JP2008103110A - Light guide plate and flat lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide plate in which light from an incident end face part is refracted and total reflected with diffusion and convergence, and uniform and bright outgoing light is obtained from an outgoing face part and a flat lighting device. <P>SOLUTION: A plurality of shapes 7 with ridge lines having curvature lines which change continuously to become gradually wide or gradually narrow to Y axis direction against X axis and X axis direction against Y axis in the X axis-Y axis direction which is a side direction of a light guide plate 2, and change continuously in depth and height in Z axis direction being the thickness direction of the light guide plate 2 according to changes in the Y axis direction and the X axis direction, are provided at the outgoing face part 6 and the opposite outgoing face part 5, and the light from the incident end face part 3 of the light guide plate 2 is deflected to a desired direction by carrying out complicated three-dimensional refraction and total reflection, and uniform and bright outgoing light is obtained from the outgoing face part 6 by convergence and diffusion or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the three-dimensional X-axis, Y-axis, and Z-axis, the present invention gradually changes in the Y-axis direction with respect to the X-axis and then gradually changes in width or narrows or changes in the X-axis direction with respect to the Y-axis. Gradually widen or narrower, and then has a spread that changes continuously in the X-axis-Y-axis direction so that it gradually narrows or widens, and the depth or height increases with changes in the Y-axis direction or the X-axis direction. A light guide plate provided with a plurality of shapes having curved lines while the ridge line of depth and height is displaced with respect to the X axis and the Y axis so as to continuously change in the Z axis direction, and the like. The present invention relates to a flat illumination device.

  As a conventional flat illumination device, a reflective member is provided on the front surface portion and the back surface portion of the light guide plate, and a cutout portion that is a band-like slit is provided on either one, and the smaller the cutout portion is closer to the light source, the light source is a dot-like shape. In some cases, an arc-shaped slit centered on the light emitting portion of the point light source is provided so that the distance between the slits becomes narrower as the distance from the light source increases.

  Further, as a conventional flat illumination device, a V-shaped cross section having a diffusion member on the front surface side of the light guide plate and a reflection member on the back surface side, and having a predetermined length on the reflection surface (back surface) of the light guide plate. The grooves are arranged in a row parallel to the light source and spaced apart from each other by a predetermined distance. Adjacent rows of each row are alternately arranged in a staggered pattern, and the intervals are gradually reduced as the distance from the light source increases. Things are known.

  Furthermore, as a conventional light guide plate, a large number of V-groove dents that are reflected and refracted on the entire front and back surfaces are provided in a staggered or arcuate manner in parallel to the incident direction, and between the dents along the light traveling direction. It is known that a gap is provided so that the interval gradually decreases as the distance from the light source increases.

Further, as a conventional flat illumination device, at least one substantially point-shaped primary light source, a light incident surface on which light emitted from the primary light source is incident, and a light output surface that guides and emits incident light And a light source element that controls the direction of light emitted from the light guide, wherein the primary light source is disposed at the corner or end surface of the light guide, and the light is deflected. It is known that a large number of lens rows are arranged in parallel in a substantially arc shape on at least one surface of the element so as to surround the primary light source.
JP 62-109003 A Japanese Patent Laid-Open No. 5-216030 JP-A-8-286037 JP 2002-245823 A

The above-described conventional flat illumination device is provided with a reflective member on the front surface portion and the back surface portion of the light guide plate, and provided with a notch portion that is a strip-shaped slit on one of them, and by making the notch portion closer to the light source, the light source is reduced. The closer it is to, the amount of light leaking from the slit is controlled and the entire light is emitted uniformly. However, since the emitted light becomes a slit shape, it looks bad. In particular, since the slit is small near the light source, there is a problem that it appears as a bright line and light energy is large due to the light close to the light source, resulting in a stronger bright line.
In addition, when the light source is point-like, an arc-shaped slit centering on the light emitting part of the point light source is provided so that the distance between the slits becomes narrower as the distance from the light source increases. There is a problem that arc-like bright lines appear for the same reason.

Further, as a conventional flat illumination device, a V-shaped cross section having a diffusion member on the front surface side of the light guide plate and a reflection member on the back surface side, and having a predetermined length on the reflection surface (back surface) of the light guide plate. The grooves are arranged in a row parallel to the light source and spaced apart from each other by a predetermined distance. Adjacent rows of each row are alternately arranged in a staggered pattern, and the intervals are gradually reduced as the distance from the light source increases. Since the light incident on the light guide plate is reflected by the inclined surface of the V-shaped groove with respect to the traveling direction and deflected to the surface side, particularly strong outgoing light is always outgoing parallel to the light source. For example, there is a problem that the luminance of the emitted light is lowered at both ends of the light source.
In particular, when the light source is a point light source, there are many cases where the luminance distribution is not uniform depending on the position from the light source.

  In addition, as a conventional light guide plate, a large number of V-groove recesses that are reflected and refracted on the entire front and back surfaces are provided in a staggered or arcuate manner in parallel with the incident direction, and between the recesses along the light traveling direction. In the case where a gap is provided so that the interval gradually decreases as the distance from the light source increases, there is a problem that even if the interval gradually decreases as the distance from the light source decreases, the large light guide plate is blocked by the depression.

  Further, even when a large number of V-groove dents are intermittently provided in an arc shape with respect to the incident direction on the entire front and back surfaces, the central portion of the cathode ray tube is strong and uniform in the peripheral portion. Although the distribution is expected, in order to reflect the light from the central portion of the cathode ray tube, the parallel light from the cathode ray tube cannot be used because of the arc shape so that the light from the central portion of the cathode ray tube cannot be used. Only light from the direction can be used. For this reason, the energy is lower than the parallel light from the cathode ray tube, the emission position (shape) of the reflected light is different (it is not uniform emission light as a whole), and there is a problem in the luminance distribution emitted from the surface. .

