JP4481348B1 - Manufacturing method of light guide plate, light guide plate, backlight device, and illumination device. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a light guide plate that can cope with optical characteristics suitable for an arbitrary shape and shape even with a large light guide plate and can reduce tact time.
A light guide plate manufacturing method according to the present invention is a method of manufacturing a light guide plate for causing light to be incident from a side surface of a light guide plate substrate and to be led out from a main surface. The processing dots are arranged in a matrix on the rectangular front end surface, and the front end surface of the ultrasonic processing horn is pressed against one main surface of the light guide plate substrate to form one main surface of the light guide plate substrate. A reflective dot reflecting the processed dot on the tip surface is formed, and the ultrasonic processing horn is moved relative to the light guide plate substrate in the plane of the main surface to form the reflective dot. Repeatedly, the reflective dots are formed in a predetermined range on one main surface of the light guide plate substrate, and are formed on both opposing main surfaces of the light guide plate substrate so that the reflective dots do not face each other. It is characterized by that.
[Selection] Figure 5

Description

  The present invention is a method for manufacturing a light guide plate for double-sided light emission that can handle flexible dot processing using an ultrasonic multihorn for manufacturing a relatively large-sized light guide plate of a small amount and a variety. The present invention relates to a light guide plate, and a backlight device and an illumination device provided with the light guide plate.

  2. Description of the Related Art Conventionally, in a light guide plate that uses a LED light to generate a surface light source, the cross-sectional shape of the light guide plate that is built in and used in a large-screen television receiver widens in the traveling direction of the light beam emitted from the light source. There is a configuration of a light guide plate provided with a reverse wedge-shaped reflective dot having a shape (see, for example, Patent Document 1).

JP 2008-305713 A

  However, the above-described configuration has a problem that it is difficult to cope with optical characteristics suitable for an arbitrary shape and shape in the production of a small variety of products, and a tact for manufacturing is required.

  Therefore, in view of the above technical problems, the present invention has optical characteristics suitable for any shape and shape in the production of a small variety of products even for a relatively large light guide plate used for a guide display plate or the like. Provided are a light guide plate manufacturing method that can cope with the manufacturing process, a light guide plate manufactured by the manufacturing method, and a backlight device and a lighting device provided with the light guide plate. For the purpose.

In order to solve the above-described problems, the light guide plate manufacturing method according to the present invention is configured to diffuse light generated from concave reflective dots formed on one main surface and the other main surface by entering light from the side surface of the light guide plate substrate. A light guide plate manufacturing method for deriving light from a main surface , wherein a plurality of processing dots arranged in a matrix are provided on a tip surface of an ultrasonic processing horn, and the tip surface of the ultrasonic processing horn The processed dots are pressed against the one main surface and the other main surface of the light guide plate substrate, and the processed dots on the tip surface are reflected on the one main surface and the other main surface of the light guide plate substrate. The reflective dots are formed, and the ultrasonic processing horn is moved relative to the light guide plate substrate in the plane of the one main surface and the other main surface to repeat the formation of the reflective dots, at said one main surface and the other main surface of the light guide plate substrate The reflective dots are formed in a range, to the light guide plate substrate such orthogonal along the two directions or one direction not a face identical the reflection dots a plane of the one main surface and said other main surface On the other hand, the depths of the reflection dots are formed in different stages, respectively.

  According to the method for manufacturing a light guide plate according to the present invention, even a relatively large light guide plate used for a guide display plate or the like corresponds to optical characteristics suitable for any shape or shape in the production of a small variety of products. This is possible, and the tact for manufacturing can be greatly shortened.

