TW493087B - Guide plate, surface light source device of side light type and liquid crystal display - Google Patents

Description

493087 A7 B7 V. Description of the invention G) [[Field of the invention] The present invention is a liquid crystal display device for a light guide plate and an edge-light type light source device. More specifically, the invention relates to the use of an improved light guide plate and a light guide plate for side light. Type light source device and the same surface light source device as a liquid crystal display device suitable for a liquid crystal display panel. [Known Technology] As for the liquid crystal display device, generally known ones include a type using a transmissive liquid crystal display panel and a type using a reflective liquid crystal display panel. Generally, the former is difficult to use external light in order to form an image. Therefore, a surface light source device such as an edge-light type surface light source device is used for the backlighting of a transmissive liquid-day display panel. In view of the above, it is possible for a reflective liquid crystal display panel to use an external light source during display. Compared with the methods mentioned previously, it can save power consumption. However, when there is insufficient external light at night, it is necessary to use a lighting device that illuminates a reflective liquid crystal display panel. That is, an edge-light-type light source device is most suitable for use in such a case. Because the light source and the light guide plate are used side by side, the thickness of the LCD panel will only increase a little. The supply of the illuminating light and the external light to provide the reflective liquid crystal display panel is generally provided through the front. However, it is known that a reflective liquid crystal display panel is also temporarily used as a transmissive liquid crystal display panel. Therefore, in this case, the backlight of the liquid crystal display panel may also be used. Since a liquid crystal display device using front lighting is disclosed in, for example, Japanese Unexamined Patent Publication No. 10-142601. Figure 12 is the t-shirt-(Please read the notes on the back before filling this page) Order the paper printed by the Employees' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. The paper size is applicable to China National Standard (CNS) 8-4 specifications (21〇 × 297) 1) 1 311015 493087 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 2 A7 B7 V. Description of the invention (2) A cross-sectional view showing its general structure. Referring to Fig. 12, it can be seen that a side-light type surface light source device is provided for front illumination of the reflective liquid crystal display panel 2. The surface light source device 1 includes a light guide plate 3 and a primary light source 4 arranged in parallel with the light guide plate 3. The light guide plate 3 is disposed on the display panel side of the reflective liquid crystal display panel 2. The primary light source 4 is formed of, for example, a fluorescent lamp 5 and reflected light 6 surrounding a peripheral portion thereof. The primary light source 4 supplies the illumination light 1 to the incident end face 3 A formed by the end face 3 A of the light guide plate 3 through the opening of the reflected light 6. The light guide plate 3 is made of a transparent material such as an acrylic resin (PMMA resin) into a plate shape, and is then manufactured using an injection molding technique. The light guide plate 3 mainly includes an inner surface 3B and an outer surface 3C facing away from the inner surface 3B. The inner surface 3B and the liquid crystal display panel 2 face each other. After being introduced into the light guide plate 3, the illuminating light L is repeatedly reflected internally between the inner side surface 3b and the outer side surface 3C, and gradually moves away from the incident end surface 3A in the light guide plate 3 and propagates. In such a process, light is gradually generated from the inner side 3 B and the outer side 3 C. The emitted light emitted from the inner surface 3b is supplied to the liquid crystal display panel 2 to facilitate display in a conventional manner. In order to promote the emitted light reflected from the inner surface 3B, a plurality of protrusions 3E are provided on the inner surface 3B. Here, the so-called "protrusion" is defined as "a protrusion having a narrow width extension". The ridge 3E here extends parallel to 3A of the incident end surface (that is, perpendicular to the paper surface). As shown in the enlarged part with the symbol A, each of the protrusions 3e has a pair of ventral surfaces (sides) 3F that are substantially perpendicular to the inner side surface 3B, and the Chinese National Standard (CNS) A4 specifications (21 〇χ297 公 酱） 311015 (Please read the notes on the back before filling in this page}

A7

The side surface 3B is parallel to the top surface 3G. One 49308 of the illumination light 1 that enters each of the protrusions 3E. 5. Description of the invention (㈣ 'is emitted from the ventral surface or the top 3G. When it is emitted, Snell s Laus produces a refraction phenomenon, and it goes without saying. The output light generated through the above process is directly or indirectly incident into the liquid crystal display panel 2. In other words, the inner side 3B liquid crystal display panel 2 provides an "exiting function surface", and the output light of this exiting function surface enters the liquid crystal Inside the display panel 2. As for the portion of external light, it is first introduced into the light guide plate 3 through the outer side 3C, and then passes through the exit function surface 3b to enter the liquid crystal display panel 2. The light (illumination) entering the liquid crystal display panel 2 Light or extraneous light), after being adjusted in a known manner, the light guide plate 3 is used to emit light from the outer side 3C to the outside to promote the display screen. However, according to the above-mentioned conventional technology, there are considerable problems. That is, That is to say, when looking at the light guide plate 3 from above the outer side 3C, many obvious protrusions 3E will be seen, which also reduces the quality of the illumination light. Of course, the display of the liquid crystal display device is inevitable Deterioration of quality. Of course, if the protrusion 3E is removed and the inner surface 3B is smoothed, the situation can be improved. However, when the fluorescent lamp 5 is lit, the smooth inner surface cannot function as a shooting function surface. The reason It is known that the light that is introduced into the light guide plate 3 from the side is difficult to be emitted from such a flat inner side. In addition, the size (especially the width) of the projection 3E can be greatly reduced. It can solve this part of the problem. However, if this method is adopted, the smaller the size, the lower the quality of its ejection function, which means that the paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 311015 Batch of clothes 1T ------ ^ (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Description (4) —-* It is more difficult to provide Bright illumination and excellent display [Summary of the invention]

