TW522258B - Light Guiding Plate - Google Patents

Description

522258 5. Description of the invention (1) Background of the invention The present invention relates to a light guide plate for guiding light from a light source to illuminate a liquid crystal display. Description of the Related Art Generally, a liquid crystal display includes a light guide plate for guiding a light beam from a light source to irradiate the entire surface of the liquid crystal display. For example, the light guide plate is located on the display side of the liquid crystal display and plays a role of a front light that irradiates light on the display side. Figures 14 (A) and 14 (B) show a conventional light guide plate 9 and Figures 15 (A) and 15 (B) show a conventional light guide plate 90. The light source 2 is located on the side of each of the light guide plates 9,90. The light beam 4 emitted from the light source 2 is introduced into the light guide plates 9,90. When certain conditions are met, the light beam 4 will hit the first surface 93 of the light guide plate 9, 90. After striking the first surface 93, the light beam 4 will shine through the flat second surface 92 facing the liquid crystal display 3 and hit the liquid crystal display 3 on. As shown in Fig. 14 (A), the first surface 93 of the light guide plate 9 includes a sawtooth-shaped cross section and a groove 95. Each groove 95 is defined by a first group of inclined surfaces 951 and a second group of inclined surfaces 952. Each of the first inclined surfaces 95 1 reflects the light beam 4 from the light source 2 and guides the light beam 4 toward a certain side 9 9 of the light guide plate 9 on the side opposite the light source 2. Each of the second inclined surfaces 95 2 reflects the light beam 4 from the light source 2 and guides the light beam 4 toward the second surface 92. The light beam 4 in the light guide plate 9 is transmitted through the light guide plate 9 and is reflected on the second table 522258 5. Invention description (2) plane 92 and the first inclined plane 95 1. During propagation, the light beam 4 is reflected by the second inclined surface 952 and penetrates the second surface 92. Then, the light beam 4 is irradiated onto the display 3. When the light beam 4 is totally reflected by one of the first inclined surfaces 95 1, the propagation angle of the light beam 4 will be changed, which will guide the light beam 4 away from the light source 2. Therefore, the light beam 4 is also irradiated to a position far from the light source 2 in the display 3. The propagation angle refers to the angle defined by the second surface 92 and the vector of the propagation beam. In the light guide plate 90 shown in FIGS. 15 (A) and 15 (B), a V-shaped groove 96 is formed on the first surface 93. At the same time, the reflector 91 is located on the side opposite to the light source 2. Each groove 96 includes a first set of inclined surfaces 9 6 2 and a second set of inclined surfaces 9 6 1. Each first * inclined surface 9 6 2 reflects the light beam 4 from the light source 2 and directs the light beam 4 onto the second surface 92. Each of the second inclined surfaces 96 1 guides the light beam 4 1 which has been reflected by the reflector 9 1 onto the second surface 92. Each portion of the first surface 93 that does not include any grooves 96 is flat and is referred to as a flat surface 963. The light beam 4 in the light guide plate 90 is transmitted through the light guide plate 90 and is reflected on the second surface 92 and the flat surface 963. During propagation, the light beam 4 is reflected by the first inclined surface 962 or the second inclined surface 96 1 and penetrates the second surface 92. Then, the light beam 4 is irradiated onto the display 3. As shown in Figures 14 (A) and 14 (B), the light guide plate 9 will not be in phase with the light source 2 -4- 522258 V. Description of the invention (3) Opposite sides 9 9 contain reflectors, so 'arrive Light from side 9 9 will penetrate this side 99. As a result, it is impossible to irradiate the light which has penetrated the side 99 onto the display 3. Therefore, the amount of light from the light guide plate 9 such as a surface light source is insufficient. Unlike the light guide plate 90, the light guide plate 9 does not include a reflector because no surface is formed on the first surface 93 that reflects the light beam from the side 99 and guides the light beam to the display 3. That is, 'even if there is a reflector, since the reflected light beam of the reflector is not guided and penetrates the second surface 92. The light guide plate 90 shown in FIGS. 15 (A) and 15 (B) includes a reflector 91 and a second inclined surface 96 1. The second inclined surface 96 1 will guide the light beam 41 reflected by the reflector 9 1 onto the second surface 92. Therefore, only a very small amount of light is wasted. However, in an area very far from the light source 2, the amount of light that penetrates the second surface 92 to generate uneven brightness is very small. The reason why I think this uneven brightness occurs is as follows. The light beam 4 enters the light guide plate 90 having a substantially uniform propagation angle. At the same time, after the first and second inclined surfaces 962 and 96 1 are reflected, the light beams 4 and 41 will penetrate the second surface 92 only when the light beams 4 and 4 1 satisfy a restriction condition of a propagation angle. Therefore, in the area very close to the light source 2, more light beams 4 satisfying this condition will be emitted from the light guide plate 90. This reduces the amount of light beam 4 reaching the area far from the light source 2. Accordingly, the brightness