  Further, as a conventional flat illumination device, at least one substantially point-shaped primary light source, a light incident surface on which light emitted from the primary light source is incident, and a light output surface that guides and emits incident light And a light source element that controls the direction of light emitted from the light guide, wherein the primary light source is disposed at the corner or end surface of the light guide, and the light is deflected. In a case where a large number of lens arrays are arranged in parallel in a substantially arc shape so as to surround the primary light source on at least one side of the element, first, light from the primary light source is completely emitted from the light guide from the light incident surface. There is no means to emit. Secondly, since all the light from the back surface is positively raised upward by the light deflecting element, there is a problem that the emitted light does not spread and becomes a narrow viewing angle as well as luminance spots.

(Object of invention)
In the present invention, the three-dimensional X-axis, Y-axis, and Z-axis are gradually changed gradually or gradually narrowing in the Y-axis direction with respect to the X-axis and in the X-axis direction with respect to the Y-axis. A shape in which a ridge line that continuously changes in depth and height in the Z-axis direction along with a change in the Y-axis direction and the X-axis direction has a curved shape, for example, a projection shape (observation from the Z-axis direction) is a rhombus Shapes, triangles, quadrilaterals, leaf shapes, saddle shapes, etc. are provided on the light guide plate surface individually or continuously in a convex or concave shape to spread or condense light from the incident end surface of the light guide plate An object of the present invention is to provide a light guide plate that can be refracted and totally reflected to obtain uniform and bright outgoing light from an output surface portion, and a flat illumination device using the light guide plate and the like.

  The light guide plate according to claim 1 of the present invention has a spread continuously changing in the X-axis-Y-axis direction, and has a depth or height continuously changing in the Z-axis direction. The height ridgeline is displaced with respect to the X axis or the Y axis, and a plurality of shapes having curves are provided.

  The light guide plate according to claim 1 has a spread that continuously changes in the X-axis-Y-axis direction, a depth or height that continuously changes in the Z-axis direction, and has a depth or height of Since the ridge line is displaced with respect to the X axis or the Y axis and a plurality of shapes having a curve are provided, inclined surfaces can be obtained at both hems of the X axis and the Y axis from the ridge line having the X axis or Y axis curve. A linear or curvilinear shape can be obtained at the boundary with the flat portion of the light guide plate.

  Further, the light guide plate according to claim 2 is characterized in that at least two or more shapes are connected by a ridge line.

  Since the light guide plate according to claim 2 is connected by at least two or more ridge lines, the light deflection direction can be made constant continuously.

  Furthermore, the light guide plate according to claim 3 has a shape that gradually increases in the Y-axis direction with respect to the X-axis and then gradually decreases, and a depth or height in the Z-axis direction with the change in the Y-axis direction. It is characterized in that the depth or height changes in the Z-axis direction along with the change, or gradually decreases in the X-axis direction and then gradually decreases with respect to the Y-axis.

  The light guide plate according to claim 3 has a shape that gradually becomes wider in the Y-axis direction with respect to the X-axis and then gradually becomes narrower, and a depth or height changes in the Z-axis direction along with a change in the Y-axis direction, Alternatively, after gradually widening in the X-axis direction with respect to the Y-axis, the width gradually changes and the depth or height changes in the Z-axis direction along with the change in the X-axis direction. (Observation) is formed into a diamond shape (diamond) or a leaf shape of a tree, and side surfaces (observation from the X-axis direction or the Y-axis direction) are formed into a mountain shape or a valley shape (ship shape).

  The light guide plate according to claim 4 has a shape that gradually decreases in the Y-axis direction with respect to the X-axis and then gradually changes in width and has a depth or height in the Z-axis direction along with the change in the Y-axis direction. The depth or height changes in the Z-axis direction along with a change or gradually decreases in the X-axis direction after the change or gradually decreases in the X-axis direction.

  The light guide plate according to claim 4 gradually changes in shape after gradually narrowing in the Y-axis direction with respect to the X-axis, and changes in depth or height in the Z-axis direction along with the change in the Y-axis direction. Alternatively, since it gradually narrows in the X-axis direction with respect to the Y-axis, it gradually changes and the depth or height changes in the Z-axis direction along with the change in the X-axis direction. Observation) is formed into a mortar shape or hourglass shape, and a side surface (observation from the X-axis direction or the Y-axis direction) is formed into a mountain shape or a valley shape (a bowl shape).

  Further, in the light guide plate according to claim 5, the shape gradually changes in the Y-axis direction with respect to the X-axis, or changes gradually in the Y-axis direction, and the depth or height changes in the Z-axis direction with the change in the Y-axis direction. Alternatively, it is characterized in that it gradually changes in the X-axis direction with respect to the Y-axis, or changes gradually in the X-axis direction, and changes in depth or height in the Z-axis direction with changes in the X-axis direction.

  In the light guide plate according to claim 5, the shape gradually changes in the Y-axis direction with respect to the X-axis, or changes gradually in the Y-axis direction, and the depth or height changes in the Z-axis direction with the change in the Y-axis direction, or Y The projection plane (observation from the Z-axis direction) is triangular because the depth or height changes gradually in the X-axis direction and gradually changes in the X-axis direction and changes in the X-axis direction along with the change in the X-axis direction. It is formed in a claw shape or a hook shape, and the side surface (observation from the X-axis direction or the Y-axis direction) is formed in a mountain shape or a valley shape.

  The light guide plate according to claim 6 is characterized in that the shape in the Y-axis direction is symmetric or asymmetric with respect to the X-axis, or the shape in the X-axis direction is symmetric or asymmetric with respect to the Y-axis. And

  The light guide plate according to claim 6 continues from the ridgeline because the shape of the light spread in the Y-axis direction is symmetric or asymmetric with respect to the X-axis, or the shape of spread in the X-axis direction is symmetric or asymmetric with respect to the Y-axis. It is possible to obtain a tilt angle that is symmetric or asymmetric with respect to the X axis or the Y axis.

