitudinal cross-sectional view of an inner side reflection means, (c) is a modification longitudinal cross-sectional view of an inner side reflection means. (A) is the longitudinal cross-sectional view of the surface illumination light source device of 18th Embodiment, (b) is the cross-sectional top view. It is a longitudinal cross-sectional view of the surface illumination light source device of 19th Embodiment. (A) is the schematic longitudinal cross-sectional view which changed the shape of the reflector and the radiation | emission side reflection means, (b) is the perspective view, (c) is the perspective view of the 2nd radiation | emission side reflection means, (d). These are perspective views of a 1st radiation | emission side reflection means, (e) is a perspective view of a reflector. It is a longitudinal cross-sectional view which shows the surface lighting apparatus of 20th Embodiment. This is an arrangement of the structure introduced in FIG. (A) is a sectional plan view of an arrangement of surface illumination light source devices, (b) is a perspective view thereof, (c) is a view showing a modification of a partition wall, and (d) is a perspective view thereof. It is operation | movement explanatory drawing of a 2nd radiation | emission side reflection means. (A) is action explanatory drawing of the modification of a 2nd radiation | emission side reflection means, (b) is the elements on larger scale. It is another modified example operation explanatory drawing of the 2nd radiation side reflection means. It is another modified example operation explanatory drawing of the 2nd radiation side reflection means. It is a longitudinal cross-sectional view which shows the surface illumination light source device of 22nd Embodiment. It is operation | movement explanatory drawing of a 2nd radiation | emission side reflection means. (A)-(d) is explanatory drawing of the opening pattern of the 1st radiation | emission side reflection means put into practical use, respectively.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, for example, the surface illumination light source device 1 according to the present invention includes a light emitting source 2 having a strong directivity that is a light emitting diode group composed of one light emitting diode or a plurality of light emitting diodes, and radiation of the light emitting source 2. The light guide 3 has a radiation surface 3A in the direction, and the casing 4 surrounds the light source 2 and closes the light guide 3 other than the radiation surface. An inner reflecting portion 5 as an inner reflecting means is provided in the entire space between them, and a radiation side as a radiation side reflecting means for reflecting light from the light emitting source 2 which is a feature of the present application at a predetermined ratio on the radiation surface 3A. The reflection part 6 is provided.

The inner reflection part 5 and the radiation side reflection part 6 are made of a material with little light absorption. This point is common to all the following embodiments.
As described above, the casing 4 has the inner reflection portion 5 on the bottom surface and the side reflection portion (not shown) on the side surface, so that the light emitted from the light source 2 is absorbed by these reflection portions. Multiple reflection without being performed. Thereby, it has the structure which can obtain uniform illumination light using substantially all the light radiated | emitted from the light emission source 2. FIG.

Further, the casing 4 may have a shape in which the side surface expands upward as shown in FIG. 19C, for example, in addition to the side surface extending vertically upward.
The light source 2 is a concept including a light emitting diode and a laser diode (LD). Further, as described above, the light emitting source 2 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.

  Further, FIG. 1 shows the case where one light emitting source 2 is arranged in the casing 4, but the present invention is not limited to this, and a plurality of light emitting sources 2 may be arranged in the casing 4. The arrangement of the light emitting sources 2 in this case may be a matrix arrangement, or may be a point symmetrical arrangement with respect to one light emitting source 2 arranged in the center (FIG. 16 to be described later). reference). Moreover, even when a plurality of light emitting sources 2 are arranged in the casing 4, uniform surface illumination can be obtained without arranging the light emitting sources 2 closely.

By the way, the size of the casing 4 and the shape of the radiation side reflection part 6 are important factors for obtaining uniform illumination of the radiation side reflection part 6.
Therefore, the inventor conducted an experiment using, for example, a rectangular parallelepiped having a size of the casing 4 of 10 cm × 10 cm × 1.5 cm (height), and an LED that emits light of 64 lm at approximately 1 W. In this case, the shape of the radiation side reflection part 6 was implemented by something similar to the shape of FIG.

  Moreover, as the inner reflection part 5 and the radiation side reflection part 6, an ultrafine foamed light reflection plate (trade name MCPET) was used. And the diffuser was arrange | positioned on the radiation | emission side, the influence by the shape of the radiation | emission side reflection part 6 was remove | excluded, and the illumination intensity was measured as uniform light. Then, an illuminance of 6000 lux was obtained. This means that 94% of the light emitted from the LED could be used.

  Next, the inventor conducted an experiment using the above-described ultrafine foamed light reflecting plate as the inner reflecting portion 5. In this case, an emulsion of titanium white fine particles used as the radiation-side reflecting portion 6 was used. The shape of the radiation side reflection part 6 was implemented by screen printing and similar to the shape of FIG.

Thus, when the illuminance was measured by making the light uniform, an illuminance of 5830 lux was obtained. This means that 91% of the light emitted from the LED could be used.
Furthermore, when the inventor used polytetrafluoroethylene fine particles (trade name G-80 Hallon) for the radiation-side reflecting portion 6, an illuminance of 5950 lux was obtained. This means that 93% of the light emitted from the LED could be used.

  Even when fine particles of titanium white or polytetrafluoroethylene were used as the inner reflecting portion 5, 90% or more of the light emitted from the LED could be used.

That is, according to the surface illumination light source device 1 of the present embodiment, uniform illumination light can be obtained while using almost 90% or more (nearly 100%) of the light emitted from the LED.
In the following description of the embodiments, the same reference numerals in the drawings denote the same and the same effects, and therefore the description may be omitted.

(First embodiment)
2A and 2B show the radiation side reflection section 6 of the present embodiment. 2A and 2B, for example, the radiation-side reflecting unit 6 includes a central reflecting unit 6A that reflects light traveling straight forward from the light emitting source 2 within a predetermined range inside the light-transmitting substrate 9. ing. As the light transmissive substrate 9, a highly transparent plastic plate such as a glass plate or acrylic resin is used, for example. The light transmission substrate 9 is coated with a uniform reflection / transmission film. For example, titanium oxide or magnesium nitride is used as the reflection / transmission film.

  FIG. 2C shows the light distribution when the light absorption is small and the reflectance R is 0% to 50% and 75% as the properties of the coating film. FIG. 2D shows the light distribution when the light absorption is small and the reflectance R is 98% to 99.3% as the properties of the coating film.

  According to FIG. 2C, when the reflectance R is 0% to 50%, the illuminance directly above the light source 2 is locally high, and when the reflectance R is 75%, it is slightly relaxed. Furthermore, according to FIG. 2D, when the reflectance R is set to 98% to 99.3%, the distribution of light transmitted at the peripheral portion A of the light emitting source 2 can have a flat characteristic. However, a bright spot remains in the center.

FIG. 2E shows the relationship between the amount of transmitted light and the reflectance R at the peripheral point A in FIG. 2D.
As can be seen from FIG. 2E, the amount of light increases as the reflectance R increases.

  Further, in order to effectively use the above-described bright spot light, more light can be reflected on the light emitting source 2 side using the central reflecting portion 6A, and the uniformity of the light can be improved. However, since the center reflection portion 6A becomes dark when the reflectance of the center reflection portion 6A is too high, the center reflection portion 6A is preferably made of a member with a little transmittance and a small light absorption. Alternatively, a small light transmission part is formed in the central part of the central reflection part 6A, or a film is formed thinly so as to increase the uniformity of light.

Here, by experiment, the illuminance by uniform light was measured when the diffuser was arranged on the radiation surface side of FIG. 2A to form the central reflecting portion 6A.
In this case, the casing 4 was a rectangular parallelepiped having a size of 10 cm × 10 cm × 1.5 cm (height), and an ultrafine foamed light reflecting plate (trade name MCPET) having a reflectance of 88% was used as the coating film. Further, the diameter of the central reflecting portion 6A was set to Φ10, and a + -shaped slit (transmitting portion) was further provided in the central portion. Further, as the light emitting source 2, an LED that emits light of 43 lm was used.

As described above, a uniform surface illumination light source device 1 of 4010 lux can be obtained. This means that 93% of the light emitted from the light source 2 could be used.
As a result, the amount of light at the central portion radiated from the light emitting source 2 with high directivity can be limited, and further, the overall amount of light can be secured by the light reflected by the inner reflecting portion 5, so that uniform illumination light can be obtained. Can do. In FIG. 2A, the case where the central reflecting portion 6A is formed inside the light transmitting substrate 9 has been described. However, the present invention is not limited thereto, and the central reflecting portion 6A may be formed outside the light transmitting substrate 9, for example.