becomes uneven. Brief description of the invention 522258 5. Description of the invention (4) Accordingly, the object of the present invention is to provide a light guide plate with sufficient and uniform brightness. To achieve the above object, the present invention provides a light guide plate for guiding light from a light source to illuminate a liquid crystal display. The light guide plate includes a reflector on an opposite side of the light guide plate from the light source. The reflector reflects light from a light source. The first surface selectively transmits or reflects the light. The flat second surface is located between the display and the first surface. The second surface selectively transmits or reflects the light. The first region is formed on the first surface very close to the light source. The first region includes a first inclined surface and a second inclined surface. The first inclined surface reflects the light from the light source and guides it to the reflector. The second inclined surface reflects light from the light source and guides it onto the second surface. The second area is formed on the first surface at a position far from the light source. The second region includes a third inclined surface and a fourth inclined surface. The third inclined surface reflects light from the light source and guides it to the second surface. The third inclined surface reflects the light reflected by the reflector and guides it onto the second surface. The present invention also provides a light guide plate for guiding light from a light source to illuminate a liquid crystal display. The light guide plate includes a reflector on an opposite side of the light guide plate from the light source. The reflector reflects light from a light source. The first surface selectively transmits or reflects the light. The flat second surface is located between the display and the first surface. The second surface selectively transmits or reflects the light. A plurality of depressions are located on the first surface at predetermined intervals. Each depression includes a first inclined surface and a second inclined surface. The first inclined surface reflects light from the light source and guides it to the second surface. 522258 5. Description of the invention (5) The second inclined surface will reflect the light reflected by the reflector and guide it to the second surface. A plurality of third inclined surfaces are located on the first surface. Each third inclined surface is located between a pair of adjacent depressions and is inclined relative to the second surface. Light from a light source and directs it onto the second surface. The second region is formed on the first surface at a position far from the light source. The second region includes a third inclined surface and a fourth inclined surface. The third inclined surface reflects light from the light source and guides it onto the second surface. The third inclined surface reflects the light reflected by the reflector and guides it onto the second surface. Other ideas and advantages of the present invention will become apparent from the following description of examples of the principles of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The following is a description of the preferred embodiments of the present invention with reference to the accompanying drawings, so that we can best understand the objects and advantages of the present invention. Fig. 1 is a sectional view showing a light guide plate according to a first embodiment of the present invention. Figure 2 is a plan view showing the light guide plate of Figure 1. Figure 3 (A) is a partial cross-sectional view showing the first group of grooves formed on the light guide plate of Figure 1. Figure 3 (B) is a partial cross-sectional view showing the second set of grooves formed on the light guide plate of Figure 1. Fig. 4 is a graph showing changes in the brightness of the light guide plate of Figs. 1 to 3 (B) due to the length of the second region. FIG. 5 is a cross-sectional view showing a light guide plate 522258 according to the second embodiment of the present invention. 5. Description of the invention (6). Fig. 6 is a partial cross-sectional view showing a third group of grooves formed on the light guide plate of Fig. 5. The seventh layer is a partial cross-sectional view showing a second area on a light guide plate according to a third embodiment of the present invention. Fig. 8 is a sectional view showing a light guide plate according to a fourth embodiment of the present invention. Fig. 9 is a partial cross-sectional view showing a groove formed in the light guide plate of Fig. 8. Figure 10 is a plan view showing the light guide plate of Figure 8. Figure (A) is a cross-sectional view showing a light guide plate according to a fifth embodiment of the present invention. Fig. 11 (B) is a sectional view showing a light guide plate according to a sixth embodiment of the present invention. Fig. 12 is a sectional view showing a light guide plate according to a seventh embodiment of the present invention. Fig. 13 is a partial cross-sectional view of the light guide plate shown in Fig. 12; Figure 14 (A) is a sectional view showing a conventional light guide plate. Figure 14 (B) is a plan view showing the light guide plate of Figure 14 (A). Fig. 15 (A) is a sectional view showing another conventional light guide plate. Figure 15 (B) is a plan view showing the light guide plate of Figure 15 (A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the present invention will now be described with reference to Figs. As shown in Figure 1, the light guide plate 1 having a substantially uniform thickness has 522258.