It is a schematic diagram which shows the light-guide plate of the 1st Embodiment of this invention, (a) is a schematic diagram which shows the surface part of a light-guide plate, (b) is a schematic diagram which shows the side part of a light-guide plate, (c) is It is a schematic diagram which shows the back surface part of a light-guide plate. It is a schematic diagram which shows a part of surface part of the light-guide plate of the 1st Embodiment of this invention. It is a schematic diagram which shows the processing tool for embossing which forms the concave pattern trace provided in the light-guide plate of the 1st Embodiment of this invention, (a) is a schematic diagram which shows the support part of a processing tool, (b) ) Is a schematic diagram showing an ultrasonic processing part of the processing tool, It is a perspective view which shows the ultrasonic processing apparatus for embossing which forms the concave pattern trace provided in the light-guide plate of the 1st Embodiment of this invention. It is a schematic diagram which shows the state of the embossing which forms the concave pattern trace provided in the light-guide plate of the 1st Embodiment of this invention, (a) thru | or (e) are processing of a process member before performing embossing It is a schematic diagram which shows in order the state which measures a start reference | standard height and performs embossing with respect to a process member next according to this process | work start reference height. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the side part of the light-guide plate of the 1st Embodiment of this invention, (a) is a schematic diagram which shows the side part of a light-guide plate in case a processing member does not have a curve and a thickness spot, (b) is It is a schematic diagram which shows the side part of a light-guide plate in case a process member has a curve and thickness unevenness. It is a schematic diagram which shows the side part of a light-guide plate in case the curvature or thickness spot exists in a process member in manufacture of the conventional light-guide plate. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram shown in the state which permeate | transmitted the surface part concave pattern trace formed in the surface part of the light-guide plate of the 1st Embodiment of this invention, and the back surface concave pattern trace formed in the back surface part, (a) Is a schematic diagram showing a state in which the back side concave pattern trace is formed in the same direction with respect to the front side concave pattern trace, (b) is a half of the back side concave pattern trace in the X direction with respect to the front side concave pattern trace. (C) is a schematic diagram showing a state in which the back surface concave pattern trace is formed with a half pitch eccentricity in the Y direction with respect to the front surface concave pattern trace. ) Is a schematic diagram showing a state where the back surface concave pattern trace is formed with a half-pitch eccentricity in both the X and Y directions with respect to the front surface concave pattern trace. It is a perspective view which shows the backlight apparatus using the light-guide plate of the 1st Embodiment of this invention in the state decomposed | disassembled into each structural member, (a) is a diffusion plate and a reflection sheet | seat being arrange | positioned on both surfaces of a light-guide plate. FIG. 4B is a perspective view showing the backlight device when the reflection sheet is provided on only one surface of the light guide plate, and FIG. And FIG. 6D is a perspective view showing a backlight device when a reflection sheet is provided on the other surface of the light guide plate, and FIG. 6D is a backlight device when diffuser plates are provided on both surfaces of the light guide plate. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a guide lamp according to a backlight device using a light guide plate according to a first embodiment of the present invention, and (a) is a perspective view showing a state in which a guide lamp provided with a light guide plate is assembled; (B) is a perspective view showing a state in which a guide display plate is disposed on one surface of the light guide plate and a reflection sheet is disposed on the other surface of the light guide plate, and (c) is a guide display plate on both surfaces of the light guide plate. It is a perspective view which shows the state arrange | positioned. It is a schematic diagram which shows the side part of the light-guide plate which varied the depth of the surface part concave pattern trace and back surface concave pattern trace of the 2nd Embodiment of this invention, respectively. It is a schematic diagram which shows the side part of the light-guide plate which varied the depth of the surface part concave pattern trace and back surface concave pattern trace of the 2nd Embodiment of this invention, respectively. It is a schematic diagram which shows the side part of the reflective tape adhere | attached on the light guide plate which made the surface part concave pattern trace and the back surface concave pattern trace of the 3rd Embodiment of this invention differ, respectively.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a method for manufacturing a light guide plate, a light guide plate, a backlight device, and an illumination device according to the present invention will be described with reference to the drawings. The light guide plate manufacturing method, the light guide plate, the backlight device, and the illumination device of the present invention are not limited to the following descriptions, and can be appropriately changed without departing from the gist of the present invention.

[First Embodiment]
First, the structure of the light guide plate manufactured by the method of manufacturing the light guide plate according to the present invention will be described, then the light guide plate processing tool and processing device will be described, the light guide plate manufacturing method will be described, and finally the present application The optical specification of the light guide plate manufactured by the light guide plate manufacturing method according to the invention will be described.

  First, the structure of the light guide plate 10 manufactured by the method of manufacturing the light guide plate 10 according to the present invention will be described with reference to FIGS. 1 and 2.

  1 is a schematic diagram showing the light guide plate 10. FIG. 1A is a front surface portion 10A of the light guide plate 10, and FIG. 1B is a side surface portion 10C of the light guide plate 10. FIG. (C) is a schematic diagram showing a back surface portion 10D of the light guide plate 10. FIG. FIG. 2 is a schematic view showing a part of the surface portion 10A of the light guide plate 10 in an enlarged manner.