Please read the background first. The present invention was created under the above background. An object of the present invention is to improve a light guide plate used in a conventional technology, and to provide a light guide plate which does not degrade the emission function quality and also has inconspicuous protrusions. In addition, another object of the present invention is to provide an edge-light type surface light source device capable of rotating out high-intensity and high-quality illumination light by using an improved light guide plate. Another object of the present invention is to provide the use of? The liquid crystal display device of Wenliang's side-light type surface light source device used to illuminate the liquid crystal display panel, especially the front light, so as to obtain high-brightness and high-quality image display. First, the present invention is applicable to an incident end surface with the introduction of illumination light. , And the aforementioned light guide plate having an emitting function surface having a function of emitting illumination light. The former functioning surface has a first ventral surface facing the incident end surface and a second ventral surface opposite to the incident end surface, each of which has a plurality of protrusions printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs and the present invention is important. It is characterized in that each of the front ridges has an extending direction which is inclined to the aforementioned incident end surface within a predetermined angle range. The aforementioned angles range between 5 and 45 degrees, and especially between 15 and 30 degrees. It is conventionally known that, compared with the projections parallel to the incident end surface, the projections extending in an oblique direction act on the illumination light introduced to each projection from the direction of the incident end surface to enlarge the width. Therefore, even if the size of each protrusion is reduced, the ejection function will not be reduced more than the conventional technique. As described above, if the size of each ridge is reduced, the ridges are relatively inconspicuous. As a result, it is possible to prevent a decrease in the ejection function by using the inconspicuous protrusion (a small-sized protrusion) employed in accordance with the present invention. This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 Gong 4 311015 Eject nyjvo / V. Description of the invention (5 *: ㈣- and the second ventral surface 'at least make the latter tilt closer to each other') = end # The farther away from the aforementioned person is better. It is better that both of them are tilted, and the other end of the dog strip is farther away from the aforementioned incident end surface. With this aspect, the lighting entering each of the protrusions & , It is easier to perform intrinsic reflection in the second ventral surface: as a result, the direction of the light emitted from the exit function surface can be improved 14. That is to say, it is easy to generate light about the exit function surface close to the front direction, and the protrusions are from the aforementioned exit function. The "general surface" of the surface protrudes. Therefore, the first and first ventral surfaces are connected to the above-mentioned ejection functional surface at a pair of foundations with respect to each ridge. In addition, in this specification, the "(exjective functional surface) general surface" "" Stands for the exit function surface, and the line that intersects with the aforementioned incident end surface provides one side of the aforementioned incident end surface. According to a preferred embodiment according to the characteristics of the base portion, the foregoing = 2 base portions correspond to the foregoing The first base formed a step difference to increase the aforementioned light guide plate -fT 丨 fill thickness • Due to the formation of such a step at the base, the direction of the ψ 1 illumination light that may enter each protrusion is limited to the aforementioned second ventral surface Forming a large internal incident meridian angle. As a result, it is easier for the exit function surface to choose to approach the front side to emit intelligent light. Property Bureau The present invention is also applicable to the case where the incident end surface for introducing illumination light is used to eliminate the aforementioned illumination light. A light guide plate J with a functioning surface and a side-light type side light source having a primary light source for supplying the aforementioned illumination light JJL · I and arranged side by side with the light guide plate are used as the surface printing light source of the company. The surface light source device adopts various methods as described above. The light guide plate J with improved state preparation can thus provide 5 311015 493087 A7 B7 which can output both bright and high quality. 5. Description of the invention (6) Side-light type surface light source device for illumination light. The present invention is further The above-mentioned improved side-light type surface light source device is configured for the illumination of a liquid crystal display panel, and provides a liquid crystal display device capable of obtaining a brighter and more high-quality display effect. It is particularly worth mentioning that the improved side The light type surface light source device is more suitable for front lighting of a liquid crystal display panel. The above features and other features of the present invention will be more easily understood from the following detailed description with reference to the accompanying drawings. In addition, in order to make it easier to understand, some graphics and dimensions are enlarged. [Brief description of the drawings] Fig. 1 is an exploded perspective view of a liquid crystal display device according to a first embodiment of the present invention as viewed from the bottom. Fig. 2 is a sectional view taken along line b-B in Fig. 1. Fig. 3 is a cross-sectional view showing an optical path of external light in an example in which a protrusion having a ventral surface which is substantially perpendicular to a general surface of an emitting function surface is used. Fig. 4 is a cross-sectional view of a road sign of external light in an example in which a projection having a ventral surface inclined to a general plane (not perpendicular) of the exit plane is used in the same drawing manner as in Fig. 3. Figures 5a, 5b, and 5c are plan views illustrating the function of the obliquely extending front. Fig. 5a is a conventional technique, and Fig. 5b is a diagram-Fig. 5c is a case according to the present invention. Fig. 6 is an exploded perspective view showing a liquid crystal display device according to a second embodiment of the present invention. Fig. 7 is a sectional view taken along the line G-G in Fig. 6; ^ Zhang scale is applicable to China National Standard (CNS) ----- 311015 • ffj— —i I I 1 · (Please read the precautions on the back before filling out this page) Order Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 6

