JP6375008B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  An illumination device that includes a plurality of superimposed light guide plates and a light source that causes light to enter the end surfaces of the respective light guide plates, and that irradiates light incident on each light guide plate from a light guide plate disposed on the illuminated side, for example, Patent Document 1 discloses this.

WO2011 / 129117A1

  However, the lighting device is required to increase the amount of light while suppressing an increase in size.

    In order to meet such a demand, an object of the present invention is to provide an illumination device capable of increasing the amount of light while suppressing an increase in size.

In order to solve the above problems, the present invention is overlapped with each other, facing a plurality of plate-shaped light guide plates having an end surface as a light incident surface and a wide surface as a light output surface, and end surfaces of the plurality of light guide plates. is disposed at a position, a light source for light to the light guide plates, have a, the end face where the light source is arranged, adjacent to each other in the light guide plate adjacent to Sarezu outermost among the plurality of light guide plates superimposed A light output surface of the light guide plate disposed on the first light output surface, which is a light output surface that emits light on the side opposite to the side on which the light guide plates are superimposed, is disposed from the first light output surface. A light diffusing plate having a first light incident surface on which the emitted light is incident and a second light emitting surface from which the light incident from the first light incident surface is emitted; A second light incident that projects toward the exit surface and faces the periphery of the first light exit surface and is incident from the periphery. A protrusion having a surface, and the protrusion has an outer peripheral end surface that is flush with an outer peripheral edge that is an outer peripheral edge of the second light emitting surface, and an inner peripheral side surface that faces the outer peripheral end surface. I will have it.

  Further, in addition to the above invention, a light shielding member is provided between the peripheral portion and the second light incident surface to limit the amount of light incident on the second light incident surface from the peripheral portion. And

  In addition to the above invention, a recess for separating the first light emitting surface and the first light incident surface is provided on the inner side of the ridge formed over the entire circumference of the peripheral portion of the light diffusing plate. Suppose that

  In addition to the above invention, the light source is mounted on a flexible substrate, and the flexible substrate is also disposed at a position facing the end surface of the adjacent light guide plate.

  In addition to the above invention, the surface of the flexible substrate on the light guide plate side is white or silver.

  In addition to the above invention, the light source uses different color lights for at least two light guide plates.

  Further, in addition to the above invention, the light sources provided in the light guide plate are a plurality of light sources, and the light exit surface of the light guide plate is provided with a light diffusing unit between adjacent light sources of the plurality of light sources. And

It is a whole perspective view which shows the schematic structure of an illuminating device. It is a disassembled perspective view which shows the structure of the outline of the illuminating device shown in FIG. It is a disassembled perspective view of the overlapping light-guide plate which comprises the illuminating device shown in FIG. It is a figure explaining the comparative example with the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure explaining the comparative example with the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a top view which shows the schematic structure of the illuminating device which concerns on other embodiment of this invention. It is a fragmentary sectional view which shows the schematic structure of the AA cut surface of FIG. It is a fragmentary sectional view which shows the schematic structure of the BB cut surface of FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the side surface of the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG. It is a figure which shows the modification of the illuminating device shown in FIG.

  Hereinafter, an illumination device 1 according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
The configuration of the illumination device 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is an overall perspective view showing a schematic configuration of the illumination device 1. FIG. 2 is an exploded perspective view showing a schematic configuration of the illumination device 1. FIG. 3 is an exploded perspective view of a superposed light guide plate (hereinafter referred to as a polymerization light guide plate) 2 constituting the lighting device 1.

  In the following description, the arrow X1 direction shown in FIGS. 1, 2 and 3 is left, the arrow X2 direction is right, the arrow Y1 direction is front, the arrow Y2 direction is backward, the arrow Z1 direction is upward, and the arrow Z2 The direction will be described below. The designation of these directions is for convenience of explanation, and does not designate (limit) the installation direction of the lighting device 1 or the arrangement direction of the members constituting the lighting device 1.

(Overall configuration of lighting device 1)
As shown in FIGS. 1 and 2, the lighting device 1 includes a superposed light guide plate 2, two flexible boards (hereinafter referred to as FPC) 4 on which a plurality of LEDs 3 are mounted, and a plurality of LEDs 3. And two FPCs 5.

(Polymerization light guide plate 2)
As shown in FIGS. 2 and 3, the polymerization light guide plate 2 is configured by two light guide plates 8 and a light guide plate 9 being stacked one above the other. The light guide plate 8 and the light guide plate 9 are rectangular parallelepipeds that are flat in the vertical direction, exhibit a plate-like body that is a positive direction shape in plan view, and both have the same shape. The light guide plate 8 has an upper surface 8A and a lower surface 8B, and end surfaces 8C, 8D, 8E, and 8F. The light guide plate 9 also has an upper surface 9A and a lower surface 9B, and end surfaces 9C, 9D, 9E, 9F. In the drawing, the thickness and size of the light guide plates 8 and 9 are exaggerated. As an example, the thickness and size of the light guide plates 8 and 9 are about 1.5 mm in thickness and about 10 cm in length and width. It may be thicker or thinner than this, and the size may be larger or smaller.

  The light guide plate 8 and the light guide plate 9 have the same shape. Therefore, as shown in FIG. 2, when the light guide plate 8 and the light guide plate 9 are overlapped so that the lower surface 8B overlaps the upper surface 9A, the end surfaces of the two light guide plates are flush with each other in the vertical direction. (On the same plane). Accordingly, the superposed light guide plate 2 is also a rectangular parallelepiped flat in the vertical direction, and presents a plate-like body that is square in plan view.

  The top surface 2A of the superposed light guide plate 2 is flush with the top surface 8A of the light guide plate 8, and the bottom surface 2B is flush with the bottom surface 9B of the light guide plate 9. The end surface 2C of the superposed light guide plate 2 is formed by the end surface 8C of the light guide plate 8 and the end surface 9C of the light guide plate 9. The end surface 2D of the superposed light guide plate 2 is formed by the end surface 8D of the light guide plate 8 and the end surface 9D of the light guide plate 9. The end surface 2E of the superposed light guide plate 2 is formed by the end surface 8E of the light guide plate 8 and the end surface 9E of the light guide plate 9. The end surface 2F of the superposed light guide plate 2 is formed by the end surface 8F of the light guide plate 8 and the end surface 9F of the light guide plate 9.

  The light guide plates 8 and 9 scatter light incident on the light guide plates 8 and 9 by mixing light scattering particles with a transparent material such as acrylic resin, polycarbonate resin, or glass, for example. It can be configured. As the light scattering particles, for example, light scattering particles disclosed in JP2010-97088A, JP2010-123309A, and the like can be used. Moreover, it is good also as a structure which forms a light-scattering surface by methods, such as forming a dot pattern on the surface of the light-guide plates 8 and 9, instead of mixing light-scattering particle | grains.

(FPC4)
The FPC 4 includes a mounting part 4A on which a plurality of LEDs 3 are mounted, and a connection part 4B connected to a control part (not shown). The surface shape of the mounting portion 4A is substantially the same as the shape and size of the end surface 2C (end surface 2D) of the superposition light guide plate 2. A plurality of LEDs 3 are arranged in the upper half of the mounting portion 4A along the longitudinal direction of the mounting portion 4A.

  Of the two FPCs 4, one FPC 4 is arranged with respect to the superposition light guide plate 2 such that the side on which the LED 3 is mounted faces the end surface 2 </ b> C, and the LED 3 faces the end surface 8 </ b> C. Therefore, the light emitted from the LED 3 can enter the light guide plate 8 from the end face 8C. The surface shape of the mounting portion 4A is substantially the same as the shape and size of the end surface 2C of the polymerization light guide plate 2. Therefore, the FPC 4 is arranged with respect to the superposed light guide plate 2 as described above, so that the lower half portion of the mounting portion 4 </ b> A faces the end surface 9 </ b> C of the light guide plate 9.

  The other FPC 4 is arranged with respect to the superposition light guide plate 2 so that the LED 3 is mounted on the end surface 2D side and the LED 3 is opposed to the end surface 8D. Therefore, the light emitted from the LED 3 enters the light guide plate 8 from the end face 8D, and the lower half portion of the mounting portion 4A faces the end face 9D of the light guide plate 9.

(FPC5)
The FPC 5 includes a mounting part 5A on which a plurality of LEDs 3 are mounted, and a connection part 5B connected to a control part (not shown). The surface shape of the mounting portion 5A is substantially the same as the shape and size of the end surface 2E (end surface 2F) of the superposition light guide plate 2. A plurality of LEDs 3 are arranged in the lower half of the mounting portion 5A along the longitudinal direction of the mounting portion 5A.

  Of the two FPCs 5, one FPC 5 is disposed with respect to the superposition light guide plate 2 such that the side on which the LED 3 is mounted faces the end surface 2E, and the LED 3 faces the end surface 9E. Therefore, the light emitted from the LED 3 can enter the light guide plate 9 from the end face 9E. The surface shape of the mounting portion 5A is substantially the same as the shape and size of the end surface 2E of the polymerization light guide plate 2. Therefore, the FPC 5 is arranged with respect to the superposition light guide plate 2 as described above, so that the upper half portion of the mounting portion 5 </ b> A faces the end surface 8 </ b> E of the light guide plate 8.

  The other FPC 5 is arranged with respect to the superposition light guide plate 2 so that the LED 3 is mounted on the end surface 2F and the LED 3 faces the end surface 9F. Therefore, the light emitted from the LED 3 enters the light guide plate 9 from the end face 9F, and the upper half portion of the mounting portion 5A faces the end face 8F of the light guide plate 8.

  The number of LEDs 3 mounted on the FPCs 4 and 5 is not limited to the seven shown in FIGS. 1 and 2 but may be larger or at least better. One LED 3 may be provided, for example.

(Operation of lighting device 1)
Next, operation | movement etc. of the illuminating device 1 which has the above-mentioned structure are demonstrated.

  The polymerization light guide plate 2 is a light guide plate in which a light guide plate 8 and a light guide plate 9 are overlapped, and an air layer is formed between the light guide plate 8 and the light guide plate 9. The LEDs 3 are disposed on the end faces 8C and 8D of the light guide plate 8, respectively, and light can enter the light guide plate 8 from the end faces 8C and 8D. That is, the end surfaces 8C and 8D function as light incident surfaces. Further, the LEDs 3 are also arranged on the end surfaces 9E and 9F of the light guide plate 9, respectively, so that light can enter the light guide plate 8 from the end surfaces 9E and 9F. That is, the end surfaces 9E and 9F function as light incident surfaces.

