JP2013134939A - Method of manufacturing surface light-emitting light guide plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity of a surface light-emitting light guide plate and to reduce manufacturing cost by simultaneously forming a large number of reflection recesses on a face of a transparent platy substrate to be a raw material of the surface light-emitting light guide plate to thereby reduce time and man-hour needed for the processing of the formation of the reflection recesses.SOLUTION: In forming a large number of reflection recesses on a plate face of the substrate for the light guide plate made of a platy transparent material, a press mold equipped with one or more platy blades in which a large number of blade tips each having a blade face slanted at a given angle from a blade-tip ridge line are formed in one direction at intervals is pressed against the plate face of the substrate so that the blade tips dig into the plate face at the same time, whereby a large number of reflection recesses are to be formed at the same time on the plate face of the substrate.

Description

  The present invention relates to a method for manufacturing a large-sized surface-emitting light guide plate, and more particularly to a method for forming a large number of reflective recesses on the surface of a substrate made of a transparent material that is a material of the light guide plate.

  As a backlight of a large liquid crystal TV or a backlight of a signboard, an edge light type surface emitting light guide plate is often used. The edge-light surface emitting light guide plate allows light to be incident on the light guide plate from a light source such as an LED from its end face, and emit light entirely from one of the two plate surfaces of the light guide plate, It emits surface light. In this type of surface light-emitting light guide plate, several configurations are known as a configuration for emitting light incident from the end surface as a whole from one plate surface. As described above, reflection concave portions such as a large number of V-shaped grooves are formed on the plate surface of the light guide plate in such a manner that it is dispersed in the two-dimensional direction of the plate surface, and light incident from the end surface is reflected on each reflection concave portion. A configuration has been proposed in which light is emitted from the other plate surface side to the outside so as to emit surface light as a whole (for example, Patent Document 1). A typical example of such a light guide plate is shown in FIGS.

  13 and 14, of the two plate surfaces 3A and 3B of the plate-like substrate 1 made of a transparent material such as acrylic resin, one plate surface 3A has a vertical or V-shaped cross section. A large number of reflecting recesses 5 are formed in a state of being dispersed in a two-dimensional direction including the plate surface 3A. In these reflective recesses 5, at least one of the inner side surfaces 5A and 5B (for example, 5A) functions as a reflective surface. That is, when used as a light guide plate, a light source 7 such as an LED is disposed on one end surface 3C perpendicular to the plate surface 3A, and light enters the substrate 1 from the light source 7 via the end surface 3C. Is incident on the substrate 1, and the light is reflected toward the other plate surface 3B of the substrate 1 by at least one of the inner surfaces 5A and 5B (the reflection surface 5A) of the recess 5 for reflection. The light can be emitted from 3B to the outside. Depending on the shape of the reflecting recess and the angle of the inner surface, light may be emitted to the outside from the plate surface on the side where the reflecting recess is formed. In any case, light can be emitted from the plate surface in a state close to surface light emission by forming a large number of minute reflecting recesses 5 in a two-dimensional direction with high density.

  In manufacturing this type of surface light-emitting light guide plate, a large number of minute reflective recesses are formed on the surface of the light guide plate substrate made of a transparent material such as acrylic resin in a two-dimensional direction of the plate surface with high density. It is necessary to form in a dispersed state. Conventionally, laser processing or mechanical cutting has been applied to the manufacture of such a light emitting plate for surface light emission, and in particular to the formation processing of the concave portion for reflection. However, in laser processing, there is a limit to the processing speed, and it is difficult to simultaneously form a large number of reflecting recesses, and thus it takes a long time to form a large number of reflecting recesses at a high density. There is a problem in terms of productivity, and it must be expensive. Also, when forming a reflective recess by machining such as cutting, it usually has to be processed for each reflective recess, which is also inferior in productivity and inevitably high in cost. Attempts have been made to simultaneously operate a plurality of processing tools to simultaneously form a plurality of reflective recesses, but in order to form a large number of reflective recesses at a high density, it is also necessary to improve productivity. There was a limit.

Japanese Patent No. 4615393

  The present invention has been made against the background of the above circumstances, and it is possible to simultaneously form a large number of concave portions for reflection on a plate surface of a transparent plate-like substrate such as an acrylic resin to be a material of a light guide plate at a high density. Thus, it is an object of the present invention to reduce the time and man-hours required for processing for forming the reflective recesses, improve the productivity of the surface light-emitting light guide plate, and reduce the manufacturing cost.