Hy3〇87 A7 B7 V. Description of the invention (7) Fig. 8 is a cross-sectional view of the light path of the illuminating light of the projection with no step difference. Fig. 9 is a cross-sectional view of the light path of the illuminating light of the projection in Fig. 7. Fig. 10 is an exploded perspective view showing a liquid crystal display device according to a third embodiment of the present invention. Fig. 11 is an exploded perspective view showing a liquid crystal display device according to a fourth embodiment of the present invention. Fig. 12 is a cross-sectional view of a liquid crystal display device in which a conventional edge-light type surface light source device is applied to a headlight. (Please read the precautions on the back before filling this page) • Department-r · Printed by the Consumer Property Cooperative of the Intellectual Property Bureau of the Sewing Department 1 Surface light source device 10, 20, 30, 40 LCD display device 12, 22, 32, 42 Edge-light type surface light source devices 2, 11 LCD display panels 3, 13, 23, 33, 43 Light guide plates 3A, 13A, 23A, 33A Incident end faces 3B, 13B, 23B, 33B Inner side 3C, 13C, 23C Outer side 3E , 13E, 23E, 33E, 43E protrusion 3G, 13G top surface 4, 14 primary light source 5, 15 fluorescent lamp 6, 16 reflector [Embodiment] S1 > First Embodiment Refer to FIGS. 1 and 2 It can be seen that the liquid crystal display device 10 of the first embodiment is provided with a reflective liquid crystal display panel 11 and an edge-light type surface light source device. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 7 311015 line 493087 A /

5. Description of the Invention U) The surface light source device 12 is arranged for the front light of the liquid crystal display panel η, and is arranged outside the liquid crystal display panel 11 (the display side or the observation side). (Please read the precautions on the back before filling in this page) The structure and operation of the liquid crystal display panel 11 are generally known. That is, the liquid crystal display panel 11 includes a laminated reflective plate 11A, a glass substrate 11B, a liquid crystal layer lie, a glass substrate 11D, and a polarizing plate PL. The glass substrates 11B and 11D are formed with matrix-shaped transparent electrodes (not shown). The transparent electrode is driven by a driving circuit to control the polarized cancer of the light transmitted through the liquid crystal layer 11C. The liquid crystal display panel I forms an image by outputting light according to the action of the aforementioned liquid crystal layer lie. The surface light source device 12 includes a light guide plate 13 and a primary light source 14. The light guide plate 13 receives the illumination light emitted from the primary light source 14 through the incident end surface 13A of the light guide plate 13. The primary light source 14 is formed of, for example, a fluorescent lamp i 5 and a reflective surface 16 disposed on the back surface. The illuminating light passes through the opening of the reflecting surface 16 and enters the incident end surface 13A. The illumination light enters the light guide plate 13 as a light beam 'diffusing at a certain angle. For convenience of explanation, "illumination light l" is represented in Fig. 2. The light guide plate 13 printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is made of a transparent material such as acrylic resin (pmmA resin), and is made by injection molding technology. The light guide plate 13 has an inner side surface 13B and an outer side surface 13C facing away from it as main surfaces. The inner side 13B is close to and faces the liquid crystal display panel i. The inner side surface 13B is provided with a plurality of protrusions 13E in order to provide the exit function surface of the inner side surface 13B with an emission promotion function. In addition, as mentioned earlier, the definition of "protrusion" is "a protrusion with a narrow width." 311015 This paper size applies to China National Standard (CNS) A4 (210X297 mm) A7

493087 V. Description of the invention (9) The most important feature of the present invention is that the protrusion 13E and the incident end surface BA are not actually parallel, but are inclined at a predetermined inclination angle α. The inclination angle α depends on the design, but it is most suitable to be in the range of 5 to 45 degrees', especially in the range of 15 to% degrees. According to this oblique arrangement, the illuminating light projected onto each oblique projection is larger than the conventional parallel arrangement. Reference is made to Figures 5a and 5c to supplement this explanation. In Fig. 5a (previous technique), the actual width of each ridge 13 (the vertical transverse distance of each ridge) is the same as the effective width w. Here, the so-called "effective width W" refers to the width of each of the protrusions 13E which is "actually effective" from the light source 15 emission point, and generally has a relationship of W = WD / cos α. In contrast, each of the protrusions 13E having an inclined angle as shown in Figs. 5b and 5c has a function of having an effective width W which is larger than the actual width WD. In other words, compared with the prior art, the effective width W can be maintained even if a ridge having a smaller width and width WD than before is used. Of course, the small-sized protrusions are less noticeable, and it is possible to prevent the quality of the surface light source device 12 and the quality of the liquid crystal display device 11 from being lowered. In addition, the obliquely aligned protrusions 13E can also reduce the possibility of Moir'e stripes caused by transparent electrodes and other periodic configuration factors. This also prevents degradation in lighting quality and image display quality. In addition, the significance of the above-mentioned range of the angle α on the technical level will be described below. This paper size is applicable to China National Standard (CNS) Α4 specification (210 × 297 mm) ------- installation -------- II ------ line (please read the precautions on the back before Fill out this page} Printed by the Consumers' Cooperative of the Ministry of Economic Affairs and Intellectual Property Bureau 3115015 493087 A7 ------------ ____ i. Invention Description U) One by one " First, if the angle α is below 5 degrees, It is quite difficult to achieve the above effects. When the angle α exceeds 15 degrees, the effect is quite remarkable. However, if the angle exceeds too much, for example, more than 45 degrees, the effective width W becomes large, and the internal incident angle in the protrusion also becomes large, which reduces the output efficiency, and the direction of the light supplied to the liquid crystal display panel will also be irradiated. Therefore, there is a large tilt phenomenon. This phenomenon gradually appears when α exceeds 30 degrees. Because of the above considerations, the angle ^ is more practical in the range of 5 degrees to 45 degrees, especially in the range of 15 degrees to 30 degrees. The shape of the ridges 13E in this embodiment is made on the condition that the following conditions are satisfied. (1) Ren Datiao 13E has the same 3-dimensional shape. (2) The cross-sectional area of the “section parallel to the outer side 13C” of each protrusion 13E starts from the bottom and decreases toward the front end. (3) Each of the first ventral surface 13EA and the second ventral surface 13EB starts to incline from the bottom to become more distal from the incident end surface 13A. The tilt is represented by the angles a and b formed by the ventral surfaces 13EB, 13EA and the general surface of the ejection function surface (inner side 13b in this embodiment) printed by the Consumer Affairs Agency of the Intellectual Property Office of the Ministry of Economic Affairs. Among them, a < 90 degrees and b > 90 degrees. The line of intersection formed by this general plane and the incident end surface 13A constitutes one side (such as the bottom side in FIG. 2) of the incident end surface 13A. On the whole, each ridge is inclined to start from the bottom of the ridge, and the front end part is further away from the incident end face 13A.