  Light that has entered the light guide plate 8 from the end faces 8C and 8D of the light guide plate 8 is scattered within the light guide plate 8 and out of the light guide plate 8 from the upper surface 8A and the lower surface 8B that are wider than the end surfaces 8C and 8D. Exit. Similarly, light that has entered the light guide plate 8 from the end surfaces 9E and 9F of the light guide plate 9 is also scattered in the light guide plate 9 and from the upper surface 9A and the lower surface 9B that are wider than the end surfaces 9E and 9F. 9 is emitted to the outside.

  The light emitted from the lower surface 8B of the light guide plate 8 enters the light guide plate 9 and is emitted from the lower surface 9B of the light guide plate 9 to the outside of the light guide plate 9. Further, the light emitted from the upper surface 9 </ b> A of the light guide plate 9 enters the light guide plate 8, and exits from the upper surface 8 </ b> A of the light guide plate 8 to the outside of the light guide plate 8. Therefore, in addition to the light incident from the end faces 8C and 8D of the light guide plate 8, the light emitted from the upper surface 9A of the light guide plate 9 is also emitted from the upper surface 2A of the superposed light guide plate 2. In addition to the light incident from the end surfaces 9E and 9F of the light guide plate 9, light emitted from the lower surface 8B of the light guide plate 8 is also emitted from the lower surface 2B of the superposed light guide plate 2.

  Light enters the light guide plate 8 from a plurality of end faces, that is, the end face 8C and the end face 8D. Moreover, light also enters the light guide plate 9 from a plurality of end surfaces, that is, the end surface 9E and the end surface 9F. Thus, by making light enter the light guide plate from a plurality of end faces, the amount of illumination light emitted from the illumination device 1 can be increased.

  The color of the light of the LED 3 incident on the light guide plate 8 and the color of the light of the LED 3 incident on the light guide plate 9 may be different from each other. For example, the color light of the LED 3 incident on the light guide plate 8 can be white, and the color light of the LED 3 incident on the light guide plate 8 can be warm. The warm color is, for example, a so-called light bulb color, which is a brownish color compared to white. The light color of the LED 3 incident on the light guide plate 8 and the light color of the LED 3 incident on the light guide plate 9 should be a desired combination such as white and red, yellow and green, regardless of the combination of white and warm color. Can do.

  In addition, for example, a plurality of LEDs 3 that make light incident on the light guide plate 8 are alternately arranged with LEDs having different color lights, and a plurality of LEDs 3 that make light incident on the light guide plate 9 are alternately arranged with LEDs having different color lights It is also possible to adopt a configuration to However, in the case of such a configuration, different light LEDs are adjacent to each other, and color unevenness is likely to occur in the light emitted from the superposition light guide plate 2 in the portion where the different light LEDs are adjacent. On the other hand, the color of the light emitted from the light guide plate 8 and the color of the light emitted from the light guide plate 9 are each one color, and the colors of the light emitted from the respective light guide plates are different from each other. Color unevenness in the light emitted from the light plate 2 can be made difficult to occur.

  The end surfaces 8C and 8D of the light guide plate 8 provided with the LEDs 3 and the end surfaces 9E and 9F of the light guide plate 9 are not adjacent to each other in the light guide plate 8 and the light guide plates 9. That is, the end surface 9C of the light guide plate 9 where the LEDs 3 are not provided is adjacent to the end surface 8C of the light guide plate 8. Further, the end surface 9D of the light guide plate 9 where the LEDs 3 are not provided is adjacent to the end surface 8D of the light guide plate 8. Further, the end surface 8E of the light guide plate 8 where the LEDs 3 are not provided is adjacent to the end surface 8E of the light guide plate 9. The end face 8F of the light guide plate 8 where the LEDs 3 are not provided is adjacent to the end face 8F of the light guide plate 9.

  For example, as shown in FIG. 4, for example, as shown in FIG. 4, the LED 3 is provided on each of the end faces adjacent to the light guide plate 8 and the light guide plate 9 (for example, the end face 8C and the end face 9C, and the end face 8D and the end face 9D). In the case of the configuration, the LEDs 3 are mounted on one FPC 100 in two upper and lower rows. It is necessary to mount a circuit or the like for driving the LED 3 on the mounting portion 100A of the FPC 100. That is, when the LEDs 3 are mounted in two rows on the mounting portion 100A, the width in the vertical direction of the mounting portion 100A secures the width W1 in which the drive circuit and the like are arranged in addition to the width on which the LED 3 itself is mounted. There is a need. Therefore, as shown in FIG. 4, the vertical width W <b> 2 of the mounting portion 100 </ b> A exceeds the thickness W <b> 3 of the light guide plate 2, which may increase the size of the lighting device 1.

  On the other hand, as shown in FIGS. 1 to 3, the end surfaces 8C and 8D of the light guide plate 8 provided with the LED 3 and the end surfaces 9E and 9F of the light guide plate 9 provided with the LED 3 are the light guide plate 8 and the light guide plate. By adopting a configuration in which the nines are not adjacent to each other, the LEDs 3 can be prevented from being arranged in two upper and lower rows. For this reason, the widening of the mounting parts 4A and 5A in the vertical direction (thickness direction of the light guide plate 2) can be suppressed. By suppressing the widening of the mounting parts 4A and 5A in the vertical direction, it is possible to suppress an increase in the size of the lighting device 1.

  Moreover, in the illuminating device 1, as mentioned above, the end surfaces 8C and 8D of the light guide plate 8 provided with the LEDs 3 and the end surfaces 9E and 9F of the light guide plate 9 are adjacent to each other between the light guide plate 8 and the light guide plate 9. It is not configured. Therefore, the mounting portion 4 </ b> A of the FPC 4 for arranging the LEDs 3 on the end surface 8 </ b> C of the light guide plate 8 can be extended to the end surface 9 </ b> C of the light guide plate 9. That is, the FPC 4 is also arranged at a position facing the end surface 9C of the light guide plate 9 adjacent to the light guide plate 8. Thereby, the area of the mounting part 4 can be enlarged, suppressing the enlargement of the illuminating device 1. FIG. Similarly, for the FPC 4 in which the LEDs 3 are arranged on the end face 8D of the light guide plate 8, the area of the mounting portion 4 can be increased while suppressing an increase in the size of the lighting device 1.

  Similarly, for the FPC 5 in which the LEDs 3 are arranged on the end surface 9E of the light guide plate 9, the mounting portion 5A can be extended so as to face the end surface 8E of the light guide plate 8, and the enlargement of the lighting device 1 is suppressed. The area of the mounting part 5 can be increased. Further, the FPC 5 in which the LEDs 3 are arranged on the end surface 9F of the light guide plate 9 can similarly increase the area of the mounting portion 5 while suppressing the increase in size of the lighting device 1.

(Modification of lighting device 1)
As shown in FIG. 5, the mounting portion 4 </ b> A of the FPC 4 is extended in a position facing the end faces 9 </ b> C and 9 </ b> D of the light guide plate 9 adjacent to the light guide plate 8 to increase the area. Thereby, the thermal radiation part 10 can be provided under LED3, suppressing the enlargement of the illuminating device 1. FIG. Similarly, for the FPC 5, the area of the mounting portion 5 </ b> A can be increased, and the heat dissipation portion 10 can be provided on the upper side of the LED 3 without increasing the size of the lighting device 1. The heat radiation part 10 can be comprised by sticking metal foil, such as aluminum, or a thin metal plate, for example.

  The light guide plate 2 side surfaces of the mounting portion 4A of the FPC 4 and the mounting portion 5A of the FPC 5 are preferably white or silver. For example, by applying a white or silver paint to the mounting part 4A and the mounting part 5A, the surface of the mounting part 4A and the mounting part 5A on the light guide plate 2 side can be white or silver. It is good also as a structure which sticks a white or silver film to the mounting part 4A and the mounting part 5A.

  The heat radiation part 10 may be provided on either the side of the FPCs 4 and 5 facing the light guide plate 2 or the opposite side. When the heat radiating portion 10 is provided on the side of the FPC 4, 5 facing the light guide plate 2, the heat radiating portion 10 is also preferably white or silver.

  Generally, FPC has a brown color. Therefore, the color of FPC may be visually recognized from the light emission surface of the light guide plate. On the other hand, the surface of the mounting part 4A and the mounting part 5A on the light guide plate 2 side is white or silver, whereby the color of the light emitted from the light guide plate 2 can be brought close to the emission color of the LED 3.

  The white or silver mounting portion 4A is preferably opposed to the end surfaces 9C and 9D of the light guide plate 9, and the white or silver mounting portion 5A is also preferably opposed to the end surfaces 8E and 8F of the light guide plate 8. By comprising in this way, the color of the light radiate | emitted from the light-guide plate 2 can be closely approached by the luminescent color of LED3.

  The surface shapes and sizes of the mounting portions 4A and 5A are larger than the shape of each end surface of the light guide plate 2 (the same shape as the end surface, or when the end surface is projected onto the mounting surfaces 4A and 5A, It is preferable to have a size that can be included in the mounting surfaces 4A and 5A). By making the surface shapes and sizes of the mounting portions 4A and 5A in this way, when the mounting portions 4A and 5A are white or silver, the color of light emitted from the light guide plate 2 is made closer to the emission color of the LED 3. be able to.

  As shown in FIG. 6, the reflecting surface 11 may be provided on the lower surface 9B (see FIGS. 2 and 3) of the light guide plate 9, that is, the lower surface 2B of the light guide plate 2 (see FIGS. 2 and 3). By providing the reflecting surface 11 on the lower surface 2 </ b> B of the light guide plate 2, the lighting device 1 can be configured to emit one side. Further, by providing the reflective surface 11 on the lower surface 2B of the light guide plate 2, light emitted from the lower surface 2B can be returned again into the light guide plate 2 and emitted from the upper surface 2A, and the amount of light emitted from the upper surface 2A is increased. be able to. The reflective surface 11 may be provided on the upper surface 2A side. In this case, the amount of light emitted from the lower surface 2B can be increased.

  When there are a plurality of LEDs 3 mounted on the FPC 4, as shown in FIG. 7, a plurality of light diffusing portions 12 (on the end surfaces 8C and 8D on the side where the LEDs 3 are disposed on the upper surfaces 8A and 8B of the light guide plate 8 are provided. It is preferable to form the upper surface 8B side). The light diffusion portion 12 is formed in a portion corresponding to a portion between adjacent LEDs 3. Further, even when there are a plurality of LEDs 3 mounted on the FPC 5, a plurality of light diffusion portions 12 (on the upper surface 9B side) are provided on the end surfaces 9E and 9F on the side of the LED 9 on the upper surfaces 9A and 9B of the light guide plate 9. (Not shown) is preferably formed. The light diffusion portion 12 formed on the upper surfaces 9A and 9B is also formed in a portion corresponding to a portion between the adjacent LEDs 3.

