JP2009301064A - Manufacturing method of light guide plate, light guide plate, and light emission type signboard using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent irregularity from occurring on a surface by adjusting nonuniformity of a reflecting pattern when the reflecting pattern is formed by ultrasonic machining. <P>SOLUTION: A manufacturing method of a light guide plate, in which the light entered from an end face emits from a first main face and a second main face, includes: a first forming process in which the first main face of the light guide plate contacts a horn for an ultrasonic machining having a plurality of processing dots, and a first recessed-part group comprising a plurality of recessed parts corresponding respectively to the shape of the plurality of processing dots deflecting the moving direction of the light entered from the end face is formed; and a second forming process in which the second main face of the light guide plate contacts the horn for an ultrasonic machining having the plurality of processing dots, and a second recessed-part group comprising a plurality of recessed parts corresponding respectively to the shape of the plurality of processing dots deflecting the moving direction of the light entered from the end face is formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light guide plate, a light guide plate, and a light-emitting signboard using the light guide plate.

  Conventionally, a light guide plate that emits light incident from an end face from both main surfaces of the light guide plate is known. As such a light guide plate, there is a light guide plate used in the illumination device described in Patent Document 1.

  Specifically, the lighting device described in Patent Document 1 includes a light guide plate, and a first display panel and a second display panel arranged so as to sandwich the light guide plate. And such an illuminating device emits the light which injected into the light guide plate from light sources, such as LED arrange | positioned at the end surface of a light guide plate, from both main surfaces of a light guide plate, and the 2nd display panel and 2nd. The display panel is illuminated from the back.

  However, when such an illuminating device is applied to a relatively large device such as a liquid crystal monitor or a light-emitting signboard, it performs its function due to the insufficient amount of light emitted from the light guide plate. There was a problem that was difficult. Therefore, as a method of increasing the amount of light emitted from such a light guide plate, there is a method of forming a reflection pattern on the light guide plate by ultrasonic processing as in the invention described in Patent Document 2. When such a reflection pattern is formed, the reflection pattern is formed by mounting the ultrasonic processing horn on a predetermined ultrasonic processing machine and bringing the ultrasonic processing horn into contact with the light guide plate work a plurality of times.

JP 2007-299716 A JP 2007-66699 A

  However, when such a reflection pattern is formed by ultrasonic processing, the reflection pattern is formed by bringing an ultrasonic processing horn 101 as shown in FIG. 12 into contact with the light guide plate work. For example, when the output of the ultrasonic processing horn 101 is taken into consideration, the reflection pattern is formed over the entire surface of the light guide plate work due to the fact that the size of the processed portion of the horn cannot be more than a certain size. When doing so, the ultrasonic processing horn 101 is repeatedly brought into contact with the light guide plate workpiece. At this time, the ultrasonic processing horn 101 once contacts the processing surface of the light guide plate workpiece, and then moves in the direction of arrow A from the upper left of the processing surface of the light guide plate workpiece 103, for example, as shown in FIG. It contacts the processed surface of the light guide plate work 103 again. At this time, the ultrasonic processing horn 101 moves so that each reflection pattern does not overlap with an adjacent reflection pattern, and performs processing. When the ultrasonic processing horn 101 reaches the right end of the light guide plate workpiece 103, the ultrasonic processing horn 101 moves downward in the light guide plate 3 and moves from the left side to the right side of the light guide plate 3 (in the direction of arrow B). ) Apply processing while moving. The light guide plate formed by such a series of processing is in a state in which a reflection pattern is formed over the entire surface, as shown in FIG.

  Then, when light is incident from one end face of the light guide plate subjected to such a series of processing, the light guide plate emits light as shown in FIG. The light guide plate of the photograph shown in the figure has a diffusion plate disposed on the main surface thereof. As is clear from the figure, streaks are generated in the vertical and horizontal directions on the surface of the light guide plate. This is a processing mark generated during processing by the ultrasonic processing horn 101. That is, since the ultrasonic processing horn 101 is relatively large compared to the size of each reflection pattern, the reflection pattern formed on the surface of the light guide plate even when the ultrasonic processing horn 101 is slightly inclined. Unevenness occurs in the size. When light is incident on the light guide plate on which the reflection patterns having different sizes are formed, unevenness occurs on the surface due to the unevenness of the reflection patterns.

