WO2005090855A1

WO2005090855A1 - Light guide plate

Info

Publication number: WO2005090855A1
Application number: PCT/JP2004/019534
Authority: WO
Inventors: Kazuhisa Saito; Kenichi Yoshikawa
Original assignee: System-Lab For K.G.
Priority date: 2004-03-22
Filing date: 2004-12-27
Publication date: 2005-09-29
Also published as: JPWO2005090855A1; JP4524282B2

Abstract

A light guide plate capable of efficiently reflecting the light introduced from an end face toward the front face is characterized by comprising a light-transmitting plate (10) having light-transmitting properties, a plurality of recessed portions (3) formed in the back face (9) of the light-transmitting plate (10), and peripheral projected portions (4) formed around respective recessed portions (3) so as to protrude from the back face (9). By having such a structure wherein the recessed portions (3) are surrounded by the peripheral projected portions (4) protruding from the back face (9), light incident on the peripheral projected portions (4) is reflected toward the in-plane direction and the front face of the light-transmitting plate, so that the light introduced from the end face can be efficiently reflected toward the front face.

Description

Specification

Light guide plate

Technical field

The present invention relates to a television receiver, a monitor of a personal computer, a liquid crystal display for electronic devices such as a mobile phone, various lamps such as a guide light, a direction indicator lamp, a brake lamp, an illumination lamp, and a back of a large signboard. The present invention relates to a light guide plate which is convenient and extremely suitable for use as a light.

Background art

Conventionally, as a liquid crystal display for electronic devices such as a television receiver, a personal computer, and a mobile phone, various lamps such as a guide light, a direction indicator lamp, a brake lamp, an illumination light, and a backlight of a large signboard. It is known to use a cold-cathode tube display device, a fluorescent tube display device and an LED (Light Emitting Device) array device. For example, in a thin type liquid crystal display device, a backlight unit as a light emitter is provided on the back side of the liquid crystal image cell. The arrangement is arranged on the end face of a transparent flat plate called a light guide plate made of acrylic or the like, and the incident light of the end face force is scattered to the front side using a prism sheet or a light scattering sheet. FIG. 32 is a view showing a conventional backlight unit using such a light guide plate. As shown in the figure, a large number of reflective printing surfaces 224 are provided on the back portion 223 of the acrylic resin plate 222 by printing, and light introduced from the light source 220 provided on the end surface 225 of the acrylic resin plate 222 is provided. The light is reflected through the plurality of reflective printing surfaces 224 and is guided to the surface 221 of the acryl resin plate 222. On the surface 221 of the acrylic resin plate 222, an optical member usually called a prism sheet or a light scattering sheet is disposed between the acrylic resin plate 222 and the liquid crystal cell.

[0003] However, the light guide plate body used as a backlight of a conventional liquid crystal display or a large signboard other than the liquid crystal display has a high brightness and efficient light evenly over the entire surface of the liquid crystal display or the large signboard. It is difficult to illuminate the display, and the display and the light projection part may be uneven, and the performance of the liquid crystal display cannot be fully exploited. There were drawbacks. In recent years, LED arrays and the like have been attracting attention as electronic components that are excellent in terms of low power consumption and energy efficiency.However, optical members called prism sheets and diffuser sheets are required, and only these components are needed. The manufacturing cost of liquid crystal displays is increasing.

Disclosure of the invention

[0004] The present invention has solved the above-mentioned problems, and has high brightness and high efficiency over the entire surface of a liquid crystal display such as a television receiver, a monitor of a personal computer, or a mobile phone or the entire surface of a large signboard. The purpose of the present invention is to obtain a light guide plate, which can improve the performance of a liquid crystal display or a large signboard by irradiating light well, is convenient to use, is extremely easy to use, and is easy to use. It is another object of the present invention to provide a light guide plate in which a backlight unit has a relatively simplified structure and which can realize a dramatic reduction in manufacturing cost.

[0005] In order to achieve the above object, a light guide plate of the present invention includes a light-transmitting plate having a light-transmitting property, and a plurality of recesses formed on the back surface of the light-transmitting plate. The peripheral portion of the recess has a peripheral ridge formed so as to protrude from the back surface force. Due to the structure having a peripheral ridge formed so as to protrude from the back surface at the periphery of such a concave portion, the light incident on the peripheral ridge is in the in-plane direction and the surface of the translucent plate. The light is reflected to the side, and the light introduced from, for example, the end face of the light-transmitting plate can be efficiently reflected to the front side.