  Furthermore, the light guide plate according to claim 7 is arranged in a direction in which the shape is aligned, arranged in parallel or in series in the X-axis direction or the Y-axis direction, the shapes are provided in a staggered manner, or in the direction in which the shape spreads in the X-axis direction or the Y-axis direction The interval between adjacent shapes is changed.

  The light guide plates according to claim 7 are arranged adjacent to each other in a direction in which the shape is aligned, arranged in parallel or in series in the X-axis direction or the Y-axis direction, the shapes are provided in a staggered manner, or spread in the X-axis direction or the Y-axis direction. Since the interval between the matching shapes is changed, it can be controlled according to the size of the light guide plate and the emission luminance.

Moreover, the flat illumination device according to claim 8 includes a light source,
It has an incident end face part that guides light from the light source, an outgoing face part that emits light from the incident end face part, and a counter outgoing face part that is located on the opposite side of the outgoing face part. In the three-dimensional space of the X, Y, and Z axes has a continuously changing spread in the X-axis to Y-axis direction, and has a depth or height that changes continuously in the Z-axis direction. And a light guide plate provided with a plurality of shapes each having a curved shape while the ridge line of depth or height is displaced with respect to the X axis or the Y axis.

The flat illumination device according to claim 8 comprises a light source,
It has an incident end face part that guides light from the light source, an outgoing face part that emits light from the incident end face part, and a counter outgoing face part that is located on the opposite side of the outgoing face part. In the three-dimensional space of the X, Y, and Z axes has a continuously changing spread in the X-axis to Y-axis direction, and has a depth or height that changes continuously in the Z-axis direction. And at least a light guide plate provided with a plurality of shapes having a curved line while the ridge line of depth or height is displaced with respect to the X axis or the Y axis, and has a curved surface or a flat surface with respect to the X axis direction or the Y axis direction. An inclined surface can be obtained, and a curved line or a straight ridge line can be obtained in the Z-axis direction.

As described above, the light guide plate according to claim 1 has a spread continuously changing in the X-axis-Y-axis direction, and has a depth or height continuously changing in the Z-axis direction. Since a plurality of shapes having curved lines are provided while the ridge line of height or height is displaced with respect to the X-axis or Y-axis, inclined surfaces are provided on both hems of the X-axis and Y-axis from the ridge line having the X-axis or Y-axis curve. It is possible to obtain a linear or curved shape at the boundary with the flat portion of the light guide plate.
Therefore, since the inclined surface forms a curved surface, the reflected light and refracted light can obtain diffused light and convergent light, and these diffused light and convergent light can be selected by selecting the incident direction of the incident light with respect to the inclined surface. Can be selected.

Further, since the light guide plate according to claim 2 is connected by at least two or more ridge lines, the light deflection direction can be made constant continuously.
Therefore, the reflected light can be obtained continuously without any spots of light.

Furthermore, the light guide plate according to claim 3 has a shape that gradually increases in the Y-axis direction with respect to the X-axis and then gradually decreases, and a depth or height in the Z-axis direction with the change in the Y-axis direction. Change, or gradually widen in the X-axis direction with respect to the Y-axis and then gradually narrow, and the depth or height in the Z-axis direction changes with the change in the X-axis direction. Observation) is formed in a diamond shape (diamond) or a leaf shape of a tree, and a side surface (observation from the X-axis direction or the Y-axis direction) is formed in a mountain shape or a valley shape (ship shape).
Therefore, various reflection directions and refraction directions can be obtained by various shapes, and necessary light can be selected.

The light guide plate according to claim 4 has a shape that gradually decreases in the Y-axis direction with respect to the X-axis and then gradually changes in width and has a depth or height in the Z-axis direction along with the change in the Y-axis direction. Change, or gradually narrower in the X-axis direction with respect to the Y-axis and then gradually change in width and the depth or height in the Z-axis direction with the change in the X-axis direction. Observation) is formed into a mortar shape or hourglass shape, and side surfaces (observation from the X-axis direction or Y-axis direction) are formed into a mountain shape or a valley shape (a bowl shape).
Therefore, various reflection directions and refraction directions can be obtained by various shapes, and necessary light can be selected.

Further, in the light guide plate according to claim 5, the shape gradually changes in the Y-axis direction with respect to the X-axis, or changes gradually in the Y-axis direction, and the depth or height changes in the Z-axis direction with the change in the Y-axis direction. Alternatively, the projection surface (observation from the Z-axis direction) is gradually narrowed or gradually changed in the X-axis direction with respect to the Y-axis and the depth or height is changed in the Z-axis direction with the change in the X-axis direction. Are formed in a triangular shape, a claw shape, and a hook shape, and side surfaces (observation from the X-axis direction or the Y-axis direction) are formed in a mountain shape or a valley shape.
Therefore, various reflection directions and refraction directions can be obtained by various shapes, and necessary light can be selected.

The light guide plate according to claim 6 has a ridgeline because the shape of the light spreading in the Y axis direction is symmetric or asymmetric with respect to the X axis, or the way of spreading in the X axis direction is symmetric or asymmetric with respect to the Y axis. As a result, it is possible to obtain a tilt angle that is symmetric or asymmetric with respect to the X axis or the Y axis.
For that purpose, various reflection directions and refraction directions can be obtained by various shapes, and necessary light can be selected, or reflected light and refraction can be selected by selecting the incident direction of light by an asymmetric inclination angle. The amount of light can be selected.

The light guide plates according to claim 7 are arranged adjacent to each other in a direction in which the shape is aligned, arranged in parallel or in series in the X-axis direction or the Y-axis direction, the shapes are provided in a staggered manner, or spread in the X-axis direction or the Y-axis direction. Since the interval between the matching shapes is changed, it can be controlled according to the size of the light guide plate and the emission luminance.
Therefore, high-luminance outgoing light can be obtained regardless of the size of the light guide plate.