  In order to solve the above-mentioned problems, in the present invention, basically, a cutting die having a cutting edge corresponding to the reflecting recess to be formed is used, and the cutting edge is bitten into the plate-like substrate plate surface. Assuming that the concave portion for reflection is formed on the plate surface by pressing the pressing die against the plate surface of the substrate, a plate-like blade body in which a large number of blade edge portions are arranged in one direction at intervals as the pressing die. In use, a large number of cutting edge portions are bitten into the plate surface of the substrate at the same time by a single pressing, thereby forming a large number of concave portions for reflection at the same time.

That is, in the method of manufacturing the surface light-emitting light guide plate according to the basic aspect (first aspect) of the present invention, the light from the light source is transmitted from the end surface forming a predetermined angle to the plate surface of the light guide plate into the light guide plate. Is produced, and the light is reflected by the reflecting surfaces in a large number of reflecting recesses formed by dispersing the light in the two-dimensional direction of the plate surface of the light guide plate, thereby producing a light guide plate that emits surface light. In the method
In forming the multiple reflective recesses on the plate surface of the light guide plate substrate made of a plate-like transparent material,
A plurality of cutting edge portions each having a blade surface are formed at intervals along one direction, and using a pressing die having one or more plate-like blade bodies, the multiple blade edge portions are formed on the plate surface of the substrate. The pressing mold is pressed against the plate surface of the substrate so as to be pushed in at the same time, thereby forming a large number of reflective recesses simultaneously on the plate surface of the substrate.

  According to the method for manufacturing the light emitting plate for surface light emission of the first aspect as described above, by pressing a plate-like blade body having a large number of blade edge portions against the substrate, the large number of blade edge portions are simultaneously pushed into the plate surface of the substrate. Thus, a large number of reflective recesses are formed simultaneously. Therefore, even when a large number of reflection recesses are formed at a high density, the number of steps for forming the reflection recesses can be reduced, the productivity can be improved, and the manufacturing cost of the light guide plate can be reduced.

  In the circuit board manufacturing method according to the second aspect of the present invention, in the first aspect, as the pressing mold, two or more plate blades are spaced apart so that their plate surfaces are parallel to each other. In order to press the pressing die against the plate surface of the substrate, a large number of cutting edge portions of two or more plate blades are bitten into the substrate surface of the substrate at the same time. A large number of concave portions for reflection dispersed in the two-dimensional direction are simultaneously formed.

  According to the method for manufacturing the surface light-emitting light guide plate of the second aspect, the blade edge portions of the two or more plate-shaped blade bodies are arranged in a two-dimensional direction (that is, vertically and horizontally) on the blade edge side of the pressing die. Therefore, if the pressing die is pressed against the plate surface of the substrate, a large number of reflective recesses dispersed in the two-dimensional direction of the plate surface of the substrate can be formed simultaneously. Therefore, it is possible to further reduce the man-hours for forming the concave portions for reflection, thereby dramatically improving the productivity, and further reducing the manufacturing cost of the light guide plate. The number of cutting edge portions in one plate-like blade body and the number of plate-like blade bodies held in one pressing die are particularly adapted to correspond to all of the large number of reflection recesses to be formed on one substrate. If the number is set, all the concave portions for reflection can be formed at the same time by one pressing operation, and the productivity can be further improved.

  Moreover, the manufacturing method of the light-emitting plate for surface light emission by the 3rd aspect of this invention is set so that the space | interval between the two or more plate-shaped blade bodies may change as the said press die in the said 2nd aspect. This is characterized in that a held pressing die is used to change the interval between a plurality of reflecting recesses formed on the plate surface of the substrate.

  According to the method for manufacturing the surface light-emitting light guide plate of the third aspect, since the interval between the many reflecting recesses can be changed, the dispersion density of the reflecting recesses depends on the distance from the light source and the like. Can be changed appropriately. For example, in a place where the distance from the light source in the substrate is far, the intensity of the light reaching the reflecting recess is usually low, so the density of the reflecting recess in the place far from the light source is In the case where the distance from the light source is set to be the same as that of the portion where the distance from the light source is short, the surface emission light emitted from the plate surface tends to be weak at a position where the distance from the light source is far. However, if the distance between the reflective recesses at a location far from the light source is reduced and the dispersion density of the reflective recesses at that location is increased, a location where the distance from the light source is close even at a location far from the light source. It is possible to cause surface emission with a light quantity equivalent to or close to that.