  Therefore, the present invention has been made in view of such circumstances, and when a reflection pattern is formed by ultrasonic processing, unevenness of the reflection pattern is adjusted to prevent unevenness on the surface. It is an object to provide a light guide plate manufacturing method, a light guide plate, and a light-emitting signboard using such a light guide plate.

  In order to solve the above-mentioned problems, a light guide plate manufacturing method according to the present invention is a light guide plate manufacturing method in which light incident from an end surface is emitted from a first main surface and a second main surface. An ultrasonic processing horn having a plurality of processing dots is brought into contact with the first main surface, and a plurality of recesses respectively corresponding to the shapes of the plurality of processing dots deflecting the traveling direction of light incident from the end surface A first forming step for forming a first recess group, and the ultrasonic processing horn having the plurality of processing dots in contact with the second main surface of the light guide plate, and is incident from the end surface And a second forming step of forming a second recess group composed of a plurality of recesses respectively corresponding to the shapes of the plurality of processed dots for deflecting the traveling direction of light.

  According to this configuration, the size of the recess formed in the light guide plate by the forming process is adjusted to be substantially uniform. Thereby, the light emitted from the light guide plate becomes uniform.

  As described above, according to the present invention, it is possible to prevent unevenness on the surface by adjusting the non-uniformity of the recesses.

It is a perspective view of a light emission type signboard. It is a perspective view of a light-guide plate. It is an expanded sectional view at the time of manufacturing a light-guide plate. It is an expanded sectional view of a light-guide plate. It is an expanded sectional view of a light-guide plate. It is a top view of a light-guide plate. It is a top view of a light-guide plate. It is an enlarged plan view of a light guide plate. It is a photograph which shows the state which the light-guide plate is light-emitting. It is an expansion perspective view of a light-guide plate. It is a perspective view of a light emission type signboard. It is an expansion perspective view of the horn for ultrasonic processing. It is a top view for demonstrating the manufacturing method of a light-guide plate. It is a photograph which shows the state which the light guide plate used conventionally is light-emitting.

  As shown in FIG. 1, the light-emitting signboard 1 according to the embodiment includes a light guide plate 3, a diffusion plate 5, and a display plate 7. Such a light-emitting signboard 1 emits light incident from the side surface of the light guide plate 3 from the main surface of the light guide plate 3. The light emitted from the main surface of the light guide plate 3 is diffused by the diffusion plate 5 and irradiated from the back surface of the display plate 7.

  As shown in FIG. 2, the light guide plate 3 is formed by processing a plurality of concave portions 11 on the surface of a light guide plate work 9 made of, for example, an acrylic plate having a predetermined size. Such a recess 11 deflects the traveling direction of light incident on the light guide plate 3 from the end face of the light guide plate 3. The recess 11 is formed by ultrasonic processing.

  The ultrasonic processing apparatus for forming the recess 11 includes the ultrasonic processing horn 101 as shown in FIG. 12 as described above. A processing dot 105 having a shape corresponding to the recess 11 is formed at the tip of the ultrasonic processing horn 101. Each processing dot 105 has a quadrangular pyramid shape with a height of about 0.3 mm, for example. The length of the diagonal line on the bottom surface of each processing dot 105 is about 1.8 mm. At the tip of the ultrasonic processing horn 101, an even number of such processing dots 105 are arranged in the vertical and horizontal directions. Then, when the ultrasonic processing horn 101 is moved by a predetermined carrier and each processing dot 105 is brought into contact with the surface of the light guide plate workpiece 9, 144 pieces of 12 × 12, for example, are formed on the surface of the light guide plate workpiece 9. The recess 11 is formed. When manufacturing the light guide plate 3, the tip of the ultrasonic processing horn 101 is brought into contact with the light guide plate workpiece 9 to form the 144 concave portions 11, and then the ultrasonic processing horn 101 is removed from the light guide plate workpiece 9. After the separation, the ultrasonic processing horn 101 is brought into contact with the light guide plate workpiece 9 again. By repeatedly executing these operations, the concave portion 11 is formed uniformly on the surface of the light guide plate 3.