  The light guide plate 10 is composed of a plate-shaped portion having a predetermined size and having a plurality of concave pattern marks formed of, for example, a methacrylic resin (Polymethylmethacrylate) plate. Specifically, the size of the plate-like portion is, for example, a rectangular shape of 100 mm × 100 mm to 1450 mm × 1030 mm corresponding to the B0 plate size, and corresponds to a thickness of 4 mm to 12 mm. Here, as shown in FIG. 1, a front surface concave pattern mark 10 </ b> B is formed on the front surface part 10 </ b> A of the light guide plate 10, and a back surface concave pattern mark 10 </ b> E is formed on the back surface part 10 </ b> D of the light guide plate 10. The concave pattern trace is formed from a square pyramid-shaped trace having a major axis of 0.6 mm and a depth of 0.4 mm, for example, as a pitch pattern, for example, 1.2, 1.5, 2.0, and 8.0 mm pitch. It is formed with a matrix-shaped molding mark composed of the like.

  Next, the processing tool and processing apparatus of the light guide plate 10 will be described. Specifically, the processing tool 20 and the ultrasonic processing apparatus 30 that form the concave pattern marks provided on the light guide plate 10 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a schematic view showing a processing tool 20 for embossing which forms a concave pattern mark provided on the light guide plate 10, and FIG. 3A is a view of a support portion 20B of the processing tool 20 as well. 3 (b) is a schematic diagram showing the ultrasonic processing section 20A of the processing tool 20. FIG. 4 shows an embossing ultrasonic processing apparatus 30 for forming concave pattern marks provided on the light guide plate 10. FIG. It is a perspective view.

  The processing tool 20 is an ultrasonic processing horn, and supports the ultrasonic processing unit 20A in which processing dots are arranged in a matrix on the rectangular front end surface of the ultrasonic processing horn, and the ultrasonic processing unit 20A. It is comprised from the support part 20B. In the ultrasonic processing section 20A, each processing dot is formed in a quadrangular pyramid shape. FIG. 2B shows an ultrasonic processing unit 20A in which processing dots are arranged in a matrix of 4 rows and 4 columns as an example.

  The ultrasonic processing apparatus 30 includes a machine base 31, a work table 32, a moving mechanism 33, a vacuum pump 34, an ultrasonic oscillator 35, and the like. As the ultrasonic machining apparatus 30, for example, an ultrasonic machining apparatus that has been filed for a utility model registration by the same applicant as the present invention and has been registered as registration No. 3140292 can be used. By attaching the support portion 20B of the processing tool 20 to such an ultrasonic processing device 30 and applying ultrasonic vibration to the ultrasonic processing portion 20A of the processing tool 20, the front surface or the back surface of the processing member 5, or The light guide plate 10 is manufactured by forming concave pattern marks on both sides.

  Specifically, in the ultrasonic processing apparatus 30, the ultrasonic processing unit 20 </ b> A of the processing tool 20 is pressed against one main surface of the processing member 5, thereby providing the ultrasonic processing unit 20 </ b> A on one main surface of the processing member 5. Reflective dots reflecting the processed dots are formed. In addition, the reflective dot is formed in the predetermined range of one main surface of the processing member 5 by moving the processing tool 20 relative to the processing member 5 and repeating the formation of the reflective dots. Further, at least one direction of the extending direction of the quadrangular pyramid ridge line of the processing dots is substantially parallel to the incident direction of the light incident from the side surface of the light guide plate 10 formed by processing the processing member 5. Similarly, the ultrasonic processing portion 20 </ b> A of the processing tool 20 is pressed against one main surface of the processing member 5. Note that a more specific method for forming the concave pattern trace in consideration of the shape error of the processed member 5 will be described later with reference to FIG.

  Next, a method for manufacturing the light guide plate 10 will be described. Specifically, the formation of the concave pattern marks provided on the light guide plate 10 in consideration of the shape error of the processed member 5 will be specifically described with reference to FIG.

  5 is a schematic view showing a state of embossing for forming a concave pattern mark provided on the light guide plate 10, and FIGS. 5A to 5E are views of the processed member 5 before embossing. It is a schematic diagram which shows the state which measures a process start reference | standard height and performs embossing with respect to the process member 5 according to this process start reference | standard height next.

  As shown in FIG. 5 (a), the processing start reference height H 1 of the surface of the processing member 5 is set to the movable probe D disposed in a measurement unit (not shown) of the ultrasonic processing apparatus 30. Detect by contacting the surface. For the processed member 5, for example, a transparent methacrylic resin plate having a predetermined shape is used. The probe D is not limited to a mechanical configuration. For example, the probe D emits measurement light from a measurement unit (not shown) of the ultrasonic processing apparatus 30 and receives reflected light from the surface of the processing member 5. It is good also as a structure.