[0006] According to a preferred example of the light guide plate of the present invention, the light transmissive plate is made of a polymer material, and the peripheral ridge is formed on the rear surface of the light transmissive plate when the concave portion is formed. It is characterized by being formed simultaneously by hot pressing the sides. Examples of the translucent plate include acrylic resin such as polyester resin, amorphous polyester resin, polymethylmethacrylate HPMMA), polycarbonate resin, polystyrene resin (PS), styrene and acrylonitrile resin ( SAN), urethane resin, cycloolefin resin, alicyclic polyolefin resin, cyclic polyolefin resin, alicyclic acrylic resin, amorphous fluorine resin, epoxy resin, polyimide resin, polyamide. Various transparent polymer materials such as fats and vinyl ester resins can be used, and a modified material of these and a combination of a plurality of resin materials may be used. The translucent plate has a function of reflecting light from the end face to the front side. By performing the hot pressing widely used in the plastic wrapping, it is possible to relatively easily form the above-mentioned peripheral ridge in a shape protruding to the rear side of the translucent plate. it can.

[0007] Further, according to a preferred example of the light guide plate of the present invention, the translucent plate made of the polymer material has a flat plate shape, and the hot pressing includes heating having projections corresponding to recesses. This can be done with a plate or roll for application. By using a plate or a roll for heat processing, the structure of the processing apparatus becomes relatively simple, which is suitable for mass production.

[0008] Further, in order to achieve the above object, another light guide plate of the present invention includes a light-transmitting plate made of a polymer material having a light-transmitting property, and an entire rear surface of the light-transmitting plate. A plurality of concave portions provided with depressions over the entire length. Light from the light source is introduced into a translucent plate made of a polymer material having translucency, and the introduced light is converted into a large number of concave portions having depressions provided on the back surface of the translucent plate. Turn around and proceed. As a result, it emits light without causing unevenness, and is extremely suitable as a backlight for a liquid crystal display of a television receiver, a personal computer, and a mobile phone.

According to a preferred example of the light guide plate of the present invention, the concave portion has a large number of wavy streaks, a large number of inclined parallel inclined streaks having a crossed portion, and a crossed portion. It is possible to include a large number of parallel, parallel and orthogonal streaks! /, Formed by deviation, and the concave portion can include a shape formed by a large number of point-shaped concave portions. It is. Further, as a method of processing the concave portion of the light guide plate of the present invention, high frequency processing or ultrasonic processing can be used.

[0010] In the light guide plate of the present invention, as described above, a plurality of recesses are formed on the back surface of the translucent plate, and the back surface is formed so as to protrude at the periphery of the recess. Light incident on the peripheral ridge at this portion is reflected in the in-plane direction and toward the surface of the light-transmitting plate, and the light-transmitting plate has a light-transmitting property. For example, the end face force of the optical plate body The introduced light can be efficiently reflected to the surface side.

Further, as described above, another light guide plate of the present invention has a large number of concave portions provided with depressions over the entire back surface of a light-transmitting plate such as an acrylic resin plate having a light-transmitting property. Has a structure with A light source for introducing light to the light-transmitting plate is provided adjacent to the end wall surface of the light-transmitting plate, and light emitted from the light source when the light source is energized transmits light having a light-transmitting property. Introduced into the light plate. The introduced light changes its direction due to a number of concave portions provided with depressions provided on the back surface of the light-transmitting plate, and travels as the light comes out of the surface of the light-guiding substrate, causing unevenness of the light-transmitting plate. It emits light without generation, and is extremely suitable as a knock light for a liquid crystal display for electronic devices such as a television receiver, a personal computer monitor, and a mobile phone.

[0012] Further, in particular, by providing a plurality of depressions deeper than the depressions in the center of the back surface of the light guide substrate, reflection of light from the light source is promoted, and light is uniformly and highly illuminated over a wide range. It improves the performance of large signboards and works very conveniently as a backlight for large signboards.

[0013] Further, the plurality of concave portions provided with the concave portions provided over the entire back surface of the light-transmitting plate body are formed in the form of a large number of corrugated lines having intersecting portions, so that they are emitted from the light source. The light is irregularly reflected in a number of waves in various directions in various directions to increase the brightness of light emitted from the entire surface of the light guide substrate.

[0014] Further, the plurality of concave portions provided with depressions provided over the entire back surface of the light-transmitting plate body are formed in the shape of a large number of inclined parallel orthogonal streaks having intersections, and are emitted from the light source. The reflected light is reflected by a multiplicity of perpendicular parallel orthogonal stripes having intersections to increase the brightness of light emitted from both end portions of the light guide substrate corresponding to the direction in which the light source of the light guide substrate is provided. .

[0015] Further, the plurality of concave portions provided with depressions provided over the entire back surface of the translucent plate body are formed in the shape of a large number of parallel parallel inclined streaks having intersecting portions, and are emitted from the light source. The reflected light is reflected by a multiplicity of perpendicular parallel orthogonal stripes having intersections to increase the brightness of light emitted from both end portions of the light guide substrate corresponding to the direction in which the light source of the light guide substrate is provided. .

[0016] Furthermore, the plurality of concave portions provided with the concave portions provided over the entire back surface of the translucent plate body are formed by a large number of point-shaped concave portions, and the intervals between the point-shaped concave portions are different. It is easy to form a light guide substrate, a light guide substrate having a luminance suitable for a liquid crystal display or a large signboard can be used, and it can be used efficiently as a backlight.