5. Description of the invention (7) The upper first surface Π and the lower second surface 12. The first surface I] and the second surface 12 may transmit or reflect the light beam 4 depending on the propagation angle of the light beam 4. The light source 2 is located on a certain ... side of the light guide plate 1. The light beam 4 emitted from the light source 2 is guided to the liquid crystal display 3 in this embodiment to illuminate the object. As shown in the figure, the light guide plate 1 also includes a reflector 11 located opposite to the light source 2. The reflector 11 reflects the light beam 4 toward the light source 2. As shown in Figs. 1 and 2, a first region 131 and a second region 132 are formed on the first surface 13. The cross-sectional shape of the first region 131 is different from the cross-sectional shape of the second region 131. The first region 1 3 1 includes a first inclined surface 5; [and a second inclined surface 5 2. Each of the first inclined surfaces 51 makes a total reflection of the light beam 4 from the light source 2. The first inclined surface 51 will guide the light onto the reflector i and change the propagation angle of the light beam 4. The first inclined surface 52 reflects the light beam 4 and guides the light beam 4 onto the second surface 12. The second region 1 3 2 includes a third group of inclined surfaces 62 and a fourth group of inclined surfaces 61. Each third inclined surface 62 reflects the light beam 4 from the light source 2 and guides the light beam 4 onto the second surface 12. Each of the fourth group of inclined surfaces 6 1 reflects the light beam 4 1 which has been reflected by the reflector 11 and guides the light beam 4 1 onto the second surface 12. The light source 2 is a linear light source whose length is substantially equal to the length of the corresponding side of the light guide plate 1. As long as the light beam 4 is emitted from the entire length of the light source 2, the light source 2 may be any type of light source. For example, we can use a cold cathode ray tube as the light source 2. Alternatively, we can also use a method with

522258 V. Description of the invention (8) A rod-shaped light guide body of a point light source such as a polar body (LED). This light source manages the light from the LED and acts as a linear light source. As shown in FIG. 3 (A), the first region 131 includes a first group of grooves 5, each of which has a sawtooth-shaped cross section. Each of the first grooves 5 is defined by one of the first inclined surfaces 51 and a corresponding second inclined surface 52. The inclination angle α of each of the first inclined surfaces 51 with respect to the second surface 12 is larger than 2 degrees. The inclination angle / 3 of each second inclined surface 52 with respect to the second surface 12 is greater than 44 degrees. As shown in FIG. 1, each of the first inclined surfaces 51 is inclined, so that the distance between the first surface 13 and the second surface 12 increases toward the reflector 11. Each of the second inclined surfaces 5 2 is inclined, so that the distance between the first surface 13 and the second surface 12 decreases toward the reflector 11. As shown in Fig. 3 (B), the region 132 contains a second set of grooves 6 each having a V-shaped cross section. Each second set of grooves 6 is defined by one of the third inclined surfaces 62 and a corresponding fourth inclined surface 61. The inclination angle r of each of the third inclined surfaces 62 with respect to the second surface 12 is larger than 46 degrees. The inclination angle δ of each of the fourth inclined surfaces 61 with respect to the second surface 12 is 46 degrees. As shown in FIG. 1, each of the fourth inclined surfaces 61 is inclined, so that the distance between the first surface 13 and the second surface i 2 increases toward the reflector 11. Each of the third inclined surfaces 62 is inclined, so that the distance between the first surface 13 and the second surface 2 will decrease toward the reflector Π. -10- 522258

5. Description of the invention (9) As shown in FIG. 3 (A), the depth d 1 of each of the first grooves 5 is larger than 6 μm. The pitch P1 of the first groove 5 is 200 micrometers. As shown in FIG. 3 (B), the depth D2 of each of the grooves 6 in the second group is approximately 7 micrometers. The pitch P2 of the second set of grooves 6 is 200 microns. The light guide plate 1 is made of an acrylic sheet having a thickness of 1 mm. The reflector 11 is formed by evaporating silver onto one side of the acrylic sheet.

As shown in Fig. 1, the light guide plate 1 plays the role of a front light and faces the display side 31 of the liquid crystal display 3 which is a reflective display. That is, some of the light beams 4 penetrating the light guide plate 1 and reaching the display 3 are irradiated onto the display side 31. The reflected light beam 42 due to the display side 31 will penetrate the light guide plate 1 and reach the eye E of the observer. We can make the display 3 visible in this way. The first embodiment of the present invention has the following disadvantages.