  Furthermore, the manufacturing method of the surface emitting light guide plate according to the fourth aspect of the present invention is the method of manufacturing the surface emitting light guide plate according to the second or third aspect, wherein two or more plate blades are used as the pressing die. Using a pressing die held so that the height of each blade edge portion changes, thereby changing the depth of the concave portion for reflection formed on the plate surface of the substrate. Is.

  According to the method for manufacturing the surface light-emitting light guide plate of the fourth aspect, the depths of the many reflecting recesses can be changed. Therefore, the depth of each reflecting recess can be set according to the distance from the light source. It can be changed appropriately. That is, the depth of the concave portion for reflection corresponds to the area of the inner surface of the concave portion for reflection functioning as a reflective surface. If the area of this reflective surface changes, the amount of light reflected by one reflective concave portion can be reduced. Change. Therefore, for example, if the depth of the recess for reflection at a location far from the light source is set deeper than the depth of the recess for reflection at a location close to the light source, the depth for reflection at a location far from the light source The amount of light reflected by the reflecting surface of the recess also increases. At the same time, if the depth of the recess for reflection at a location far from the light source is set to be deeper than the depth of the recess for reflection at a location close to the light source, the light from the light source is distant from the light source. However, the rate at which the amount of light decreases through the other reflective recesses before reaching the reflective recesses at a distant location is also reduced. In combination, even at a location far from the light source, it is possible to cause surface emission with a light quantity equivalent to or close to a location near the distance from the light source.

  Furthermore, the manufacturing method of the surface light-emitting light guide plate according to the fifth aspect of the present invention is the method of manufacturing the surface light-emitting light guide plate according to any one of the second to fourth aspects, wherein the thickness of the blade edge portion is set to 2. By changing for each of the above plate-like blade bodies, a pressing die that changes the area of the blade surface of each blade edge portion is used, thereby changing the area of the reflecting surface of the reflecting recess formed on the plate surface of the substrate. It is characterized by doing so.

  According to the method for manufacturing the surface light-emitting light guide plate of the fifth aspect, the area of the reflecting surface of each reflecting recess can be changed by changing the area of the blade surface of each cutting edge. Therefore, for example, the blade of each cutting edge part is set so that the area of the reflecting surface of the reflecting recess at a location far from the light source is larger than the area of the reflecting surface of the reflecting recess at a location close to the light source. If the area of the surface is set, the amount of light reflected by the reflecting surface of the reflecting recess at a location far from the light source becomes large. At the same time, if the area of the reflecting surface of the reflecting recess at a location far from the light source is larger than the area of the reflecting surface of the reflecting recess at a location close to the light source, the light from the light source The rate of decrease in the amount of light due to passing through the reflecting surface of another reflecting recess is reduced until it reaches the reflecting recess at a location far from. In combination, even at a location far from the light source, it is possible to cause surface emission with a light quantity equivalent to or close to a location near the distance from the light source.

  Furthermore, the manufacturing method of the surface light-emitting light guide plate according to the sixth aspect of the present invention is the method of manufacturing the surface light-emitting light guide plate according to any one of the first to fifth aspects. When pushing the part into the plate surface of the substrate, the blade edge of the plate blade is bitten into the plate surface of the substrate with the substrate plate surface inclined, thereby changing the depth of the recess for reflection. It is characterized by doing so.

  According to the method for manufacturing the surface light-emitting light guide plate of the sixth aspect, the depths of a large number of the concave portions for reflection can be changed in the same manner as in the fourth aspect. The depth of each reflecting recess can be appropriately changed.

  Furthermore, the manufacturing method of the light-emitting plate for surface light emission by the 7th aspect of this invention is adjacent to the said plate-shaped blade body in the manufacturing method of the light-emitting plate for surface light emission of the said 1st-6th aspect. The present invention is characterized in that a plate-like blade body in which the distance between the blade edge portions is changed is used to change the distance between the plurality of reflective recesses formed on the plate surface of the substrate.