  The light diffusing unit 12 can be constituted by, for example, innumerable fine irregularities formed on the upper surfaces 8A and 8B or the upper surfaces 9A and 9B by roughening treatment. The shape of the light diffusing portion 12 is a triangle with the end faces 8C and 8D and the end faces 9E and 9F sides as bases. That is, the light diffusing unit 12 has a shape in which the width becomes narrower from the end face side toward the light irradiation direction of the LED 3.

  On the upper surfaces 8A and 8B, the illuminance tends to decrease in the region between the adjacent LEDs 3. Therefore, by forming the light diffusing unit 12 in the portion where the illuminance tends to be low, the light is diffused by the light diffusing unit 12, and a decrease in illuminance in the region between the adjacent LEDs 3 can be suppressed. Therefore, the illuminance distribution of the light emitted from the upper surfaces 8A and 8B can be made uniform. Similarly, in the upper surfaces 9A and 9B, the illuminance is likely to decrease in the region between the adjacent LEDs 3. Therefore, by forming the light diffusing unit 12 in the portion where the illuminance tends to be low, the light is diffused by the light diffusing unit 12, and a decrease in illuminance in the region between the adjacent LEDs 3 can be suppressed. Therefore, the illuminance distribution of the light emitted from the upper surfaces 9A and 9B can be made uniform. As a result, the illuminance distribution of the light emitted from the upper surface 2A and the lower surface 2B of the light guide plate 2 can be made uniform.

  In addition, although the superposition | polymerization light-guide plate 2 shown in FIG. 7 is the structure which light radiate | emits from both surfaces of the upper surface 2A and the lower surface 2B, only the light radiate | emitted from any one surface, for example, the upper surface 2A, is also used as illumination light. In this case, it is sufficient that the light diffusing portion 12 is formed only on the upper surface 8A for the light guide plate 8, and only on the upper surface 9A for the light guide plate 9. When only the light emitted from the lower surface 2B is used as the illumination light, the light diffusing portion 12 only needs to be formed on the lower surface 8B for the light guide plate 8 and only on the lower surface 9B for the light guide plate 9. Therefore, for example, as shown in FIG. 6, in the case where the reflecting surface 11 is provided on the lower surface 2B of the light guide plate 2, the light diffusing portion is provided on the upper surface 8A for the light guide plate 8 and on the upper surface 9A for the light guide plate 9. 12 is sufficient.

  The planar shape of the light diffusing unit 12 is a triangle as shown in the figure. The light emitted from the LED 3 tends to have a large illuminance between the adjacent LEDs 3 and the LED 3, and the illuminance drop gradually decreases in the irradiation direction of the LED 3. Therefore, it is more preferable in order to make the illuminance distribution uniform by gradually reducing the area of the light diffusing portion 12 as it moves away from the LED 3 in the irradiation direction. In this sense, the shape of the light diffusing portion 12 is preferably a shape whose width becomes narrower as the distance from the LED 3 increases, and is not necessarily a triangle. For example, the shape that becomes narrower as it goes away from the LED 3 may be a circle or a part of an ellipse. However, the illuminance distribution can be effectively uniformed by using a triangle as compared with a circle or an ellipse.

  Incidentally, for example, as shown in FIG. 8, the light diffusing portion 12 can be formed so as to correspond to the four end faces 110 </ b> C, 110 </ b> D, 110 </ b> E, and 110 </ b> F of one light guide plate 110. In addition, the FPC 111 may be provided so that the LEDs 3 are disposed on the four end faces 110C, 110D, 110E, and 110F of the light guide plate 110, respectively.

  However, in the case of such a configuration, the light incident on the light guide plate 110 from the LEDs 3 disposed on the end surfaces 110C and 110D is diffused by the light diffusion portion 12 disposed corresponding to the end surfaces 110E and 110F. . Further, in the light diffusing unit 12 disposed corresponding to the end surfaces 110E and 110F, the light incident on the light guide plate 110 from the LEDs 3 disposed on the end surfaces 110E and 110F is also diffused. Therefore, the illuminance of the light diffusing unit 12 arranged corresponding to the end faces 110E and 110F tends to be extremely high.

  In addition, the light that has entered the light guide plate 110 from the LEDs 3 arranged with respect to the end faces 110E and 110F is diffused by the light diffusion portion 12 arranged corresponding to the end faces 110C and 110D. Further, in the light diffusing section 12 arranged corresponding to the end faces 110C and 110D, the light incident on the light guide plate 110 from the LEDs 3 arranged on the end faces 110C and 110D is also diffused. Therefore, the illuminance of the light diffusing unit 12 arranged corresponding to the end faces 110C and 110D tends to be extremely high.

  As described above, when the light diffusing unit 12 is formed on each of the four end surfaces 110C, 110D, 110E, and 110F of one light guide plate 110 and light is incident from each of the end surfaces, the illuminance of the light diffusing unit 12 is It tends to be extremely high, and the uniformity of the illuminance distribution of light emitted from the upper surface 110A or the lower surface 110B is impaired.

  On the other hand, like the illuminating device 1 described above, the light guide plate 8 and the light guide plate 9 are used as two pieces. For the light guide plate 8, the LED 3 is disposed only on the end surfaces 8C and 8D, and the end surface 8C where the LED 3 is disposed. , 8D only. That is, the light diffusion portion 12 is not formed on the end faces 8E and 8F where the LED 3 is not disposed. Therefore, the illuminance distribution of light emitted from the upper surface 8A or the lower surface 8B can be made uniform.

  Moreover, also about the light-guide plate 9, LED3 is arrange | positioned only at end surface 9E, 9F, and the light-diffusion part 12 is formed only in end surface 9E, 9F in which LED3 is arrange | positioned. That is, the light diffusion portion 12 is not formed on the end faces 9C and 9D where the LEDs 3 are not arranged. Therefore, the illuminance distribution of light emitted from the upper surface 9A or the lower surface 9B can be made uniform.

  The upper surface of the light guide plate 2 is made uniform by uniformizing the illuminance distribution of the light emitted from the upper surface 8A and the lower surface 8B of the light guide plate 8, and by uniformizing the illuminance distribution of the light emitted from the upper surface 9A and the lower surface 9B of the light guide plate 9. The illuminance distribution of light emitted from 2A or the lower surface 2B can be made uniform.

  The above-mentioned light diffusion part 12 is composed of, for example, a fine concavo-convex surface formed by a roughening process, but the light diffusion part 12 is composed of, for example, a plurality of fine lens shapes as shown in FIG. It is good also as the light-diffusion part 12A formed in the uneven | corrugated | grooved part of this.

  This will be described with reference to FIG. FIG. 9 is a partial enlarged view of a portion where the light diffusion portion 12A of the end surface 8D of the light guide plate 8 is formed. The light diffusion portion 12A formed on the end surface 8C and the light guide plate 9 has the same configuration. is there. In the light diffusion portion 12A, each of the illustrated dots is formed by a fine uneven portion having a convex lens shape, a concave lens shape, or a conical shape. In the following description, the concavo-convex portion will be described as a convex portion 12B having a convex lens shape.

  12 A of light-diffusion parts are formed in the part corresponding to the part between adjacent LED3. As shown in FIG. 9, the convex portions 12 </ b> B are arranged so as to be denser toward a side corresponding to an intermediate position between the adjacent LEDs 3 and closer to the end face 8 </ b> D where the LEDs 3 are arranged. Such a position where the convex portions 12B are densely arranged is a position corresponding to an intermediate position between the adjacent LEDs 3, and is therefore a position that tends to be far from the LED 3 and dark. Moreover, the convex part 12B is arrange | positioned so that it may become rough as it goes away from the position corresponding to said intermediate | middle position, and it is far from the end surface 8D.

  In addition, although illustration is abbreviate | omitted, it is good also as a structure which provides a V-shaped groove | channel other than a convex lens shape, a concave lens shape, and a cone-shaped uneven part. The V-shaped groove is preferably arranged so as to radially spread from the position where the convex portions 12B gather most closely in the range of the illustrated light diffusion portion 12A.

  According to the present embodiment described above, the light diffusing portion 12A formed by an aggregate of convex lens shape, concave lens shape, conical concavo-convex portion and V-shaped groove is provided, and these aggregates are adjacent to the LED 3 It is a position corresponding to an intermediate position between them, and is arranged so as to be denser as it is closer to the end face 8D where the LED light source is arranged, and from the end face 8D as it moves away from the position corresponding to the intermediate position. It arranges so that it becomes rough as it goes away. By doing in this way, the fall of the brightness of the position which becomes dark easily between LED3 can be reduced, and the illuminance distribution of the light radiate | emitted from the upper surface 2A of the superposition | polymerization light-guide plate 2 can be aimed at.

  As shown in FIG. 9, the upper surface 8 </ b> A of the light guide plate 8 is dotted with convex portions 12 </ b> B at portions other than the light diffusion portion 12 </ b> A. In this way, the occurrence of uneven color can be suppressed by interposing the convex portions 12B. Similarly, with respect to the light guide plate 9, it is possible to suppress the occurrence of color unevenness by interspersing the convex portions 12B in portions other than the light diffusion portion 12A.

  In addition to forming the light diffusing portion 12 on the light guide plates 8 and 9, the surface of the mounting portions 4A and 5B on the light guide plate 2 side is white or silver, so that the upper surface 2A or the lower surface of the superposed light guide plate 2 can be obtained. The illuminance distribution of the light emitted from 2B can be made more uniform.

  Illumination device 1 shows an example in which light guide plates 8 and 9 are square in a plan view, but may be a rectangle, or may be a triangle or a polygon that is a pentagon or more. Further, the number of light guide plates to be stacked is not limited to two. In the above-described example, the configuration including the two light guide plates 8 and 9 is shown. However, as illustrated in FIG. 10, the superposition light guide plate 2 may be configured by three light guide plates 8, 9, and 13. . In this case, the colors of light incident on the light guide plates may be different from each other. For example, the color light of the LED 3 incident on the light guide plate 8 can be red, the color light of the LED 3 incident on the light guide plate 9 can be green, and the color light of the LED 3 incident on the light guide plate 13 can be blue.

  In this embodiment, the LED 3 is used as a light source. However, as the light source, a CCFL (Cold Cathode Fluorescent Lamp), a light bulb (for example, an incandescent light bulb), a fluorescent light, or the like is used. The type of the light source is not particularly limited. However, LED light sources are superior to other light sources in that they consume less power, generate less heat, are easier to miniaturize, and are less expensive. Therefore, also in the embodiment described below, a case where the LED 3 is used as a light source will be described as an example.