  Similarly, as shown in FIG. 5B, after the processing tool 20 mounted on the ultrasonic processing apparatus 30 is moved to a position above the surface portion 10A where the processing start reference height H1 is detected, With reference to the processing start reference height H1, ultrasonic vibration is applied to the ultrasonic processing portion 20A provided at the tip of the processing tool 20, and ultrasonic processing is performed from the processing start reference height H1 of the surface portion 10A to a predetermined depth. Lower part 20A. Further, the processing start reference height H2 of the surface of the processing member 5 which is the next ultrasonic processing location is detected by the movable probe D disposed in the measurement unit of the ultrasonic processing apparatus 30.

  Similarly, as shown in FIG. 5C, after moving the processing tool 20 mounted on the ultrasonic processing apparatus 30 to a position above the surface portion 10A where the processing start reference height H2 is detected, Using the processing start reference height H2 as a reference, ultrasonic vibration is applied to the ultrasonic processing portion 20A provided at the tip of the processing tool 20, and ultrasonic processing is performed from the processing start reference height H2 of the surface portion 10A to a predetermined depth. Lower part 20A. Further, the machining start reference height H3 of the surface of the machining member 5 which is the next ultrasonic machining location is detected by the movable probe D disposed in the measurement unit of the ultrasonic machining apparatus 30.

  Similarly, as shown in FIG. 5D, after moving the processing tool 20 mounted on the ultrasonic processing apparatus 30 to a position above the surface portion 10A where the processing start reference height H3 is detected, Using the processing start reference height H3 as a reference, ultrasonic vibration is applied to the ultrasonic processing portion 20A provided at the tip of the processing tool 20, and ultrasonic processing is performed from the processing start reference height H3 of the surface portion 10A to a predetermined depth. Lower part 20A. Further, the machining start reference height H4 of the surface of the machining member 5 which is the next ultrasonic machining location is detected by the movable probe D disposed in the measurement unit of the ultrasonic machining apparatus 30.

  Further, as shown in FIG. 5E, the processing tool 20 mounted on the ultrasonic processing apparatus 30 is moved to a position above the surface portion 10A where the processing start reference height H4 is detected, and then the processing is performed. With reference to the start reference height H4, ultrasonic vibration is applied to the ultrasonic processing unit 20A provided at the tip of the processing tool 20, and the ultrasonic processing unit from the processing start reference height H4 of the surface portion 10A to a predetermined depth. Lower 20A.

  Next, the effect relating to the formation of the concave pattern marks provided on the light guide plate 10 described above will be specifically described with reference to FIGS. 6 and 7.

  6 is a schematic view showing the side surface portion 10C of the light guide plate 10 according to the present invention. Further, FIG. 6A shows the side surface portion 10C of the light guide plate 10 when the processed member 5 has no curvature or uneven thickness. Similarly, FIG. 6B is a schematic diagram showing the side surface portion 10C of the light guide plate 10 when the processed member 5 has a curve or thickness unevenness. FIG. 7 is a schematic view showing the side surface portion 40A of the light guide plate 40 when the processed member 5 has a curve or thickness unevenness in the manufacture of the conventional light guide plate 40.

  As shown in FIG. 6A, when the processed member 5 has no curvature or unevenness in thickness, the surface portion 10A of the light guide plate 10 can be detected without detecting the processing start reference height of the surface portion 10A for each processing. Regardless of the position, the surface portion concave pattern mark 10B having a constant depth can be formed with respect to the surface portion 10A. Similarly, the back surface concave pattern mark 10E having a certain depth can be formed on the back surface portion 10D regardless of the position of the back surface portion 10D of the light guide plate 10.

  However, as shown in FIG. 6 (b), when the processed member 5 has a curve or thickness unevenness, if the processing start reference height of the surface portion 10A is not detected for each processing, the surface portion 10A is not detected. The surface portion concave pattern mark 10B having a certain depth cannot be formed. Similarly, unless the processing start reference height of the back surface portion 10D is detected for each processing, the back surface concave pattern mark 10E having a certain depth cannot be formed on the back surface portion 10D.

