JP2006040616A - Surface light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light source device having a reflection region with a large area, having high luminance and including a light guide with excellent uniformity. <P>SOLUTION: This surface light source device is provided with the light guide, and a light source formed at least on one side surface of the light guide and emitting luminous flux to the light guide. The light guide has a bottom face and an emission surface facing to each other. A plurality of reflection parts are formed on the bottom face and each reflection part has projecting parts and recessed parts. The recessed part is formed on the edge part of each projecting part so as to surround the projecting part. By forming the recessed part on the edge of each projecting part of the reflection part, the reflection part has multiple reflection regions, efficiency for reflecting the luminous flux is improved, and luminance and uniformity of the light guide is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surface light source device, and more particularly to a light guide of a surface light source device.

  Since the liquid crystal panel itself does not emit light, it is necessary to attach a light source device such as a surface light source to the liquid crystal panel in order to display an image on the liquid crystal panel.

  FIG. 1 is a schematic sectional view showing a conventional surface light source device of a liquid crystal panel.

  The surface light source device shown in FIG. 1 includes a light source 1, a reflection mask 2, a ride guide 3, and a reflection plate 4. The light source 1 emits light. The reflection mask 2 surrounds the light source 1 and reflects light from the light source 1 to the ride guide 3. The ride guide 3 has a front surface 3C and a back surface 3B. A light source 1 is installed adjacent to an end portion 3A of the ride guide 3, and light from the light source 1 enters the ride guide 3 from the end portion 3A. A plurality of reflecting portions 3D are formed on the back surface 3B. Each reflection part 3D consists of a single convex part or a single recessed part. The reflection plate 4 is disposed below the ride guide 3, and reflects the light that has passed through the back surface 3 </ b> B of the ride guide 3 to the ride guide 3.

  When light from the light source 1 enters the ride guide 3 from the end portion 3A, the light travels to the back of the ride guide 3 while being repeatedly totally reflected between the front surface 3C and the back surface 3B, and the reflection angle is changed by the reflection portion 3D. The liquid is emitted from the ride guide 3 to illuminate the liquid crystal panel.

  FIG. 2 is a schematic cross-sectional view showing a conventional reflecting portion 3D.

  In FIG. 2, the conventional reflecting portion 3D is composed of a single convex portion and exhibits a convex shape in all directions. Therefore, the reflecting portion 3D has only two reflecting areas 3D1 and 3D2, that is, areas other than the areas 3D1 and 3D2 do not reflect or refract the light flux to the front surface 3C of the ride guide 3. Therefore, the conventional light guide 3 has low light guide efficiency for causing the light beam to travel to the back of the ride guide 3 and emitting the light beam from the ride guide 3, and the luminance uniformity of the entire ride guide 3 is low.

  How to improve the light guide efficiency of the ride guide and increase the luminance uniformity of the entire ride guide 3 is a research subject in this industry.

  An object of the present invention is to provide a surface light source device including a light guide having a large reflective area, high brightness, and good uniformity.

  In order to achieve the above object, a surface light source device of the present invention includes a light guide and a light source that is provided on at least one side surface of the light guide and emits a light beam to the light guide. A plurality of reflective portions are formed on the bottom surface, each reflective portion has a convex portion and a concave portion, and the concave portion surrounds the convex portion. It is formed at the edge of.

  By forming the concave portion at the edge of the convex portion of the reflective portion, the reflective portion has more reflective regions, and therefore, the efficiency of reflecting the light beam is improved, and the brightness and uniformity of the ride guide are improved. .

  According to the present invention, the light guide has more reflection areas, the efficiency of reflecting the light beam is improved, and the brightness and uniformity of the ride guide are improved.

Next, an embodiment of a surface light source device of the present invention will be described with reference to the accompanying drawings.
First Embodiment FIG. 3A is a schematic side view showing a part of a surface light source device 10 according to a first embodiment of the present invention. FIG. 3B is a schematic cross-sectional view showing a part of the surface light source device 10.

  As shown in FIGS. 3A and 3B, the surface light source device 10 includes a light guide 11 and a light source 12 provided at at least one end of the light guide 11. The light guide 11 has a bottom surface 111 and an exit surface 112 facing each other, and a plurality of reflecting portions 113 are formed on the bottom surface 111 (FIG. 3B). The reflective portions 113 are distributed on the bottom surface 111 at a predetermined interval, and each reflective portion 113 has a convex portion 1131 and a concave portion 1132 formed on an edge portion 11311 of the convex portion 1131. The shape and size of the convex portion 1131 and the concave portion 1132 are determined by the arrangement position of the light source 12, for example. The convex portion 1131 is, for example, a cylindrical shape, a prism, or another column. The recess 1132 is annular, and its shape is substantially the same as the shape of the edge 11311. For example, when the edge 11311 is circular, the recess 1132 is also circular (FIG. 3B).