[0017] As described above, the light guide plate of the present invention can be used for a television receiver, a personal computer, and the like. The performance of a liquid crystal display or a large signboard can be improved by illuminating the entire surface of a liquid crystal display or a large signboard of an electronic device such as a monitor or a mobile phone or a large signboard with high brightness and efficiency. It is convenient, extremely convenient, convenient, and easy to manufacture, and has many industrial advantages such as being able to be provided at low cost.

Brief Description of Drawings

FIG. 1 is a schematic perspective view of an example of a light guide plate of the present invention.

FIG. 2 is an enlarged sectional view of a main part of an example of the light guide plate of the present invention shown in FIG. 1.

FIG. 3 is an enlarged cross-sectional view of a main part of a modification of an example of the light guide plate of the present invention.

FIG. 4 is a schematic perspective view for explaining a manufacturing process of an example of the light guide plate of the present invention shown in FIG. 1.

FIG. 5 is a schematic perspective view showing a surface of a heat roll used in the manufacturing process shown in FIG. 4.

FIG. 6 is a schematic perspective view of an embodiment of the light guide plate of the present invention.

FIG. 7 is a schematic rear view of a light guide plate according to a second embodiment of the present invention.

8 is an enlarged sectional view of a main part AA of a second embodiment of the light guide plate body of the present invention shown in FIG. 7.

FIG. 9 is an enlarged sectional view of a main part BB of the second embodiment of the light guide plate of the present invention shown in FIG. 7.

FIG. 10 is a schematic rear view of a light guide plate according to a third embodiment of the present invention.

FIG. 11 is an enlarged sectional view of a main portion AA of a third embodiment of the light guide plate of the present invention shown in FIG. 10.

FIG. 12 is an enlarged cross-sectional view of a main part BB of a third embodiment of the light guide plate of the present invention shown in FIG. 10.

FIG. 13 is a schematic rear view of a light guide plate according to a fourth embodiment of the present invention.

FIG. 14 is an enlarged sectional view of a main part AA of a fourth embodiment of the light guide plate of the present invention shown in FIG. 13.

FIG. 15 is an enlarged sectional view of a main part BB of a fourth embodiment of the light guide plate body of the present invention shown in FIG. 13. FIG. 16 is a schematic rear view of a light guide plate according to a fifth embodiment of the present invention.

17] FIG. 17 is an enlarged cross-sectional view of a main part AA of a fifth embodiment of the light guide plate body of the present invention shown in FIG.

[18] FIG. 18 is a schematic rear view of a light guide plate according to a sixth embodiment of the present invention.

[19] FIG. 19 is an enlarged cross-sectional view of a main part AA of a sixth embodiment of the light guide plate body of the present invention shown in FIG.

[20] FIG. 20 is an enlarged cross-sectional view of a main part BB of a sixth embodiment of the light guide plate body of the present invention shown in FIG.

[21] FIG. 21 is a schematic rear view of a light guide plate according to a seventh embodiment of the present invention.

[22] FIG. 22 is an enlarged cross-sectional view of main parts AA of a seventh embodiment of the light guide plate body of the present invention shown in FIG. 21.

[23] FIG. 23 is a schematic rear view of the eighth embodiment of the light guide plate of the present invention.

[24] FIG. 24 is an enlarged cross-sectional view of a main part AA of an eighth embodiment of the light guide plate body of the present invention shown in FIG. 23.

FIG. 25 is a schematic rear view of the ninth embodiment of the light guide plate of the present invention.

26] FIG. 26 is an enlarged cross-sectional view of a main part AA of a ninth embodiment of the light guide plate body of the present invention shown in FIG. 25.

FIG. 27 is a conceptual diagram of a high-frequency streak forming machine that can be used to manufacture the light guide plate of the present invention.

[28] Fig. 28 is a conceptual diagram of a high-frequency point forming machine that can be used to manufacture the light guide plate of the present invention.

FIG. 29 is a conceptual diagram of an ultrasonic streak forming machine that can be used to manufacture the light guide plate of the present invention.

FIG. 30 is a conceptual diagram of an ultrasonic point forming machine that can be used to manufacture the light guide plate of the present invention.

FIG. 31 is a schematic perspective view showing an example of an apparatus using the light guide plate of the present invention.

[32] FIG. 32 is a schematic sectional view showing an example of a conventional light guide plate.

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of an example of the light guide plate. The light guide plate of the present embodiment has an acrylic resin plate 10 that is a light-transmitting plate having a light-transmitting property, and a plurality of recesses 3 provided on the back surface thereof. It is arranged on the back side of the plate 10 in a matrix. In the present embodiment, each of the recesses 3 is a hole having the shape of a quadrangular pyramid, and the bottom surface of the quadrangular pyramid is open at the back of the acrylic resin plate 10, and the apex of the pyramid is the acrylic resin plate 1. It is formed at a depth located in the middle of the thickness of 0!