493087 A7 V. Description of the invention (π / gradually distant from the incident end face 13A propagates in the light guide plate 13. In this process, most of the illumination light [that is, there is a chance to enter any of the protrusions 13E. Generally speaking The illumination light ^ enters the ridge 13E after reflecting on the outer side 丨% and the inner P: Therefore, as shown in a partially enlarged figure E, the light entering the ridge 13E has the oblique directionality of the critical angle. . If the light guide plate 13 is made of a typical acrylic resin (refractive index I · 49) material, the angle of the critical angle 0 1 is 42 390 degrees. In other words, most of the internal reflections on the outer side 13C are total reflections, and the angle of the light entering the ridge 13E is much larger than the critical angle 01. But the incoming light is a part of the internally propagating light, and of course the entering angle is below 90 degrees. The "entrance angle" referred to here is the same as the critical angle 01, and is expressed on the basis of the perpendicular plane of the exit function surface (inner side surface 13B) to the general surface. The illumination light entering the dog bar 13E is incident on the inside of the second side i 3EB. However, the angle of incidence into the interior becomes larger due to the condition (3) above. As a result, most of the internal incident light is reflected inside the ventral surface 13eb and then incident into the top surface 13G. The angle of incidence into the interior is small, that is, almost perpendicular incidence. Therefore, it is easy to generate the emitted light from the top surface ug (refer to the enlarged drawing of the reference part). The directivity of the emitted light is almost directly facing the liquid crystal display panel 11 as indicated by F of the part injury enlargement indication. Assume that, as shown in the enlarged view of part a in Fig. 12, the second ventral surface 3F is vertical (when not standing obliquely), and the output from the ventral surface 3f is greatly increased. 11 Binding line 311015 493087 A7 B7 5. Description of the invention (12) (Please read the precautions on the back before filling this page) and provide light to the liquid crystal display panel 2 through the direction with a greater inclination (refer to the light ray M). (Refer to the route of light ray M in Figure 12). In this embodiment, this method is avoided, and light is provided from the periphery of the front surface (approximately within 30 degrees from the front surface direction). In general, the directivity of the light entering the inside of the protrusion 13E will vary somewhat depending on the thickness of the light guide plate 13, the relationship with the incident end surface 13A, and the primary light source 14. Therefore, in order to meet these conditions, the inclination angle a of the second ventral surface 13 Ε is set to be between 45 degrees < a < 90 degrees, especially between 60 degrees &80; and 80 degrees. . The angle is set so that the light entering the abdominal surface 13EB has a good overall reflection, and the light enters the liquid crystal display panel 11 from the top surface 13G at a small incident angle. On the other hand, as for the inclination angle b of the first ventral surface 13EA, it is necessary to take into consideration that the incident light entering the ventral surface 13EB is not blocked. In addition, care must be taken not to cause the difficulty of "off-mold" when the light guide plate 13 is formed. More specifically, the most suitable range of angle is between "90 degrees + critical angle < 9 1" to "180 degrees-an angle a". The height h of the protrusion 13E is printed by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, and the most suitable height is 20em. And, the optimal ratio of the height h to the width (actual width WD) is between 0.5 and 1 · 0. In this embodiment, the formation interval of the protrusion 13E becomes smaller in accordance with the distance of the incident end surface 13a. This is to prevent the internally propagated light that decreases with the distance from the incident end surface 13A from becoming insufficient due to the distance from the liquid crystal display panel 11 being conceived. In other words, to make the paper size of the surface light source device I1 applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 12 311015 ⑽ 3087 A7 B7 V. Description of the invention (13) The light intensity distribution emitted is uniform By. I --------- Appropriate clothing-(Please read the precautions on the back before filling this page) This embodiment uses the front light configuration. Therefore, it can be said that when the external light source is quite sufficient, the liquid crystal display device can display an image without turning on the fluorescent light. Generally, the external light is introduced into the light guide plate 13C from the outer side surface 13C regardless of whether or not the fluorescent lamp 15 is lit. The principle that external light contributes to liquid crystal display is the same as the conventional technology. External light 'supplied to the liquid crystal display panel 11 via the inner side surface 13B (including the protrusion 13E) of the light guide plate 13 promotes display according to a well-known principle. In other words, the travel path of external light is: external-light guide plate 13-polarizing plate PL-glass substrate 11D-liquid crystal layer lie-glass substrate iiB-reflective plate 11A-glass substrate 11B-liquid crystal layer lie-glass substrate iid-polarized light Plate pl—light guide plate 13—external. As is well known, the position of light that is finally emitted to the outside through the above-mentioned round-trip path depends on the voltage controller formed on the matrix-shaped transparent electrodes (not shown) of the substrates 11B and 11D. As a result, a portrait is formed by the output light of the liquid crystal display panel 11. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the People's Republic of China, but in more detail, the action of the external light in this embodiment has a characteristic. That is, since the protrusions 13E are formed to protrude at an oblique angle, it is possible to prevent the protrusions 13E from appearing cloudy. This point will be described with reference to FIGS. 3 and 4. Fig. 3 shows the optical path of the external light LR incident at an oblique angle when the vertical protruding protrusion 13E is used. Fig. 4 shows the optical path of the external light LR incident at an oblique angle in this embodiment using the obliquely protruding protrusions 1 3E. As shown in Fig. 3 and Fig. 4, the dimensions of the paper entering from the oblique angle are in accordance with Chinese National Standard (CNS) A4 (210X297 mm) 13 311015 493087 A7 V. Description of the invention (14) Outside light LR enters the guide The light plate is refracted while approaching the thickness direction of the light guide plate. Therefore, in either case in FIG. 3 or FIG. 4, the inclined external light LR tends to have a moderate tendency to enter the inside at an angle greater than or equal to the critical angle to the side 3F or 13EB. The external light LR that is totally reflected on the ventral surface 3? Then enters the interior of the top surface 3G or 13G. The most important thing here is that the internal incident angle to the top surface 3G in FIG. 3 is larger than the internal incident angle to the top surface 13G in FIG. 4. As a result, a lot of light of the former is shown in Fig. 3, and is totally reflected once again through the other ventral surface, then passes through the light guide plate, and is emitted to the outside. Of course, such a light does not help display ', but causes a cloudy background, which is undesirable. In contrast, the latter is shown in Figure 4, and the incident light entering the top surface UG is almost vertical. Therefore, a lot of externally emitted light is generated and supplied to the liquid crystal display panel 11 (refer to FIG. 2). In addition to the protrusions αα, the external light beams that strike the inside δ 13B are also emitted toward the liquid crystal display panel 11 as shown in the figure. Therefore, little light is emitted to the outside that does not contribute to the display, and it is not easy to produce a cloudy background. < 2 > Second embodiment Figs. 6 and 7 show a liquid crystal display device 20 of a second embodiment. FIG. 9 shows the optical path of the illumination light in this embodiment. The same components as those in the first embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted. First, referring to FIGS. 6 and 7, the liquid crystal display device 20 includes a reflective liquid crystal display panel 11 and an edge-light type surface light source device 22. The paper size of this face applies to the Chinese National Standard (CNS) Α4 specification (210 × 297) -----__ 311015 ilrll · ---- Φ! (Please read the notes on the back before filling this page) Order the Ministry of Economic Affairs Printed by the Intellectual Property Bureau employee consumer cooperatives 14 493087 A7 1 V. Description of the invention (ls) The light source device 22 is arranged outside the liquid crystal display panel u (display side to observation side) in order to illuminate the liquid crystal display panel 11 in advance. Liquid crystal display panel η For the structure and operation of the plate, please read the note first, the same as that described in the embodiment. The surface light source device 22 includes a light guide plate 23 and a primary light source 24. The light guide plate 23 receives the light guide. Illumination light emitted from the incident end surface 23a of the light plate 23 from the primary light source 14. The secondary light source 14 may be the same as that used in the i-th embodiment.