  Further, as shown in FIG. 2F, a central light transmission part 6C may be provided in the central part of the central reflection part 6A. The central light transmission portion 6C may be a complete opening having a predetermined diameter, or may be formed to have a predetermined transmittance. In the case of a complete opening, the increase / decrease in the amount of light at the central portion can be adjusted by adjusting the size of the diameter.

  Further, the center reflecting portion 6A may be a well-known optical reflecting plate attached to the radiation surface 3A, or may be formed by depositing an optical reflecting film when the light guide 3 is formed. The manufacturing method is not particularly limited.

Further, the radiation-side reflecting portion 6 may be a light diffusion plate such as ground glass. In this case, the configuration is substantially the same as in FIG.
In addition, said light guide 3 can be comprised by optical glass, for example. Moreover, plastics with good transparency such as acrylic resin can be used. Furthermore, by using a flexible transparent plastic such as silicon resin, a surface illumination light source device having a curved surface partially or entirely can be realized as shown in the embodiments described later. Further, a gas or a liquid may be used. The reflective film can be easily formed by applying a known mirror surface forming resin or paint. Therefore, for example, it is suitable for a large-area advertising display device installed on the wall surface of a building. Since material costs, ease of processing, and high accuracy are not required, there is an effect that production can be performed at low cost.

(Second Embodiment)
3A to 3C show the radiation-side reflection unit 6 of the present embodiment.
As shown in FIG. 3 (a), the radiation-side reflecting portion 6 is concentric with a circular central reflecting portion 6A provided on the light guide 3 and a predetermined distance outward from the central reflecting portion 6A. A plurality of ring-shaped outward reflecting portions 6B arranged in the inner space. As a result, the outward light transmission portions 7 are formed at predetermined intervals. Further, the central reflecting portion 6A is a circular reflecting plate or reflecting film provided on the radiation surface 3A, and the outer reflecting portion 6B is a predetermined interval from the circular reflecting plate or reflecting film. It is an annular reflecting plate or reflecting film formed concentrically on the film.

  In the present embodiment, the width of the reflecting plate or the reflecting film constituting the outer reflecting portion 6B is formed so as to become narrower toward the outside. As a result, the amount of light transmitted through the central portion with a large amount of light can be limited and the amount of light transmitted outside can be increased, so that the illumination light can be made more uniform.

  Further, in FIG. 3B, as in the first embodiment, a central light transmitting portion 6C having a predetermined range may be provided in the central portion of the central reflecting portion 6A. As a result, the same effects as those of the first embodiment can be obtained.

  Further, as shown in FIG. 3C, when the casing 4 has a square shape in plan view, the central reflecting portion 6A is an elliptical reflecting plate or reflecting film provided on the radiation surface 3A. Further, the outer reflection portion 6B is an elliptical reflection plate or reflection film formed concentrically with the reflection plate or reflection film at a predetermined interval from the elliptical reflection plate or reflection film. In addition, when the casing 4 has a square shape in plan view, an arc-shaped reflecting member 5 ′ that reflects light toward the center of the casing 4 is disposed at an inner corner of the casing 4. Thereby, light can be reflected all the way to the opposite corners of the casing 4. Other configurations are the same as those of the first embodiment.

(Third embodiment)
4 (a) and 4 (b) show the radiation side reflection section 6 of the present embodiment.
As shown in FIG. 4A, the radiation-side reflecting portion 6 includes a rectangular central reflecting portion 6A formed in a shape similar to the shape of the casing 4 provided on the light guide 3, and the central reflecting portion 6A. A plurality of rectangular ring-shaped outer reflecting portions 6B arranged at predetermined intervals from the outside. Moreover, the outward light transmission part 7 is thereby formed at a predetermined interval.

  Further, the central reflecting portion 6A is a reflecting plate or reflecting film provided on the radiation surface 3A and formed in a similar shape to the casing 4, and the outer reflecting portion 6B is formed on the reflecting plate or reflecting film at a predetermined interval. It is the strip | belt-shaped reflecting plate or reflecting film which was made.

  Thereby, according to the shape of the casing 4, it is possible to limit the light transmission amount in the central portion with a large amount of light and to increase the light transmission amount on the outside, so that the illumination light can be made more uniform.

  Further, in FIG. 4B, similarly to the first embodiment, the central reflection portion 6A may be provided with a light transmission portion 6C having a predetermined range at the central portion. As a result, the same effects as those of the first embodiment can be obtained.

(Fourth embodiment)
In FIG. 5, the radiation side reflection part 6 of this embodiment is shown.
In the present embodiment, the radiation-side reflecting portion 6 is a cone-shaped reflector 8 having a predetermined apex angle that is formed in the radiation surface 3 </ b> A on the front surface of the light emitting source 2. The reflector 8 preferably has a cone shape that can be reflected uniformly or a pyramid shape that is similar to the casing shape. Further, by appropriately setting the apex angle, the light emitted from the light source to the radiation surface in a substantially straight line can be totally reflected or partially reflected. As a result, the same effects as those of the first embodiment described above can be obtained.

(Fifth embodiment)
In FIG. 6, the radiation side reflection part 10 of this embodiment is shown.
In this embodiment, the radiation side reflection part 10 is formed with the reflective dot which consists of reflecting members. The radiation-side reflecting section 10 is configured by a central-side reflecting section 10A configured by high-density distribution reflecting dots and an outer reflecting section 10B configured by reflecting dots having a density distribution lower than that of the center-side reflecting section 10A. As a result, the same effects as those of the first embodiment described above can be obtained.

(Sixth embodiment)
FIGS. 7A and 7B show an embodiment of a surface illumination device 20 formed by arranging a plurality of surface illumination light source devices 1. Fig.7 (a) is a top view of the surface illumination apparatus 20, FIG.7 (b) is the front view.
That is, the surface illumination device 20 is formed by arranging a plurality of the surface illumination light source devices 1 of the first to fifth embodiments described above so as to have a desired size. In this case, in order to improve the uniformity of the illumination distribution of the surface illumination device 20, the light diffusion plate 30 is arranged on the front surface of the surface illumination light source device 1 arranged.

(Seventh embodiment)
FIG. 8 shows another embodiment of the surface illumination device 20 ′.
In this embodiment, a honeycomb-shaped surface illumination device 20 ′ is configured by arranging a plurality of regular hexagonal surface illumination light source devices 1 ′.
That is, the light guide 3 of the surface illumination light source device 1 of the first to fifth embodiments described above is formed in a regular hexagonal column. Corresponding to this, a regular hexagonal casing 4 is formed to form a regular hexagonal column-shaped surface illumination light source device 1 'as a whole .

(Eighth embodiment)
FIG. 9 is a longitudinal sectional view of the surface illumination light source device 1 of the present embodiment and an explanatory diagram of its characteristics.
As already described with reference to FIG. 1, light is output from the light source 2 such as an LED. The plane 50 is irradiated with this light. Since the light emitting source 2 has a sufficiently small area when viewed from the plane 50, it can be regarded as a point light source. The flat surface 50 is disposed at a location away from the light emitting source 2 by a predetermined distance. The surface illumination light source device 1 has a function of irradiating the entire plane 50 as uniformly as possible. The distance between the surface illumination light source device 1 and the plane 50 is arbitrary.

  For example, an image or the like to be illuminated may be drawn at the position of the plane 50. In addition, a reflector for indirect illumination may be placed at the position of the plane 50. Furthermore, a hood that is a milky white translucent panel and irradiates the opposite side of the surface illumination light source device 1 may be placed at the position of the plane 50. Set the optimum distance according to the case. In either case, it is desirable that light be emitted with a uniform light intensity over as large an area as possible.

  Here, when the light emitted from the light emitting source 2 is directly received on the plane 50, the received light intensity distribution on the plane is shown in the upper part of the figure. The middle figure shows the distribution when there is no central reflecting portion 6A or outward reflecting portion 6B. The upper diagram shows the distribution when there is a central reflecting portion 6A and an outward reflecting portion 6B. In either case, the vertical axis of the graph represents the received light intensity, and the horizontal axis represents the position on the plane.

  In the middle graph, the received light intensity has a maximum value at the reference point 59 at the shortest distance from the light emitting source 2 and has a characteristic that gradually decreases with increasing distance from the reference point 59. When the light guide 3 is not provided, such a state is obtained when a directional light source 2 such as an LED is used.