Furthermore, the flat illumination device according to claim 8 includes a light source,
It has an incident end face part that guides light from the light source, an outgoing face part that emits light from the incident end face part, and a counter outgoing face part that is located on the opposite side of the outgoing face part. In the three-dimensional space of the X, Y, and Z axes has a continuously changing spread in the X-axis to Y-axis direction, and has a depth or height that changes continuously in the Z-axis direction. And at least a light guide plate provided with a plurality of shapes having a curved line while the ridge line of depth or height is displaced with respect to the X axis or the Y axis, and has a curved surface or a flat surface with respect to the X axis direction or the Y axis direction. An inclined surface can be obtained, and a curved line or a straight ridge line can be obtained in the Z-axis direction.
Therefore, various reflection directions and refraction directions, various diffused lights, convergent lights, and various light quantities can be selected.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
In the present invention, on the light guide plate, in the X-axis-Y-axis direction which is the side surface direction of the light guide plate, the Y-axis direction with respect to the X-axis and the X-axis direction with respect to the Y-axis gradually widen or gradually. A shape in which the ridge line has a curved line that changes continuously in depth or height in the Z-axis direction, which is the thickness direction of the light guide plate in accordance with changes in the Y-axis direction or the X-axis direction. Convex or concavity is provided individually or continuously, and performs complex three-dimensional refraction and total reflection, deflects light from the incident end face of the light guide plate in the intended direction, condenses light, diffuses, etc. Thus, the light guide plate 2 and the flat illumination device 1 capable of obtaining uniform and bright outgoing light from the outgoing surface portion are provided.

  1 is a schematic perspective view of a flat illumination device according to the present invention, FIG. 2 is a schematic front view and schematic perspective view of a shape on a light guide plate according to the present invention, and FIGS. 3 and 4 are diagrams on a light guide plate according to the present invention. FIG. 5 to FIG. 9 are schematic views on the light guide plate according to the present invention, and FIG. 10 is a schematic distribution diagram of the shape on the light guide plate according to the present invention.

The flat illumination device 1 in FIG. 1 is configured by a light guide plate 2, a light source 9, and a reflector 10.
The light guide plate 2 is formed of a transparent acrylic resin (PMMA) or polycarbonate (PC) having a refractive index of about 1.4 to 1.7. The light guide plate 2 includes an incident end face portion 3 that guides light from the light source 9, an exit face portion 6 that emits light from the incident end face portion 3, a counter-exit face portion 5 that is located on the opposite side of the exit face portion 6, and these The side surface portion 4 intersects with the exit surface portion 6 and the opposite exit surface portion 5, and the opposite incident end surface portion 3 ′ located on the opposite side of the incident end surface portion 3.

The light incident on the light guide plate 2 travels into the light guide plate 2 in a range where the refraction angle γ satisfies the expression 0 ≦ | γ | ≦ Sin ⁻¹ (1 / n). For example, since the refractive index of acrylic resin, which is a resin material used for a general light guide plate 2, is about n = 1.49, the refraction angle γ refracted at the incident end face 3 is about γ = 0 to ± 42 °. It propagates in the light guide plate 2 from the incident end face 3.

Further, the light incident on the light guide plate 2 within the range of the refraction angle γ = 0 to ± 42 ° is Sin α = (1 / n) at the boundary surface between the light guide plate 2 and the air layer (refractive index n = 1). ) Can be used to express the critical angle. For example, since the refractive index of acrylic resin, which is a resin material used for the general light guide plate 2, is about n = 1.49, the critical angle α is about α = 42 °. Therefore, if the exit surface portion 6 and the opposite exit surface portion 5 of the light guide plate 2 have no projections or depressions for deflecting light rays or do not exceed the critical angle α, the light in the light guide plate 2 is emitted from the exit surface portion 6 or the opposite exit surface portion. 5, the light travels in the opposite direction of the incident end face part 3 while being totally reflected.
However, in the above case, the thickness of the light guide plate 2 is uniform and flat, and in the case of the wedge-shaped light guide plate 2, the critical angle α is broken by the wedge-shaped taper (degree of inclination) to cause a taper leak. .

The counter-exit surface portion 5 has the X-axis as the direction of the side surface portions 4 at both ends intersecting at right angles to the incident end surface portion 3 and the anti-incident end surface portion 3 ′, and the direction connecting the incident end surface portion 3 and the anti-incident end surface portion 3 ′ as Y. The direction connecting the exit surface portion 6 and the opposite exit surface portion 5 intersecting at right angles to the X-axis and Y-axis directions is defined as the Z-axis direction, and has a spread continuously changing in the X-axis-Y-axis direction. A plurality of shapes 7 having a depth (height) continuously changing in the axial direction and a curve in which a ridge line of the depth (height) is displaced in the Y-axis direction with respect to the X-axis are provided. .
Here, the shape 7 is provided on the anti-light-emitting surface portion 5, but the shape 7 may be provided on the light-emitting surface portion 6, and the shape 7 may be provided on both the anti-light-emitting surface portion 5 and the light-emitting surface portion 6.

As shown in FIG. 2 and FIGS. 5 to 8, the shape 7 has a depth and height that continuously changes in the X-axis and Y-axis directions and continuously changes in the Z-axis direction. The ridgeline 8 of depth or height is displaced with respect to the X axis, the Y axis, etc., and has a curve.
In the following description, the direction having the ridge line 8 is defined as the X-axis direction, and the direction perpendicular to the X-axis is defined as the Y-axis direction.

The shape 7 has a ridge line 8 in the X-axis direction, and the ridge line 8 is a curved line displaced in the Y-axis direction with respect to the X-axis.
Further, the inclined curved surface in the direction in which the ridge line 8 is displaced in the Y-axis direction with respect to the X-axis has an inclined curved surface 8a opposite to the inclined curved surface 8b.