the same. The illumination light is radiated toward the incident end surface 23A through the opening of the reflection 16. The illuminating light enters the light guide plate 23 in the form of a light beam spreading at an angle of approximately one degree. For convenience of explanation, the light beam is represented by "illumination light L" in FIG. 7. The material of the light guide plate 23 may be the same as that of the light guide plate 13 used in the first embodiment. In addition, in terms of manufacturing, injection molding technology can be applied. The main surface of the light guide plate 23 includes an inner surface 23B and an outer surface 23C facing away from the inner surface 23B. The inner surface 23B faces and approaches the liquid crystal display panel i. The inner side surface 23B is provided with a plurality of protrusions 23E in order to provide the inner side surface 23B with an exit function surface having an exit promotion function. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs The most important feature of the present invention is that the protrusion 23E and the incident end surface 23A are not substantially parallel but inclined at a certain inclination angle α. The inclination angle α depends on the design; however, it is most suitable to be within 5 to 45 degrees, especially within 15 to 30 degrees. The function and numerical range of such an oblique arrangement are the same as those described in the first embodiment, so the description will not be repeated here. The protrusions 2 3E applied in this embodiment also have the effect of having an effective width larger than the actual width. Therefore, the effect can be maintained even with narrower protrusions than in the past. The paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 15 311015 493087 A7 B7 5. The width of the invention (i6). Of course, the small-sized protrusions are less conspicuous, and it is possible to prevent the illumination quality of the surface light source device 22 and the display quality of the liquid crystal display device 20 from being degraded. (Please read the precautions on the back before filling in this page.) In addition, the obliquely arranged protrusions 23E can also reduce the possibility of moiré caused by other periodic arrangement relationships such as transparent electrodes. And this function can also prevent the degradation of lighting quality or display quality. The difference between the light guide plate 23 (this embodiment) and the light guide plate 13 (the first embodiment) is that the ridges 23E and 13E are formed around them. The protrusion 23E and its root portion are formed under the condition that the following conditions are satisfied (refer to FIGS. 7 and 9 in particular). (1) Each protrusion 23E has the same 3-dimensional shape. (2) The cross-sectional area of each ridge, which is "parallel to the outer surface 23C", is approximately the same from the base to the front end. (3) The first ventral surface 23EA and the second ventral surface 23EB stand approximately perpendicular to the general surface representing the ejection function surface (inner surface 23B). The ridge 23E has a top surface 23G whose front end portion extends substantially parallel to the general surface. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs (4) The first ventral surface 23EA is connected to the ejection function surface (inner surface 23B) on the first base portion 23BA; on the other hand, the second ventral surface 23EB is connected to the second base portion 23BB The exit function surface (inner surface 23B) is connected. In addition, the second base portion 23BB forms a step difference d with respect to the first base portion 23BA. This difference is formed so that the thickness of the light guide plate 23 of the second base portion 23EB is larger than the thickness of the first base portion 23BA. In other words, the first ventral surface 23EA provides a higher cliff face than the second ventral surface 23EB. In this case, the paper size applies the Chinese National Standard (CNS) A4 (210X297 mm) 16 311015 A7