  The light guide 3 has a radiation surface 3A substantially parallel to the plane 50 and a back surface 52 substantially parallel to the radiation surface 3A. Furthermore, it has the side surface 53 arrange | positioned at the outer periphery so that 3 A of radiation surfaces and the back surface 52 may be enclosed. The light guide 3 is provided in a closed space surrounded by the radiation surface 3 </ b> A, the back surface 52, and the side surface 53. The light guide 3 is made of optically transparent glass, plastic, or the like. Gas or liquid may be used.

  The central reflecting portion 6A and the outward reflecting portion 6B are radiation side reflecting means. The radiation side reflection means is disposed on the radiation surface 3A and has a function of reflecting light propagating through the light guide 3 toward the back surface 52 or the side surface 53. In addition, the light guide 3 is comprised by the square of 10 cm, for example. At this time, in order to efficiently emit light from the radiation surface 3 </ b> A, it is preferable that a favorable reflection surface is also formed on the side surface 53.

  The inner reflection unit 5 is disposed on the back surface 52 and reflects light propagating through the light guide 3 toward the radiation surface 3 </ b> A or the side surface 53. Here, the intersection of the reference line 58 connecting the light emitting source 2 and the reference point 59 on the plane 50 and the radiation surface 3 </ b> A is referred to as a specific point 51. At this time, it is preferable that the central reflecting portion 6 </ b> A is a circular or regular polygonal reflector including the specific point 51 and centering on the specific point 51. This is because when light is directly emitted from the light emitting source 2 to the plane 50, the light intensity shows a sharp peak only at that portion. Therefore, when the brightness of the reference point 59 should be suppressed, the configuration shown in FIGS. 3A and 4B is most preferable. In addition, when the local brightness of the reference point 59 does not become a problem, the other embodiments described above may be used.

  Moreover, it is preferable that the outward reflection part 6B consists of a reflector which surrounds the center reflection part 6A, and has a slit group parallel to the circular arc or the side of a regular polygon. The slit may be continuous or discontinuous. In the embodiment shown in FIGS. 3 and 4, a large number of continuous annular slits are arranged. For example, when it is installed outdoors, there is a concern about the deterioration of the outer reflecting portion 6B due to ultraviolet rays or solar heat. At this time, if the portion where the light is emitted is made into a slit, the strength of the outer reflection portion 6B is increased, and the dropout and deformation can be sufficiently prevented.

  In addition, the opening provided in the reflection part may be sufficient as a slit, and a slit-shaped transparent body may be sufficient as it. Any gap that allows light to pass through may be used. In the following embodiments, description will be made by referring to all gap-like portions through which light is transmitted as slits.

  In this embodiment, by providing the outer reflection portion 6B and the center reflection portion 6A, the light intensity near the reference point 59 on the plane 50 is suppressed and reaches the periphery as shown in the upper part of FIG. Until, almost uniform light is emitted.

(Ninth embodiment)
10A and 10B show an embodiment of the surface illumination light source device 1. FIG. 10A is a plan view thereof, and FIG. 10B is a schematic view of a cross section taken along the line NN.
The surface illumination light source device 1 has a symmetrical structure with respect to a straight line 68 passing through a specific point 51 at the center thereof. Further, a strip-shaped light guide 3 that is long in a direction orthogonal to the straight line 68 is used. A rectangular reflector 63 that is symmetrical with respect to the straight line 68 is provided at the center. This corresponds to the central reflecting portion. A reflector 64 is provided so as to sandwich the reflector 63 therebetween. The reflector 64 has a slit group 65 parallel to the straight line 68. The reflector 64 is equivalent to the outward reflection part of the previous embodiments. In the illustrated example, the width of the reflector 64 becomes narrower as the distance from the central straight line 68 increases.

  On the other hand, the width of the slit 65 increases as the distance from the central straight line 68 increases. Thereby, the light of flat intensity can be radiated as a whole. In the case of this embodiment, since the shape of the reflector is simple, it can be manufactured easily and inexpensively. In addition, a light source that emits light that is robust and linear in the longitudinal direction can be realized. In addition, when using a strip | belt-shaped light guide, reflection of the light in the side surface 69 is very important. It is preferable to arrange a reflector having a good reflectance on the side surface 69. Further, the end face 61 is also efficient when a good reflecting surface is provided.

(Tenth embodiment)
FIG. 11 shows another embodiment of the surface illumination light source device 1.
FIG. 11 is a perspective view of a curved surface illumination light source device 1, for example.
If the light guide 3 described above is formed of a flexible plate-like body such as transparent plastic, it can be freely curved as shown in FIG. Therefore, for example, it can be attached to a curved surface such as a column and used as a linear light source or a strip light source. Similarly, the surface illumination light source device 1 described in the other embodiments can be used by being curved along an arbitrary curved surface when configured by a flexible plate-like body. Of course, a curved light guide may be manufactured by molding a hard material with a mold or the like.

(Eleventh embodiment)
FIG. 12 shows still another embodiment of the surface illumination light source device 1.
In this embodiment, the surface illumination light source device 1 has a strip shape curved in an S shape on a flat surface as a whole. The light guide 3 is not limited to the S shape, and may be curved in any way. Further, various shapes of the light guide 3 can be used in combination. This can be widely used for neon signs, for example.

(Twelfth embodiment)
FIGS. 13A and 13B show an embodiment in which the band-shaped surface illumination light source device 1 is applied.
In this embodiment, the surface illumination light source device 1 is formed by using a light guide 3 having a three-dimensional shape of an alphabetic letter A.
The surface illumination light source device 1 includes six point light sources 2, a light guide 3 that forms the letter A of the alphabet, and a light diffusion plate 30. Further, for example, the reflectors 63 and 64 shown in FIGS. 10A and 10B described above are provided on the radiation surface 3A of the light guide 3. When such a light guide 3 is used, the reflection of light at the side surface 69 is very important. It is preferable to arrange a reflector having a good reflectance on the side surface 69. Further, it is preferable to provide a good reflection surface for the end surface 61 as well.

  In addition, as shown in FIG.13 (c), you may divide between the adjacent point light sources 2 by the partition 115 as a reflecting plate, and you may divide into six blocks. This is because the partition walls 115 can collaborate with the reflectors 63, 64 and the like to multiplexly reflect the light from the point light source 2 and emit uniform light.

  In this embodiment, the light guide 3 has been described by taking a three-dimensional alphabet letter A as an example. However, the light guide 3 is not limited to this, and for example, other characters, figures, or symbols are three-dimensionalized to obtain a surface illumination light source The device 1 can also be used.

  According to the present embodiment, it can be widely applied to various signboards, vehicle interior lighting, traffic signs, information boards, and the like.

(13th Embodiment)
FIG. 14A is a plan view of an embodiment of the polygonal surface illumination light source device 1 in which a plurality of point light sources 2 are arranged.
In this embodiment, the surface illumination light source device 1 can be comprised by the polygon of various shapes, for example. Combining shapes such as a right triangle, square, hexagon, etc., it can be used as an illumination or light source device that covers the entire wall surface of a building or the like.

  A solid line 72 on the wall 71 shown in FIG. 14A is a boundary of the single surface illumination light source device 1. In this case, the point light sources 2 are respectively provided at the center positions of regular hexagons. And the continuous line 72 is a partition as a reflecting plate. In addition, this partition is provided in order to obtain more uniform illumination light. However, uniform illumination light can be obtained practically without this partition.

FIG. 14B is a plan view of another embodiment of a polygonal surface illumination light source device 73 in which a plurality of point light sources 2 are arranged.
As shown in FIG. 14B, for example, the surface illumination light source device 73 may be configured by combining six equilateral triangles with the above-described partition walls as the reflecting plates. In this case, the point light source 2 is provided at the center position of the equilateral triangle. Moreover, in this embodiment, the radiation side reflection part 6 is formed corresponding to six equilateral triangular surfaces. By this radiation side reflection part 6, the slit 74 is formed linearly and discontinuously. In this way, as already described, since it is a regular hexagonal structure (honeycomb structure), the strength is high and the manufacture is also easy.

  FIGS. 14C and 14D are sectional plan views of the surface illumination light source device 1 of still another embodiment. FIG. 14C shows a state in which the radiation side reflection portion 6 is removed from FIG. 14D.

  This surface illumination light source device 1 is divided into a plurality of equilateral triangular partitions 72 as reflecting plates. Further, the point light sources 2 are respectively provided at the center positions of the equilateral triangular partition walls 72. Moreover, as shown in FIG.14 (d), the radiation | emission side reflection part 6 which has a predetermined pattern is formed for every part partitioned off by the partition 72 of an equilateral triangle.