  Also according to the manufacturing method of the surface light-emitting light guide plate of the seventh aspect, the dispersion density of the concave portions for reflection formed on the plate surface of the substrate is appropriately determined according to the positional relationship with the light source and the distance from the light source. Can be adjusted.

    According to the method for manufacturing a light-emitting plate for surface light emission of the present invention, by pressing a plate-like blade body having a large number of cutting edge portions against the substrate, the large number of blade edge portions are simultaneously pushed into the plate surface of the substrate, and a large number of cutting edge portions are pressed. A reflective recess is formed at the same time. Therefore, even when a large number of reflective recesses are formed at high density, the man-hour and time required for forming the reflective recesses are reduced, improving the productivity, and thus reducing the manufacturing cost of the light guide plate. can do.

It is a front view which shows the 1st example of the pressing die used for the manufacturing method of the light-emitting plate for surface emitting of this invention. It is a left view of the push type | mold shown by FIG. It is a perspective view from the bottom face side which shows an example of the plate-shaped blade body used for the pressing die shown by FIG. 1, FIG. It is a front view which shows the 2nd example of the pressing die used for the manufacturing method of the light-emitting plate for surface emitting of this invention. It is a left view of the push type | mold shown by FIG. It is a front view which shows the 3rd example of the pressing die used for the manufacturing method of the light-emitting plate for surface emitting of this invention. It is a front view which shows the 4th example of the pressing die used for the manufacturing method of the light-emitting plate for surface emitting of this invention. It is a front view which shows the 5th example of the pressing die used for the manufacturing method of the light-emitting plate for surface emitting of this invention. FIG. 3 is a schematic diagram showing a situation where the manufacturing method of the present invention is carried out using the pressing mold shown in FIGS. 1 and 2. FIG. 7 is a schematic diagram showing a situation where the manufacturing method of the present invention is implemented using the pressing die shown in FIG. 6. FIG. 8 is a schematic diagram showing a situation where the manufacturing method of the present invention is implemented using the pressing die shown in FIG. 7. It is a schematic diagram which shows the other example of the condition which is implementing the manufacturing method of this invention. It is an approximate perspective view showing an example of a light emitting plate for surface light emission. FIG. 14 is a schematic longitudinal sectional view taken along line XX in FIG. 13.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 and FIG. 2 show a first example of a pressing die 10 for forming a large number of recesses for reflection on the plate surface of a substrate which is a light guide plate material in the method for manufacturing a light emitting plate for surface light emission of the present invention. FIG. 3 shows an example of a plate-like blade body 12 used for the pressing die 10.
In FIG. 1 and FIG. 2, the pressing die 10 includes a large number (10 in the illustrated example) of plate-like blade bodies 12 made of hard resin, metal, ceramic, or the like so that the plate surfaces are parallel at intervals. It is set as the structure embedded in the pressing die base material 14 which becomes. Here, the interval S1 between the adjacent plate blades 12 may be all the same, but in the case of the present embodiment, the interval from the one end 10A side in the direction in which the plate blades 12 are arranged in the pressing die 10 is different. The interval S1 is determined so as to gradually narrow toward the end 10B. Further, each plate-like blade body 12 is embedded in the base material 14 so that at least each blade edge portion 16 protrudes from the pressing die base material 14. In addition, the protrusion height H1 of each blade edge | tip part 16 from the pressing die base material 14 is defined so that all may become the same in this embodiment.

  As shown in FIG. 3, each plate-like blade body 12 has a blade surface 16 </ b> B that is inclined at a predetermined angle from the cutting edge ridge line 16 </ b> A on one side of a plate material that is made of a hard material such as steel and has a generally square shape as a whole. A large number of cutting edge portions 16 are formed at intervals S2 along the cutting edge ridge line direction. The top (blade edge line 16A) of each blade edge portion 16 is positioned on a straight line, and the blade surface 16B is a surface along the same plane. Here, in the example shown in FIG. 3, the width W (width in the direction along the edge direction of the blade edge) of each blade edge portion 16 is the same. The intervals S2 between the adjacent blade edge portions 16 are all the same. However, in some cases, the interval S2 can be changed as will be described later. Further, the inclination angle θ (see FIG. 1) of the blade surface 16B of each blade edge portion 16 in one plate-like blade body 12 is determined to be the same. The inclination angle θ of the blade surface 16B is not particularly limited. However, since the inclination angle θ corresponds to the angle of the reflection surface of the reflection recess to be finally formed on the light guide plate, the required reflection surface angle. In general, it is preferably within a range of 30 to 50 degrees. . In the present embodiment, the blade edge portion 16 is configured as a single-edged blade having a cross-section letter shape in which the inclined blade surface 16B is formed only on one side of the plate surface of the plate-like blade body 12. Can also be configured as a double-edged blade having a V-shaped cross-section, with blade surfaces inclined on both sides of the plate surface.