  In addition, a reflection plate 13 is formed on the other main surface of the light guide plate 3 that faces the main surface on which the concave portion 11 is formed. The reflection plate 13 is configured by sticking, for example, a polycarbonate film to the other main surface of the light guide plate 3. Thereby, the light guided to the other main surface side in the light guide plate 3 is reflected by the reflecting plate 13 in the direction of the recess 11.

  By the way, such an ultrasonic processing horn 101 is fixed to a carrier by an operator's manual work, for example, but in the case of manual fixing, it is difficult to fix the ultrasonic processing horn 101 accurately. . As described above, since the size of each recess 11 is very small, even when the ultrasonic processing horn 101 is slightly shifted and fixed, each recess 11 is formed unevenly. For example, when the axis of the ultrasonic processing horn 101 is tilted as shown in FIG. 3, the recess 11 formed thereby has a non-uniform shape as shown in FIG. Specifically, among the plurality of recesses 11, the recesses 11 in the direction in which the ultrasonic processing horn 101 is inclined increase, and the size of the recesses 11 decreases as the distance from the recess 11 increases. And the depth of the some recessed part 11 formed in this way becomes non-uniform | heterogenous, and the nonuniformity will arise also in the light inject | emitted from a light-guide plate as shown in FIG. Especially when the light guide plate is mass-produced, the inclination of the ultrasonic processing horn 101 is slightly shifted every time the ultrasonic processing horn 101 comes into contact with the light guide plate work 9, and this phenomenon is remarkable. Occurs.

  Accordingly, an object of the present invention is to prevent the occurrence of light unevenness even when the ultrasonic processing horn 101 is slightly inclined.

  In order to prevent the occurrence of such unevenness, in the method of manufacturing the light guide plate according to the present invention, the concave portion 11 is once formed by the ultrasonic processing horn 101 and then the ultrasonic processing horn 101 is used again. To adjust the size of the recess 11. In other words, in the present invention, the light guide plate workpiece 9 is hit twice with the ultrasonic processing horn 101 to form the concave portion 11 and then adjust. And when adjusting the magnitude | size of the recessed part 11, after moving the horn 101 for ultrasonic processing to the position different from the time of formation of the recessed part 11, the horn 101 for ultrasonic processing is made to contact the light-guide plate work 9. FIG. Thereby, as shown in FIG. 5, since the size of the relatively small recesses 11 is enlarged, the size of each recess 11 becomes relatively uniform. Further, when adjusting the size of the recess 11, the ultrasonic processing horn 101 is moved to a position different from that at the time of forming the recess 11 so as to overlap the recess 11 in which the processing dots are already formed. Adjust the size.

  Specifically, as shown in FIG. 13, the ultrasonic processing horn 101 executes processing while the newly formed recess 11 moves so as to be adjacent to the already formed recess 11. Thereafter, the ultrasonic processing horn 101 performs a process of adjusting the size of the recess 11. At this time, the ultrasonic processing horn 101 moves to a position different from that at the time of forming the recess 11 and overlaps the recess 11 where the processing dots are already formed. For example, as shown in FIG. 6, when the recesses 11 are formed, a group of recesses 11 composed of a set of 144 recesses 11 formed when the ultrasonic processing horn 101 once contacts the light guide plate work 9 is formed. These areas are designated as areas A1 to A32. That is, the ultrasonic processing horn 101 performs the formation process 32 times when the concave portion 11 is formed on the surface of the light guide plate work 9. After that, the ultrasonic processing horn 101 moves to a location where the axis is located above the intersection of the area A1, the area A2, the area A9, and the area A10 near the corner of the light guide plate work 9, for example. To do. As a result, each processing dot is positioned directly above the recess 11 in the region A1, the region A2, the region A9, and the region A10. Then, the ultrasonic processing horn 101 moves downward to come into contact with the light guide plate workpiece 9 and enlarges the size of the recess 11 using ultrasonic waves. The recessed part 11 expanded at this time is a recessed part 11 smaller than the size to be originally formed. At this time, a region where the concave group 11 formed by the ultrasonic processing horn 101 is formed is defined as B1. The region B1 is shifted from the region A1, the region A2, the region A9, and the region A10 by a length corresponding to half of the width or height of each region, and the region A1, the region A2, the region A9 , And the region A10 is formed so as to evenly straddle. The ultrasonic processing horn 101 forms the regions B2 to B21 by the same processing. Such regions B1 to B21 are formed so as to overlap with a part of the regions A1 to 32, as shown in FIGS.