2A and 2C are schematic front views of the shape 7, and FIGS. 2B and 2D are schematic perspective views of the shape 7. FIG.
A shape 7 in FIGS. 2A and 2B has an inclined curved surface 8b and an inclined curved surface 8a extending in the Y-axis direction, and extends in the X-axis direction with the Y-axis direction width being constant. A ridge line 8 having a constant height (depth) in the Z-axis direction extends in the X-axis direction, and the boundary between the light exit surface 6 of the light guide plate 2 and the flat surface portion of the anti-light exit surface portion 5 has a linear shape. .
2 (c) and 2 (d) has an inclined curved surface 8b and an inclined curved surface 8a extending in the Y-axis direction, is bent in the inclined curved surface 8b direction, and has a height (depth) in the Z-axis direction. The ridge line 8 having a constant length extends in the X-axis direction, bends along the ridge line 8 with the width in the Y-axis direction constant, and extends in the X-axis direction. The border has a curved shape.
In some cases, the height (depth) of the ridgeline 8 in the Z-axis direction is lower or higher in the Z-axis direction at the center position in the X-axis direction.

5A shows a schematic front view of the shape 7, and FIGS. 5B and 5C show a schematic perspective view of the shape 7. FIG.
The shape 7 in FIG. 5A is an inclined curved surface that expands in the Y-axis direction as it proceeds in the X-axis direction, and that the ridgeline 8 becomes a curve while extending in the X-axis direction, and expands in the Y-axis direction as it proceeds in the X-axis direction. It has 8b and the inclined curved surface 8a, and the boundary with the output surface part 6 of the light-guide plate 2 and the plane part of the counter-emission surface part 5 has acquired the linear shape.
In addition, the shape 7 in FIG. 5B has an expansion in the Y-axis direction as it proceeds in the X-axis direction, and the ridgeline 8 extends in the X-axis direction while increasing the height (depth) in the Z-axis direction. And has an inclined curved surface 8b and an inclined curved surface 8a that are bent along the ridge line 8 and expand in the Y-axis direction as it proceeds in the X-axis direction, and the flat surface portion of the light-exiting surface portion 6 and the anti-light-emitting surface portion 5 of the light guide plate 2 The border has a curved shape.
Further, the shape 7 in FIG. 5C has a spread in the Y-axis direction as it advances in the X-axis direction, and the ridgeline 8 extends in the X-axis direction while the height (depth) in the Z-axis direction is attenuated. The inclined curved surface 8b and the inclined curved surface 8a that expand in the Y-axis direction as it advances in the X-axis direction have a linear shape at the boundary between the emission surface portion 6 of the light guide plate 2 and the flat surface portion of the non-emission surface portion 5. ing.
In this case, as shown in FIG. 5B, the boundary between the light exiting surface portion 6 of the light guide plate 2 and the flat surface portion of the anti-light emitting surface portion 5 also has a curved shape.
In some cases, the height (depth) of the ridgeline 8 in FIGS. 5B and 5C is constant in the Z-axis direction.

FIG. 6 shows a schematic front view of shape 7. The shape 7 in FIG. 6A has a spread in the Y-axis direction as it advances in the X-axis direction, has a spread in the maximum Y-axis direction at a certain position, and further spreads in the Y-axis direction as it advances in the X-axis direction. Becomes narrower, the ridgeline 8 becomes a curve while extending in the X-axis direction, and the height (depth) in the Z-axis direction increases with the maximum expansion in the Y-axis direction, and then attenuates again, and the maximum expansion in the Y-axis direction And the inclined surface portion 8b and the inclined surface portion 8a extending in the Y-axis direction, and the boundary between the light exiting surface portion 6 of the light guide plate 2 and the flat surface portion of the anti-light emitting surface portion 5 has a linear shape.
6B has an extent in the Y-axis direction as it proceeds in the X-axis direction, has an extent in the maximum Y-axis direction at a certain position, and further proceeds in the Y-axis direction as it proceeds in the X-axis direction. The ridgeline 8 becomes a curve while extending in the X-axis direction, and the height (depth) in the Z-axis direction increases with the maximum expansion in the Y-axis direction, and then attenuates again. The boundary between the exit surface portion 6 of the light guide plate 2 and the flat surface portion of the opposite exit surface portion 5 has a curved shape.
Further, the shape 7 in FIG. 6C is the same as that in FIG. 6A, but has an extension in the Y-axis direction as it advances in the X-axis direction, and has an extension in the maximum Y-axis direction at a certain position. Further, the spread in the Y-axis direction becomes narrower as the process proceeds in the X-axis direction, and the length in the X-axis direction until the maximum spread in the Y-axis direction is equal to the length in the X-axis direction from the maximum spread to the convergence.
Furthermore, unlike FIG. 6C, the shape 7 in FIG. 6D has an expansion in the Y-axis direction as it proceeds in the X-axis direction, and has an expansion in the maximum Y-axis direction at a certain position. The spread in the Y-axis direction becomes narrower as it proceeds in the X-axis direction, and the length that travels in the X-axis direction until the maximum spread in the Y-axis direction is different from the length that travels in the X-axis direction from the maximum spread until convergence.
Here, the length in the X-axis direction from the maximum expansion to the convergence is longer than the length in the X-axis direction until the maximum expansion.
In some cases, the height (depth) of the ridgeline 8 in the Z-axis direction is attenuated low near the center, or the height (depth) of the ridgeline 8 in the Z-axis direction is constant.

7A and 7C are schematic perspective views of the shape 7, and FIGS. 7B and 7D are cross-sectional views of the shape 7 on the X axis.
7 (a) and 7 (b) are similar to the shape 7 shown in FIGS. 6 (a) and 6 (c), but the ridgeline 8 in the X-axis direction, the Y-axis direction, and the Z-axis direction. All have a curvilinear shape.
The shape 7 in FIG. 7A has a curve extending in the Y-axis direction as it advances in the X-axis direction, has a maximum expansion in the Y-axis direction at a certain position, and further curves as it advances in the X-axis direction. The spread in the Y-axis direction becomes narrower, the ridgeline 8 becomes a curve while extending in the X-axis direction, and the height in the Z-axis direction is curved in accordance with the maximum spread in the Y-axis direction as shown in FIG. (Depth) also increases and attenuates again in a curvilinear manner, and has an inclined curved surface 8b and an inclined curved surface 8a extending in the Y-axis direction centering on the maximum Y-axis direction expansion, and the exit surface portion 6 of the light guide plate 2 The boundary with the flat surface portion of the counter-light emitting surface portion 5 has a curved shape.