I installed ---- !, can ------ ii -------- (Please read the precautions on the back before filling this page) 493087 A7 -------- B7_ V. DESCRIPTION OF THE INVENTION (18) The illumination light L having a larger angle approaching the protrusion 23E is refracted and directed toward the liquid crystal display panel U in a direction close to the front direction. (Please read the precautions on the back before filling in this page.) However, like the illumination light L1, there are many components that have an internal incident angle of almost 0 degrees and reach the side 23EB. This kind of illumination light is easily emitted from the side 3F to the outside. There is some refraction when emitted, but the emitted light has a large tilt angle to the front direction (normal line) of the liquid crystal display panel U. In contrast, the example shown in FIG. 9 is because of a step difference. For example, the component of the illumination light L1 approaching the protrusion 23E at a small angle is actually not incident on the second ventral surface 23EB internally, but rather the A large internal incidence angle enters the inside of the second base portion 23BB. On the other hand, the illumination light l approaching the protrusion 23E at a deeper angle is directed toward the liquid crystal display panel U in a direction close to the front direction after being twisted. According to the above mechanism, the configuration of FIG. 9 provides a lighting output with more directivity in the front direction than the configuration of FIG. 8. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Further, due to the inclination in the diagram of the second base 23BB, the illumination light L, after being reflected internally, corrects its direction toward the thickness direction of the light guide plate 23. As a result, after the internal reflection of the outer surface 2 3 c is subsequently performed, it is easy to enter the ridge at the next opportunity to enter the interior of the abdominal surface 23EB with a relatively large internal incidence angle. Therefore, the internal reflection generated by the second base portion 23BB hardly interferes with the ejection function. Generally speaking, under the conditions of the step difference d, the interval 23EA and 23EB on the ventral surface w (the width of the protrusion 2 3E), tan-i (d / w) = φ〇, and the internal incident angle is small> ψ〇 as the illumination light. Conditions for reaching the ventral 23EB. In other words, the internal incident angle φ of this & Zhang scale applies to China's national standard (CNS) Α ^ (21〇 × 297 公 褒) '-18 311015 1 / Α7 V. Description of the invention (19 $ Φ. Illumination light, then It will be hindered. The step difference d is designed according to this condition so that it is an appropriate small angle, such as $ degrees. As for the interval W ', it is designed to be a small size that is difficult to identify by the protrusion 23E. In fact, the interval W ranges from 5 to 50. // m. 3 embodiment is referred to the figure H) 'This figure shows the liquid crystal display device of the third embodiment, 30 ° The liquid crystal display device 30 does not use a side-light type surface light source device 12 ^ 2, money is used on the side Light type surface light source device 32. The surface light source device u k uses a light guide plate 13 or 22 'instead of a light guide plate 33. Except for this part, the basic structure of this embodiment is the same as that of the i-th embodiment and the second embodiment. In addition, the structure of this embodiment is more simplified than that of the previous embodiment. The same parts as those in the first or second embodiment are denoted by the same reference numerals and the same explanations are omitted. A light source device i 32 is arranged on the outside of the liquid crystal display surface S 11 (the display 2 or the observation side) and illuminates the front side of the liquid crystal display panel 11 #. The structure and function of the liquid crystal display are the same as those described in the first embodiment. The surface light source device 32 is provided with a light guide plate 23 and a primary light source / light guide plate 33 which receives an incident end face provided through an end face of the light guide plate 33 and supplies illumination light emitted from the first light source 14. -Second light source "The same β illumination light used in the first embodiment is irradiated toward the incident end face 13A through the opening of the reflection surface 16. The illumination light diffuses into the light guide plate 2 with a certain angle of incidence: the light guide plate 33 The materials can be used with the applicable injection molding technology used in the first or second example. 'China National Standards (CNS) 19 Ordering line 311015 493087 A7 ______B7 5. Description of the invention (20) The main surface of the light guide plate 33 includes the inner side 33B and The side surface facing away from the opposite side. The inner side surface 33B faces and is close to the liquid crystal display panel 11. In order to provide an ejection function surface having an ejection function, a plurality of protrusions 33E are provided in the inner part @@ 33Β. An important feature is that these protrusions 33E and the incident end surface 33A are not substantially parallel, but are inclined at a certain inclination angle. The inclination angle α 1 is determined by design, but is 5 to 45 degrees, especially 15 to 30 degrees. The range is the most suitable. The functions and numerical ranges of the inclined configuration as described above are the same as those described in the first embodiment. The protrusion 33E in this embodiment also has a width greater than the actual width. Therefore, the effective width can also be maintained by using smaller-sized protrusions than before. Of course, the use of small-sized protrusions is less conspicuous', which can prevent the lighting quality of the surface light source device 32 and the LCD The display quality of the device 30 is reduced. In addition, the obliquely arranged protrusions 3 3 Ε may reduce the possibility of moiré due to other periodic configuration factors such as transparent electrodes. This can also prevent the lighting quality or display quality. The shape of the light guide plate 33 printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is simple and made to meet the following conditions. (1) Each of the protrusions 33E has the same 3-dimensional shape. (2) Each protrusion The cross-sectional area of 33E is approximately constant from the root to the front end. (3) The paired ventral surfaces of each ridge stand perpendicularly to the general surface representing the ejection function surface (inner side 33B). Each ridge 33 £ at the front end Has a top surface that extends approximately parallel to the general surface. (4) The step difference used in the second embodiment is not used. In other words, the paper & scale applies the Chinese national standard (CNS) Α4 specifications (-210 > < 297 male sauce 1 ~ ------- ^-: 20 311015 493087 A7 0 printed by the Ministry of Economic Affairs and Intellectual Property Bureau employee consumer cooperatives V. Basic description of the invention (21) The second base part is not separated from the general surface. Even with such a simple structure, the most important and basic feature of the present invention can be maintained. That is, as has been described in detail above, the protrusion με has as if it has more than actuality. The effect of the larger width is the effect of the width; therefore, protrusions that are both inconspicuous and small in size can be used. As a result, it is possible to prevent a reduction in the lighting quality of the surface light source device 32 and the display quality of the liquid crystal display device 30. In addition, the protrusions 33E arranged in an oblique direction can prevent the occurrence of moiré, and therefore can prevent the degradation of the lighting quality or display quality. 11 ^ · 4th Embodiment In the first to third embodiments, one surface (inner side surface) of the liquid crystal display panel is provided with an emitting function surface having a projection. However, it may be provided from the outer side (the side facing away from the liquid crystal display panel). This example is shown in Fig. 11 as a fourth embodiment. The following briefly describes this embodiment, and avoids repeated description. Referring to Fig. 11, the liquid crystal display panel 11 of the liquid crystal display device 40 uses an edge-light-type light source device 42 as the front light. The surface light source device 42 uses a light guide plate 43. The structure and operation of the liquid crystal display panel 11 are the same as those described above. The material constituting the light guide plate 43 may be the same as that of the light guide plate Η. In addition, injection molding technology can be applied in manufacturing. The main surface of the light guide plate 43 has an inner surface and an outer surface opposite to the back surface. The inner side surface approaches and faces the liquid crystal display panel 11. This embodiment is characterized in that a plurality of ridges 43E are provided because an ejection function surface having an ejection promotion function is provided on the outer side surface. According to this issue, the 5's Zhang scale is applicable to the Chinese national standard (. Called 8 4 specifications (2 Shu 297 mm). See-(Please read the precautions on the back before filling this page). Thread -ma I- —m ^ i · — Mi · 21 311015 493087 A7 B7 V. Description of the invention (22)-1 ~ 1 * The most important feature is that these protrusions 43E are not substantially parallel to the end face of the injection, but are inclined at a certain inclination angle. The inclination angle is best from 5 (please read the notes on the back before filling this page) to 45 degrees, especially within 15 degrees to 30 degrees. Such an inclined configuration can also make the protrusion 43E have a ratio The function of the effective width with a larger actual width. Therefore, the effective width can be maintained even with a smaller width than the conventional size. Of course, the small size of the protrusion is less conspicuous, which prevents the lighting quality of the surface light source device 42 and The degradation of the display quality of the liquid crystal display device 4 (). In addition, as mentioned earlier, the generation of moiré can also be reduced. This can also prevent the degradation of the lighting quality or the display quality. There is a pair of each of the female protrusions Ventral 4 3E A and 43 EB. Ben In the embodiment, the ventral surfaces 43EA and 43EB each provide an inclined surface facing the incident end surface side and an inclined surface facing the rear surface of the incident end surface side. The ventral surfaces 43Ea and 43EB form a ridge line after meeting the front end portions of the protrusions. The shape of the protrusion 43E is It belongs to the category of "thin front end." After the fluorescent lamp 15 printed by the Employee Cooperative of the Intellectual Property Bureau of the Ministry of Economy lights up, the light beam represented by the illumination light l enters the light guide plate 4 3. The illumination light l enters the light guide plate 4 After 3, the internal reflection of the inner and outer sides repeats internal reflection, and gradually moves away from the incident end face and propagates inside the light guide plate 43. In this process, most of the illumination light L has entered any of the protrusions 43E. Opportunity. As shown in the figure, most of the illumination light l is reflected inside the second side (bevel) 43EB after entering the protrusion 43e, and then is emitted from the inner side toward the liquid crystal display panel 11. As explained above, part of this emitted light After repeatedly passing back and forth through the liquid crystal display panel 11, it is emitted to the outside. The paper size of the paper is applicable to China National Standard (CNS) A4 (210X297 mm) 22 311015 A7