(Another embodiment of the present invention)
As shown in FIGS. 11 to 13, the lighting device 1 may be configured as a lighting device 20 that further includes a light diffusing plate 21, a frame 22, and a reflecting plate 23 (see FIGS. 12 and 13). FIG. 11 is a plan view showing a schematic configuration of the illumination device 20. As shown in FIG. 11, the lighting device 20 includes a light source unit 24 on the left end surface side, a light source unit 25 on the right end surface side, a light source unit 26 on the front end surface side, and a light source unit 27 on the rear end surface side. Yes. FIG. 12 is a partial cross-sectional view showing a schematic configuration of the light source unit 24 along the AA section of FIG. 11. FIG. 13 is a partial cross-sectional view showing a schematic configuration of the light source unit 27 along the BB cut surface in FIG. 11. In addition, about the member similar to the illuminating device 1, the same code | symbol is attached | subjected and the description may be abbreviate | omitted or simplified.

  In the illuminating device 20, the light source unit 24 includes an end surface 2 </ b> D, an LED 3 disposed on the end surface 2 </ b> D side, a mounting portion 4 </ b> A (see FIG. 12) of the FPC 4, a frame 22, and a protruding portion 28 of the light diffusion plate 21. In addition, it refers to a portion where a peripheral portion 29A (see FIG. 12), which is a portion facing the protruding strip portion 28 of the polymerization light guide plate 2, is disposed. Further, the light source unit 25 includes the end surface 2C, the LED 3 disposed on the end surface 2C side, the mounting portion 4A of the FPC 4, the frame 22, the ridges 28 of the light diffusion plate 21, and the ridges of the superposition light guide plate 2. The part where the peripheral part 29B which is a part facing the part 28 is arranged is said.

  The light source unit 26 includes the end surface 2E, the LED 3 disposed on the end surface 2E side, the mounting portion 5A of the FPC 5, the frame 22, the projecting strip portion 28 of the light diffusion plate 21, and the projecting strip of the superposition light guide plate 2. The part where the peripheral part 29C which is a part facing the part 28 is arranged is said. The light source unit 27 includes an end surface 2F, an LED 3 disposed on the end surface 2F side, a mounting portion 5A (see FIG. 13) of the FPC 5, a frame 22, a protruding portion 28 of the light diffusion plate 21, and a polymerization guide. It refers to a portion where a peripheral portion 29D (see FIG. 13), which is a portion facing the protruding strip portion 28 of the optical plate 2, is disposed.

  The light source unit 24 and the light source unit 25 are arranged so as to face each other, but have a common configuration. The light source unit 26 and the light source unit 27 are also arranged so as to face each other, but have a common configuration. The light source unit 24 and the light source unit 25 are different from the light source unit 26 and the light source unit 27 in the light guide plate on which the LEDs 3 are arranged (in the light source unit 24 and the light source unit 25, the LED 3 is arranged on the light guide plate 8 and the light source unit 26 And in the light source part 27, LED3 is arrange | positioned at the light-guide plate 9), and is the same structure. The light source unit 24 and the light source unit 25 will be described with reference to the light source unit 24 in FIG. 12, and the light source unit 26 and the light source unit 27 will be described with reference to the light source unit 27 in FIG. . 12 and 13, the same components as those of the light source unit 24 and the light source unit 27 are denoted by the same reference numerals.

  The illuminating device 20 has a flat panel shape in the vertical direction as a whole, and has an outer shape viewed from above, that is, a contour shape in plan view. The light diffusing plate 21 is disposed on the upper surface 2A side of the superposed light guide plate 2 as the first light emitting surface. As the light diffusing plate 21, a light scattering light guide containing a large number of light scattering particles is used. By using a light scattering light guide for the light diffusion plate 21, the light incident on the light diffusion plate 21 is scattered in the light diffusion plate 21. The frame 22 is provided on each of the end surfaces 2C, 2D, 2E, and 2F of the polymerization light guide plate 2 and has a function of an attachment member that attaches the LED 3 to the polymerization light guide plate 2. That is, each frame 22 holds the FPC 4 or FPC 5 on which the LED 3 that makes light incident on each end face is mounted, and each frame 22 is attached to the peripheral edge of the superposition light guide plate 2, so that the LED 3 becomes the superposition light guide plate 2. Attached to. The frame 22 also functions as a light shielding member that shields light emitted from the LEDs 3 from directly entering the light diffusion plate 21.

  In the illumination device 20, a reflection plate 23 is disposed on the lower surface 9 </ b> B side of the light guide plate 9 (in the direction opposite to the light diffusion plate 21). Further, a circuit 30 that controls the driving of the LED 3 is disposed on the lower surface side of the reflecting plate 23. The reflection plate 23 may be a reflection sheet, or may be configured to apply a reflective paint. The color of the reflection part is preferably white or silver.

  The LED 3 is disposed on the end surface 2C on the right side, the end surface 2D on the left side, the end surface 2E on the front side, and the 2F on the rear side of the superposition light guide plate 2, and light emitted from the LED 3 is transmitted from each end surface. The light enters the polymerization light guide plate 2. Light incident on the polymerization light guide plate 2 from each end face is scattered in the polymerization light guide plate 2 and is emitted from the upper surface 2A to the light diffusion plate 21 side.

  In the superposition light guide plate 2, the light guide plate 8 and the light guide plate 9 are overlapped, the LED 3 is arranged on the end faces 8C and 8D in the light guide plate 8, and the LED 3 is arranged on the end faces 9E and 9F in the light guide plate 9. Yes. Therefore, as shown in FIG. 12, the light incident on the light guide plate 8 from the end face 8D is mainly scattered in the light guide plate 8 and is emitted from the upper surface 2A (upper surface 8A) to the light diffusion plate 21 side. Similarly, the light incident on the light guide plate 8 from the end face 8C is mainly scattered in the light guide plate 8 and emitted from the upper surface 2A (upper surface 8A) to the light diffusion plate 21 side. Further, as shown in FIG. 13, the light incident on the light guide plate 9 from the end surface 9 </ b> F is mainly scattered in the light guide plate 9, emitted from the upper surface 9 </ b> A to the light guide plate 8 side, and diffused through the light guide plate 8. The light is emitted to the plate 21 side. Similarly, the light incident on the light guide plate 9 from the end face 9E is mainly scattered in the light guide plate 9 and emitted from the upper surface 9A to the light guide plate 8 side, and then emitted to the light diffusion plate 21 side through the light guide plate 8.

  The lower surface 2B is in intimate contact with the reflecting plate 23, and the lower surface 2B also functions as a reflecting surface 31 for light traveling inside the superposed light guide plate 2. Therefore, the light incident on the light guide plate 9 from the light guide plate 8 is reflected upward by the reflection surface 31 and can be emitted from the upper surface 2A (upper surface 8A) to the light diffusion plate 21 side. Further, the light traveling in the light guide plate 9 is also reflected upward by the reflection surface 31 and can be emitted from the upper surface 2A (upper surface 8A) to the light diffusion plate 21 side.

  As described above, the light guide plates 8 and 9 contain a large number of light scattering particles. Therefore, the light incident on the light guide plates 8 and 9 can be scattered inside the light guide plate, and the illuminance distribution of the light emitted from the superposed light guide plate 2 can be made uniform.

  In addition, although LED3 is arrange | positioned in the thickness range of each light-guide plate 8 and 9, it is preferable to arrange | position to the approximate center of the thickness of the light-guide plates 8 and 9. FIG. By disposing at the center, light incident on the light guide plates 8 and 9 can be efficiently emitted from the upper surface 2A as compared with the case where the light is not disposed at the center.

  The frame 22 is formed by bending a metal plate, and includes a base portion 32 extending along the end surfaces 2C, 2D, 2E, and 2F, and a light shield that is bent and extended from the base portion 32 to the upper surface 2A side of the polymerization light guide plate 2. And a light shielding part 34 that is bent and extended toward the reflecting plate 23 side. The frame 22 is attached to the illumination device 20 by sandwiching the light guide plate 2 and the reflection plate 23 between the light shielding unit 33 and the light shielding unit 34.

  Further, the frame 22 has the light-shielding portion 33 and the light-shielding portion 34 in close contact with the superposed light guide plate 2 and the reflective plate 23 so as to sandwich the superposed light guide plate 2 and the reflective plate 23. In the light shielding part 33, the light emitted from the LED 3 does not enter the light diffusion plate 21 as it is, that is, the light from the LED 3 is not directly incident on the light diffusion plate 21 arranged in the upward direction of the LED 3. Has a light shielding function. The light shielding part 34 has a light shielding function for preventing light from the LED 3 from leaking to the outside on the back side of the reflecting plate 23.

  The reflection plate 23 is a plate member having substantially the same shape as that of the polymerization light guide plate 2 in a plan view, is in close contact with the lower surface 2B of the polymerization light guide plate 2, and reflects light traveling in the polymerization light guide plate 2 on the reflection surface 31. Let In FIG. 12, the position of the end surface 35 on the left side of the reflecting plate 23 coincides with the position of the end surface 2 </ b> D of the superposed light guide plate 2, but it may protrude outward and extend below the LED 3. . The same applies to the light source units 25, 26, and 27.

  The light diffusion plate 21 is quadrangular in plan view. The planar shape and planar size of lighting device 20 in the present embodiment are defined. That is, the outer peripheral end surface 36 of the light diffusing plate 21 is disposed in the same plane as the outer side surface 37 of the frame 22 or protrudes outward from the outer side surface 37 (the side that increases the plain size of the light diffusing plate 21). . On the light diffusing plate 21, a protruding strip portion 28 is formed so as to project toward the upper surface 2 </ b> A of the polymerization light guide plate 2. The protruding portion 28 is provided in each of the light source portions 24, 25, 26, and 27. The ridge portion 28 is disposed at a position facing the peripheral edge portions 29A, 29B, 29C, 29D on the side where the LED 3 of the polymerization light guide plate 2 is disposed.

  A light incident surface 38 as a second light incident surface, which is a tip portion of the ridge 28, is a flat surface and faces the peripheral portions 29 </ b> A, 29 </ b> B, 29 </ b> C, 29 </ b> D of the superposition light guide plate 2. Of the upper surface 2A, light emitted mainly from the peripheral portions 29A, 29B, 29C, and 29D is incident on the light incident surface 38. In the illuminating device 20, the ridge 28 is provided over the entire circumference of the light diffusing plate 21, that is, with respect to the peripheral portions 29 </ b> A, 29 </ b> B, 29 </ b> C, and 29 </ b> D. By forming it over the entire circumference in this way, the rigidity of the light diffusing plate 21 can be increased.