  The shape 7 in FIG. 7C has a curve that expands in the Y-axis direction as it proceeds in the X-axis direction, has a maximum expansion in the Y-axis direction at a certain position, and further curves as it proceeds in the X-axis direction. The spread in the Y-axis direction becomes narrower, the ridgeline 8 becomes a curve while extending in the X-axis direction, and the height in the Z-axis direction is curved in accordance with the maximum spread in the Y-axis direction as shown in FIG. (Depth) also attenuates and increases again in a curved line, and has an inclined curved surface 8b and an inclined curved surface 8a extending in the Y-axis direction around the maximum Y-axis direction spread, The boundary with the flat surface portion of the counter-light emitting surface portion 5 has a curved shape.

FIG. 8A shows a schematic front view of the shape 7, and FIG. 8B shows a schematic perspective view of the shape 7.
In the shape 7 of FIG. 8A, the Y-axis direction attenuates as it advances in the X-axis direction, the spread in the Y-axis direction has a minimum at a certain position, and further, the Y-axis direction spreads as it advances in the X-axis direction. The ridgeline 8 becomes curved while extending in the X-axis direction, and the height (depth) in the Z-axis direction attenuates and increases again with the minimum expansion in the Y-axis direction. It has the inclined curved surface 8b and the inclined curved surface 8a which have spread, and the boundary between the exit surface portion 6 of the light guide plate 2 and the flat portion of the non-exit surface portion 5 has a linear shape.

  In the shape 7 of FIG. 8B, the Y-axis direction attenuates as it advances in the X-axis direction, and the spread in the Y-axis direction has a minimum at a certain position, and further, the spread in the Y-axis direction increases as it advances in the X-axis direction. The ridgeline 8 becomes curved while extending in the X-axis direction, and the height (depth) in the Z-axis direction attenuates and increases again with the minimum expansion in the Y-axis direction. The boundary between the light emitting plate 6 and the flat surface portion of the non-light emitting surface portion 5 has a curved shape having the inclined curved surface 8b and the inclined curved surface 8a.

FIG. 9 has a shape 7 in which the two shapes 7 in FIGS. 6 and 7 are connected.
In the shape 7 in FIG. 9A, all of the ridgelines 8 in the X-axis direction, the Y-axis direction, and the Z-axis direction have a curved shape.
The shape 7 in FIG. 9A has an extension in the Y-axis direction as it advances in the X-axis direction, has an extension in the Y-axis direction at a certain position, and further decreases in the Y-axis direction as it advances in the X-axis direction. Then, as it advances again in the X-axis direction, it has an extension in the Y-axis direction, has a maximum extension in the Y-axis direction at a certain position, and further decreases in the Y-axis direction as it advances in the X-axis direction. While extending in the X-axis direction, it becomes a curve, and along with the expansion in the Y-axis direction, the height (depth) in the Z-axis direction also increases and attenuates again, and again extends in the X-axis direction with the maximum expansion in the Y-axis direction. The height (depth) in the Z-axis direction also increases and attenuates again, and has an inclined curved surface 8b and an inclined curved surface 8a that extend in the Y-axis direction with the maximum Y-axis direction spread as a center. The boundary between the emission surface portion 6 and the flat surface portion of the anti-light emission surface portion 5 has a curved shape. .

In the shape 7 of FIG. 9B, the X-axis direction and the Y-axis direction have curved and linear shapes.
The shape 7 in FIG. 9B has a spread in the Y-axis direction as it proceeds in the X-axis direction, has a spread in the maximum Y-axis direction at a certain position, and further expands in the Y-axis direction as it proceeds in the X-axis direction. Becomes narrower, and the boundary between the light emitting plate 6 and the flat surface of the non-light emitting surface 5 has a curved shape and expands again in the Y-axis direction as it advances in the X-axis direction. And the spread in the Y-axis direction becomes narrower as it advances in the X-axis direction, the boundary between the light-emitting plate 6 and the flat surface of the anti-light-emitting surface 5 is linear, and the ridgeline 8 is While extending in the X-axis direction, the height (depth) in the Z-axis direction increases along with the maximum expansion in the Y-axis direction and attenuates again. After extending in the X-axis direction, a curve is formed and the expansion in the Y-axis direction occurs. The height (depth) in the Z-axis direction also increases and attenuates again, increasing the maximum Y-axis direction expansion. It has an inclined curved surface 8b that has spread in the Y-axis direction as heart and inclined curved surface 8a.

  Thus, since the ridgeline 8 is displaced in the Y-axis direction with respect to the X-axis, the inclined surface forms a curved surface, and the inclined curved surface 8b and the inclined curved surface 8a are formed. For this reason, reflected light and refracted light can obtain diffused light and convergent light, and these diffused light and convergent light can be selected by selecting the incident direction of the incident light with respect to the inclined curved surface 8b and the inclined curved surface 8a. Can do.

FIG. 3 is a schematic cross-sectional view of the shape 7 in the X-axis.
In the shape 7 of FIG. 3A, the left and right inclined curved surfaces 8 b and the inclined curved surfaces 8 a are linearly centered on the ridge line 8 and have the same length (size).
Further, in the shape 7 of FIG. 3B, the left and right inclined curved surfaces 8b and the inclined curved surfaces 8a have the same length (size) in a concave curve with the ridgeline 8 as the center.
In the shape 7 of FIG. 3C, the left and right inclined curved surfaces 8 b and the inclined curved surfaces 8 a have the same length (size) in a convex curve with the ridge line 8 as the center.
Further, in the shape 7 of FIG. 3D, the left inclined curved surface 8b is linearly shorter than the right inclined curved surface 8a with the ridgeline 8 as the center.
Further, the shape 7 in FIG. 3E has a length (size) in which the left inclined curved surface 8b is concavely curved with respect to the ridgeline 8 as compared with the right inclined curved surface 8a.
Furthermore, in the shape 7 of FIG. 3F, the left inclined curved surface 8b has a shorter length (size) than the right inclined curved surface 8a in a convex curve with the ridgeline 8 as the center. .