Installation-(Please read the precautions on the back before filling this page) • ί Thread ------ 23 311015 A7

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 493087 V. Description of Invention u)

"Some cross-sectional area" and "vertical projections now itL and big out" conditions. (b) In the second embodiment, in order to take into account the difference between the base portion 23Ba and the second ventral surface 23EB of the heart, the inner side of the large strip adjacent to the mesh is along its entire length. tilt. In addition, instead of tilting the county's pull-up pin σ + chen, it is also possible to partially tilt to cause a step difference. (C) In the above embodiment. It is used for a long time. However, you can change to Oda without using a uniform thickness. The wiper uses a light guide plate with a wedge-shaped cross section. ⑷ In the above embodiment, the light guide plate is illuminated by one incident end surface, but the present invention is not limited to this method. For example, two incident end surfaces may be provided by two end surfaces facing each other. (e) In the above embodiment, the primary light of the surface light source device is supplied by a rod-shaped light source (fluorescent lamp). However, it is also possible to use a primary light source configured by a plurality of point light sources of light emitting diodes. (f) In the above embodiment, the main surface facing away from the exit function surface (the first to third embodiments is the outer surface; the fourth embodiment is the inner surface) is a smooth surface. However, instead of a smooth surface, a processed panel can be used instead. Also, a rough surface like anti-glare treatment may be used. (g) In the above-mentioned embodiment, the incident end surface is perpendicular to the main surface (outer side surface or inner side surface). However, the present invention is not limited to this form. That is, the incident end surface and the main surface (outer side surface or inner side surface) are inclined. (H) In the above embodiment, the present invention is applicable to a surface light source device for a liquid crystal display device. However, 'this embodiment does not limit the applicable paper size of the present invention to the Chinese National Standard (CNS) A4 specification (21〇 < 297mm) --- ~-24 311015 (Please read the note on the back first (Fill in this page again)

_ 493087 A7 B7 V. Description of the invention (25) ^ Usability. That is, the present invention can be widely applied to various lighting equipment, side-light type surface light source devices for display devices, and light guide plates used in these devices. Economics • Printed by I --------- ^ ------- 1T ------ ^ (Please read the notes on the back before filling out this page ) This paper size applies to China National Standard (CNS) A4 (210X297 mm) 25 311015