(Fourteenth embodiment)
FIG. 15 is a plan view of the film 80 having the slits 81.
In the present embodiment, for example, the film 80 is attached on the radiation surface 3A of the light guide 3 shown in FIG. The film 80 is, for example, a plastic film such as polyethylene or polycarbonate, and may be attached to the radiation surface 3A by heat or an adhesive. The film 80 has a large number of slits 81. The back surface may be a reflective film such as an aluminum laminate film. It is for making said multiple reflection. These slits 81 are preferably provided on a concentric arc surrounding the specific point 51 (see FIG. 9) in the center on the radiation surface 3A. Further, the slit 81 may have a linear shape substantially parallel to an arbitrary polygonal side surrounding the specific point 51.

  If a large number of wide slits 81 are provided in the film 80, wrinkles are generated in the film 80, which requires careful handling. Therefore, for example, a portion where the slit 81 is to be provided is a transparent or translucent film 80, and the other portion is a reflective film. Thereby, the strength of the film 80 is improved. Moreover, handling of the film 80 becomes easy and productivity is improved. Note that, as described above, the reflector that reflects light may not only reflect all incident light. The reflectance may be set to a predetermined value by an absorber that partially absorbs and an irregular reflector that diffusely reflects.

  These may be appropriately distributed on the radiation surface 3A. In addition, there is a film that reflects part of the light and transmits the remaining part. The film having this film may be arranged so that the portion close to the specific point 51 is stacked in multiple layers, and the number of laminated films decreases as the distance from the specific point 51 increases. That is, a laminate of reflective films may be used.

(Fifteenth embodiment)
FIGS. 16A to 16D are schematic explanatory views of a surface illumination light source device 90 having a plurality of light sources 91.
FIG. 16A is a plan view of the light guide 3. Here, illustration of the outward reflection part 6B and the center reflection part 6A shown in FIG.
The inner reflection portion 5 is disposed on the back surface 52 and the side surface 53 and has a reflection surface that reflects light propagating through the light guide 3 toward the radiation surface 3 </ b> A or the side surface 53. As a result, the light emitted from the light emitting source 91 is multiple-reflected without being absorbed by these reflecting surfaces. In this way, a structure in which uniform illumination light can be obtained using substantially all of the light emitted from the light emitting source 91 is obtained.

  As shown in the drawing, the surface illumination light source device 90 is provided with five point light sources 91. This QQ cross-sectional view is shown in FIG. In the present embodiment, five point light sources 91 are arranged point-symmetrically at a portion corresponding to the back surface of the light guide 3. Note that the number of point light sources 91 is not limited to five, and, for example, a large number of point light sources 91 may be arranged in a matrix.

Further, as shown in FIG. 19C to be described later, the side surface 53 may have a shape that widens upward.
At this time, it is preferable to use the pattern 95 designed for one point light source by superimposing the pattern 95 designed for one point light source as shown by the arrows in the drawing. In this case, if the originals are superimposed as they are, the amount of light radiated to the outside as a whole is reduced. Therefore, it is preferable to realize a light source having a bright and uniform brightness by making the slit width wider than that of a single case.

  FIG. 16C is a plan view of the surface illumination light source device 90 described above. In this embodiment, as the radiation-side reflecting portion 6, a circular central reflecting portion 6A provided on the light guide 3, and a plurality of ring shapes concentrically arranged at predetermined intervals outward from the central reflecting portion 6A. The outer reflection part 6B is provided. Thereby, the outward light transmission portions 7 are formed at predetermined intervals. In addition, although the radiation side reflection part 6 demonstrated as an example the circular thing, it is not restricted to this, For example, a belt-like thing may be sufficient.

FIG. 16D is a graph of the same format as that shown in the upper part of FIG. 9 and shows the light intensity on the QQ line in FIG. The points y and z on the horizontal axis are the positions of the point light source 91.
According to the present embodiment, by combining the light from the plurality of point light sources 91, a very flat characteristic X is obtained over a wide area.

(Sixteenth embodiment)
FIG. 17A is a longitudinal sectional view of the surface illumination light source device 90 of the present embodiment, and FIG. 17B is a plan view thereof.
In the present embodiment, the light guide 3 of the surface illumination light source device 90 is dry air. And the glass plate 96 is arrange | positioned so that the whole radiation surface of the upper surface of the light guide 3 may be covered. This is a plate-like transparent body. The point light source 91 is disposed on the central bottom surface of the light guide 3. A reflective film 97 is formed on the surface of the glass plate 96 facing the point light source 91 by vapor deposition of silver or the like. The thickness of the reflective film 97 is adjusted so that the portion corresponding to the specific point closest to the point light source 91 is the thickest and becomes thinner as the distance from the specific point increases.

  As shown in FIG. 17B, the reflection film 97 is elliptical because the glass plate 96 is not circular and is not equidistant from the point light source 91, so the reflection film 97 is also adapted to this. It is. In this way, the light can be made uniform by making it rectangular or elliptical according to the shape of the glass plate 96. By making the reflection film 97 an ellipse, for example, when a plurality of surface illumination light source devices 100 are arranged, the light overlaps and becomes dense in the short side direction, and conversely, the brightness becomes uniform in the long side direction. There is a risk of not becoming.

  Further, when the reflection film 97 is composed of an extremely thin vapor deposition film as described above, 50% of light is reflected at a thin part and 90% at a thick part. The remaining light passes through the reflective film 97. Such a film can be easily formed by evaporating and evaporating the deposited metal as it is with the glass plate facing the deposited metal reservoir in the deposition apparatus. Depending on the position where the glass plate 96 is supported during the vapor deposition process and the processing time, the thickness of the film and the degree of thickness deviation can be freely adjusted.

  According to this embodiment, compared with the case where a slit etc. are provided as mentioned above, since it is only necessary to perform the vapor deposition process with existing equipment, the manufacturing cost can be reduced. The transmittance can be adjusted by changing various types of metal to be deposited. In the portion of the reflective film 97, light is transmitted as it is, reflected in a predetermined direction, or scattered. Although some light is absorbed, the metal vapor deposition film reflects light well and acts to radiate uniform light to the outside as a whole. In the example of this figure, in order to protect the reflective film 97, the reflective film 97 is directed toward the point light source 91, but the reflective film 97 may be disposed outward. The effect is almost the same. If the material to be deposited is not a glass plate but a film, productivity is further improved.

(Seventeenth embodiment)
FIG. 18 is a longitudinal sectional view showing the surface illumination light source device 100 of the present embodiment.
The surface illumination light source device 100 includes a point light source 102, a light guide body 103, an inner reflection unit 110, and a radiation side reflection unit 260. The radiation side reflection means 260 includes a first radiation side reflection means 120 and a second radiation side reflection means 140. The configuration up to the point light source 102 and the light guide 103 is not different from the previous embodiments. The light guide 103 has a radiation surface 104, a back surface 105, and a side surface 106. The first radiation side reflection means 120 is disposed on the radiation surface 104. This configuration may be the same as in the previous embodiments.

  That is, the inner reflection means 110 is disposed on the back surface 105 and the side surface 106 and has a reflection surface that reflects light propagating through the light guide 103 toward the radiation surface 104 or the side surface 106. Thereby, the light emitted from the light source 102 is multiple-reflected without being absorbed by these reflecting surfaces. In this way, a structure in which uniform illumination light can be obtained using substantially all the light emitted from the light emitting source 102 is obtained. As described above, in order to efficiently emit light from the radiation surface 104, it is preferable that a good reflection surface is also formed on the back surface 105 and the side surface 106.

Furthermore, as shown in FIG. 19C to be described later, the side surface 106 may have a shape that widens upward.
The first radiation side reflecting means 120 is provided with an aperture group 125 so that the specific points 101 are distributed around the center of symmetry. Since the second radiation side reflecting means 140 is provided and the effect of uniformizing the amount of light by multiple reflection is enhanced, the aperture distribution of the aperture group 125 may be substantially uniform except for the vicinity of the specific point 101. The first radiation-side reflecting means 120 is provided with a second reflecting surface 122 on the back side of the first reflecting surface 121. The second reflecting surface 122 reflects the return of light emitted through the aperture group 125.

  The first radiation-side reflecting means 120 can obtain the same effect even if any of the patterns shown in FIGS. 32A to 32D described later is used. FIG. 18 illustrates the cross section of the pattern shown in FIG. Then, the second radiation-side reflecting means 140 in which the microhole groups 142 are uniformly arranged as shown in FIG. 19A described later is overlaid on the first radiation-side reflecting means 120. did.