  Thus, since the shape 7 spreads in the Y-axis direction is symmetric or asymmetric with respect to the X-axis, the inclination angle of the inclined curved surface 8a and the inclined curved surface 8b continuing from the ridge line 8 is symmetrical with respect to the X-axis. An asymmetric inclination angle can be obtained. Moreover, various reflection directions and refraction directions can be obtained by various shapes 7, and necessary light can be selected, or reflected light and refraction can be selected by selecting the incident direction of light by an asymmetric inclination angle. The amount of light can be selected.

4 is a schematic cross-sectional view of the shape 7 in the Y-axis.
In the shape 7 in FIG. 4A, the height of the ridge line 8 gradually increases in the Z-axis direction in a curve, the Z-axis direction becomes maximum near the center of the X-axis, and the height of the ridge line 8 in the Z-axis direction again. Gradually decays.
Further, in the shape 7 of FIG. 4B, the height of the ridge line 8 gradually increases in the Z-axis direction and attenuates again, and the Z-axis direction becomes minimum near the center of the X-axis and increases again. The height of the ridgeline 8 gradually attenuates in the Z-axis direction (the locus of the ridgeline 8 is a sine curve).
In the shape 7 of FIG. 4C, the height of the ridge line 8 is gradually attenuated in the Z-axis direction along the curve, the Z-axis direction becomes the minimum near the center of the X-axis, and the ridge line 8 again in the Z-axis direction. The height of the gradually increases.
Furthermore, in the shape 7 of FIG. 4D, the height of the ridgeline 8 gradually decreases in the Z-axis direction and increases again in a curved manner, and the Z-axis direction becomes maximum near the center of the X-axis and attenuates again. The height of the ridge line 8 gradually increases in the Z-axis direction (the locus of the ridge line 8 is a sine curve).
Furthermore, in the shape 7 of FIG. 4E, the height of the ridgeline 8 in the Z-axis direction is linear minimum and maximum at both ends of the X-axis.

Thus, the light guide plate 2 changes gradually after the shape 7 gradually becomes wider in the Y-axis direction with respect to the X-axis, or after the shape 7 becomes gradually narrower in the Y-axis direction with respect to the X-axis. Since the depth or height changes gradually in the Z-axis direction along with a change in the Y-axis direction, the projection surface (observation from the Z-axis direction) is formed in a rhombus (diamond) or a tree leaf shape. (Observation from the X-axis direction or the Y-axis direction) is formed in a mountain shape or valley shape (ship shape), or formed in a mortar shape or a drum shape, and the side surface (observation from the X-axis direction or Y-axis direction) is It is formed in a valley shape (a saddle shape), the projection surface (observation from the Z-axis direction) is formed in a triangle shape, a claw shape, or a saddle shape, and the side surface (observation from the X-axis direction or the Y-axis direction) is a mountain shape or a valley shape. Formed into a shape.
Therefore, various reflection directions and refraction directions can be obtained by various shapes, and necessary light can be selected.
Although not shown here, for example, when the light source 9 is provided on both sides of the side surfaces 4 of the light guide plate 2 that are the incident end surfaces 3, the shape 7 is formed from the center position of the light guide plate 2. By providing the inclined curved surface 8a and the inclined curved surface 8b in opposite directions (with the inclined curved surface 8a side facing the light source 9 with the center position as a boundary), brighter outgoing light can be obtained.
Similarly, in the case of the light guide plate 2 having one incident end face part 3, the inclined curved surface 8b having the shape 7 is directed to a position close to the incident end face part 3, and the shape 7 having a shape close to the counter incident end face part 3 'is directed. By distributing so as to provide the inclined curved surface 8a, uniform emitted light can be obtained.

Further, FIG. 10 shows a shape distribution of the shape 7 provided on the light guide plate 2.
In the distribution of the shape 7 shown in FIG. 10A, the shape 7 shown in FIG. 6A, FIG. 6C, FIG. 7A, etc. is provided in series in the X-axis direction. Are provided in parallel in the Y-axis direction. In particular, in the example of FIG. 10A, adjacent rows 7 are provided in a zigzag shape.

  Further, the distribution of the shape 7 shown in FIG. 10B is such that at least two or more of the shapes 7 shown in FIG. 7A and FIG. 9 are connected by the ridge line 8 (not shown) in the X-axis direction. 7 columns are provided in parallel in the Y-axis direction, the light deflection direction can be made constant continuously, and reflected light can be obtained continuously without leakage, so there is no light spot.

  Furthermore, the distribution of the shape 7 shown in FIG. 10C is a shape in which at least two or more of the shapes 7 shown in FIG. 6A or FIG. 6C are connected by a ridge line 8 (not shown) in the X-axis direction. Seven rows are arranged so that the shapes 7 of rows adjacent in the Y-axis direction are staggered.

Further, the distribution of the shape 7 shown in FIG. 10D is obtained by providing the shape 7 shown in FIGS. 6A, 6C, 7A, etc. in series in the X-axis direction. The rows in the direction are provided in parallel in the Y-axis direction, and the parallel intervals are gradually reduced as the rows in the X-axis direction go in the Y-axis direction.
As described above, various shape distributions of the shape 7 provided on the light guide plate 2 can be controlled in accordance with the size of the light guide plate 2 and the emission luminance. Can be obtained.

  The light source 9 is an array of semiconductor light emitting elements composed of integrated red light emission (R), green light emission (G), and blue light emission (B), a single color light emitting semiconductor light emitting element of these semiconductor light emitting elements, and a single color light emitting semiconductor light emitting element. , Three-element light of R, G and B in an array, a pseudo white semiconductor light emitting device using a blue light emitting semiconductor light emitting device and a fluorescent material, CCFL (cold cathode fluorescent discharge tube) or HCFL (heat Cathode fluorescent discharge tube).