  The light diffusing plate 21 has a recess 39 in a cross-sectional shape in an AA cut surface (BB cut surface), that is, a plane orthogonal to the arrangement direction of the LEDs 3. The recessed part 39 is formed inside the protruding strip part 28 formed in the light diffusing plate 21 over the entire circumference. The ridge inner bottom surface 40 as the first light incident surface, which is the bottom surface of the recess 39, is a light incident surface on which light emitted from the upper surface 2A is incident. The outer peripheral end surface 36 is a surface in contact with air. In addition, an inner peripheral side surface 41 which is the surface opposite to the outer peripheral end surface 36 with the convex strip portion 28 interposed therebetween and which is the inner side surface of the concave portion 39 is also a surface in contact with air.

  Therefore, the light incident on the outer peripheral end surface 36 beyond the critical angle inside the ridge 28 is totally reflected by the outer peripheral end surface 36. Further, the light that enters the inner peripheral side surface 41 beyond the critical angle inside the ridge 28 is totally reflected by the inner peripheral side surface 41. The outer peripheral end surface 36 and the inner peripheral side surface 41 are parallel to each other, and the light incident surface 38 is a surface orthogonal to the outer peripheral end surface 36 and the inner peripheral side surface 41.

  The light incident surface 38 of the ridge 28 is shielded by the light shielding portion 43 and the light shielding portion 43, which is a region where the light emitted from the LED 3 or the upper surface 2 </ b> A (particularly the peripheral portion 29 </ b> A) is shielded by the light shielding portion 33. And an incident region 44 that is an incident region without incident. That is, by arranging the light shielding part 33 between the light incident surface 38 of the ridge 28 and the peripheral part 29A on the side where the LED 3 of the superposition light guide plate 2 is arranged, the light emitted from the peripheral part 29A can be obtained. The amount of light incident on the light incident surface 38 can be limited.

  The light shielding region 43 has at least a width (width dimension in the thickness direction of the ridge portion 28) that does not allow the light emitted from the LED 3 to directly enter the light diffusion plate 21 without passing through the superposition light guide plate 2. Further, in the present embodiment, the width of the light shielding region 43 and the width of the incident region 44 (the width dimension in the thickness direction of the ridge portion 28) are the light incident on the light incident surface 38 from the upper surface 2A. When the light is emitted from the upper surface 42 as the light emitting surface, the entire illuminance distribution of the upper surface 42 is set to be uniform. The light incident on the light incident surface 38 from the upper surface 2A is mainly emitted from the peripheral edge of the upper surface 42. The width of the light shielding region 43 and the width of the incident region 44 are set so that the brightness of the peripheral edge of the upper surface 42 approaches the brightness inside the peripheral edge.

  The light incident surface 38 of the convex portion 28 of the light diffusing plate 21 and the light shielding portion 33 of the frame 22 are in close contact. In the lighting device 20, the overlapped light guide plate 2 and the reflection plate 23 are overlapped with each other, and the periphery of the overlap light guide plate 2 and the reflection plate 23 is between the light shielding portion 33 and the light shielding portion 34 of the frame 22. It is sandwiched between. The polymerization light guide plate 2, the reflection plate 23, and the frame 22 are fixed to each other by screws (not shown) penetrating from the light shielding part 34 side to the reflection plate 23 and the polymerization light guide plate 2. The contact surfaces may be fixed and integrated with an adhesive having a high light transmittance. The light diffusing plate 21 can be fixed to the light shielding portion 33 of the frame 22 by an adhesive in the light shielding region 43 of the light incident surface 38.

  Next, in the illumination device 20, a light path until the light emitted from the LED 3 is emitted from the upper surface 42 of the light diffusion plate 21 will be described with reference to FIGS. 11 and 12. As described above, the light source unit 24 and the light source unit 25 and the light source unit 26 and the light source unit 27 have the same configuration except that the light guide plate on which the LEDs 3 are arranged is different. Therefore, in the following description, the light source unit 24 will be exemplified and described mainly with reference to FIG. 12, and the light source unit 26 and the light source unit 27 will be described with reference to FIG. 13 as necessary.

  In the light source unit 24, a part of the light emitted from the LEDs 3 arranged on the end surface 8 </ b> D on the light guide plate 8 side in the end surface 2 </ b> D of the superposed light guide plate 2 enters the light guide plate 8 from the end surface 8 </ b> D. Then, for example, as indicated by a broken line L1 shown in FIG. 12, the light travels toward the right side (end surface 8C side) while being totally reflected by the upper surface 8A and the lower surface 8B of the light guide plate 8, and proceeds while being scattered by the light scattering particles. These are emitted in a diffused state from the upper surface 8A to the light diffusion plate 21 side. Other part of the light emitted from the LED 3 of the light source unit 24 is not totally reflected by the upper surface 8A or the lower surface 8B but proceeds while being scattered by the light scattering particles, and is emitted from the upper surface 8A in a diffused state. There is also.

  Similarly to the light source unit 24, the light emitted from the LED 3 arranged with respect to the end face 8C also enters the light guide plate 8 from the end face 8C. Then, the light incident on the light guide plate 8 is scattered by the total reflection and light scattering particles on the upper surface 8A and the lower surface 8B of the light guide plate 8, and eventually diffuses from the upper surface 8A to the light diffusion plate 21 side. It is emitted at.

  As shown in FIG. 13, in the light source unit 27, a part of the light emitted from the LEDs 3 arranged on the end surface 9 </ b> F on the light guide plate 9 side of the end surface 2 </ b> F of the superposed light guide plate 2 is transmitted from the end surface 9 </ b> F to the light guide plate 9. Incident in. For example, as indicated by a broken line L2, the light guide plate 9 proceeds toward the front side (end surface 9E side) while being totally reflected by the upper surface 9A and the lower surface 9B, and proceeds while being scattered by the light scattering particles. Enters the light guide plate 8 from the upper surface 9A. The light that has entered the light guide plate 8 is emitted in a diffused state from the upper surface 8 </ b> A to the light diffusion plate 21 side via the light guide plate 8. Other part of the light emitted from the LED 3 of the light source unit 27 proceeds while being scattered by the light scattering particles without being totally reflected by the upper surface 9A or the lower surface 9B, and enters the light guide plate 8 from the upper surface 9A. There are also things.

  Similarly to the light source unit 27, the light emitted from the LEDs 3 arranged with respect to the end surface 9E also enters the light guide plate 9 from the end surface 9E. The light incident on the light guide plate 9 is scattered by the total reflection and light scattering particles on the upper surface 9A and the lower surface 9B of the light guide plate 9, and eventually enters the light guide plate 8 from the upper surface 9A. The light is emitted in a diffused state from the upper surface 8A to the light diffusion plate 21 side.

  Light emitted from the LEDs 3 of the light sources 24, 25, 26, and 27, incident on the polymerization light guide plate 2, and emitted from the upper surface 2 </ b> A in a diffused state is generated in the light guide plate 8 and the light guide plate 9 in the polymerization light guide plate 2. Illuminance is made uniform by total reflection and scattering.

  The light emitted from the top surface 2A of the superposition light guide plate 2 is incident on the convex inner side bottom surface 40 of the convex strip portion 28 of the light diffusing plate 21 and the light incident surface 38 of the convex strip portion 28. Then, the light is emitted from the upper surface 42. The light diffusing plate 21 contains light scattering particles. Therefore, the light incident on the light diffusing plate 21 is scattered in the light diffusing plate 21, and the illuminance distribution of the light emitted from the upper surface 42 can be made uniform.

  The light emitted from the LED 3 is bright at a position close to the LED 3 and becomes dark as the distance increases. However, the lighting device 20 includes a light source unit 24 and a light source unit 25 on the left and right sides, and includes a light source unit 26 and a light source unit 27 on the front and rear sides. Therefore, since light advances toward the left and right and front and back, the light source unit 24 and the light source unit 25 complement each other and the light source unit 26 and the light source unit 27 complement each other. The brightness at is equalized.

  As shown in FIG. 12, the light shielding portion 33 of the frame 22 is disposed on the peripheral edge portion 29 </ b> A near the LED 3 of the superposition light guide plate 2. The light incident on the convex portion 28 from the LED 3 and the peripheral portion 29 </ b> A is limited (light-shielded) by the light-shielding portion 33, and a part of the light incident surface 38 is a light-shielding region 43. The light shielding unit 33 also shields light directed directly from the LED 3 disposed on the light guide plate 8 toward the light incident surface 38.

  On the other hand, in the incident region 44, a part of the light emitted from the LED 3 and incident from the end face 8D and emitted from the upper surface 2A toward the light incident surface 38 of the ridge 28 is incident. A part of the light incident from the light incident surface 38 of the ridge portion 28 is totally reflected by the inner peripheral side surface 41 and the outer peripheral end surface 36 of the ridge portion 28 as shown by a broken line L3, and light scattering. Proceed while being scattered by particles. And it is radiate | emitted mainly from the arrangement | positioning area | region of the protruding item | line part 28 of the upper surface 42 of the light-diffusion plate 21, ie, the peripheral part of the side by which LED3 of the upper surface 42 is arrange | positioned. That is, a part of the light emitted from the LED 3 and incident from the end surface 8D and entering the ridge portion 28 is totally reflected by the inner peripheral side surface 41 and the outer peripheral end surface 36 and scattered by the light scattering particles. The light is emitted from the upper surface 42 in a diffused state by proceeding with the movement. The light incident on the ridge 28 is mainly emitted from the upper portion of the upper surface 42 above the ridge 28.

  Further, as shown in FIG. 13, the light shielding portion 33 of the frame 22 is also disposed in the peripheral portion 29 </ b> D near the LED 3 of the superposition light guide plate 2. Therefore, also in the light source unit 27, the light incident on the convex portion 28 from the LED 3 and the peripheral portion 29 </ b> D is limited (shielded) by the light shielding unit 33, and a part of the light incident surface 38 is a light shielding region 43. . The light shielding unit 33 also shields light directed directly from the LED 3 disposed on the light guide plate 9 toward the light incident surface 38.

  On the other hand, in the incident region 44 of the peripheral portion 29D, light is incident from the end surface 9F of the light guide plate 9, and is emitted from the upper surface 2A toward the light incident surface 38 of the ridge portion 28 via the light guide plate 9 and the light guide plate 8. Is incident. Also in the peripheral portion 29D, as in the peripheral portion 29A, a part of the light incident from the light incident surface 38 of the ridge portion 28 is, as indicated by a broken line L4, the inner peripheral side surface 41 and the outer peripheral end surface of the ridge portion 28. 36, while being totally reflected by 36 and scattered by light scattering particles, is emitted in a diffused state from the peripheral portion of the upper surface 42 on the side where the LED 3 is disposed. Also in the peripheral portion 29 </ b> D, the light incident on the ridge 28 is mainly emitted from the upper portion of the upper surface 42 from the ridge 28.