[0020] The acrylic resin plate 10 is a thermoplastic synthetic resin having a high light transmittance, and is a rectangular flat plate in the present embodiment. The thickness of the acrylic resin plate 10 can be arbitrarily selected according to the function and the application. For example, the thickness of the light emitting diode or the cold cathode tube arranged on the end face of the acrylic resin plate 10 is exemplified. It is also possible to choose according to the size. Further, in the present embodiment, the acrylic resin plate has a flat plate shape, but may have a curved surface such as a tubular shape, or may have a structure in which the thickness of the plate is partially changed. . Further, the acrylic resin plate 10 is adopted by using a thermoplastic synthetic resin having a high light transmittance, but other thermoplastic synthetic resins having a high light transmittance can also be used. .

The plurality of recesses 3 are holes for reflecting light incident from the end face 11 of the acrylic resin plate 10 toward the surface 8 of the acrylic resin plate 10, and in the present embodiment, The hole has the shape of an approximately four-sided pyramid. At the periphery of each recess 3, there is provided a peripheral ridge 4 formed so as to protrude from the rear surface of the acrylic resin plate 10. The peripheral ridges 4 are formed by projecting when a pyramid-shaped projection formed on the surface of a heat roll or a heat plate is pressed against the back surface 9 of the acrylic resin plate 10 when forming the recess 3. This is a portion that is once melted by heat at the time of pressurization, cooled, and solidified at the periphery of each recess 3. The light that travels in the in-plane direction of the back surface 9 of the acrylic resin plate 10 is diffused by the peripheral ridge portion 4, and the light extraction efficiency around the concave portion 3 is improved. Since each recess 3 has a required inclined surface, the light incident from the end surface 11 of the acrylic resin plate 10 is reflected to the surface 8 of the acrylic resin plate 10 where the efficiency is high. Light that travels in the in-plane direction of the back surface 9 of the acrylic resin plate 10 due to irregular reflection in the concave portion 3 together with the incident light from 11 is effectively applied to the surface 8 side of the acrylic resin plate 10 by the peripheral ridges 4. It will be reflected. [0022] The size of the plurality of recesses 3 is, for example, 0.05 mm to 0.3 mm in diameter on the back side, and the pitch between adjacent recesses 3 is, for example, 0.1 mm to 2. Omm, and more preferably 0.3 mm. — It can be set to 0.7 mm. The angle at the apex side of the concave portion 3 can be set to about 90 degrees like a corner cube. Force slightly smaller than that, about 60-70 degrees is acceptable. On the other hand, an obtuse angle of about 120 degrees may be used. In addition, the size, pitch, shape, direction, depth, etc. of the plurality of recesses 3 may be changed between the peripheral portion and the central portion of the acrylic resin plate 10. Since the strength tends to be insufficient, the plurality of recesses 3 may be arranged at a relatively high density.

[0023] The plurality of concave portions 3 for reflecting to the surface 8 side of the acrylic resin plate 10 include a light source 12 that can be effectively disposed in a relatively small space such as a cold cathode tube or an LED array. The emitted light is reflected directly or on the reflecting surface 13 and is incident on the end face 11 of the acrylic resin plate 10, and the incident light is reflected on the plurality of recesses 3 and the peripheral ridges 4, and the Light is efficiently illuminated with high brightness over the entire surface or the entire surface of a large signboard.

The shape of the pyramid-shaped recess 3 shown in FIG. 2 is not limited, and the light guide plate body of the present invention can take various shapes such as a cone, a prism, a cylinder, a truncated cone, and a truncated pyramid. For example, as in a modified example shown in FIG. 3, it is possible to form a plurality of truncated conical recesses 23 on the back surface 26 of the acrylic resin plate 20. Even with such a truncated conical recess 23, a pyramid or cylindrical projection with a flat head formed on the surface of a heat roll or a heat plate is formed on the back 26 of the acrylic resin plate 20. By pressing, the peripheral ridge portion 24 can be formed simultaneously with the concave portion 23 having a desired shape. Further, in a shape such as a cone or a pyramid, the pointed portion may be eccentric. Further, the plurality of recesses 3 need not all have the same shape, and some may have different shapes and sizes, or may have a pattern in which a plurality of recesses 3 are combined. .

FIG. 4 shows an example of a method for manufacturing the light guide plate of the present embodiment using a heat roll. An acrylic resin plate 16 is supported on a movable table 15 on a base 17. The acrylic resin plate 16 is fixed on the movable table 15 so that the rear side is the upper side as a final product, and the acrylic resin plate 16 is heated so as to press the acrylic resin plate 16 on the movable table 15. Roll 18 is provided. The heat roll 18 heats and spreads the acrylic resin plate 16. Pressing is performed, and as shown in FIG. 5, projections 19 are formed according to the shape of the concave portion to be formed. When the heat roll 18 is pressed against the acrylic resin plate 16, the protrusions 19 bite into the surface of the acrylic resin plate 16, melt and cool as the temperature rises on the surface, and are cooled at the periphery of each recess. The peripheral ridges will harden.