  4A, 4B, and 4C are diagrams showing other specific examples of the shape of the reflecting portion 13 of the light guide 11. FIG.

  As shown in FIGS. 4A, 4B, and 4C, the recess 1132 may have an elliptical annular shape (FIG. 4A), a rectangular annular shape (FIG. 4B), or a polygonal annular shape (FIG. 4C).

  The light source 12 is provided at at least one end of the light guide 11, and light from the light source 1 enters the ride guide 11 from the end.

  As shown in FIG. 3A, the light beam from the light source 12 enters the ride guide 11, and is reflected by the four reflection regions 1133A, 1133B, 1133C, and 1133D formed by the convex portions 1131 and the concave portions 1132 of the reflective portion 113, Proceeds to the back of the ride guide 11 or exits from the ride guide 11 to illuminate a liquid crystal panel (not shown).

  Since the annular recessed portion 1132 is formed at the edge portion 11311 of the protruding portion 1131, the reflecting portion 113 has more reflecting areas. That is, in addition to the reflection regions 1133B and 1133C in the convex portion 1131, reflection regions 1133A and 1133D are formed in the annular concave portion 1132.

  As described above, in the related art, one reflecting portion has only two reflecting regions. On the other hand, in the present embodiment, since the reflection unit 113 includes more reflection regions, it is possible to improve the efficiency of reflecting the light beam and improve the luminance uniformity of the ride guide 11.

  Further, a rough surface treatment may be applied to the outer surface of the convex portion 1131 and the bottom portion of the concave portion 1132. By making the outer surface of the convex portion 1131 and the bottom portion of the concave portion 1132 rough, irregular reflection occurs, and the light beam is reflected in each direction and emitted from the emission surface 112 more uniformly.

  For example, the roughness of the concave portion 1132 is Ra 0.05 mm to 5.0 mm, the depth is 0.001 mm to 0.5 mm, the roughness of the convex portion 1131 is Ra 0.05 mm to 5.0 mm, and the height is 0.001 mm. When the diameter is 0.5 mm and the diameter is 0.03 mm to 2.0 mm, a good optical effect can be obtained.

  5A, FIG. 5B, FIG. 5C, and FIG. 5D are diagrams showing an annular portion at the edge of the concave portion 1132 of the reflecting portion 13.

As shown in FIGS. 5A, 5B, 5C, and 5D, at least one annular portion 1134 may be sequentially provided from the edge 11321 of the recess 1132 toward the outside. The area of the reflection region is further increased by the annular portion 1134. The annular portion 1134 may be a protrusion (FIG. 5B) or a recess (FIGS. 5A and 5C) as a whole, or may be a protrusion and a recess (FIG. 5D). . The shape and size of the annular portion 1134 are determined by, for example, the arrangement position of the light source 12. In FIG. 5B, the depth of the annular portion 1134 is the same as the height of the convex portion 1131.
Second Embodiment FIG. 6 is a view showing a part of a light guide 21 according to a second embodiment of the present invention.

  As shown in FIG. 6, the light guide 21 has a bottom surface 211 and an exit surface 212 that face each other, and a plurality of reflecting portions 213 are formed on the bottom surface 211. The reflection portions 213 are distributed on the bottom surface 211 at a predetermined interval, and each reflection portion 213 has a recess 2132 and a protrusion 2131 formed on an edge portion 21132 of the recess 2132. The convex portion 2131 is annular, and its shape is substantially the same as the shape of the edge portion 21321.

  The light beam from the light source 22 enters the ride guide 21 and is reflected by the reflection region formed by the concave portion 2132 of the reflection portion 213 and the reflection regions 2133A and 2133B formed by the convex portion 2131 of the reflection portion 213. Therefore, the area of the reflection region is increased, the efficiency of reflecting the light beam is improved, the luminance is increased, and the uniformity is also improved.

  Further, in order to further increase the area of the reflection region, an annular portion may be provided from the edge of the convex portion 2131 to the outside. The annular part may be a protrusion or a recess as a whole, or a part may be a protrusion and a part may be a recess.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and all modifications to the present invention are within the scope of the present invention unless departing from the spirit of the present invention.