  The method for producing the plate-like blade body 12 as described above is not particularly limited. For example, a blade edge that is continuous in the length direction is formed in advance on one side of a blade material made of a square plate, and thereafter It is easy to form each blade edge portion 16 at an interval in the blade body material by cutting away a portion corresponding to a space between the blade edge portions 16 by cutting or punching.

  With reference to FIG. 9, a method for forming the concave portions for reflection on the light guide plate material (substrate) using the pressing die 10 provided with a large number of plate-like blade bodies 12 as described above will be described.

  As shown in FIG. 9, a substrate 1 made of a transparent material such as an acrylic resin or a polycarbonate resin to be a material of a light emitting plate for surface light emission is prepared, and the substrate 1 is mounted on a mounting table 18 whose upper surface forms a horizontal plane. . A spacer 20 is disposed on one plate surface 3 </ b> A of the substrate 1. The spacer 20 is made of hard resin, metal, ceramic, or the like, and is formed with a number of cavities (guide portions) 20A through which the cutting edge portions 16 of the pressing die 10 can pass. The height H2 of the spacer 20 is a dimension obtained by subtracting the depth D1 of the reflecting recess 5 to be formed on the plate surface 3A of the substrate 1 from the protruding height H1 of each cutting edge 16 in the pressing die 10. . With the spacers 20 arranged on the plate surface 3A of the substrate 1 as described above, the pressing die 10 is lowered from above the plate surface 3A, and each blade edge portion 16 is placed in a space (guide portion) 20A of the spacer 20. If the cutting die 10 is further lowered and the cutting edge 16 of the pressing die 10 is pressed against the plate surface 3A of the substrate 1 by any pressing means (not shown) such as a press machine, the substrate 1 Each cutting edge portion 16 bites into the plate surface 3A, and a large number of reflecting recesses 5 having a shape corresponding to the cutting edge shape of each cutting edge portion 16 are formed simultaneously. In other words, in the case of the present embodiment, a large number of reflection concave portions 5 having a depth D1 whose cross section has a letter shape are dispersed at a high dispersion density in a two-dimensional direction in a plane along the plate surface 3A. It is formed. After a large number of the reflective recesses 5 are formed on the plate surface 3A of the substrate 1 in this way, the series of reflective recess formation steps is completed by raising the pressing die 10 and further removing the spacer 20. A light emitting plate for surface light emission is obtained. In order to push the cutting edge portion 16 of the pressing die 10 into the plate surface of the substrate 1, the substrate 1 may be softened by heating one or both of the pressing die 10 and the substrate 1 as necessary. The necessity of heating may be appropriately selected according to the material of the substrate 1 and the like.

  Here, as the pressing die 10, as described above, the interval S <b> 1 between the adjacent plate blades 12 is such that the one end 10 </ b> B from the one end 10 </ b> A side in the direction in which the plate blades 12 are arranged in the pressing die 10. The one set so as to become gradually narrower toward the side is used. For this reason, the large number of reflective recesses 5 on the plate surface 3A of the substrate 1 are also formed so that the distance S3 between them gradually decreases from one end surface 3C of the substrate 1 to the other end surface 3D. In other words, a large number of reflection recesses 5 are formed so that the dispersion density of the reflection recesses 5 gradually increases from one end surface 3C of the substrate 1 to the other end surface 3D. Such a surface light-emitting light guide plate is advantageous when, for example, a light source is disposed on one end surface 3C side. That is, in the place where the distance from the light source is far in the substrate, the intensity of the light reaching the reflecting recess is usually low, so the density of the reflecting recess in the place far from the light source is In the case where the distance from the light source is set to be the same as that of the portion where the distance from the light source is short, the surface emission light emitted from the plate surface tends to be weak at a position where the distance from the light source is far. However, as shown in the present embodiment, if the distance between the reflection recesses at a location far from the light source is reduced and the dispersion density of the reflection recesses at that location is increased, even at a location far from the light source. Thus, it is possible to perform surface light emission with a light quantity equivalent to or close to a place where the distance from the light source is short.