The first inclined surface 51 is formed on the first region 1 3 1 of the light guide plate 1. The first inclined surface 51 changes the angle of the light beam 4 and guides a sufficient amount of light to an area far from the light source 2. In addition, some of the light beams 4 from the light source 2 are reflected by the second inclined surface 52 of the first region 1 31 or by the third inclined surface 62 | M of the second region 1 32. That is, the light beam 4 from the light source 2 is reflected by the second inclined surface 52 or the third inclined surface 62 and penetrates the second surface 12. A sufficient amount of light is directed onto the display 3 at any distance from the light source 2. The fourth inclined surface 6 1 is formed on the second region Π 2 of the light guide plate 1. Therefore, the light beam 41 which has been reflected by the reflector Π will be reflected by the fourth inclined surface 61 according to the (11) fifth invention description (10). That is, the light beam 41 from the reflector 11 is reflected by the fourth inclined surface 6 1 ffn and penetrates the second surface 12. In this way, the light beam 4 1 which has been reflected by the reflector 11 can also be guided onto the display 3. Therefore, a sufficient amount of light is directed onto the display 3 in an area very far from the light source 2. The light beam 4 emitted from the light source 2 into the light guide plate 1 is uniformly irradiated from the entire area of the second surface 12. Therefore, the light guide plate 1 plays the role of a surface light source that emits uniform light with sufficient brightness. The first groove 5 and the second groove 6 formed on the first surface 13 will allow the light beam 4 to be more than the conventional light guide plates 9, 90 shown in 14 (A) to 15 (B) The display 3 is efficiently irradiated. That is, the inclination angle of each inclined surface 5 1,5 2,62,61 will allow the light beam 4 emitted from the light source 2 to propagate toward the reflector 11, and according to, for example, 14 (A) to 15 (B) The conventional light guide plates 9, 90 shown in the figure guide it onto the second surface 12 in a more efficient manner. The light guide plate 1 of the first embodiment of the present invention will be more efficient because the reflector 11 is reflected by the conventional light guide plates 9, 90 as shown in Figs. The light beam 41 is directed onto the second surface 12. Fig. 4 is a graph showing the measurement results of the brightness change of the light guide plate 1 when the length of the second area 134 is changed. Specifically, the length L from the side of the first region 1 31 to the reflector 11 is set to 62 mm. The length K of the second region Π2 is changed in a range from 10 to 27 mm, and the brightness of the light guide plate 1 is measured at various lengths. -12- 522258 5. Description of the invention (11) As shown in FIG. 4, when the length K of the second region 132 is 22 mm, the light guide plate 1 has the strongest brightness. Therefore, if the length L between the side of the first region 1 3 1 and the reflector 11 is 62 mm, setting the length K of the second region 132 to 22 mm makes the first region 1 3 1 pairs The ratio of this second region Π2 is optimized. That is, in this example, the propagation and irradiation functions of the light beam 4 can be optimized, and the light guide plate 1 can have the maximum brightness. A light guide plate 10 according to a second embodiment of the present invention will now be described with reference to Figs. 5 and 6. In the second embodiment, the first surface 13 is divided into three regions. Specifically, the first surface 13 is divided into a first region 131 closest to the light source 2, a second region 132 closest to the reflector 11, and falling between the first region Π1 and the second region 132. Third area 133. The cross-sectional shapes of the first region Π 1 and the second region 132 are the same as those of the embodiment shown in FIGS. 1 to 3 (B). That is, the first region 131 includes the first groove 5 and the second region 132 includes the second groove 6. As shown in FIG. 6, the third region 133 includes the fifth inclined surface 81 , A sixth inclined surface 82, and a seventh inclined surface 83. The third region 133 is formed to have a combination of the first groove 5 and the second groove 6 as shown in FIG. The fifth inclined surface 81 will reflect the light from the light source 2 and guide it to the reflector 11. The sixth inclined surface 82 reflects the light from the light source 2 and guides it to the second surface 12. The seventh inclined surface 83 will guide the reflected light U 丨 from the reflector 11 to the first surface 1 2 because of the reflection. The other structures of the light guide plate of Fig. 6 are the same as those shown in Figs. 1 to 3 (B). In the embodiment of Figs. 5 and 6, the light beam 4 is transmitted and irradiated in the same efficient manner as the embodiment shown in Figs. 1 to 3 (B). Therefore, the 'light