  The second radiation side reflection means 140 is disposed on the second reflection surface 122 side of the first radiation side reflection means 120. The second radiation side reflection means 140 is a diffuser plate and is arranged at a certain distance so as to face the first radiation side reflection means 120. And it has the 3rd reflective surface 141 which reflects the light radiated | emitted through the opening group 125 of the 1st radiation | emission side reflection means 120 toward the 2nd reflective surface 122 direction. In the second radiation side reflecting means 140, a microhole group 142 is formed so as to be distributed with a substantially uniform density over the entire surface.

  In this embodiment, the radiation side reflecting means has a two-layer structure. Light 131 that has undergone multiple reflection inside the light guide 103 is emitted from the opening of the first radiation-side reflecting means 120. Further, the light 132 is subjected to multiple reflections between the first radiation side reflection means 120 and the second radiation side reflection means 140. The microhole groups 142 of the second radiation side reflecting means 140 are uniformly dispersed. Due to complex multiple reflection, uniform light 133 is emitted from the microhole group 142 over the entire surface. Thereby, the undulation of the light intensity depending on the distribution of the openings of the first radiation side reflecting means 120 can be leveled.

  Further, according to the present embodiment, when the surface illumination light source device 100 is viewed from above in the radiation direction, the second radiation side is located at a position where a pattern such as an opening of the first radiation side reflecting means 120 is not visible. Since the reflecting means 140 is disposed, the thickness of the surface illumination light source device 100 in the radial direction can be reduced.

  For example, according to an experiment, when the first radiation side reflection means 120 is not provided, the surface illumination light source device 100 needs to have a thickness of about 100 mm in order to obtain uniform illumination light. By providing the side reflecting means 120, the thickness was reduced to about 30 mm. In this case, the distance between the first radiation side reflecting means 120 and the second radiation side reflecting means 140 was about 20 mm. It has been found that providing this distance is one of the important conditions for obtaining uniform illumination light.

  The second radiation-side reflecting means 140 may be a multilayer coating layer with little absorption, and the reflectance is preferably 50% to 99%, and the transmittance is 50% to 1%. As the second radiation side reflecting means 140, a single layer coating layer may be used, but a multilayer coating layer is preferably used. Further, the second radiation side reflecting means 140 may be a diffusion plate.

FIGS. 19A to 19C are explanatory views of main parts of the surface illumination light source device 100. FIG.
FIG. 19A is a plan view of the second radiation side reflecting means 140. As shown in the figure, the microhole groups 142 are uniformly distributed over the entire surface of the second radiation side reflecting means 140. The micropore group has a diameter of 10 μm or more and 100 μm or less. If the diameter of the micropore is less than 10 μm, the amount of transmitted light is insufficient and the energy efficiency is lowered. On the other hand, when the diameter of the microhole exceeds 100 μm, light is transmitted to the outside through the microhole before the multiple reflection is sufficiently performed. Therefore, the micropore group preferably has a diameter of 10 μm to 100 μm.

  Further, the sum of the opening areas of the microhole group 142 is 10% or more and 60% or less of the total area of the second radiation side reflection means 140. If the total opening area of the microhole group 142 is less than 10% of the total area of the second radiation-side reflecting means 140, the amount of transmitted light 133 is insufficient and energy efficiency is lowered. On the other hand, if the total opening area of the microhole group 142 exceeds 60% of the total area of the second radiation-side reflecting means 140, the light will be transmitted to the outside through the microholes before being sufficiently multiple-reflected. Therefore, the total sum of the opening areas of the microhole group 142 is preferably 60% or less of the total area of the second radiation side reflecting means 140.

  FIG. 19B is a longitudinal sectional view of the inner reflecting means 110. According to experiments, as shown in the figure, it was found that the reflection of not only the back surface 105 but also the side surface 106 is extremely effective when multiple reflections are made. Without the side surface 106, the amount of emitted light is greatly reduced at locations away from the point light source 102. It has also been found that it is easier to make the amount of emitted light uniform when the configuration as in this embodiment is used than when a plurality of point light sources 102 are arranged on the back surface 105.

  Note that the side surface 106 is not necessarily perpendicular to the back surface 105. FIG. 19C is a vertical sectional view of a modified example of the inner reflecting means 110. In this way, the side surface 106 may have a shape that expands upward.

(Eighteenth embodiment)
20A and 20B are diagrams showing another embodiment of the surface illumination light source device 100. FIG.
In this embodiment, in the surface illumination light source device 100, at least one point light source 102 (six in this embodiment) is arranged in a matrix in a portion corresponding to the back surface of the light guide 103. The number of point light sources 102 can be set arbitrarily. Other configurations are the same as those described in the seventeenth embodiment.

  That is, as described above, the inner reflecting means 110 is disposed on the back surface 105 and the side surface 106 and has a reflecting surface that reflects light propagating through the light guide 103 toward the radiation surface 104 or the side surface 106. ing. Thereby, the light emitted from the light source 102 is multiple-reflected without being absorbed by these reflecting surfaces. In this way, a structure in which uniform illumination light can be obtained using substantially all the light emitted from the light emitting source 102 is obtained.

  Moreover, in this embodiment, the partition as a reflecting plate which partitions off between the adjacent point light sources 102 is not provided. Further, as shown in FIG. 19C, the side surface 106 may have a shape that widens upward.

  This is because the light emitted from each point light source 102 is reflected on the back surface 105 and the side surface 106 of the inner reflection means 110, the first radiation side reflection means 120, and the second radiation side reflection means. This is because the reflection is repeated at 140 and the amount of light is made uniform by multiple reflection. However, of course, in order to obtain more uniform illumination light, it is better to provide the above-mentioned partition.

  In addition, when the external shape of the surface illumination light source device 100 becomes large, there is a possibility that the vicinity of the center of the device may bend. In this case, as the reinforcing plate, for example, a transparent plate or a reflecting plate may be attached to the central portion of the apparatus.

(Nineteenth embodiment)
FIG. 21 is a longitudinal sectional view of a surface illumination light source device 100 that combines the embodiments shown in FIGS. 18 and 19.
In this figure, the reflector 150 is arranged so as to surround the space between the first radiation side reflection means 120 and the second radiation side reflection means 140. The reflector 150 has the same function as the inner reflecting means 110. The space between the first radiation side reflection means 120 and the second radiation side reflection means 140 may be constituted by, for example, a transparent acrylic plate. Of course, the air layer may be left as it is. The second radiation-side reflecting means 140 may be a plastic film that has been perforated.

  Also, a multilayer coating with low absorption may be used, and this multilayer coating is preferably one having a reflectance of 50% to 99%. Further, a diffusion plate may be used instead of the multilayer coating.

  FIG. 22A is a schematic longitudinal sectional view of the surface illumination light source device 100 in which the shapes of the reflector and the radiation side reflecting means are changed. Moreover, FIG.22 (b) is the perspective view, and FIG.22 (c)-(e) is each exploded perspective view.

  In this embodiment, the first radiation-side reflecting means 120, the second radiation-side reflecting means 140, and the reflector 165 on the back surface of the light guide 103 have a reference line 168 passing through the point light source 102 as an axis of symmetry. It is a polyhedron. The first radiation-side reflecting means 120 is formed with a pattern having a predetermined shape as shown in FIG. Further, in the second radiation side reflecting means 140, as shown in FIG. 19A, the microhole groups 142 are uniformly distributed over the entire surface, or are formed in a ground glass shape. Further, the reflector 165 has a parabolic antenna shape opened so that the upper surface is expanded.

  Only the reflector 165 may have such a shape, and the first radiation side reflection means 120 and the second radiation side reflection means 140 may have a flat plate shape. Further, only one of the first radiation side reflection means 120 and the second radiation side reflection means 140 may have such a shape. Furthermore, the shape of the reflector 165 may be a part of a spherical surface instead of a polyhedron.

  The reflector 165 on the back surface of the light guide 103 converts the light from the point light source 102 into a beam having a predetermined width by the same effect as the parabolic antenna. That is, in FIG. 22A, the light reflected by the reflector 165 is emitted so as to spread outward with respect to the normal line. Similarly, the first radiation side reflecting means 120 and the second radiation side reflecting means 140 convert the light of the point light source 102 into a beam having a predetermined width by the lens effect. Therefore, it is suitable as a light source that outputs a light beam having a predetermined width.

(20th embodiment)
FIG. 23 is a longitudinal sectional view showing the surface illumination device 130 of the present embodiment.
In FIG. 23, the surface illumination device 130 uses the surface illumination light source device 100 described in FIG. 21 as a unit module, and the surface illumination light source devices 100 are arranged in a matrix in a large number (5 in the left-right direction in the figure). It is a thing. That is, each surface illumination light source device 100 includes the point light source 102 and the first radiation side reflecting means 120 in the housing of the inner reflecting means 110. And the surface illumination device 130 has the large diffusion plate 30 of the single plate arrange | positioned so that the upper part of these several surface illumination light source devices 100 may be covered collectively. The diffusion plate 30 corresponds to the second radiation side reflection means 140.