  When light is incident on the end face of the light guide plate 3 formed in this way, the light guide plate 3 emits light as shown in FIG. In the figure, a photograph of a state in which a diffusion plate is arranged on the main surface of the light guide plate 3 is shown. As is clear from the figure, the light distribution of the light guide plate shown in the figure is different from the light distribution of the light guide plate 3 shown in FIG. It can be seen that is shrinking. This is because, in the technique used in the past, when the recess 11 is processed, the size of the recess 11 becomes non-uniform, so that light deflected by the recess 11 smaller than the other recesses 11 is irradiated. The portion irradiated with the light deflected by the relatively large concave portion 11 was relatively bright. As a result, in the conventionally used technology, the surface of the light guide plate 3 is uneven. However, when the light guide plate 3 according to the present invention is used, since the size of the recess 11 is adjusted, the relatively small recess 11 is eliminated. Thereby, according to this invention, the nonuniformity of the light inject | emitted from the light-guide plate 3 can be reduced.

  The diffusion plate 5 diffuses light emitted from the main surface of the light guide plate 3. The diffusion plate 5 is configured by, for example, forming a polycarbonate resin into a plate shape. Further, the size of the main surface of the diffusion plate 5 is substantially the same as the size of the main surface of the light guide plate 3. Such a diffusion plate 5 is arranged such that one main surface thereof faces the main surface of the light guide plate 3. When the light emitted from the light guide plate 3 enters one main surface, the diffusion plate 5 diffuses the light and emits the light from the other main surface. Thereby, the other main surface of the diffusion plate 5 emits light uniformly.

  The display board 7 is made of a plastic material having a predetermined translucency. Predetermined information is printed on the main surface of such a display board 7. The display plate 7 is arranged so that one main surface faces the other main surface of the diffusion plate 5. When the light diffused in the diffusion plate 5 enters one main surface of the display plate 7, the incident light passes through the display plate 7 and the other main surface of the display plate 7 emits light. Thereby, the visibility of the information printed on the display board 7 is improved.

  In addition to the above-described configuration, such a light-emitting signboard 1 is formed with an LED (Light Emitting Diode) array in the vicinity of one end face. At this time, the LED array may be formed along one end face of the light guide plate 3, or may be arranged along two opposing end faces. Further, when the LED array is formed along one end surface of the light guide plate 3, it is also possible to dispose a reflecting plate on the end surface facing the end surface. Thereby, the light intensity of the light-emitting signboard 1 can be kept constant. For example, when the light emitting sign 1 is hung on the ceiling or the like, the LED array can be formed along the end surface corresponding to the upper side of the light guide plate 3. Thereby, the wiring of the LED array can be easily performed, and it is not necessary to arrange various devices on the end surface corresponding to the bottom side of the light guide plate 3.

  According to experiments by the inventors, it has been found from the following experiment that the luminance of light emitted from a light guide plate having a recess formed on one main surface is about 600 candela or more. Specifically, the inventors used an acrylic resin light guide plate having a width of 1000 mm, a height of 600 mm, and a thickness of 8 mm, and arranged 108 LED elements along both end faces in the width direction. And the pitch between each LED element was 8.2 mm. A current of 20 mA per LED element was passed through such an LED array at a voltage of DC 24V. At this time, the relationship between the distance from the light source and the luminance was as shown in Table 1.