guide plate 10' has a strong and uniform brightness. A light guide plate 100 according to a third embodiment of the present invention will now be described with reference to FIG. Instead of the second groove 6 in the first figure, the light guide plate 100 includes a conical depression 7 in the second region 1 32. The diameter of the bottom plane of the depression 7 is 22 µm in diameter. The height of the depression 7 is 10 micrometers. The number of depressions 7 in a square centimeter is 150. The portion of each depression 7 facing the light source 2 is a first inclined surface 72, and the portion facing the reflector Π is a second inclined surface 71. Each first inclined surface 72 will guide light from the light source 2 onto the second surface 12. The second inclined surface 71 will guide the light beam 41 reflected by the reflector 11 to the second surface 12. The other structures on the light guide plate 100 of Fig. 7 are the same as those shown in Figs. 1 to 3 (B). In the embodiment of FIG. 7, the light beams 4 and 41 reaching the second region 132 are reflected by the first inclined surface 72 and the second inclined surface 7 1 on each recess 7, respectively. The reflected light beams 4,41 are then directed onto the second surface 12 as in the embodiment of Figs. 1 to 3 (B). Therefore, the light guide plate 100 has the same advantages as the embodiment of Figs. 1 to 3 (B). A light guide plate 101 according to a fourth embodiment of the invention (^) will now be described with reference to FIGS. 8 to 10 according to the fourth embodiment of the present invention. This light guide plate 101 is different from the first to third (B) round light guide plates 1 in the shape of the first surface 13. The other structures on the Z light guide plate 101 of Fig. 8 are the same as those shown in Figs. 1 to 3 (B). Those elements which are similar or the same as the corresponding elements in the embodiment of Figs. 1 to 3 (B) are denoted by similar or identical symbols. Recesses 17 are formed in the first surface 13 of the light guide plate 101 at predetermined intervals. Each of the depressions 17 includes a first inclined surface 15 and a second inclined surface 16. The first inclined surface 15 reflects the light beam 4 from the light source 2 and guides the light beam 4 onto the second surface 12. The second inclined surface 16 reflects the light beam 4 which is reflected by the reflector 11 and guides the light beam 4 onto the second surface 12. The third inclined surface 14 is formed between a pair of adjacent depressions 17. Each third inclined surface 14 is inclined at a predetermined angle with respect to the second surface 12. The joint 145 between each of the first inclined surfaces 15 and the corresponding third inclined surface 14 is farther than the joint 1 46 between the third inclined surface 14 and the second inclined surface ratio. Two surfaces 1 2 farther. Each third inclined surface 14 is inclined, so that the distance between the first surface 1 3 and the second surface 12 will increase toward the reflector. As shown in FIG. 9, the inclination angle α 1 of each of the third inclined surfaces 14 with respect to the second surface 12 is larger than 2 degrees. The inclination angle /? 1 of each of the first inclined surfaces 15 with respect to a surface 1 2 of the table is 46 degrees. The inclination angle y 1 of each second inclined surface 16 with respect to the second surface 12 is larger than 50 °. The length of each first inclined surface 15 is also at the bottom of each 1-7 -15-522258. V. Description of the invention (14) The distance between the part 1 7 1 and the corresponding first joint 1 4 5 A 1 is 7 μm in diameter. The length of each second inclined surface 16 is the distance B 1 between the bottom 17 1 of each depression 17 and the corresponding second joint 1 46 is 2 μm. The dotted lines in FIG. 9 are all parallel to the second surface 12. Each depression 17 is defined by a corresponding first and second inclined surface 15 and 16 and each has a V-shaped cross section. The pitch P1 of each of the depressions 17 is larger than 200 m. As shown in FIG. 10, each depression 17 extends in a manner parallel to the side where the light source 2 is located and parallel to the side where the reflector 11 is located. The light guide plate 101 is formed on an acrylic sheet having a thickness of 1 mm. The embodiments of Figs. 8 to 10 have the following advantages. The light guide plate 101 includes a third inclined surface 14. Therefore, a sufficient amount of the light beam 4 emitted from the light source 2 arrives far away from the light source 2 to change its propagation angle. In other words, a sufficient amount of light beam 4 will penetrate the area of the second surface 12 away from the light source 2. When the light beam 4 emitted by the light source 2 propagates in the light guide plate 101, each of the first inclined surfaces 15 reflects some of the light beams 4 and guides them onto the first surface 12. The light guide plate 101 includes a reflector 11 and