Next, FIG. 6 shows an example in which light sources 38 and 38 are arranged on both end surfaces 37 and 37 of a light-transmitting plate 31 such as an acrylic resin plate having a light-transmitting property. A large number of concave portions with depressions are provided over the entire surface 32 of the rear surface 32 of the transparent plate 31, and a large number of depressions 35 are provided at the center of the rear surface, which are deeper than the depressions, to form the translucent plate 31. are doing. Part of the light from the light sources 38, 38 is directly incident on both end faces 37, 37 of the translucent plate 31, and part of the light is reflected on the reflecting surfaces 40 of the support plates 41, 41, and both ends 37. , 37 incident.

When the light sources 38, 38 are energized, light emitted from the light sources 38, 38 is introduced into the translucent plate 31 having translucency, and the light introduced into the translucent plate 31 is transmitted. The back surface 32 of the light-transmissive plate 31 is turned around by a number of concave portions 36 provided with recesses, and light is emitted from the surface of the light-transmissive plate 31 to form the light-transmissive plate 31. It emits light without causing unevenness, and is extremely suitable as a knock light of a liquid crystal display for electronic devices such as a television receiver, a monitor of a personal computer, and a mobile phone. A light source such as a cold-cathode tube or an LED light source for introducing light into the translucent plate 31 as the light source 38 is provided in the supporting plates 41 and 41 having the reflecting surfaces 40 and 40, and is provided on the supporting plate 41. The reflecting surface 40 promotes the introduction of light into the translucent plate 31, thereby increasing the brightness of the light guide plate and further improving the performance of the liquid crystal display.

FIGS. 7 to 9 are views showing a second embodiment of the present invention, FIG. 7 is a schematic rear view of a light guide plate according to a second embodiment of the present invention, and FIG. FIG. 9 is an enlarged cross-sectional view of an essential part AA of a second embodiment of the light guide plate of the present invention shown in FIG. 9, and FIG. 9 is an enlarged BB of an essential part of the second embodiment of the light guide plate of the present invention shown in FIG. It is sectional drawing. In the second embodiment of the present invention, a large number of concave portions provided with concave portions provided over the entire surface of the rear surface 32 of the light-transmitting plate 36 are formed by a large number of corrugated shapes 34, 39. A large number of deep dents 35 are also formed substantially in the center of the many mesh-shaped concave portions.

[0029] Such a large number of wavy lines in the second embodiment are described in the third embodiment described below. A plurality of protruding blade tips each having a saw-tooth shape are provided similarly to the multi-parallel parallel-inclination streaks in the embodiment and the multi-parallel parallel-orthogonal streaks in the fourth embodiment. At the same time, it is formed by a streak-forming device heated via electric heat, and the streaks are formed by contacting a number of protruding cutting edges of the streak-forming device with the rear surface of the light-transmitting plate, and furthermore, by using a number of streaks-forming devices. By moving either the protruding blade tip or the back of the translucent plate, the required portion of the translucent plate is melted and cut, and a large number of corrugated, It is possible to easily form inclined parallel inclined streaks and a large number of perpendicular parallel orthogonal streaks.

[0030] Further, the plurality of deep dent portions 35 are formed by melting and cutting required portions of the light transmitting plate member 36 by rotating and moving the roller member for forming the deep depression portion heated via electric heat. Necessary portions of the rear surface 32 of the 36 can be melt-cut to form a large number of deep depressions 35 on the rear surface of the translucent plate 36 easily.

FIGS. 10 to 12 are views showing a third embodiment of the present invention, FIG. 10 is a schematic rear view of a third embodiment of the light guide plate of the present invention, and FIG. FIG. 12 is an enlarged sectional view of a main part AA of a third embodiment of the light guide plate of the present invention shown in FIG. 10, and FIG. 12 is a main part BB of the second embodiment of the light guide plate of the present invention shown in FIG. It is an expanded sectional view. In the third embodiment of the present invention, a large number of concave portions provided with depressions provided over the entire surface of the rear surface 52 of the light-transmitting plate body 56 are provided with a large number of inclined parallel inclined stripes having intersections. The shape is formed by the shapes 54 and 57, and the parallel inclined streaks 54 and 57 also form a large number of deep depressions 55 at substantially the center of the mesh-shaped concave portions. Light incident from the end face, not shown, of the translucent plate 56 is reflected by these many concave portions, is reflected from the surface 51 of the translucent plate 56 with high efficiency, and further increases the luminance. Improve the performance of liquid crystal displays.