  According to experiments, although a single LED was used, the practical size was 10 centimeters in length and breadth, and by this configuration, a flat and uniform surface light source of several meters square could be obtained.

FIG. 24 is a front view of a surface illumination device 130 in which a number of modules 160 including the inner reflecting means 110 introduced in FIG. 19C are arranged in a matrix.
In the surface illumination device 130, the first radiation side reflection means 120 and the second radiation side reflection means 140 are not shown.

  In the figure, each module 160 includes an inner reflecting means 110, and an extra space 161 is formed between adjacent inner reflecting means 110. For this reason, this surplus space 161 can be used, for example, for a structural material, electrical wiring, or the like.

25A to 25D are plan views of the surface illumination device 130 formed by arranging a large number of surface illumination light source devices 100 in a matrix.
That is, also in the surface illumination device 130, the first radiation side reflection means 120 and the second radiation side reflection means 140 are not shown.

  25 (a) and 25 (b), one point light source 102 is provided for each surface illumination light source device 100 partitioned by a grid-like partition wall 162. At this time, a portion corresponding to the partition wall 162 functions very effectively. In addition, by arranging a large number of surface illumination light source devices 100 in this way, it is extremely advantageous in terms of uniformity of output light as compared with a case where a plurality of point light sources are arranged inside a large-area light guide. I was able to prove that.

  The barrier ribs 162 may have a lattice shape as shown in FIGS. 25 (a) and 25 (b), or may have a spiral shape as shown in FIGS. 25 (c) and 25 (d). In the case of the spiral partition 162, one partition 162 is disposed for each surface illumination light source device 100 disposed in a matrix.

  Note that the lattice-shaped or spiral-shaped partition 162 may be disposed between the first radiation-side reflecting means 120 and the second radiation-side reflecting means 140 in FIG. Further, the spiral partition wall 162 may be formed large and arranged between the first radiation side reflection means 120 and the second radiation side reflection means 140 together.

  In general, in the case of an “LED signboard using a light guide plate”, it is very difficult to make a huge uniform signboard with no joints because the units are connected horizontally due to the structure. This is because the LED position and the light guide plate position overlap and cannot be arranged unless a gap is provided between adjacent light guide plates. However, in this embodiment, since LEDs are arranged in the same plane as the surface to be illuminated, it is possible to obtain a huge and uniformly illuminated signboard without joints.

  According to the present embodiment, the light mixing property and the performance of projecting light forward are excellent.

(21st Embodiment)
FIG. 26 is an explanatory diagram of the operation of the second radiation side reflection means 140.
As shown in FIG. 26, the surface illumination light source device 100 includes a first radiation-side reflecting means 120 and a second radiation-side reflecting means 140 arranged at a certain distance so as to face the first radiation-side reflecting means 120. I have. The second radiation side reflecting means 140 includes a large number of microhole groups 142. The light emitted from the first radiation side reflection means 120 is diffused uniformly by repeating reflection between the first radiation side reflection means 120 and the second radiation side reflection means 140. Then, a part of the light 147 is uniformly emitted from the minute hole group 142 of the second radiation side reflecting means 140 as indicated by arrows. That is, as indicated by a one-dot chain line circle 145, the light 147 that has been repeatedly subjected to multiple reflections is emitted at a wide angle with uniform intensity. Accordingly, it is possible to obtain a wide-angle and wide light beam without unevenness.

FIGS. 27A and 27B are operation explanatory views of a modified example of the second radiation side reflecting means 140. FIG.
Also in this modified example, as shown in FIG. 27A, the second radiation side reflecting means 140 has a microhole group 142. Then, as shown in FIG. 27B, each hole of the microhole group 142 is formed in a mirror surface so that light incident on the hole is reflected many times inside the hole.

FIG. 28 is a diagram for explaining the operation of another modification of the second radiation side reflecting means 140.
In this example, the second radiation side reflecting means 140 is constituted by a multilayer half mirror. This multilayer half mirror is formed almost uniformly on the entire reflecting surface. For example, part of the light transmitted through the first layer half mirror is reflected by the back surface of the second layer half mirror, and the remainder of the light transmitted through the first layer half mirror is the second layer half mirror. It passes through the mirror and reaches the third layer half mirror.

  A very thin metal vapor deposition film is also suitable. You may form a vapor deposition layer in a multilayer. A coating film may be formed in multiple layers. As indicated by an alternate long and short dash line circle 175, light is variously reflected on the boundary surface of the multilayer film due to the difference in refractive index. Therefore, the light 173 is multiple-reflected between the layers of the half mirror, and part of the light is transmitted through the uppermost layer and emitted to the outside. For this reason, this modified example also performs the same operation as the second radiation side reflecting means 140 having the microhole group 142.

FIG. 29 is an operation explanatory diagram of another modified example of the second radiation side reflecting means 140.
In this modification, the second radiation side reflecting means 140 is constituted by one having light reflecting particles 182 formed so as to be distributed with a substantially uniform density over the entire reflecting surface. The light reflecting particles 182 are formed in a plate shape so as to be covered with a transparent resin. The light reflecting particle body 182 may be any granular material that reflects light. Glass beads dispersed in a transparent body may be used.

  According to this modified example, as indicated by the dashed-dotted circle 181, a part of the light 184 is reflected and a part is emitted to the outside from the gap, so that the second radiation side reflection having the microhole group 142 is provided. The same operation as the means 140 is performed. Further, the amount of emitted light can be made uniform by a light scattering uneven structure portion formed on the entire reflecting surface like ground glass. A glass surface that has been sandblasted is suitable. Further, surface processing having an action like a diffraction grating may be performed. That is, the amount of emitted light can be made uniform by configuring the entire reflecting surface with the light diffraction structure.

  In the above embodiment, the first radiation-side reflecting means 120 has a specific point on the first reflecting surface 121 as the center of symmetry, and the total opening area per unit area increases as the distance from the specific point increases. It is preferable to form the aperture group 125 distributed as described above. As the distance from the specific point increases, the amount of light passing through the aperture increases, and uniform light can be emitted as a whole. Needless to say, when the structure of the radiation side reflection means as shown in the previous embodiment is adopted, the uniformity of the quantity of emitted light is increased. Further, the first radiation side reflection means 120 and the second radiation side reflection means 140 may have the same structure.

  In the above embodiment, the light that has undergone multiple reflections is finally emitted to the outside. When the degree of multiple reflection using the second radiation side reflection means 140 is examined to determine whether the amount of emitted light is uniform or the degree of multiple reflection, the following conclusions were obtained. That is, it is preferable that the third reflecting surface 141 of the second radiation side reflecting means 140 reflects 70% or more of incident light when the reflection loss is assumed to be zero.

  When the reflection loss is assumed to be zero, the multiple reflection function of the second radiation side reflection means 140 can be sufficiently exhibited by using one that reflects 70% or more of incident light. If it is less than 70%, the amount of light is not sufficiently uniform, and considering the cost, it is better to omit the second radiation side reflecting means 140.

(Twenty-second embodiment)
FIG. 30 is a longitudinal sectional view showing the surface illumination light source device 100 of the present embodiment.
The surface illumination light source device 100 includes radiation-side reflecting means 190 having a substantially uniform light scattering surface and a light transmission hole on the entire radiation surface 104 of the light guide 103. That is, the same configuration as the second radiation side reflection means 140 of each embodiment shown in FIGS. 26 to 29 is used as the radiation side reflection means 190 so that multiple reflection is performed only inside the light guide 103. did. This can provide a very simplified and inexpensive surface light source.

FIG. 31 is an explanatory view of the effect of the second radiation side reflection means 140 in FIG.
In the figure, the horizontal axis represents the position coordinates of the radiation surface 104 of the surface illumination light source device 100, and the vertical axis represents the amount of emitted light.

  As shown in this figure, when only the first radiation side reflection means 120 is used, the amount of emitted light P shows a variation affected by the pitch of the openings. On the other hand, when the second radiation side reflecting means 140 is used in combination, a very uniform characteristic of the emitted light quantity Q can be obtained as a whole.