a second inclined surface 16. As shown in FIG. 8, each of the second inclined surfaces 16 reflects a light beam 41 reflected by the reflector 1 1 and makes the light beam 41 pass through the second surface 12 and illuminate the display 3. -16- V. Description of the Invention (M) Therefore, the light beam 41 will be irradiated on the display 3 to increase the brightness of the light guide plate 101. The light guide plate 101 includes a third inclined surface 14 and a second inclined surface 16. Therefore, a sufficient amount of the light beam 4 is directed to an area far from the light source 2. At the same time, the light beam 41, which is reflected by the reflector II, can be reliably guided onto the second surface 12. Therefore, the light beam 4 introduced into the light guide plate 101 is radiated from the entire second surface 12. If so, the light guide plate 101 has sufficient and uniform brightness. Generally, the light guide plate 101 has a uniform thickness from the light source 2 to the reflector 11. Therefore, the thickness of the light guide plate 101 can be reduced, and a product using the light guide plate 101 can be made thinner. The distance between the second surface 12 and the first joint 145 is greater than the distance between the second surface 12 and the second joint 146. After being totally reflected by each of the third inclined surfaces 14, the propagation angle of the light beam 4 is reduced. Therefore, a sufficient amount of the light beam 4 from the light source 2 arrives away from the light source 2. Some light beams 4 whose propagation angle is suitable to be radiated from the second surface 12 will be totally reflected by each third inclined surface 14. Accordingly, the propagation angle of the light beam 4 is changed. This will reduce the amount of the light beam 4 radiated from the area near the light source 2 and direct more light beams 4 to the area far from the light source 2. Some parts of the light guide plate 101 far from the light source 2 have sufficient brightness. A light guide according to a fifth embodiment of the present invention will be described with reference to FIG. 11 (A).

5. Description of the invention (16) Board 201. The light guide plate 201 includes recesses 17. The depth of each recess 17 will increase as the distance from the light source 2 increases. The other structures on the light guide plate 201 of Fig. U (A) are the same as those shown in Figs. 8 to 10. A light guide plate 301 according to a sixth embodiment of the present invention will be described with reference to Fig. 11 (B). The light guide plate 301 includes recesses 17. The pitch of each depression 17 decreases as the distance from the light source 2 increases. The other structures on the light guide plate 3 0 1 of Fig. 1 (B) are the same as those shown in Figs. 8 to 10. In addition to the advantages of the embodiments of Figs. 8 to 10, the fifth and sixth embodiments have the following advantages. That is, in the light guide plate as shown in Figs. 11 (and 11 (B), a larger amount of light beam 4 is radiated from the area far from the light source 2. Therefore, the area far from the light source 2 is improved The light guide plate 40 1 according to the seventh embodiment of the present invention will now be described with reference to FIGS. 12 and 13. The difference between the seventh embodiment and the embodiment of FIG. 8 is that each of the inclined surfaces 1 4 Are all inclined, so that the distance between the first surface 13 and the first surface 12 decreases toward the reflector 11. In addition, the first joint 145 will be more than the second joint 146 Close to the second surface 12. As shown in FIG. 13, the inclination angle α 2 of the third inclined surface 14 with respect to the second surface 12 is greater than 2 degrees. The first inclined surface 15 is relative to the second The inclination angle / 3 2 of the surface 12 is 44 ° large. The inclination angle r 2 of the second inclined surface 16 with respect to the second surface 12 is 44 ° large. The length of each first inclined surface 15 That is, the distance A2 between the bottom 1 7 1 of each depression 1 7 and the corresponding first joint 1 45 is 3 槪 522258.

Meter. The length of each second inclined surface 16 is the distance b 2 between the bottom 1 7 1 of each recess 7 and the corresponding first joint 1 4 6 is 7 μm. The pitch P2 of each depression 17 is 200 μm. Each dotted line in FIG. 3 is flat on the second surface 12. The other structures on the light guide plate 301 in the u (B) diagram are the same as those shown in FIG.

In addition to the advantages of the embodiments of Figs. 8 to 10, the embodiments of Figs. 12 and 13 also have the following advantages. The area of each second inclined surface 16 on the light guide plate 40 1 is quite large. Therefore 'because it has been reflected by the reflector 1 1]: the light beam 4 1 which reaches the first surface 13 is reflected in a reliable manner by each of the second inclined surfaces 16 and is guided to the second surface 1 2 on.