FIGS. 13 to 15 are views showing a fourth embodiment of the present invention, FIG. 13 is a schematic rear view of a light guide plate according to a fourth embodiment of the present invention, and FIG. FIG. 15 is an enlarged sectional view of a main part AA of the fourth embodiment of the light guide plate of the present invention shown in FIG. 13, and FIG. 15 is a main part BB of the fourth embodiment of the light guide plate of the present invention shown in FIG. It is an expanded sectional view. In the fourth embodiment of the present invention, a number of concave portions provided with depressions provided over the entire back surface 62 of the translucent plate 66 are formed of a number of inclined parallel inclined stripes having an intersection. Formed in shape 64, 67 The parallel inclined streaks 64 and 67 also form a large number of deep depressions 65 at substantially the center of a large number of concave portions forming a lattice shape at the intersection 60. The unillustrated end face force of the translucent plate 66 The incident light is reflected by these many concave portions, is reflected from the surface 61 of the translucent plate 66 with high efficiency, and the brightness is further increased. Improve display performance

FIGS. 16 and 17 are views showing a fifth embodiment of the present invention. FIG. 16 is a schematic rear view of a fifth embodiment of the light guide plate of the present invention, and FIG. FIG. 17 is an enlarged sectional view of a main part AA of a fifth embodiment of the light guide plate body of the present invention shown in FIG. In the fifth embodiment of the present invention, a large number of concave portions provided with concave portions provided over the entire back surface 72 of the light-transmitting plate 76 are formed by a large number of dot-shaped concave portions 74. A large number of deep depressions 75 are also formed near the center of the translucent plate 76. The light that has also entered the end face force (not shown) of the translucent plate 76 is reflected by these many point-shaped concave portions, is reflected from the surface 71 of the translucent plate 76 with high efficiency, and has a higher brightness. To further improve the performance of the liquid crystal display.

Here, the many point-like concave portions in the fifth embodiment are formed by providing a number of protruding blade tips on the peripheral wall surface of the roller body and using a point-like forming device heated via electric heating. The point-forming device is formed by contacting a number of protruding cutting edges of the point-forming device with the rear surface 72 of the light-transmitting plate 76, and further rotating the roller member of the point-forming device on the rear surface 72 of the light-transmitting plate 76. By moving, a required portion of the translucent plate is melt-cut to form a large number of dot-shaped concave portions on the back surface 72 of the translucent plate 76 easily. In particular, by using point-forming devices with different numbers of protruding blade tips provided on the peripheral wall surface of the roller body, the interval between the many point-shaped concave portions formed on the back surface 72 of the translucent plate 76 can be reduced. A different light guide plate can be obtained.

FIGS. 18 to 20 are views showing a sixth embodiment of the present invention, FIG. 18 is a schematic rear view showing a sixth embodiment of the light guide plate of the present invention, and FIG. FIG. 18 is an enlarged sectional view of an essential part AA of the light guide plate according to the sixth embodiment of the present invention shown in FIG. 18, and FIG. 20 is a sectional view of the light guide plate according to the sixth embodiment of the present invention shown in FIG. It is a BB enlarged sectional view of a part. In the sixth embodiment of the present invention, a number of concave portions provided with depressions provided over the entire surface of the rear surface 82 of the translucent plate 86 are provided by high-frequency processing or ultrasonic processing as described later. Many books It is formed by wavy lines 84 and 89. The light that has also entered the not-shown end face force of the light-transmitting plate 86 is reflected by these numerous concave portions of the wave streaks 84 and 89, and is reflected from the surface 81 of the light-transmitting plate 86 with high efficiency. Raise the brightness to improve the performance of the LCD.

FIGS. 21 to 22 are views showing a seventh embodiment of the present invention, FIG. 21 is a schematic rear view of a light guide plate according to a seventh embodiment of the present invention, and FIG. FIG. 22 is an enlarged sectional view of a main part AA of a light guide plate body according to a seventh embodiment of the present invention shown in FIG. In the seventh embodiment of the present invention, a large number of concave portions provided with depressions provided over the entire rear surface 92 of the light-transmitting plate body 96 are provided with a large number of inclined parallel The inclined streaks 94 and 97 are formed by high frequency processing or ultrasonic machining, and the substantially central portions of a large number of concave portions forming a mesh shape by the parallel inclined streaks 94 and 97 are different from those of the third embodiment. In contrast, many deep depressions are not formed. The light that has also entered the end face force (not shown) of the light-transmitting plate 96 is reflected by these many concave portions, is reflected from the surface 91 of the light-transmitting plate 96 with high efficiency, and further increases the brightness to increase the brightness of the liquid crystal display. To further improve the performance.

FIG. 23 to FIG. 24 are views showing an eighth embodiment of the present invention. FIG. 23 is a schematic rear view of the eighth embodiment of the light guide plate of the present invention, and FIG. FIG. 24 is an enlarged sectional view of a main part AA of an eighth embodiment of the light guide plate body of the present invention shown in 23. In the eighth embodiment of the present invention, a large number of concave portions provided with depressions provided over the entire surface of the rear surface 102 of the light-transmitting plate 106 have a large number of inclined parallel portions having intersections. The inclined streaks 104 and 107 are formed by high-frequency processing or ultrasonic processing, and the parallel inclined streaks 104 and 107 form a grid with intersection points 100. The light that has also entered the end face force (not shown) of the light-transmitting plate 106 is reflected by these many concave portions, is reflected from the surface 101 of the light-transmitting plate 106 with high efficiency, and has a higher brightness and a liquid crystal. Improve display performance.