  Here, the processing member 5 that becomes the substrate for the light guide plate 10 is, for example, a resin plate, specifically, a methacrylic resin plate or the like. Since the methacrylic resin plate is manufactured by an extrusion manufacturing method, the individual difference in the thickness of the methacrylic resin plate is about ± 1 mm when the standard value is 8 mm. Further, even in a single methacrylic resin plate, the thickness unevenness is large. Specifically, the difference between the maximum thickness and the minimum thickness is about 0.4 mm. In addition, a methacrylic resin board may deform | transform so that it may warp by absorbing a water | moisture content. As described above, the methacrylic resin plate has a large error in the thickness component due to individual differences in thickness, thickness unevenness, warping, and the like. On the other hand, the depth of the front surface concave pattern mark 10B formed on the front surface part 10A of the light guide plate 10 and the depth of the back surface concave pattern mark 10E formed on the back surface part 10D of the light guide plate 10 are 0.3 mm to 0 respectively. Often set to 5 mm.

  Therefore, in the processing of the methacrylic resin plate of the processing member 5 serving as the substrate for the light guide plate 10, the processing start reference height is detected after being detected by the movable probe D attached to the measurement unit of the ultrasonic processing apparatus 30. As a reference, it is essential to lower the ultrasonic processing unit 20A from the surface of the methacrylic resin plate to a predetermined depth while applying ultrasonic vibration to the ultrasonic processing unit 20A provided at the tip of the processing tool 20. It is.

  When the processing start reference height of the surface of the methacrylic resin plate is not detected, the surface portion concave pattern trace having a certain depth in the surface portion 40A of the light guide plate 40 as in the conventional light guide plate 40 shown in FIG. 40B cannot be formed. Similarly, the back surface concave pattern mark 40E having a certain depth cannot be formed on the back surface portion 40D of the light guide plate 40.

  Next, optical specifications of the light guide plate 10 manufactured by the method for manufacturing the light guide plate 10 will be described. Specifically, the optical specifications relating to the concave pattern marks formed on both surfaces of the light guide plate 10 will be specifically described with reference to FIG.

  FIG. 8 is a schematic view showing a state in which the front surface concave pattern mark 10B formed at the pitch P1 on the front surface portion 10A of the light guide plate and the back surface concave pattern mark 10E formed at the pitch P1 on the back surface portion 10D are transmitted. Further, FIG. 8A shows a state in which the back surface concave pattern mark 10E is formed in the same manner as the front surface concave pattern mark 10B, and FIG. 8B similarly shows the front surface concave pattern mark 10B. FIG. 8C shows a state in which the back surface concave pattern mark 10E is formed in the Y direction with respect to the front surface concave pattern mark 10B. Similarly, in FIG. 8D, a back surface concave pattern mark 10E is formed with a half pitch P2 eccentricity in both the X and Y directions with respect to the front surface concave pattern mark 10B. State It is.

  Here, LED light is irradiated to the front surface concave pattern mark 10B formed on the front surface part 10A of the light guide plate and the back surface concave pattern mark 10E formed on the back surface part 10D, respectively. Specifically, in each of FIGS. 8A to 8D, the incident light L1 of LED light is irradiated from the horizontal direction X of FIG. Similarly, in each of FIGS. 8A to 8D, the incident light L2 of LED light is irradiated from the vertical direction Y of FIG. Hereinafter, with respect to the optical characteristics related to the specification of the concave pattern mark, the condition that the front surface concave pattern mark 10B and the back surface concave pattern mark 10E shown in FIG. Optical characteristics under three conditions in which the back surface concave pattern mark 10E is decentered by a half pitch P2 with respect to the front surface concave pattern mark 10B shown in FIGS.

  First, as shown in FIG. 8B, the optical characteristics under the condition that the back surface concave pattern mark 10E is formed by decentering by a half pitch P2 in the X direction with respect to the front surface concave pattern mark 10B. ) And explain. Under this condition, the density at which the concave pattern marks formed on the light guide plate 10 in the X direction visible from the surface portion 10A side of the light guide plate 10 can be seen is twice that in the case of FIG. . For this reason, compared with the case of FIG. 8A, the bright spot due to the concave pattern trace visible from the surface portion 10A side of the light guide plate 10 is doubled in the X direction, so the difference in light brightness is small. Further, the density of the concave pattern marks formed in the light guide plate 10 in the Y direction that can be visually recognized from the surface portion 10A side of the light guide plate 10 is the same as in the case of FIG. For this reason, compared with the case of Fig.8 (a), the difference of the brightness of light is the same in the Y direction.