  In the lighting device 20 described above, the light shielding region 43 is formed by the light shielding unit 33 of the frame 22. Thereby, the light emitted from the LED 3 is prevented from directly entering the light diffusion plate 21. Further, a part of the light incident on the polymerization light guide plate 2 is emitted as diffused light from the upper surface 2A while being totally reflected in the light guide plates 8 and 9 and scattered by the light scattering particles. 21 is incident. The light emitted from the upper surface 2A passes through the light diffusion plate 21 and is emitted from the upper surface 42 while being further diffused by the light diffusion plate 21.

  Further, the light diffusing plate 21 of the illuminating device 20 is provided with a ridge portion 28 corresponding to each of the peripheral edge portions 29A, 29B, 29C, and 29D. By providing the protruding strip portion 28, the outer peripheral end surface 36 and the inner peripheral side surface 41 that are in contact with air are formed. Therefore, part of the light emitted from the peripheral edge portions 29A, 29B, 29C, and 29D of the superposed light guide plate 2 and incident on the light incident surface 38 of the ridge 28 is the inner peripheral side surface 41 and the outer peripheral end surface 36 of the ridge 28. And diffused light is emitted from the peripheral portion of the upper surface 42 of the light diffusion plate 21 while being totally reflected by the light scattering particles and scattered by the light scattering particles.

  That is, by forming the light shielding region 43 with the light shielding part 33, the light emitted from the LED 3 can be incident on the superposition light guide plate 2 without being directly incident on the light diffusion plate 21. A part of the light incident on the polymerization light guide plate 2 is emitted as diffused light from the upper surface 2A while being totally reflected in the polymerization light guide plate 2 and diffused by the light scattering particles, and is incident on the light diffusion plate 21. The Thereby, when the upper surface 42 which has radiate | emitted light is seen, it can prevent that the part of LED3 is conspicuously seen as a part with high illumination intensity compared with the circumference | surroundings.

  In the illuminating device 20, the protruding portion 28 is formed on the light diffusing plate 21 so as to correspond to the peripheral portions 29 </ b> A, 29 </ b> B, 29 </ b> C, and 29 </ b> D of the superposed light guide plate 2. Therefore, the light emitted from the peripheral portions 29 </ b> A, 29 </ b> B, 29 </ b> C, and 29 </ b> D can be guided into the ridge portion 28 from the light incident surface 38 of the ridge portion 28. The light diffused by the light diffusing plate 21 while being totally reflected by the inner peripheral side surface 41 and the outer peripheral end surface 36 of the ridge 28 and scattered by the light scattering particles. Diffuse light is emitted from the peripheral edge of the upper surface 42 of the light source. Accordingly, even when the light shielding part 33 is provided, it is possible to prevent a dark part that is shielded and bordered by the light shielding part 33 from occurring on the peripheral part of the upper surface 42 on the side where the light shielding part 33 is provided. it can.

  Accordingly, the peripheral portion of the light emitting surface is not darkened as if the peripheral portion of the light emitting surface is trimmed, while excluding that the appearance of the LED 3 from the upper surface 42 is conspicuously visible as a portion with high illuminance. Thus, it is possible to provide the lighting device 20 that uniformizes the overall brightness of the upper surface 42.

  Note that the size of the light incident region 44 of the ridge 28 can be adjusted by increasing or decreasing the width of the ridge 28, and thereby the light is emitted from the polymerization light guide plate 2. By adjusting the amount of light incident on the ridges 28, the illuminance distribution at the central part and the peripheral part on the light exit surface of the light diffusing plate 21 can be easily made uniform.

  That is, by adjusting the width of the incident region 44 (the dimension in the left-right direction in FIG. 12 and the dimension in the front-rear direction in FIG. 13), the amount of light incident on the ridges 28 from the upper surface 2A can be adjusted. Thereby, the light quantity emitted from the peripheral edge portion of the upper surface 42 of the light diffusing plate 21 can be adjusted. For example, by adjusting the width of the incident region 44, the difference in the amount of light emitted from the peripheral portion of the upper surface 42 of the light diffusing plate 21 and the inner side thereof can be reduced, and the entire illuminance of the upper surface 42 can be made uniform. Can do. The width of the incident region 44 can be adjusted by adjusting the width of the light shielding unit 42.

  In the illuminating device 1 according to the present embodiment, the light shielding region 43 is formed by the light shielding portion 33 provided in the frame 22. However, the light shielding region 43 may be formed by, for example, attaching a light shielding tape to the light incident surface 38 or applying a light shielding coating. By providing the light shielding portion 33 on the frame 22, it is possible to reduce the number of members such as omitting a tape or paint, or to omit the attaching or applying process.

  As shown in FIGS. 7 and 9, the superposed light guide plate 2 held by the frame 22 has the light diffusion portion 12 or the light diffusion portion 12A formed on the upper surface 8A and the upper surface 9A of the light guide plate 8 and the light guide plate 9. It may be. By forming the light diffusing portion 12 or the light diffusing portion 12A on the light guide plate 8 and the light guide plate 9, the illuminance distribution of the light emitted from the upper surface 2A of the superposed light guide plate 2 can be made uniform. Therefore, in addition to providing the light diffusing plate 21 with the ridges 28, the light diffusing portion 12 or the light diffusing portion 12A is formed on the light guide plate 8 and the light guiding plate 9, so that the illuminance at the peripheral portion of the light diffusing plate 21 is increased. Can be effectively prevented from decreasing. That is, the illuminance distribution on the upper surface 42 that is the light emitting surface of the light diffusing plate 21 including the periphery of the light diffusing plate 21 can be made uniform.

(Modification of lighting device 20)
In the lighting device 20, the brightness of the upper surface 42 can be made more uniform by devising the shape of the light shielding portion 33 of the frame 22, the shape of the light diffusion plate 21, and the like. This will be described below as a modification of the lighting device 20.

(Modification 1)
FIG. 14 is a partial plan view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 intersect with each other, showing an illumination device 201 which is a modification of the lighting device 20. In the lighting device 201, the shape of the frame 45 is different from the shape of the frame 22 of the lighting device 20. The lighting device 201 has the same configuration as the lighting device 20 except for the frame 45. Therefore, in FIG. 14, the same components as those of the lighting device 20 are denoted by the same reference numerals, and the description thereof is omitted.

  The light shielding portion 33 of the frame 45 includes convex portions 45A and concave portions 45B that are alternately arranged along the arrangement direction of the plurality of LEDs 3. The convex portion 45A protrudes inward from the end surface side of the superposition light guide plate 2 to the upper surface 2A, covers the upper part of the LED 3 on the light diffusion plate 21 side, and the light emitted from the LED 3 is light within the formation range of the convex portion 45A. The light is shielded so that it does not directly enter the ridge 28 of the diffuser plate 21. The concave portion 45B has an opening corresponding to the portion between the adjacent LEDs 3, and the light emitted from the LED 3 passes through the concave portion 45B and escapes to the light diffusion plate 21 side. The light enters the portion 28.

  As described above, in the frame 45, the light shielding part 33 has the convex part 45A that shields the light emitted from the LED 3, and the concave part 45B that allows the light emitted from the LED 3 to pass therethrough. This makes it possible to reduce the difference in brightness of light incident on the ridges 28 as compared to the frame 22 without the projections 45A and the recesses 45B as in the light shielding part 33 shown in FIGS. it can. As a result, it is possible to provide the illuminating device 201 that can make the illuminance distribution on the upper surface 42 more uniform.

  The shape of the convex portion 45A may not be rectangular as shown in the figure, but may be a trapezoid with a thin tip, a triangle, or a circular tip. The concave portion 45B and the light incident on the convex stripe portion 28 may be used. What is necessary is just to set the vertical and horizontal dimension and shape which can make the difference in brightness small. Moreover, the frame 45 of the present example provided with the convex part 45A and the concave part 45B can be used for each embodiment described below.

(Modification 2)
Next, an illumination device 202 which is another modification of the illumination device 20 will be described with reference to FIG. In the lighting device 202, the shape of the light diffusion plate 46 is different from the shape of the light diffusion plate 21 of the lighting device 20. The lighting device 202 has the same configuration as that of the lighting device 20 except for the light diffusion plate 46. Therefore, in FIG. 15, the same components as those of the lighting device 20 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 15 is a partial bottom view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 46 intersect as viewed from below.

  On the inner peripheral side surface 41 connected to the light incident area 44 of the convex portion 28 of the light diffusing plate 46, a corrugated uneven surface 47 is formed along the arrangement direction of the plurality of LEDs 3. In FIG. 15, the corrugated shape of the uneven surface 47 is exaggerated. Moreover, the pitch of the corrugated uneven surface 47, the arrangement pitch of the LEDs 3, and the depth of the uneven surface 47 can be arbitrarily set. In the illuminating device 202, the uneven surface 47 is formed over the entire upper and lower widths (width in the depth direction of the recess 39) of the inner peripheral side surface 41. For example, the uneven surface 47 is formed in the lower half, the upper half, etc. May be.

  Next, the progression of light in the ridges 28 of the lighting device 20 will be described with reference to FIGS. The light emitted from the LED 3 enters the polymerization light guide plate 2 from the end faces 2C, 2D, 2E, 2F of the polymerization light guide plate 2. A part of the light incident on the superposition light guide plate 2 enters the light incident surface 38 of the ridge 28 in the incident region 44. A part of the light incident from the light incident surface 38 of the ridge portion 28 proceeds while being totally reflected on the inner peripheral side surface 41 and the outer peripheral end surface 36 of the ridge portion 28 and diffused by the light scattering particles. The light is emitted mainly from above the arrangement position of the ridges 28 on the light emission surface of the plate 21.

  An uneven surface 47 is formed on the inner peripheral side surface 41 of the ridge 28. Therefore, the light is easily diffused on the concavo-convex surface 47 as shown by an arrow R1 in FIG. By doing in this way, even if the frame 22 exists, the peripheral part of the light diffusing plate 21 can be brightened, and it can be prevented from becoming dark as if the peripheral part of the light diffusing plate 21 was edged. Therefore, the illuminance distribution of the entire light exit surface of the light diffusing plate 21 can be made more uniform.

(Modification 3)
Next, an illumination device 203 that is another modification of the illumination device 20 will be described with reference to FIGS. In the lighting device 203, the shape of the light diffusion plate 48 is different from the shape of the light diffusion plate 21 of the lighting device 20. The illuminating device 203 has the same configuration as the illuminating device 20 except for the light diffusion plate 48. Therefore, in FIG. 16, the same components as those of the lighting device 20 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 16 is a partial bottom view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 48 intersect as viewed from below. FIG. 17 is a side view showing a schematic configuration of the light diffusing plate 48 viewed from the arrow A direction.