If the propagation angle of the light beam 4 is not suitable for radiating from the second surface 12, the light beam 4 will change its propagation angle because the third inclined surface 14 is subjected to total reflection. This will guide the light beam 4 away from the light source 2. Area. Therefore, 'the brightness on the area far from the light source 2 is increased. In Figures 8 to 13, you can adjust the pitch (P 丨, p2), tilt angle (αΐ, / 31, T1, α2, 02, T2), the first and second inclined surfaces 15, 16 The length (Al, Bl, A2, B2) and other parameters are used to define the shape of each depression 17 (see Figures 9 and 13) in order to further increase its brightness and reduce its unevenness in brightness. In the embodiment of Fig. 7, various parameters can be changed to increase its brightness and reduce its unevenness in brightness. In the embodiments of Figs. 1 to 7, the parameters used to define the first and -19-522258 can be adjusted. 5. Description of the invention (18) The parameters of the second grooves 5 and 6 or the depth (Dl, D2), section Distance (pi, P2), and inclination angles (a, / 3, r, δ ') (see Figures 3 (A) and 3 (B)) to increase its brightness and reduce its unevenness in brightness. In the embodiments of FIGS. 8 to 13, a flat surface parallel to the second surface 12 may be formed between each of the third inclined surfaces 14 and the corresponding first inclined surface 15. We can also use the light guide plates 1,10,100,101,201,301,401 to illuminate other objects besides the display 3. For example, light guide plates 1, 10, 100, 101, 201, 301, 401 can be used to illuminate negatives. It is possible to make the light guide plate KK10,10 (Μ〇1,2 0 1,3 0), 401 on the side opposite to the display side of the display 3 and make it play the role of backlight. I can change the first The shape of each first groove 5 in the figure. For example, a parallel to the second surface 12 may be formed between the first inclined surface 51 and the second inclined surface 52 of each first groove 5. Surface. In the light guide plate as shown in FIG. 1, a flat surface falling between a pair of adjacent second grooves 6 may be omitted. That is, the second grooves 6 may be formed in a continuous manner. Therefore, the examples and embodiments of the present invention are to be shown rather than restricted, and the present invention is not limited to the details given here, but can be applied without departing from the patent attached to the present invention. Various amendments are made under the spirit and framework of the scope. Explanation of Symbols 1, 10, 100, 101, 201, 301, 401 ..... Light guide plate 2 ..... Light source-20- 522258 V. Description of the invention (19) 3 ..... LCD monitor 4.41.42 ..... Beam 5 ..... The first group of grooves 5 ..... The second group of grooves 9.90 .. Light guide plate 11-reflection Device 12 .... Second lower surface 13 .. Upper first surface 14 .. Third inclined surface 15 ... First inclined surface 16 ... Second inclined surface 17 ... Depression 31 .. .. Display side 5 1——First inclined surface 52 .. Second inclined surface 61 .. .. Fourth group of inclined surfaces 62 .. .. Third group of inclined surfaces 71.… Second inclined surface 72.… First inclined surface 81.… Fifth inclined surface 82.… Sixth inclined surface 83.… Seventh inclined surface 9 1... Reflector 92 ... Second surface -21- 522258 5. Explanation of the invention (20) 9 3 .... first surface 95.96 ... groove 99 .... side 101.301 ... light guide plate 1 3 1 ... first area 1 3 2 ... second area 133 ... The third area 1 4 5 ... the first joint 146... The second joint 1 7 1 ... the bottom of the depression 9 5 1,962 — the first group of inclined surfaces 952, 96 1 .... the second group of inclined Surface 963 ........ Flat surface-22

Claims (1)

522258 6. Scope of patent application 1. A light guide plate for guiding light from a light source (2) to illuminate a display (3), and characterized in that the light guide plate (1, 10) includes: a reflector (11) Is located on the side of the light guide plate opposite to the light source (2), wherein the reflector (1 1) reflects light from the light source; the first surface (1 3) is used to selectively transmit or reflect the light Light; a flat second surface (12) is located between the display and the first surface, wherein the second surface selectively transmits or reflects the light; the light guide plate is characterized by: a first area ( 131) is formed on the first surface (13) at a position very close to the light source (2), and the first area (131) includes: a first inclined surface (5 1) for reflecting the light from the light source Light and guide it to a reflector; and a second inclined surface (52) for reflecting light from a light source and guiding it to the second surface; a second area (132) formed on the first surface On a surface (13) at a position far from the light source, the second region (1 3 2) is Including: a third inclined surface (62) for reflecting the light from the light source (2) and guiding it to the second surface (12); and a third inclined surface (6 1) for reflecting the light The light reflected by the reflector (1 1) is guided onto the second surface (12). 