FIGS. 32A to 32D introduce the opening pattern of the first radiation-side reflecting means 120 that has been put into practical use. Although the arrangement and shape of the aperture group 125 of the first radiation side reflecting means 120 are slightly different, the amount of emitted light is made uniform to the extent that there is no practical problem.
(Appendix 1)
A light emitting source with strong directivity, a light guide having a radiation surface in the radiation direction of the light emission source, and a casing that is surrounded by the light emission source and closes a surface other than the radiation surface of the light guide. In the surface illumination light source device,
Inner reflection means provided between the casing and the light guide;
A surface illumination light source device, comprising: radiation side reflection means provided on the radiation surface and configured to reflect light from the light emission source at a predetermined ratio.
(Appendix 2)
2. The surface illumination light source device according to claim 1, wherein the radiation side reflecting means is a central reflecting portion that reflects light traveling straight forward from the light emitting source within a predetermined range.
(Appendix 3)
Item 3. The supplementary note 2, wherein the radiation-side reflecting means includes a ring-shaped outer reflecting portion disposed at a predetermined interval outward from a central reflecting portion provided in the light guide. Surface illumination light source device.
(Appendix 4)
The surface illumination light source device according to appendix 2 or 3, wherein the central reflection portion includes a light transmission portion in a predetermined range at a central portion thereof.
(Appendix 5)
The central reflecting portion is a circular reflecting plate or reflecting film provided on the radiation surface, and the outer reflecting portion is at a predetermined interval from the circular reflecting plate or reflecting film. The surface illumination light source device according to any one of appendices 2 to 4, wherein the surface illumination light source device is an annular reflecting plate or reflecting film formed concentrically with each other.
(Appendix 6)
The central reflection part is a reflection plate or a reflection film provided on the radiation surface and formed in a shape similar to the casing, and the outer reflection part is formed on the reflection plate or the reflection film at a predetermined interval. It is a strip | belt-shaped reflecting plate or a reflecting film, The surface illumination light source device as described in any one of Additional remarks 2-4 characterized by the above-mentioned.
(Appendix 7)
3. The surface illumination light source device according to appendix 2, wherein the central reflecting portion is a cone-shaped reflector having a predetermined apex angle formed on the radiation surface of the front surface of the light emitting source.
(Appendix 8)
When light output from a point light source is directly received on a plane arranged at a predetermined distance from the point light source, the received light intensity distribution on the plane is the highest at the reference point at the shortest distance from the point light source. A point light source having an output characteristic that shows a value and gradually decreases with increasing distance from the reference point around the reference point;
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
Radiation-side reflecting means that is disposed on the radiation surface and reflects light propagating through the light guide in the back or side direction;
An inner reflection means that is disposed on the back surface and reflects light propagating through the light guide in the radiation surface or side surface direction;
When an intersection point between a reference line connecting the point light source and the reference point and the radiation surface is referred to as a specific point, the radiation-side reflecting means includes the specific point, and is a circle or regular polycenter including the specific point. A surface illumination light source device comprising a rectangular reflector and a reflector that surrounds the reflector and has a slit group parallel to the arc of the circle or the side of the regular polygon.
(Appendix 9)
When light output from a point light source is directly received on a plane arranged at a predetermined distance from the light source, the received light intensity distribution on the plane has the highest value at the reference point at the shortest distance from the light source. A point light source having an output characteristic that gradually decreases as the distance from the reference point is increased.
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
Radiation-side reflecting means that is disposed on the radiation surface and reflects light propagating through the light guide in the back or side direction;
An inner reflection means that is disposed on the back surface and reflects light propagating through the light guide in the radiation surface or side surface direction;
When an intersection of a reference line connecting the light source and the reference point with the shortest distance and the radiation surface is referred to as a specific point, the radiation-side reflecting means includes the specific point, and a straight line passing through the specific point A planar illumination light source device comprising: a rectangular reflector having a symmetrical shape; and a reflector having a slit group sandwiched between the reflectors and parallel to the straight line.
(Appendix 10)
The surface illumination light source device according to appendix 8 or 9, wherein the light guide body is curved so as to follow an arbitrary curved surface.
(Appendix 11)
10. The surface illumination light source device according to appendix 8 or 9, wherein the light guide is made of a flexible plate.
(Appendix 12)
10. The surface illumination light source device according to appendix 8 or 9, wherein the slit is provided in a film pasted on the radiation surface.
(Appendix 13)
The surface illumination light source device according to appendix 12, wherein the film attached on the radiation surface has a slit-shaped transparent portion and a reflector portion.
(Appendix 14)
The surface illumination light source device according to appendix 8 or 9, wherein the reflector is a light absorber, an irregular reflector, or a laminate of reflective films.
(Appendix 15)
When light output from a point light source is directly received on a plane arranged at a predetermined distance from the point light source, the received light intensity distribution on the plane is the highest at the reference point at the shortest distance from the point light source. A point light source having an output characteristic that shows a value and gradually decreases with increasing distance from the reference point around the reference point;
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
Radiation-side reflecting means that is disposed on the radiation surface and reflects light propagating through the light guide in the back or side direction;
An inner reflection means that is disposed on the back surface and reflects light propagating through the light guide in the radiation surface or side surface direction;
When an intersection of a reference line connecting the point light source and the reference point and the radiation surface is referred to as a specific point, the metal deposition on the radiation surface is thicker at a portion closer to the specific point and thinner as the distance from the specific point is increased. A surface illumination light source device characterized in that a film is formed.
(Appendix 16)
A surface illumination device comprising a plurality of point light sources according to any one of appendices 1 to 12 arranged in a light guide.
(Appendix 17)
When light output from a light source is received directly on a plane arranged at a predetermined distance from the light source, the received light intensity distribution on the plane shows the highest value at the reference point at the shortest distance from the light source. , A point light source having an output characteristic that gradually decreases with increasing distance from the reference point around the reference point;
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
Inner reflecting means disposed on the back and side surfaces and having a reflecting surface for reflecting light propagating through the light guide;
A first reflecting surface that is disposed on the radiation surface and reflects light propagating through the light guide in the back or side direction; a reference line that connects the light source and the reference point; and the radiation surface. When an intersection is called a specific point, an aperture group formed on the first reflecting surface so as to be distributed with the specific point as the center of symmetry, and on the back side of the first reflective surface, passes through the aperture group. First radiation-side reflecting means having a second reflecting surface for reflecting the return of the light emitted by
The first radiation side reflection means is disposed at a certain distance so as to face the first radiation side reflection means, and the light emitted through the opening of the first radiation side reflection means is emitted from the first radiation side reflection means. A second radiation-side reflecting means having a third reflecting surface that reflects in the direction of the second reflecting surface, and a group of micro holes formed so as to be distributed with a substantially uniform density over the entire reflecting surface; A surface illumination light source device.
(Appendix 18)
In the surface illumination light source device according to attachment 17,
The surface illumination light source device, wherein the microhole group has a diameter of 10 μm or more and 100 μm or less.
(Appendix 19)
In the surface illumination light source device according to attachment 17,
The surface illumination light source device characterized in that the sum of the aperture areas of the microhole group is 10% or more and 60% or less of the total area of the second radiation side reflection means.
(Appendix 20)
In the surface illumination light source device according to attachment 17,
Instead of the second radiation side reflecting means having a group of minute holes formed so as to be distributed with a substantially uniform density over the entire reflecting surface, a multilayer half mirror formed substantially uniformly over the reflecting surface is used. A surface illumination light source device characterized by comprising.
(Appendix 21)
In the surface illumination light source device according to attachment 17,
The second radiation side reflecting means is formed so as to be distributed with a substantially uniform density over the entire reflecting surface, instead of having a group of micropores formed so as to be distributed with a substantially uniform density over the entire reflecting surface. A surface illumination light source device, characterized in that it comprises a light reflecting particle body.
(Appendix 22)
In the surface illumination light source device according to attachment 17,
The second radiation side reflecting means is constituted by a light scattering concavo-convex structure portion formed on the entire reflecting surface, instead of having a group of microholes formed so as to be distributed with a substantially uniform density on the entire reflecting surface. A surface illumination light source device.
(Appendix 23)
In the surface illumination light source device according to attachment 17,
The second radiation side reflecting means is constituted by a light diffractive structure provided on the entire reflecting surface, instead of having a group of minute holes formed so as to be distributed with a substantially uniform density on the entire reflecting surface. A surface illumination light source device.
(Appendix 24)
In the surface illumination light source device according to attachment 17,
The first radiation-side reflecting means has a group of apertures distributed on the first reflecting surface such that the sum of the aperture areas per unit area increases with the specific point as the center of symmetry and the distance from the specific point. The surface illumination light source device characterized by forming.
(Appendix 25)
In the surface illumination light source device according to attachment 24,
Instead of the second radiation-side reflecting means having a group of micropores formed so as to be distributed with a substantially uniform density on the entire reflecting surface, the specific point is the center of symmetry and is far from the specific point. A surface illumination light source device in which aperture groups are formed so that the total sum of aperture areas per unit area increases.
(Appendix 26)
In the surface illumination light source device according to any one of appendices 1 to 25,
The surface illumination light source device, wherein the third reflective film reflects 70% or more of incident light when a reflection loss is assumed to be zero.
(Appendix 27)
When light output from a light source is received directly on a plane arranged at a predetermined distance from the light source, the received light intensity distribution on the plane shows the highest value at the reference point at the shortest distance from the light source. , A point light source having an output characteristic that gradually decreases with increasing distance from the reference point around the reference point;
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
Inner reflecting means disposed on the back and side surfaces and having a reflecting surface for reflecting light propagating through the light guide;
A radiation side disposed on the radiation surface and reflecting light propagating through the light guide in the back or side direction, and a radiation side having a substantially uniform light scattering surface and a light transmission hole on the entire reflection surface. A surface illumination light source device comprising a reflection means.
(Appendix 28)
In the surface illumination light source device according to any one of appendices 1 to 27,
All or a part of the first radiation side reflection means, the second radiation side reflection means, and the back surface of the light guide is a spherical surface or a polyhedron with the reference line passing through the light source as an axis of symmetry. A surface illumination light source device.
(Appendix 29)
A surface illumination device comprising a plurality of the surface illumination light source devices according to any one of appendices 1 to 27.
(Appendix 30)
When light output from a light source is received directly on a plane arranged at a predetermined distance from the light source, the received light intensity distribution on the plane shows the highest value at the reference point at the shortest distance from the light source. , A point light source having an output characteristic that gradually decreases with increasing distance from the reference point around the reference point;
A closed surface having a radiation surface parallel to the plane, a back surface substantially parallel to the radiation surface, and a side surface disposed on an outer periphery of the radiation surface and the back surface, and surrounded by the radiation surface, the back surface, and the side surface. An optically transparent light guide provided in the space;
An inner reflection means disposed on the back surface and the side surface and having a reflection surface for reflecting light propagating through the light guide;
Identifying the intersection of the radiation surface with a reference surface that is disposed on the radiation surface and reflects light propagating through the light guide in the back or side direction, and a reference line that connects the light source and the reference point When called a point, radiation-side reflecting means having an aperture group formed in the reflecting surface so as to be distributed with the specific point as the center of symmetry,
2. A surface illuminating device comprising light source device modules that radiate light, which is reflected back and side surfaces of the light guide and a space surrounded by the radiation surface, to the outside.