FIGS. 25 and 26 are views showing a ninth embodiment of the present invention. FIG. 25 is a schematic rear view of the ninth embodiment of the light guide plate of the present invention, and FIG. FIG. 26 is an enlarged sectional view of a main part AA of a ninth embodiment of the light guide plate body of the present invention shown in FIG. In the ninth embodiment of the present invention, the concave portion provided with the concave portion provided over the entire back surface 112 of the translucent plate 116 is formed by a plurality of dot-shaped concave portions 114 and 113 by high-frequency processing. Or formed by ultrasonic processing Things. The light that has also entered the end face force (not shown) of the translucent plate 116 is reflected by these many point-shaped concave portions, is reflected from the surface 111 of the translucent plate 116 with high efficiency, and further increases the luminance. To further improve the performance of the liquid crystal display.

FIGS. 27 to 30 are conceptual diagrams of processing machines that can be used to manufacture the light guide plate of the present invention, respectively. FIG. 27 is a conceptual diagram of a high-frequency streak forming machine. 28 is a conceptual diagram of a high-frequency dot forming machine, FIG. 29 is a conceptual diagram of an ultrasonic streaking machine, and FIG. 30 is a conceptual diagram of an ultrasonic dot forming machine.

[0040] A large number of corrugated lines in the second embodiment, a large number of inclined parallel inclined lines in the third embodiment, a large number of orthogonal parallel lines in the fourth embodiment. One of the devices for forming the orthogonal streak is a high-frequency streak forming machine 135 in which a number of protruding cutting edges 134 are provided on a flat plate 133 like a saw blade shown in FIG. At the time of formation, a number of protruding cutting edges 134 of the high-frequency streak forming machine 135 abut against the rear surface 132 of the translucent plate 131, and furthermore, the deviation of the protruding cutting edge 134 or the rear surface 132 of the translucent plate 131 is shifted. By moving the light-transmissive plate 131, the required portions of the translucent plate 131 are melted and cut, and a large number of wavy lines, a large number of slanted parallel inclined lines, a large number of It is possible to easily form the parallel orthogonal streaks.

One of the devices for forming a large number of point-like concave portions in the fifth embodiment is a high-frequency point-like device provided with a number of protruding blade tips 144 on the peripheral wall surface of a roller body 145 shown in FIG. Formed caro machine 146. At the time of formation, a large number of protruding cutting edges 144 of the high-frequency point forming machine 146 abut against the back surface 143 of the translucent plate 142 supported on the support table 141, and further a high-frequency point forming machine 146 is formed. Rotating the roller body 145 of 146 on the back 143 of the translucent plate 142 melts and cuts a required part of the translucent plate 142 to form a large number of points on the back 14 3 of the translucent plate 142. The high-frequency point forming machine 146 having a different number of protruding blade tips 144 provided on the peripheral wall surface of the roller body 145 can be formed easily. It is possible to obtain a light guide plate in which the intervals between a large number of dot-shaped concave portions formed on the back surface 143 of the optical plate 142 are different.

[0042] A large number of corrugated lines in the second embodiment, a large number of parallel parallel inclined lines in the third embodiment, a large number of orthogonal parallel lines in the fourth embodiment. Form orthogonal streaks Another apparatus to be formed is an ultrasonic streak forming machine 135 in which a plurality of protruding cutting edges 154 are provided on a flat plate-like member 153 having a saw blade shape as shown in FIG. At the time of forming, the many protruding blade tips 154 of the ultrasonic streak forming machine 155 abut against the back 152 of the translucent plate 151, and furthermore, either the protruding blade tip 154 or the back 152 of the translucent plate 151 By moving the surface, the required portions of the translucent plate 151 are melted and cut, and a large number of wavy lines, a large number of inclined parallel inclined stripes, and a large number of orthogonal lines are formed on the back surface 152 of the translucent plate 151. Thus, it is possible to easily form the parallel orthogonal streaks.

One of the devices for forming a large number of point-like concave portions in the fifth embodiment is an ultrasonic point having a large number of protruding blade tips 164 provided on the peripheral wall surface of a roller body 165 shown in FIG. The shape-forming caro machine 166. At the time of formation, a large number of protruding cutting edges 164 of the ultrasonic point forming machine 166 abut against the back surface 163 of the translucent plate 162 supported on the support base 161, and the ultrasonic point forming machine 166 is further formed. By rotating and moving the roller body 165 of the machine 166 on the back surface 163 of the translucent plate body 162, a required portion of the translucent plate body 162 is melted and cut to form a large number of parts on the back surface 163 of the translucent plate body 162. A point-shaped concave portion can be easily formed, and an ultrasonic point-shaped forming machine 166 having a different number of protruding blade tips 164 provided on the peripheral wall surface of the roller body 165 is used. Accordingly, it is possible to obtain a light guide plate in which the intervals between a large number of dot-shaped concave portions formed on the back surface 163 of the light-transmitting plate 162 are different.