  As shown in FIGS. 16 and 17, the light diffusing plate 48 has a V-shaped crossing (from the outer peripheral end surface 36 to the inner peripheral side surface 41) across the convex portion 28 on the light incident surface 38 of the convex portion 28. A groove 49 is formed. The V-shaped groove 49 has a prism effect of light, and as shown in FIG. The A part of the incident light is diffused by the inclined surface of the V-shaped groove 49 and is incident on the ridge 28 as shown by an arrow R2, for example. The light travels while being totally reflected between the peripheral side surface 41 and being scattered by the light scattering particles, and is emitted mainly from above the position where the ridges 28 are disposed on the upper surface 42 of the light diffusion plate 21.

  FIG. 17 shows the portion of the light source unit 24, but similarly for the light source unit 27, the light emitted from the LEDs 3 arranged on the end face 9 </ b> F of the light guide plate 9 is projected through the light guide plate 8. The light is incident from the incident region 44 of the light incident surface 38. Then, a part of the incident light is diffused by the slope of the V-shaped groove 49 and enters the ridge 28, and is entirely between the outer peripheral end surface 36 and the inner peripheral side 41 of the ridge 28. The light travels while being reflected and scattered by the light scattering particles, and exits mainly from the upper position of the convex portion 28 on the upper surface 42 of the light diffusion plate 21.

  Therefore, the light emitted from the superposition light guide plate 2 is diffused by the light incident surface 38 and is incident on the ridge 28. As a result, even if the light shielding portion 33 of the frame 22 is present, the peripheral portion of the light emitting surface on which the ridge portion 28 is disposed is brightened, and the peripheral portion is not darkened as if the peripheral portion was trimmed. The illuminance distribution of the light emitted from 42 can be made uniform.

  16 and 17, the size of the V-shaped groove 49 is exaggerated. The V-shaped groove 49 only needs to have a light prism effect, and the relative position to the LED 3, the depth of the groove 49, and the pitch can be set arbitrarily. Accordingly, a so-called prism sheet can be used as the V-shaped groove 49.

  In FIG. 16, the V-shaped groove 49 crosses from the outer peripheral end surface 36 to the inner peripheral side surface 41 of the ridge 28, but the same effect can be obtained even if it is formed in the range of the light incident region 44. It is done. Moreover, you may form so that the protruding item | line part 28 may be cut longitudinally (along the arrangement direction of LED3).

(Modification 4)
Next, an illumination device 204, which is another modification of the illumination device 20, will be described with reference to FIG. In the lighting device 204, the shape of the light diffusion plate 50 is different from the shape of the light diffusion plate 21 of the lighting device 20. Specifically, the shape of the light incident surface 38 in the ridge 28 of the light diffusing plate 50 is such that the corrugated uneven surface 47 formed on the light diffusing plate 46 used in the illuminating device 202 and the illuminating device 203. A V-shaped groove 49 formed in the used light diffusion plate 48 is used in combination. The lighting device 204 has the same configuration as the lighting device 20 except for the light diffusion plate 50. Therefore, in FIG. 18, the same components as those of the lighting device 20 are denoted by the same reference numerals and description thereof is omitted. FIG. 18 is a partial bottom view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 48 intersect as viewed from below.

  As shown in FIG. 18, an uneven surface 47 is formed on the inner peripheral side surface 41 of the ridge 28 of the light diffusing plate 50, and a groove 49 is formed on the light incident surface 38 of the ridge 28. ing. The concavo-convex surface 47 has the same configuration as the concavo-convex surface 47 formed on the inner peripheral side surface 41 of the ridge 28 of the light diffusion plate 46 of the lighting device 202. The groove 49 has the same configuration as the groove 49 formed on the light incident surface 38 of the convex portion 28 of the light diffusing plate 46 of the lighting device 203.

  In the lighting device 204 configured in this way, as described in the second modification, the uneven surface 47 is formed on the inner peripheral side surface 41 of the ridge 28, so that the light is provided on the uneven surface 47. And is incident on the ridge 28. Further, as described in the third modification, the light emitted from the superposition light guide plate 2 is diffused by the V-shaped groove 49 and is incident on the convex portion 28. As described above, by providing the convex and concave portions 29 with the concave and convex surfaces 47 and the grooves 49, even if the frame 22 is present, the peripheral portion of the light emitting surface on which the convex strips 28 are arranged is brightened and light is emitted. It is possible to eliminate the darkening as if the peripheral portion of the diffusion plate 21 was trimmed, and to more effectively achieve the uniform illuminance distribution of the light emitted from the upper surface 42.

(Modification 5)
Next, an illumination device 205 which is another modification of the illumination device 20 will be described with reference to FIG. The illuminating device 205 is configured by combining the light diffusing plate 46 (see FIG. 15) used in the illuminating device 202 and the superposed light guide plate 2 on which the light diffusing portion 12 shown in FIG. 9 is formed. The illuminating device 205 has the same configuration as the illuminating device 20 except that the light diffusing portion 12 is formed on the superposed light guide plate 2 and the light diffusing plate 46 is used. Accordingly, in FIG. 19, the same components as those of the lighting device 20 are denoted by the same reference numerals and description thereof is omitted. FIG. 19 is a partial plan view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 46 intersect as viewed from above.

  In the illuminating device 205, the light diffusing portion 12 is formed on the superposed light guide plate 2, so that the illuminance distribution of light emitted from the upper surface 2 </ b> A of the superposed light guide plate 2 can be made uniform. In addition, by forming a corrugated uneven surface 47 on the inner peripheral side surface 41 of the ridge 28 of the light diffusing plate 46, the light incident from the upper surface 2A of the polymerization light guide plate 2 is diffused on the uneven surface 47 surface. The illuminance at the peripheral edge of the light diffusing plate 46 where the illuminance tends to decrease can be increased. Therefore, the upper surface of the light diffusing plate 46 is formed by a synergistic effect of the formation of the light diffusing portion 12 on the polymerization light guide plate 2 and the provision of the corrugated uneven surface 47 on the inner peripheral side surface 41 of the light diffusing plate 46. The illuminance distribution on the upper surface 42 including the rim of the light diffusing plate 46 can be more effectively uniformed without the rim of the rim 42 becoming dark.

(Modification 6)
Next, an illumination device 206 as another modification of the illumination device 20 will be described with reference to FIG. The illuminating device 206 is configured by combining the light diffusing plate 48 (see FIG. 16) used in the illuminating device 203 and the superposed light guide plate 2 on which the light diffusing portion 12 shown in FIG. 9 is formed. The illuminating device 206 has the same configuration as the illuminating device 20 except that the light diffusing portion 12 is formed on the superposed light guide plate 2 and the light diffusing plate 48 is used. Therefore, in FIG. 20, the same components as those of the lighting device 20 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 20 is a partial plan view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 46 intersect as viewed from above.

  In the illuminating device 206, the light diffusing portion 12 is formed on the superposed light guide plate 2, so that the illuminance distribution of light emitted from the upper surface 2 </ b> A of the superposed light guide plate 2 can be made uniform. Further, the V-shaped groove 49 is formed on the light incident surface 38 of the convex portion 28 of the light diffusing plate 48, so that the light incident from the upper surface 2 </ b> A of the superposition light guide plate 2 is V-shaped groove 49. It is possible to increase the illuminance at the peripheral portion of the light diffusing plate 48 which is diffused by the prism effect and the illuminance tends to decrease. Therefore, the light diffusion portion 12 is formed on the polymerization light guide plate 2 and the light effect is obtained by synergistic effect with the V-shaped groove 49 formed on the light incident surface 38 of the convex portion 28 of the light diffusion plate 48. The illuminance distribution on the upper surface 42 including the peripheral portion of the light diffusing plate 48 can be more effectively uniformed without darkening the peripheral portion of the upper surface 42 of the diffusing plate 48.

(Modification 7)
Next, an illumination device 207, which is another modification of the illumination device 20, will be described with reference to FIG. The illuminating device 207 is configured by combining the light diffusing plate 50 (see FIG. 18) used in the illuminating device 204 and the superposed light guide plate 2 on which the light diffusing portion 12 shown in FIG. 9 is formed. The illuminating device 207 has the same configuration as the illuminating device 20 except that the light diffusing portion 12 is formed on the superposed light guide plate 2 and the light diffusing plate 50 is used. Therefore, in FIG. 21, the same components as those of the lighting device 20 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 21 is a partial plan view showing a schematic configuration of a portion where the light source unit 24 and the light source unit 27 of the light diffusing plate 50 intersect as viewed from above.

  In the illuminating device 207, the light diffusing portion 12 is formed on the superposed light guide plate 2, whereby the illuminance distribution of the light emitted from the upper surface 2 </ b> A of the superposed light guide plate 2 is made uniform. In addition, by providing the ridges 28 and the grooves 49 on the ridges 28 of the light diffusing plate 50, even if the frame 22 is present, the peripheral edge of the light emitting surface on which the ridges 28 are arranged is brightened. Thus, it is possible to prevent the peripheral edge of the light diffusing plate 50 from being darkened and to make the illuminance distribution of the light emitted from the upper surface 42 uniform. Therefore, the synergistic effect of the formation of the light diffusing portion 12 on the superposed light guide plate 2 and the provision of the concave and convex surfaces 47 and the grooves 49 on the convex portion 28 of the light diffusing plate 50 leads to the upper surface 42 of the light diffusing plate 50. The illuminance distribution on the upper surface 42 including the peripheral edge of the light diffusion plate 50 can be more effectively uniformed without darkening the peripheral edge.

(Modification 8)
Next, an illumination device 208, which is another modification of the illumination device 20, will be described with reference to FIG. The illuminating device 208 is an application example of the illuminating device 20 described above, and in addition to the light diffusing plate 21, the light diffusing plate 51 having the same configuration as the light diffusing plate 21 is provided on the lower surface 2B side of the superposed light guide plate 2. The light can be emitted from both the upper and lower surfaces. In FIG. 22, the same components as those of the lighting device 20 are denoted by the same reference numerals and description thereof is omitted.

  The upper part (A) of FIG. 22 is a partial cross-sectional view showing the light source part 24 (the part on the end face 2D side) of the illumination device 208. The lower part (B) of FIG. 22 is a partial cross-sectional view showing the light source unit 27 (part on the end face 2F side) of the illumination device 208.