  As described above, according to the first embodiment, it is possible to prevent unevenness of light from occurring on the light emitting surface of the light emitting signboard 1 while maintaining a certain luminance or more.

  Moreover, in the above-mentioned embodiment, although detailed description was given as what forms the recessed part 11 in the single side | surface of the light-guide plate 3, the recessed part 11 can also be formed in both the main surfaces of the light-guide plate 3. FIG.

  In this case, after performing formation processing and adjustment processing on one main surface, the light guide plate work is reversed, and the same processing is performed on the other main surface. Thereby, as shown in FIG. 10, a recessed part is uniformly formed in both main surfaces by the light-guide plate. And the light guide plate which performed the formation process and adjustment process to both main surfaces is pinched | interposed with a diffuser plate and a display board. Thereby, as shown in FIG. 11, the light emission type signboard which can display predetermined information in both directions can be formed.

  According to the experiments by the inventors, it has been found from the following experiments that the luminance of light emitted from the light guide plate having recesses formed on both main surfaces is 300 candela or more. Specifically, the inventors used an acrylic resin light guide plate having a width of 1380 mm, a height of 270 mm, and a thickness of 8 mm, and arranged 160 LED elements along one end face in the width direction. And the pitch between each LED element was 8.25 mm. In addition, a reflecting plate was formed on the other end face in the width direction. A current of 20 mA per LED element was passed through such an LED array at a voltage of DC 24V. At this time, the relationship between the distance from the light source and the luminance and illuminance was as shown in Table 2.

  In this way, the diffusion plates are arranged on both main surfaces of the light guide plate, and the luminance of each surface is at least 300 candela. Thus, according to the present invention, even when light is emitted from both main surfaces of the light guide plate, it is possible to obtain sufficient brightness as a light-emitting signboard while preventing the occurrence of unevenness.

  The present invention is not limited to the above-described embodiment, and each configuration can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Light emission type sign board 3 Light guide plate 5 Diffusion plate 7 Display board 9 Light guide plate work 11 Recess 13 Reflection plate 101 Horn for ultrasonic processing 103 Light guide plate work 105 Processing dot

Claims (3)

In the method of manufacturing a light guide plate that emits light incident from the end face from the first main surface and the second main surface,
An ultrasonic processing horn provided with a plurality of processing dots is brought into contact with the first main surface of the light guide plate, and each corresponds to the shape of the plurality of processing dots for deflecting the traveling direction of light incident from the end surface. A first forming step of forming a first recess group consisting of a plurality of recesses;
The ultrasonic processing horn provided with the plurality of processing dots is brought into contact with the second main surface of the light guide plate, and each of the plurality of processing dots has a shape that deflects the traveling direction of light incident from the end surface. And a second forming step of forming a second group of recesses consisting of a plurality of corresponding recesses. A method of manufacturing a light guide plate, comprising: In the light guide plate that emits light incident from the end face from the first main surface and the second main surface,
A plurality of shapes respectively corresponding to the shapes of the plurality of machining dots for deflecting the traveling direction of light incident from the end face formed by contacting an ultrasonic processing horn having a plurality of machining dots on the first main surface. A first recess group comprising recesses of
Corresponding to the shapes of the plurality of machining dots for deflecting the traveling direction of light incident from the end face formed by contacting an ultrasonic processing horn provided with the plurality of machining dots on the second main surface. A light guide plate comprising: a second recess group composed of a plurality of recesses. A light guide plate according to claim 2;
A light source that emits the light incident on the end face of the light guide plate;
A first diffusion plate formed so that one main surface faces the first main surface of the light guide plate;
A second diffusion plate formed so that one main surface faces the second main surface of the light guide plate;
Predetermined information is formed on a plate having a certain translucency, and the first display plate is arranged so that one main surface of the plate faces the other main surface of the first diffusion plate. Predetermined information is formed on the translucent plate, and the second display plate is disposed so that one main surface of the plate faces the other main surface of the second diffusion plate. This is a light-emitting signboard.