  In the example shown in FIG. 9, by inserting the spacer 20 between the plate surface 3 </ b> A of the substrate 1 and the pressing die 10, the pushing depth of the blade edge portion 16 into the substrate plate surface 3 </ b> A of the blade edge portion 16 is stable. As a result, the depth D1 of each reflecting recess 5 can be easily uniformized. Moreover, since each space | gap 20A plays the role of the guide which guides the blade edge | tip part 16, respectively, the position in which each recessed part 5 for reflection is formed is also stabilized. However, when such a guide function is not required, a rectangular frame-like member that surrounds a large number of cutting edge portions 16 as a whole may be used as the spacer. Further, in some cases, the spacer may be omitted.

  Furthermore, in the example shown in FIGS. 1 and 2, as the pressing die 10, a large number of plate-like blade bodies 12 are embedded in the pressing die base material 14, but in some cases, as shown in FIGS. 4 and 5. Alternatively, the jig 32, the space plate 34, and the holding plate 36 may be assembled. That is, space plates 34 having different thicknesses are sandwiched between a large number of plate-like blade bodies 12, holding plates 36 are disposed on both sides of the space plates 34, and connected by an arbitrary jig 32 such as a rod shape or a bolt shape. It is good also as an integrated structure.

FIG. 6 shows another example of the pressing die 10 used in the method for manufacturing a surface-emitting light guide plate of the present invention.
In FIG. 6, a large number of plate-like blade bodies 12 in the pressing die 10 are provided such that the protruding height H1 of the blade edge portion 16 gradually increases from the one end 10A side of the pressing die 10 toward the other end 10B side. It has been. FIG. 10 shows a situation in which a large number of recesses 5 for reflection are formed on the plate surface 3A of the substrate 1 for the light guide plate using such a pressing die 10.
In this case, as apparent from FIG. 10, the depth of penetration of the blade edge portion 16 with respect to the substrate plate surface 3A gradually increases from one end surface 3C of the substrate 1 toward the other end surface 3D. The depth D <b> 1 gradually increases in the same direction. Here, the depth D1 of the reflecting recess 5 affects the area of the inner surface (reflecting surface) of the reflecting recess 5, and the area of the reflecting surface also affects the amount of reflected light. Therefore, for example, when the light source is disposed on the side of the one end face 3C and used, if the depth of the concave portion for reflection at a location far from the light source, and thus the area of the reflective surface, is increased, Even at a location where the distance is long, it is possible to reflect with a light amount equivalent to or close to a location where the distance from the light source is close. Furthermore, by setting the depth of the concave portion for reflection at a location far from the light source to be deeper than the depth of the concave portion for reflection at a location where the distance from the light source is close, the light from the light source is separated from the light source. However, the rate of decrease in the amount of light due to passing through another reflecting recess is reduced until it reaches the reflecting recess at a distant place. In combination, even at a location far from the light source, it is possible to cause surface emission with a light quantity equivalent to or close to a location near the distance from the light source.

FIG. 7 shows still another example of the pressing die 10 used in the method for manufacturing the surface light-emitting light guide plate of the present invention.
In FIG. 7, many plate-like blade bodies 12 in the pressing die 10 have a thickness T of the blade edge portion 16 (maximum thickness of the blade surface 16B) T from the one end 10A side to the other end 10B side of the pressing die 10. It is provided so as to become gradually thicker. In this example, the distance between the blade edges 16 and the protruding height are uniform.
FIG. 11 shows a situation in which a large number of recesses 5 for reflection are formed on the plate surface 3A of the substrate 1 for the light guide plate using such a pressing die 10.
In this case, since the thickness T (maximum thickness of the blade surface 16B) T of the blade edge portion 16 corresponds to the area of the blade surface 16B of the blade edge portion 16, the reflection of the reflection recess 5 formed on the substrate 1 of the light guide plate material. The area of the surface (slope) 5A will be affected. Therefore, for example, when the light source is disposed on the side of the one end face 3C, the distance from the light source can be reduced by increasing the area of the reflecting surface of the reflecting recess at a location far from the light source. Even at a distant place, it is possible to reflect with a light amount equivalent to or near the place where the distance from the light source is short.