DESCRIPTION OF SYMBOLS 1, 1 'surface illumination light source device 2 Light emission source 3 Light guide 3A Radiation surface 4 Casing 5 Inner reflection part 5' Reflective member 6, 10 Radiation side reflection part 6A, 10A Central reflection part 6B, 10B Outer reflection part 6C Center Light transmissive portion 7 Outside light transmissive portion 8 Reflector 9 Light transmissive substrate 20, 20 ′ Surface illumination device 30 Light diffusing plate 50 Flat surface 51 Specific point 52 Back surface 53 Side surface 58 Reference line 59 Reference point 61 End surface 63 Reflector 64 Reflector 65 slit group 68 straight line 69 end surface 71 wall 72 solid line 73 surface illumination light source device 74 slit 80 film 81 slit 90 surface illumination light source device 91 point light source 95 pattern 96 glass plate 97 reflective film 100 surface illumination light source device 101 specific point 102 point light source 103 Light guide body 104 Radiation surface 105 Back surface 106 Side surface 110 Inner reflection means 115 Bulkhead 120 First radiation side reflection means 121 First reflection 122 Second reflection surface 125 Aperture group 130 Surface illumination device 131 Light 132 Light 133 Light 140 Second radiation side reflection means 141 Third reflection surface 142 Microhole group 145 Circle 147 Light 150 Reflector 160 Module 161 Extra space 162 Bulkhead 165 Reflector 168 Reference line 173 Light 175 Circle 181 Circle 182 Light reflecting particle 184 Light 190 Radiation side reflection means 260 Radiation side reflection means

Claims (17)

A casing having a bottom surface and a side surface of a predetermined area and an opening, provided with an internal reflection means inside, and a point light source having strong directivity disposed at the center of the bottom surface;
A radiation-side reflecting means that covers the opening at a predetermined distance from the point light source and transmits and reflects light;
The inner reflection means and the radiation side reflection means have a reference line passing through the shortest distance between the point light source and the radiation side reflection means as a symmetry axis, and at least one of the reflection means is relative to the symmetry axis. It is formed with a flat or polyhedral reflector ,
The radiation-side reflecting means is opposed to the radiation side of the first radiation-side reflecting means with a certain distance from the first radiation-side reflecting means that transmits and reflects part of the light from the point light source. A second radiation-side reflecting means that is arranged and reflects and transmits a part of the light that has passed through the first radiation-side reflecting means,
The first radiation side reflection means includes a first reflection surface that reflects a part of the light from the point light source into the casing, and a first reflection surface that is opposite to the first reflection surface and reflects the light. The second radiation side reflection means reflects the light that has passed through the first radiation side reflection means and causes multiple reflection between the second reflection surface and the second reflection surface. And a reflective surface
The first reflecting surface of the first radiation side reflecting means has a predetermined area centered on the specific point and an outside of the central reflective portion when the intersection with the front reference line is called a specific point. An outer reflecting portion around the outer reflecting portion, and the outer reflecting portion is made of a reflecting member that transmits and reflects a part of light and has a predetermined reflectivity, and the central reflecting portion is a portion of the outer reflecting portion. A surface illumination light source device, characterized in that the surface illumination light source device is formed of a light-transmissive reflecting portion having a reflectance higher than the reflectance . Before SL first, according to claim 1 wherein at least one of the reflecting means of the second radiation side reflection means is characterized in that it is formed by the reflector of the plate-shaped or polyhedral with respect to the symmetry axis Surface illumination light source device. The surface illumination light source device according to claim 2 , wherein the central reflection portion is formed in a shape similar to the opening shape of the casing. It said outer reflector part, according to claim 3, characterized in that the reflector of the width dimension of the narrow band farther from the central reflector portion of the shape is obtained provided a plurality of spaced a predetermined gap Surface illumination light source device. The central reflecting portion is formed in a circular or rectangular shape centered on the specific point, and the outer reflecting portion is formed by separating a reflector having a narrow width with a predetermined gap as the distance from the central reflecting portion of the shape increases. The surface illumination light source device according to claim 1 , wherein a plurality of the surface illumination light source devices are provided. The plants gap, the surface illumination light source device according to claim 4 or 5, characterized in that the width dimension is wider as the distance from said central reflecting portion.   The surface illumination light source device according to claim 1, wherein the point light source is formed of one light emitting diode or an aggregate of a plurality of light emitting diodes. It said central reflecting portion is partially slit or opening is provided on, or surface illumination light source device according to any one of claims 2, 3 or 5, characterized in that it is formed thinner. The central reflection part and the outer reflection part are both made of reflection dots, and the density distribution of the reflection dots in the central reflection part is higher than the density distribution of the reflection dots in the outer reflection part. The surface illumination light source device according to claim 2 or 3 .   2. The surface illumination light source device according to claim 1, wherein the inner reflection means is an ultrafine foamed light reflecting member, and the first radiation side reflecting means is a fine foamed light reflecting member.   2. The inner reflection means is an ultrafine foamed light reflection member, and the first radiation side reflection means is a coating film containing fine particles of titanium white or polytetrafluoroethylene. Surface illumination light source device.   2. The surface according to claim 1, wherein the inner reflection means is titanium white or polytetrafluoroethylene, and the first radiation side reflection means is a coating film containing fine particles of polytetrafluoroethylene. Illumination light source device. 2. The surface illumination light source device according to claim 1 , wherein the second radiation-side reflecting means includes a plurality of fine holes having a diameter of 10 μm to 100 μm dispersed therein. The surface illumination light source device according to claim 1 , wherein the second radiation side reflecting means is configured by a half mirror. The surface illumination light source device according to claim 1 , wherein the second radiation side reflection means is a light diffusion plate. The surface illumination light source device according to claim 1 , wherein the second radiation side reflection means is formed of a light diffraction structure. A surface illumination device comprising a plurality of the surface illumination light source devices according to any one of claims 1 to 16 .