  In the illumination device 208, the light guide plate 2 is sandwiched between the light shielding unit 33 and the light shielding unit 34 of the frame 22. Light incident from the end faces 2C, 2D, 2E, 2F of the light guide plate 2 is emitted from the lower surface 2B in addition to the upper surface 2A. The light emitted from the lower surface 2 </ b> B is emitted downward from the lower surface 52 of the light diffusion plate 51 through the light diffusion plate 51. The lower surface 52 functions as a light emitting surface of the lighting device 208. The light emitted from the upper surface 2A is emitted upward from the upper surface 42 of the light diffusion plate 21 through the light diffusion plate 21 as described above.

  The light shielding part 34 has the same function as the light shielding part 33 and shields the light emitted from the LED 3 so that it does not enter the light diffusion plate 51 as it is.

  On the peripheral edge of the light diffusing plate 51, a ridge 53 that protrudes toward a position facing the peripheral edges 29A, 29B, 29C, and 29D on the side where the LEDs 3 of the polymerization light guide plate 2 are disposed is formed. The light incident surface 54 that is the tip portion of the ridge 53 is a flat surface and faces the peripheral edges 29A, 29B, 29C, and 29D of the polymerization light guide plate 2. The function of the ridge 53 is the same as that of the ridge 28.

  In the lighting device 208, the light diffusion plate 21 is disposed on the upper surface 2A side of the polymerization light guide plate 2, and the light diffusion plate 51 is disposed on the lower surface 2B side of the polymerization light guide plate 2. Therefore, the illumination device 208 can irradiate light from both the upper and lower sides. The light diffusing plate 51 has the same configuration as that of the light diffusing plate 21, and a dark portion that is shielded and bordered by the light shielding portion 34 is generated at the peripheral portion of the lower surface 52 on the side where the light shielding portion 34 is provided. While preventing, the illuminance distribution of the light emitted from the lower surface 52 which is the light emitting surface of the light diffusing plate 51 can be made uniform.

  The light diffusing unit 12 or the light diffusing unit 12A may be formed on the superposed light guide plate 2 of the illuminating device 208. Instead of the light diffusing plates 21 and 51, the light diffusing plate 46, the light diffusing plate 48 or the light diffusing plate is used. A plate 50 may be used.

  In the illuminating device 20 described above and the illuminating devices 201, 202, 203, 204, 205, 206, 207, 208 which are modified examples thereof, an example in which the outer peripheral end surface 36 and the inner peripheral side surface 41 are parallel to each other is shown. . However, they do not have to be arranged parallel to each other. By changing the angle of the outer peripheral end surface 36 or the inner peripheral side surface 41 with respect to the upper surface 2A (the outer peripheral end surface 36 and the inner peripheral side surface 41 are not parallel to each other but have an angle), the outer peripheral end surface 36 or the inner peripheral side surface 41 The amount of light totally reflected and the direction of total reflection can be changed. Further, by making the light incident surface 38 parallel to the upper surface 2A or having an angle (non-parallel), the amount of light incident on the light incident surface 38 from the upper surface 2A can be changed. In the illuminating device 208, the amount of light incident on the light incident surface 54 from the lower surface 2B is changed by making the light incident surface 54 parallel to the lower surface 2B or having an angle (non-parallel). Can do.

  In addition, although the illuminating devices 20 and 201-208 demonstrated the illuminating device single item, the illuminating devices 20, 201-208 can comprise a large illuminating device by paralleling several illuminating devices. This will be described with reference to FIG.

(Modification 9)
For example, as shown in FIG. 23, it is possible to configure an illuminating device 209 in which four illuminating devices 20 are arranged side by side in front, rear, left, and right. The illuminating device 209 is juxtaposed with the illuminating devices 20 in close contact with the outer peripheral end surfaces 36 of the light diffusion plates 21.

  As described above, the illumination device 20 is not dark as if the peripheral portion of the upper surface 42 that is the light exit surface is trimmed, and the illuminance distribution is made uniform including the peripheral portion. Therefore, even when the lighting devices 20 are juxtaposed, the joint portion between the lighting devices 20 is not trimmed, and the lighting device 209 having a good-looking light emission surface can be realized.

  As shown in FIGS. 12, 13, etc., the outer peripheral end surface 36, which is the outer peripheral side surface of the light diffusion plate 21 on the side where the protruding strip portion 28 is provided, and the outer surface 37 of the base portion 32 of the frame 22 are in the same plane. Has been placed. That is, the outer peripheral edge 42 </ b> A, which is the outer peripheral edge of the upper surface 42, is disposed in the same plane as the outer surface 37. Therefore, when the lighting devices 20 are arranged in parallel, the gap between the upper surfaces 42 arranged in parallel can be reduced. For this reason, the illuminating device 209 which has the large light-projection surface which makes the upper surface 42 connect continuously and the space | gap between the parallel upper surfaces 42 is not conspicuous is realizable.

  Note that the lighting device 209 is not limited in how the lighting devices 20 are arranged. For example, the number of the lighting devices 20 may be two or three, and may be five or more.

  When a plurality of lighting devices 20 are juxtaposed, the positions of the outer peripheral edges 42A of the four sides of the light diffusing plate 21 are made to coincide with the positions of the outer surface 37 of the frame 22 and the outer peripheral end surface 36 of the superposition light guide plate 2, or The outer peripheral edges 42A of the light diffusion plates 21 are brought into close contact with each other. By doing so, it becomes easy to eliminate the gap between the adjacent light diffusion plates 21, and the entire illuminance distribution on the light emitting surface is not darkened as the peripheral edge of each light diffusion plate 21 is edged. A uniform illumination device 209 can be realized. When the plurality of lighting devices 20 are arranged in parallel, the height of the upper surface 42 may be changed to that of the lighting device 20 as long as the thickness is within the range of the light diffusion plate 21.

  In the above-described embodiment, the light diffusing plate 21 is an example of a quadrangle in plan view, but may be a polygon such as a triangle or a pentagon.

  In the illumination devices 20 and 201 to 209 described above, light emitted from the peripheral portions 29A, 29B, 29C, and 29D is incident on the light incident surface 38 between the peripheral portions 29A, 29B, 29C, and 29D and the light incident surface 38. The light shielding part 33 which restrict | limits the light quantity to perform is provided. However, the light shielding unit 33 may be omitted. Even in the case where the light shielding portion 33 is not provided, the light diffusing plate 21 is provided with the convex portion 28, so that the light is emitted from the peripheral portions 29A, 29B, 29C, and 29D and is incident on the light incident surface 38. The incident light is scattered within the ridge 28 and emitted from the peripheral edge of the upper surface 42. Therefore, light can be emitted from the entire upper surface 42. However, when adjustment of the amount of light incident on the light incident surface 38 is necessary, the amount of light emitted from the peripheral portions 29A, 29B, 29C, and 29D and incident on the light incident surface 38 can be adjusted by providing the light shielding portion 33. . That is, the amount of light emitted from the peripheral portion 29A of the upper surface 42 of the light diffusing plate 21 can be adjusted.

  The polymerization light guide plate 2 and the light diffusion plate 21 are configured to scatter light traveling inside the polymerization light guide plate 2 and the light diffusion plate 21 by containing light scattering particles. A roughening process, a convex lens shape, a concave lens shape, a conical shape, which is a process for scattering light by forming a fine uneven shape on the light emitting surface 2A of the light plate 2 and the upper surface 42 of the light diffusion plate 21. Or a V-shaped groove may be formed. By forming such a fine concavo-convex shape, light can be scattered on the upper surface 2A and the upper surface 42 even with the transparent polymerization light guide plate 2 and light diffusion plate 21 that do not contain light scattering particles.

DESCRIPTION OF SYMBOLS 1 ... Illuminating device 2A ... Upper surface (1st light-projection surface)
3 ... LED (light source)
4, 5 ... FPC (flexible substrate)
8, 9: Light guide plate 8A: Upper surface (light exit surface)
8B: Bottom surface (light exit surface)
9A: Top surface (light exit surface)
9B: Bottom surface (light exit surface)
8C-8F, 9C-9F ... Light incident surface (end surface)
DESCRIPTION OF SYMBOLS 12, 12A ... Light-diffusion part 21 ... Light-diffusion plate 20, 201-209 ... Illuminating device 28 ... Projection part 29A, 28B, 29C, 29D ... Peripheral part 33 ... Light-shielding part 38 ... Light incident surface (2nd light incidence) surface)
40 ... Inside bottom surface of ridge (first light incident surface)
42 ... Upper surface (second light exit surface)

Claims (7)

A plurality of plate-shaped light guide plates that are overlapped with each other and have an end surface as a light incident surface and a wide surface as a light output surface;
A light source disposed at a position facing the end face of each of the plurality of light guide plates, and causing light to enter the light guide plates;
I have a,
The end faces where the light sources are arranged are not adjacent to each other between the adjacent light guide plates ,
The light output surface of the light guide plate arranged on the outermost side among the plurality of the light guide plates superimposed, and is a light output surface that emits light to the side opposite to the side on which the light guide plates are superimposed. 1 light exit surface is arranged,
A light diffusion plate having a first light incident surface on which light emitted from the first light emitting surface is incident and a second light emitting surface from which light incident from the first light incident surface is emitted;
The light diffusing plate has a convex portion having a second light incident surface that protrudes toward the first light emitting surface, faces a peripheral portion of the first light emitting surface, and has a second light incident surface on which light emitted from the peripheral portion enters. ,
The protrusion has an outer peripheral end surface that is flush with an outer peripheral end edge that is an outer peripheral edge of the second light emitting surface, and an inner peripheral side surface that faces the outer peripheral end surface.
A lighting device characterized by that. The lighting device according to claim 1.
A light shielding member is provided between the peripheral edge and the second light incident surface to limit the amount of light emitted from the peripheral edge to enter the second light incident surface.
A lighting device characterized by that. The lighting device according to claim 1 or 2,
A concave portion that separates the first light emitting surface and the first light incident surface is provided inside the convex portion that is formed over the entire circumference of the peripheral portion of the light diffusing plate.
A lighting device characterized by that. In the illuminating device of any one of Claim 1 to 3,
The light source is mounted on a flexible substrate, and the flexible substrate is also disposed at a position facing an end surface of the adjacent light guide plate.
A lighting device characterized by that. The lighting device according to claim 4.
The surface of the flexible substrate on the light guide plate side is white or silver.
A lighting device characterized by that. In the illuminating device of any one of Claim 1 to 5,
The light sources are different color lights for at least two light guide plates.
A lighting device characterized by that. In the illuminating device of any one of Claim 1 to 6,
The light sources provided in each of the light guide plates are a plurality of light sources, and a light diffusing portion is provided on a light emitting surface of the light guide plate between adjacent light sources.
A lighting device characterized by that.

Images