Further, FIG. 12 shows a large number of reflective recesses on the plate surface 3A of the substrate 1 of the light guide plate material, using still another example of the pressing die 10 used in the method for manufacturing the surface light emitting light guide plate of the present invention. The situation of forming 5 is shown. In the pressing die 10 used in this example, the projection height H1 of each plate-like blade body 12 is uniform.
In this case, as shown in FIG. 12, as the mounting table 18, the surface 18A is inclined in a curved shape or a linear shape so as to rise from one end to the other end. In this case, in a state where the substrate 1 that is the material of the light guide plate is placed on the surface (inclined surface) 18A of the mounting table 18, the surface position (height) of the plate surface 3A of the substrate 1 is one end surface 3C. The height increases from the side toward the other end surface 3D. On the other hand, as the spacer 20, a spacer whose height H2 decreases from one end side to the other end side is used.

  In the above-described positional relationship, when the pressing die 10 is lowered and the cutting edge portion 16 is digged into the plate surface 3A of the substrate 1 to form the reflecting recess 5, it is close to one end surface 3C of the substrate 1. At the position, the bite depth of the blade edge portion 16 is shallow, and the bite depth of the blade edge portion 16 becomes deeper as the distance from the end surface 3C increases. Accordingly, as in the example shown in FIG. 10, the depth of each of the many reflective recesses 5 formed on the plate surface 3A of the substrate 1 gradually increases from the end surface 3C side to the end surface 3D side. Therefore, as in the case of the example of FIG. 10, for example, when a light source is arranged and used on the side of one end face 3C, even at a location far from the light source, it is equivalent to a location near the distance from the light source. Alternatively, the light can be reflected with a light quantity close to that, and the light quantity from the light source passes through another reflective concave part until it reaches the reflective concave part at a distance far from the light source, and the light quantity decreases. The percentage to do is also reduced. In combination, even at a location far from the light source, it is possible to cause surface emission with a light quantity equivalent to or close to a location near the distance from the light source.

  In each of the above embodiments, as the pressing die 10, one having the same interval S <b> 2 between the respective blade edge portions 16 in each plate-like blade body 12 is used, but the interval S <b> 2 between the respective blade edge portions 16 is not necessarily uniform. There is no need. For example, as shown in FIG. 8, a plate in which the spacing S2A of the blade edge portion 16 in the region near the both ends in the width direction of the plate-like blade body 12 is smaller than the spacing S2B of the blade edge portion 16 in the central region in the width direction. The blade 12 may be used. In this case, the reflective recess 5 formed on the substrate 1 as the light guide plate material is perpendicular to the direction connecting the one end surface 3C and the other end surface 3D of the substrate 1 (width direction of the substrate 1). The distance between the reflective recesses 5 adjacent to each other changes, and the distance between both ends in the width direction of the substrate 1 is smaller than that near the center in the width direction. In other words, the dispersion density of the reflective recesses 5 is greater near both ends in the width direction of the substrate 1 than near the center in the width direction. Therefore, for example, even when there is a small amount of light reaching the both ends in the width direction in the substrate 1 and there is a concern that the amount of reflected light decreases near both ends in the width direction, it is possible to compensate for this and make the surface emission uniformly. It becomes possible.

  In the above, in the pressing molds of FIGS. 1 and 2 and the pressing molds of FIGS. 4 and 5, the interval S1 between the adjacent plate blades 12 is changed, and in the pressing mold of FIG. Although the protrusion height H1 of the part 16 is changed and the thickness of the blade edge part 16 (maximum thickness of the blade surface 16B) T1 is changed in the pressing die of FIG. 7, these changes are applied independently. Of course, it is not limited to. That is, two or more of the interval S1 between the plate-like blade bodies 12, the protruding height H1 of the blade edge portion 16, and the thickness (maximum thickness of the blade surface 16B) T1 of the blade edge portion 16 may be changed simultaneously. Furthermore, also in the example of inclining the plate surface 3A of the substrate 1 as shown in FIG. 12, one of the interval S1 of the plate-like blade body 12 and / or the thickness of the blade edge portion 16 (maximum thickness of the blade surface 16B) T1. Or you may combine with the change of both. Furthermore, the example which changes the space | interval S2A and S2B between the blade edge | tip parts 16 in one plate-shaped blade body 12 as shown in FIG. 8 is also combined with one or more of the above-mentioned changes. Can do.