Claims (1)

^ U87 A8 B8 26 311015 Please read the notes of © © before filling in this page. I I I I I Itr / 、、 Declaring the scope of the patent The base portion increases the step between the thickness of the light guide plate. 9. The light guide plate according to item 3 of the scope of patent application, wherein the aforementioned exit function surface includes the same as that of the previous paragraph! The first cut base portion connected to the ventral surface and the second base portion connected to the second ventral surface. The second base portion has a step that increases the thickness of the other light guide plate to the aforementioned base portion. 10 · As for the guidance of item 5 of the scope of patent application, and seven persons & The first ... base portion connected to the ventral surface and the second base portion connected to the second ventral surface. Order 10: The second base portion has the thickness of the light guide plate to the first base portion. Increased step difference. 11. A surface light source device is provided with a broken product and / or a light guide plate for introducing the illumination light, and a light guide plate for illuminating the above-mentioned illumination light surface; Second & Mo Guangyue first side-by-side edge light type surface light source device arranged side by side with the aforementioned light guide plate; the above-mentioned exit function surface is provided with a surface of 1 at the north face of the product and the first ventral surface of the incident end face side And back to the aforementioned first! The ventral surface is a ridge; a majority of each of the ventral surfaces, and each of the ridges has an extending direction that is oblique to the inside of the angle range of the incident end surface.疋 12 • If the surface light source device of the μ scope of the patent application is in the range of 5 degrees to 45 degrees.刖 中 刖 角 Angle of the paper scale thorn _ 311015 27 493087 A8 B8 C8 D8 6. Application for patent scope 13. For the surface light source device of the scope of patent application No. 11 or 12, where i is at least the aforementioned second ventral surface, Inclined so as to be closer to the front end of the protrusion, and further away from the incident end surface. 14. The surface light source device according to item 13 of the patent application, wherein both the f 1 ventral surface and the second ventral surface are inclined so that the closer to the hip end portion of the protrusion, the further away from the incident end surface. 15 · If the surface light source device of the patent application scope item n or item 12, wherein each of the aforementioned protrusions has a smaller cross-sectional area closer to the front end ^ 16 ·: The surface light application of the patent application scope item 13 Among them, each of the aforementioned dog strips has a smaller cross-sectional area as it approaches the front end portion. 17 · = Applicable surface light source device of item 14 in which the aforementioned dog strips have a smaller cross-sectional area as they approach the front end portion. Area: 18: Application: The surface light source device of item u or item 12 of the patent scope, the aforesaid emitting function surface includes a t-th base portion connected to the first surface and a second base connected to the second ventral surface. Part, guide = the second base part has a step difference from the previous base part that increases the thickness of the aforementioned antecedent plates. 19. For example, the above-mentioned surface-light shooting counterfeit clothes set of item 13 of the patent application, where the aforementioned This face of the ejector includes the first base part that is in contact with the j-th ventral plane of the previous note, and the second base part that is connected to the second ventral plane. The second base part has a base part for the aforementioned ^ The step that increases the thickness of the light guide plate. The surface light source device of item 15, whose shooting function surface includes the first paper ruler of China connected to the first ventral surface of the previous note-China ^ 2, 28 311015 (Please read the phonetic notation of -t surface? Matters before filling in this Page) --1 11111111 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs / A8 B8 Please read it first. Note on the back before filling out this page. 4 493087 B8 C8 D8 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 6. Application for a patent. 26. If you apply for a liquid crystal display device with item 23 of the patent application, 苴 + _ ', Τ' states that each ridge has a smaller cross-sectional area as it approaches the front end. 27. For the liquid crystal display device according to item 24 of the scope of patent application, each of the protrusions has a smaller cross-sectional area as it approaches the front end. 28. For example, the liquid crystal display device of the 21st or 22nd patent application scope, wherein the above-mentioned emitting function surface includes a first base portion connected to the i-th ventral surface of the foregoing and a second base portion connected to the second ventral surface. The second base portion has a step that increases the thickness of the light guide plate to the second base portion. 29. The liquid crystal display device according to item 23 of the patent application scope, wherein the emitting function surface includes a first base portion connected to the ventral surface of the previous note and a second base portion connected to the second ventral surface, and The second base portion has a step that increases the thickness of the light guide plate to the second base portion. 30. According to the liquid crystal display device in the scope of application for patent No. 25, in the above, the emitting function surface includes an i-th base portion connected to the first abdominal surface and a second base portion connected to the second abdominal surface, and The second base portion has a step that increases the thickness of the light guide plate to the first base portion. For example, the liquid crystal display device of the 21st or 22nd patent application range, wherein the aforementioned side-light type light source device is arranged for the front light of the aforementioned liquid crystal display panel. 32. For example, the liquid crystal &-#gang spear d display device of the application scope of the patent application item 23, wherein the aforementioned detection & $ jU 原 T device is for the mechanical scale of the aforementioned liquid crystal display panel Applicable to Chinese National Standards (c ^^; -29 _} — The panel's photo should be equipped with 30 311015 first (please read the precautions before filling in this page)-n eMmmw · ϋ n ϋ n i-1 One OJ · Nnn ϋ all 1 · -1 I 493087 A8 B8 C8 D8 6. Those who apply for patent scope. 3 3. For the liquid crystal display device with the scope of patent application No. 25, wherein the aforementioned edge-light type light source device is for the aforementioned liquid crystal display. 34. The liquid crystal display device according to item 28 of the scope of patent application, wherein the edge-light type light source device is configured for the front light of the liquid crystal display panel. ------- -------------- ^ --------- (Please read the precautions on f before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 311015 This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) 31