It is a schematic sectional drawing which shows the surface light source device of the conventional liquid crystal panel. It is a schematic sectional drawing which shows the reflection part in the surface light source device of the conventional liquid crystal panel. A is a schematic side view showing a part of the surface light source device according to the first embodiment of the present invention, and B is a schematic sectional view showing a part of the surface light source device according to the first embodiment of the present invention. is there. A, B, and C are diagrams showing specific examples of the shape of the reflecting portion of the light guide in the surface light source device according to the first embodiment of the present invention. A, B, C, and D are diagrams showing specific examples of the annular portion of the light guide in the surface light source device according to the first embodiment of the present invention. It is a schematic side view which shows a part of surface light source device which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Surface light source device 11 Light guide 111 Bottom surface 112 Ejection surface 113 Reflection part 1131 Protrusion part 11311 Edge part 1132 Concave part 1133A, 1133B, 1133C, 1133D Reflection area 1134 Annular part 12 Light source 21 Light guide 211 Bottom surface 212 Ejection surface 213 Reflection part 2131 Convex Portion 2132 Recessed portion 21321 Edge portions 2133A and 2133B Reflection region 22 Light source

Claims (17)

A light guide and a light source provided on at least one side surface of the light guide and emitting a light beam to the light guide;
The light guide has a bottom surface and an exit surface facing each other, and a plurality of reflective portions are formed on the bottom surface, each reflective portion has a convex portion and a concave portion, and the concave portion has the convex portion. A surface light source device formed on an edge of the convex portion so as to surround. The surface light source device according to claim 1, wherein the concave portion is annular, and the shape of the concave portion is substantially the same as an edge portion of the convex portion. The surface light source device according to claim 1, wherein at least one annular portion is sequentially provided adjacently from an edge portion of the recess to the outside. The surface light source device according to claim 3, wherein the annular portion includes an annular protrusion or an annular recess. The surface light source device according to claim 1, wherein the recess is any one of a circular ring shape, an elliptical ring shape, a rectangular ring shape, and a polygonal ring shape. The surface light source device according to claim 1, wherein a bottom surface of the recess is a rough surface. The surface light source device according to claim 1, wherein a surface of the convex portion is a rough surface. The concave portion has a bottom surface roughness of Ra 0.05 mm to 5.0 mm and a depth of 0.001 mm to 0.5 mm.
The surface light source device according to claim 1, wherein the convex portion has a surface roughness of Ra 0.05 mm to 5.0 mm, a height of 0.001 mm to 0.5 mm, and a diameter of 0.03 mm to 2.0 mm. A light guide and a light source provided on at least one side surface of the light guide and emitting a light beam to the light guide;
The light guide has a bottom surface and an exit surface that face each other, and a plurality of reflective portions are formed on the bottom surface, and each of the reflective portions has a convex portion and a concave portion, and the convex portion has the concave portion. A surface light source device formed on an edge of the recess to surround the surface light source device. The surface light source device according to claim 9, wherein the convex portion is annular, and a shape of the convex portion is substantially the same as an edge portion of the concave portion. The surface light source device according to claim 9, wherein the convex portion is one of a circular ring shape, an elliptical ring shape, a rectangular ring shape, and a polygonal ring shape. The surface light source device according to claim 9, wherein a bottom surface of the recess is a rough surface. The surface light source device according to claim 9, wherein a surface of the convex portion is a rough surface. The surface light source device according to claim 9, wherein at least one annular portion is sequentially provided adjacently from an edge portion of the convex portion to the outside. The surface light source device according to claim 14, wherein the annular portion includes an annular protrusion or an annular recess. A light guide and a light source provided on at least one side surface of the light guide and emitting a light beam to the light guide;
The light guide has a bottom surface and an exit surface that face each other, and a plurality of reflective portions are formed on the bottom surface, and each of the reflective portions surrounds the first concave portion and the first concave portion. A surface light source device having an annular second concave portion formed at an edge of one concave portion. A light guide and a light source provided on at least one side surface of the light guide and emitting a light beam to the light guide;
The light guide has a bottom surface and an exit surface that face each other, and a plurality of reflective portions are formed on the bottom surface, and each of the reflective portions surrounds the first convex portion and the first convex portion. A surface light source device having an annular second convex portion formed at an edge of the first convex portion.

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