Therefore, the use effect can be enhanced by using the light guide plate according to the place of use, and the light emitted from the light source such as the cold cathode or the LED light source has a large number of wavy lines. It can be introduced into the light guide plate without unevenness through a number of inclined parallel inclined streaks, a number of perpendicular parallel orthogonal streaks, a number of point-like concave portions and a number of deep depressions.

Next, an apparatus using the light guide plate of the present invention will be described with reference to FIG.

First, the light guide plate has an acrylic resin plate 210, which is a light-transmitting plate, and a plurality of recesses 203 provided on the back surface thereof. On the back side of 210, they are arranged in a matrix. In the present embodiment, each of the concave portions 203 is a hole having a shape of a quadrangular pyramid, and the bottom surface of the quadrangular pyramid is opened at the back surface 211 of the acrylic resin plate 210, and the vertex of the quadrangular pyramid is formed of an acrylic pyramid. The fat plate 210 is formed at a depth located in the middle of the thickness. This acrylic 凹部 A peripheral ridge 204 formed to protrude from the back surface 211 of the fat plate 210 is provided. The peripheral ridge portion 204 is formed by projecting when a pyramid-shaped projection formed on the surface of a heat roll or a heat plate is pressed against the back surface 211 of the acrylic resin plate 210 when forming the concave portion 203. This is a portion that is melted by heat at the time of pressurization, cooled, and solidified at the periphery of each recess 203. The light that propagates in the in-plane direction of the back surface 211 of the acrylic resin plate 210 is diffused by the peripheral ridge portion 204, and the light extraction efficiency around the concave portion 203 is improved.

A reflecting plate 212 made of a transparent synthetic resin plate is provided so as to face the back side of the acrylic resin plate 210. The reflecting plate 212 is disposed at a predetermined interval D1 so that its main surface is parallel to the back surface 211 of the acrylic resin plate 210. When the reflection plate 212 is provided at the required distance D1 as described above, there is an advantage that the reflection efficiency is higher than when the reflection plate 212 is closely attached. Here, the interval D1 is set to, for example, an interval of about 2 to 7 mm. A plurality of projections 213 are formed on the surface 214 of the reflection plate 212, and the interval between the projections 213 is designed to be narrow at the center 215 and widened at the periphery 216. In other words, by arranging the plurality of protrusions 213 densely in the central portion 215 and conversely arranging the plurality of protrusions 213 roughly in the peripheral portion 216, the power of the light source normally arranged in the periphery is also far, so that the light The reflection efficiency at the central portion 215, which tends to be weak, can be increased. In addition, as a means for adjusting the density of the central and peripheral convex portions, it is also possible to change the height and size of each of the central and peripheral convex portions. Further, a reflector having a slightly curved surface may be used, and the distance between the reflector and the light guide plate near the center may be made slightly closer to the light guide plate side than the peripheral portion.

Claims

The scope of the claims

[I] A light-transmitting plate having a light-transmitting property, and a plurality of recesses formed on the back surface of the light-transmitting plate, and formed around the recess so as to protrude from the back surface. A light guide plate having a peripheral ridge portion formed.

[2] The translucent plate is made of a polymer material, and the peripheral ridge is formed at the same time by hot pressing the rear side of the translucent plate when forming the recess. The light guide plate according to claim 1, characterized in that:

3. The method according to claim 2, wherein the translucent plate made of the polymer material has a flat plate shape, and the hot pressing is performed by a heating plate or roll having protrusions. Light guide plate.

[4] A light guide comprising: a light-transmitting plate made of a light-transmitting polymer material; and a plurality of concave portions provided with depressions all over the rear surface of the light-transmitting plate. Light plate.

5. The light guide plate according to claim 4, wherein a plurality of deep depressions deeper than the depressions are provided in the center of the back surface of the light-transmitting plate.

[6] The concave portion has a plurality of wavy streaks, and a plurality of slanted parallel inclined streaks having intersections.

5. The light guide plate body according to claim 4, wherein the light guide plate body includes a plurality of orthogonal parallel and orthogonal streaks having an intersection and formed by displacement.

7. The light guide plate according to claim 4, wherein the concave portion includes one formed by a plurality of point-shaped concave portions.

8. The light guide plate according to claim 4, wherein the concave portion is formed by processing using high frequency or ultrasonic waves.

9. The light guide plate according to claim 1, wherein a light source for introducing light to the light guide plate is provided adjacent to the end surface of the light-transmitting plate. body.

10. The light guide plate according to claim 9, wherein the light source is an LED array or a cold cathode fluorescent lamp.

[II] The light guide plate according to claim 1, further comprising a reflector disposed on a back surface of the light guide plate, wherein the reflector is provided separately from the back surface of the light guide plate. A device that uses a light guide plate as a feature. 2. The light guide plate according to claim 1, further comprising a reflector disposed on a back surface of the light guide plate, wherein a plurality of protrusions are formed on a surface of the reflector, and a center of the reflector is provided. An apparatus using a light guide plate, wherein the projections are arranged more densely in a portion than in a peripheral portion.