2 · The light guide plate according to item 1 of the patent application scope, wherein the first region (1 3 1) includes a first group of grooves (5) having a sawtooth section, and each of the first grooves (5) is One of the first inclined plane (5 1) and the corresponding second inclined plane 23 522258 6. Defined by the scope of patent application (52), the first inclined surface (51) is inclined so that the distance between the first inclined surface (5 1) and the second surface (1 2) will face The reflector (1 1) increases. 3. The light guide plate according to item 2 of the patent application range, wherein the angle range from the first inclined surface (5 1) to the second surface (1 2) is 1 to 3 degrees. 4. The light guide plate according to item 2 of the patent application range, wherein the angle range from the second inclined surface (52) to the first surface (13) is 40 to 60 degrees. 5. The light guide plate according to item 1 of the scope of patent application, wherein the second region (1 32) includes a second group of grooves (6) having a sawtooth section, and each of the second group of grooves (6) is Defined by one of the third inclined surface (62) and the corresponding fourth inclined surface (61), the third inclined surface (62) is inclined such that the third inclined surface (62) and the second surface ( The distance between 1 2) will increase towards the reflector (1 1). 6. The light guide plate according to item 5 of the patent application range, wherein the angle range from the third inclined surface (62) to the second surface (12) is 40 to 60 degrees. 7. The light guide plate according to item 5 of the patent application range, wherein an angle range from the fourth inclined surface (6 1) to the second surface (12) is 40 to 60 degrees. 8. The light guide plate according to item 1 of the scope of patent application, wherein the first surface (1 3) contains a third region (133) between the first and second regions (1 3 1, 1 32), and The third area (133) includes: a fifth inclined surface (81) for reflecting light from the light source (2) and guiding it to the reflector (11); a sixth inclined surface (82) ) Is used to reflect the light from the light source (2) and guide 522258 6. The scope of the patent application is directed to the second surface (12); the seventh inclined surface (83) is used to reflect the reflector ( 11) The reflected light is guided onto the second surface (12), and the seventh inclined surface (83) is located between the fifth inclined surface (81) and the sixth inclined surface (82). 9 · The light guide plate according to item 1 of the patent application, wherein a plurality of conical depressions (7) are formed in the second region (132), and each of the depressions (7) includes third and fourth inclined surfaces (6 2,6 1). 10 · The light guide plate according to any one of items 1 to 9 of the scope of patent application, wherein the display (3) is a reflective liquid crystal display, and the light guide plate (1, 10) is a display located on the liquid crystal display. The side plays the role of front light. 11. A light guide plate for guiding light from a light source (2) to illuminate a display (3), and characterized in that the light guide plate (101, 201, 301, 401) includes: a reflector (1 ) Is located on the side of the light guide plate opposite to the light source, wherein the reflector (11) reflects light from the light source; the first surface (1 3) is used to selectively transmit or reflect the light, and The flat second surface (12) is located between the display and the first surface, wherein the second surface (1 2) selectively transmits or reflects the light; the light guide plate is characterized by: many depressions (1 7) are located on the first surface at a predetermined interval, and each depression includes: -25-522258 6. Patent application scope The first inclined surface (1 5) is used to reflect light from the light source (2) And guide it to the second surface (12); the second inclined surface (16) is used to reflect the light reflected by the reflector (1 1) and guide it to the second surface (12) Many third inclined surfaces (14) are located on the first surface (13), and each of them is The inclined surfaces (1 4) are all located between a pair of adjacent depressions (7) and are inclined relative to the second surface (1 2). 1 2. The light guide plate according to item 1 丨 in the scope of patent application, wherein the first joint (1 45) is located between each pair of adjacent first and third inclined surfaces (5, 1 4). The two joints (146) are located between each pair of adjacent second and third inclined surfaces (16, 1 4); and the first joint (1 45) is greater than the second joint (146) ) Is further away from the second surface (12). 1 3 · According to the light guide plate of the scope of the patent application, the first joint (1 45) is located between each pair of adjacent first and third inclined planes (15, 1 4), and the second The joint (146) is located between each pair of adjacent second and third inclined surfaces (16, 14), and the first joint (145) is closer to the second joint (146) than Second surface (12). 1 4 · The light guide plate according to any one of items 11 to 13 in the scope of patent application, wherein the display (3) is a reflective liquid crystal display, and the light guide plate (101, 201, 301, 401) is located at the The display side of the LCD monitor plays the role of front light. -26