Although not shown here, a case or a reflector may be provided under the light guide plate 2 or the light source 9. These reflectors and cases are made of a material in which a white material such as titanium oxide is mixed in a thermoplastic resin, or a material in which metal such as aluminum is deposited on a thermoplastic resin or a metal foil is laminated.
Note that the case covers other than the light source 9 and the incident end face 3 and the emission end face 6, reflects light such as leaked light other than the light emitted from the light source 9 and the emission face 6, and makes it incident on the light guide plate 2 again.

  The reflector 10 is made of a material in which a white material such as titanium oxide is mixed in a thermoplastic resin, a material in which a metal such as aluminum is deposited on a thermoplastic resin, a metal foil laminated, and a thin plate metal.

Thus, the flat illumination device 1 has a depth and a height that continuously spread in the Z-axis direction with a spread that continuously changes in the X-axis and Y-axis directions with the light source. Since the light guide plate 2 provided with a plurality of shapes having a curved line while the ridge line is displaced with respect to the X-axis and the Y-axis, the inclined surface extends from the ridge line having the X-axis or Y-axis curve to both hems of the X-axis and the Y-axis. Can be obtained, and the boundary between the light guide plate and the flat portion can be linear or curved.
Therefore, since the inclined surface forms a curved surface, the reflected light and refracted light can obtain diffused light and convergent light, and these diffused light and convergent light can be selected by selecting the incident direction of the incident light with respect to the inclined surface. Can be selected.
Various reflection and refraction directions can be obtained by various shapes, and the required light can be selected, or reflected light and refracted light can be selected by selecting the incident direction of light by an asymmetric inclination angle. Can be selected, and high-luminance outgoing light can be obtained regardless of the size of the light guide plate.

  Suitable for all sizes from small mobile product backlights to large backlights, and because the light of the final emitted light from the flat lighting device has a wide spread, it can obtain a wide viewing angle, so it can be used outdoors or in car navigation systems. It is possible to provide a light guide plate and a flat illumination device that can be used from a mobile liquid crystal device such as a large liquid crystal television.

1 is a schematic perspective view of a flat illumination device according to the present invention. (A)-(d) It is the schematic front view and schematic perspective view of the shape on the light-guide plate which concerns on this invention. (A)-(f) It is a schematic sectional drawing of the shape on the light-guide plate which concerns on this invention. (A)-(e) It is a schematic sectional drawing of the shape on the light-guide plate which concerns on this invention. (A)-(c) It is a shape figure on the light-guide plate which concerns on this invention. (A)-(d) It is a shape figure on the light-guide plate which concerns on this invention. (A)-(d) It is a shape figure on the light-guide plate which concerns on this invention. (A), (b) It is a shape figure on the light-guide plate which concerns on this invention. (A), (b) It is a shape figure on the light-guide plate which concerns on this invention. (A)-(d) It is a schematic distribution map of the shape on the light-guide plate which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar illumination apparatus 2 Light-guide plate 3 Incident end face part 3 'Anti-incident end face part 4 Side part 5 Anti-emission surface part 6 Emission surface part 7 Shape 8 Ridge line 8a, 8b Inclined curved surface 9 Light source 10 Reflector γ Refractive angle n Refractive index α Critical angle h Line connecting light source φ Angle formed with virtual horizontal plane θ Edge angle (vertical angle)

Claims (8)

In the three-dimensional space of the X axis, the Y axis, and the Z axis, it has a spread that continuously changes in the X axis-Y axis direction, and has a depth or a height that changes continuously in the Z axis direction, A light guide plate comprising a plurality of shapes having curved lines while ridgelines having a depth or the height are displaced with respect to the X axis or the Y axis. The light guide plate according to claim 1, wherein at least two of the shapes are connected by the ridge line. The shape gradually becomes wider in the Y-axis direction with respect to the X-axis and then gradually becomes narrower, and the depth or the height changes in the Z-axis direction along with the change in the Y-axis direction, or The depth or the height changes in the Z-axis direction in accordance with the change in the X-axis direction and gradually changes in the X-axis direction after gradually increasing in the X-axis direction. The light guide plate according to claim 1. The shape is gradually narrowed in the Y-axis direction with respect to the X-axis and then gradually changed, and the depth or the height is changed in the Z-axis direction along with the change in the Y-axis direction, or The depth or the height changes in the Z-axis direction along with the change in the X-axis direction, while gradually changing in width after being gradually narrowed in the X-axis direction with respect to the Y-axis. The light guide plate according to claim 1. The shape gradually narrows or gradually changes in the Y-axis direction with respect to the X-axis, and the depth or the height changes in the Z-axis direction along with the change in the Y-axis direction, or the Y 2. The depth or the height changes in the Z-axis direction along with the change in the X-axis direction while gradually narrowing or gradually changing in the X-axis direction with respect to an axis. Light guide plate. 2. The shape according to claim 1, wherein a direction of spreading in the Y-axis direction is symmetric or asymmetric with respect to the X-axis, or a direction of spreading in the X-axis direction is symmetric or asymmetric with respect to the Y-axis. The light guide plate described. The shape is arranged in the X-axis direction or the Y-axis direction, provided in parallel or in series, the shapes are provided in a staggered manner, or adjacent to each other in a direction extending in the X-axis direction or the Y-axis direction. The light guide plate according to claim 1, wherein an interval between shapes is changed. A light source;
An incident end face that guides light from the light source; an exit face that emits light from the incident end face; and a counter-exit face located on the opposite side of the exit face. Depth or height that continuously spreads in the X-axis direction in the three-dimensional space of the X-axis, Y-axis, and Z-axis on the non-emission surface portion, and continuously changes in the Z-axis direction And a light guide plate provided with a plurality of shapes having curved lines while the ridgeline of the depth or the height is displaced with respect to the X axis or the Y axis.

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