  Further, in each of the embodiments described above, the plate-like blade body 12 having the single-edged blade edge portion 16 is used to form the reflective recess 5 having a cross-section in cross section. A V-shaped reflective concave portion may be formed using a plate-like blade body having a blade edge portion. In that case, a light source is disposed on both sides of the end faces 3C and 3D of the substrate 1 and is suitable for a light guide plate that allows light to enter from both ends. In that case, one or more of the interval S1 between the plate-like blade bodies 12, the protruding height H1 of the blade edge portion 16, or the thickness (maximum thickness of the blade surface 16B) T1 of the blade edge portion 16 is selected. It is desirable that the portion close to both end faces 3C and 3D and the central portion between both ends be different.

  Although preferred embodiments of the present invention have been described above, the present invention is of course not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 3A, 3B ... Plate surface, 3C, 3D ... End surface, 5 ... Reflection recessed part, 7 ... Light source, 10 ... Push mold, 12 ... Plate shape Blade body, 16 ... blade edge part, 16A ... blade edge ridge line, 16B ... blade surface.

Claims (7)

A large number of light beams are formed by allowing light from a light source to enter a light guide plate from an end surface forming a predetermined angle with respect to the plate surface of the light guide plate, and dispersing the light in the two-dimensional direction of the plate surface of the light guide plate. In a method of manufacturing a light guide plate that is reflected by the reflecting surface in the reflecting recess of the surface, thereby causing surface light emission,
In forming the multiple reflective recesses on the plate surface of the light guide plate substrate made of a plate-like transparent material,
A plurality of cutting edge portions each having a blade surface inclined at a predetermined angle from a cutting edge ridge line are formed at intervals along one direction. The surface emitting guide is characterized in that a plurality of recesses for reflection are simultaneously formed on the plate surface of the substrate, by pressing the pressing die against the plate surface of the substrate so that the cutting edge portion of the substrate bites into the plate surface of the substrate simultaneously. Manufacturing method of light plate.   When the pressing die is pressed against the plate surface of the substrate, using the pressing die formed by holding two or more plate-like blade bodies at intervals such that the plate surfaces are parallel to each other, A number of cutting edge portions of two or more plate-like blade bodies are bitten into the plate surface of the substrate at the same time, so that a large number of reflection concave portions dispersed in the two-dimensional direction of the substrate plate surface are formed at the same time. Item 2. A method for manufacturing a light-emitting plate for surface emitting according to Item 1.   As the pressing mold, a pressing mold is used in which two or more plate blades are held so that the distance between them changes, and a plurality of reflective recesses formed on the plate surface of the substrate thereby. The method for manufacturing a surface light-emitting light-guiding plate according to claim 2, wherein the interval is changed.   As the pressing mold, a pressing mold in which two or more plate-like blade bodies are held so that the height of each blade edge portion changes is used, and thereby the depth of the concave portion for reflection formed on the plate surface of the substrate. 4. The method of manufacturing a light-emitting plate for surface light emission according to claim 2, wherein a change is given to the surface light-emitting plate.   Reflection formed on the plate surface of the substrate by changing the thickness of the blade edge portion for each of the two or more plate-like blade bodies and using a pressing die in which the area of the blade surface of each plate-like blade body changes. The method for manufacturing a surface light-emitting light-guiding plate according to any one of claims 2 to 4, wherein the area of the reflection surface of the concave portion for use is changed.   When a large number of cutting edge portions of the plate-like blade body are pushed into the board surface of the substrate, the many blade edge portions of the plate-like blade body are bitten into the board surface of the substrate with the board surface of the substrate tilted, thereby reflecting 6. The method for manufacturing a surface light-emitting light-guiding plate according to claim 1, wherein the depth of the concave portion is changed.   As the plate-like blade body, a plate-like blade body in which the interval between adjacent blade edge portions changes is used, thereby changing the interval between a plurality of reflective recesses formed on the plate surface of the substrate. The manufacturing method of the light-emitting plate for surface light emission as described in any one of Claims 1-6 characterized by the above-mentioned.

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