  Further, as shown in FIG. 8C, the optical characteristics under the condition that the back surface concave pattern mark 10E is formed by decentering by a half pitch P2 in the Y direction with respect to the front surface concave pattern mark 10B. ) And explain. Under this condition, the density of the concave pattern marks formed on the light guide plate 10 in the Y direction visible from the surface portion 10A side of the light guide plate 10 is twice that in the case of FIG. For this reason, compared with the case of FIG. 8A, since the diffused light by the concave pattern trace visually recognizable from the surface portion 10A side of the light guide plate 10 is doubled in the Y direction, the difference in light brightness is reduced. Further, the density of the concave pattern marks formed on the light guide plate 10 in the X direction visible from the surface portion 10A side of the light guide plate 10 is the same as in the case of FIG. For this reason, compared with the case of Fig.8 (a), the difference of the brightness of light is the same in the X direction.

  Similarly, as shown in FIG. 8D, the optical characteristics under the condition that the back surface concave pattern mark 10E is formed with the half pitch P2 decentered in the X and Y directions with respect to the front surface concave pattern mark 10B. This will be described in comparison with 8 (a). Under these conditions, the density of the concave pattern marks formed on the light guide plate 10 in the X and Y directions visible from the surface portion 10A side of the light guide plate 10 is twice as high as that in the case of FIG. is there. For this reason, compared with the case of FIG. 8A, the diffused light due to the concave pattern traces visible from the surface portion 10A side of the light guide plate 10 is doubled in both the X and Y directions, so the difference in light brightness is different. Get smaller.

  As described above with reference to FIGS. 8A to 8D, by forming the position of the back surface concave pattern mark 10E with respect to the front surface concave pattern mark 10B eccentrically in the X and Y directions, the optical characteristics can be improved. Can be arbitrarily selected. In particular, in the condition shown in FIG. 8D, since the difference in light brightness in the X and Y directions is smaller than in the condition shown in FIG. can get.

  Next, a configuration example of the backlight device 50 provided with the light guide plate 10 of the present embodiment will be specifically described with reference to FIGS.

  FIG. 9 is a perspective view showing the backlight device 50 using the light guide plate 10 in an exploded state, and FIG. 9A is a diffuser plate 53 and a reflection sheet 52 on both sides of the light guide plate 10. FIG. 9B is a perspective view showing the backlight device 50B when the reflection sheet 52 is provided only on one surface of the light guide plate 10. FIG. Similarly, FIG. 9C is a perspective view showing the backlight device 50 </ b> C when the diffusion plate 53 is disposed only on one surface of the light guide plate 10 and the reflection sheet 52 is disposed on the other surface of the light guide plate 10. FIG. 9D is a perspective view showing the backlight device 50D when the diffusing plates 53A and 53B are provided on both surfaces of the light guide plate 10, respectively. Hereinafter, the backlight devices 50 shown in FIGS. 9A to 9D will be described in order.

  First, in the backlight device 50 </ b> A shown in FIG. 9A, an LED unit composed of one or more white LEDs is disposed so as to face the side surface portion 10 </ b> C of the light guide plate 10. Here, when white LED light is incident on the light guide plate 10 by applying a drive current to the white LED, the white LED light is irradiated to the concave pattern marks formed on the front surface portion 10A and the back surface portion 10D of the light guide plate 10. As a result, diffused light is generated. Further, the diffused light is emitted to the front surface portion 10A and the back surface portion 10D.

  Further, in the backlight device 50B shown in FIG. 9B, the reflection sheet 52 is disposed so as to face the back surface portion 10D of the light guide plate 10 provided in the backlight device 50A. Here, in the backlight device 50B, the diffused light emitted from the back surface portion 10D side is reflected by the reflection sheet 52 and enters the light guide plate 10, and then the incident light is emitted from the front surface portion 10A side.

  Similarly, in the backlight device 50C shown in FIG. 9C, the diffusion plate 53 is disposed so as to face the surface portion 10A of the light guide plate 10 provided in the backlight device 50B. Here, in the backlight device 50 </ b> C, the diffused light emitted from the surface portion 10 </ b> A enters the diffuser plate 53, and the diffused light is further diffused by the diffuser plate 53. As a result, scattered luminescent spots become unclear and the diffusion plate 53 becomes a uniform light emitting surface. For the diffusion plate 53, for example, a milk half plate is used.

  Similarly, in the backlight device 50D shown in FIG. 9D, the diffusion plate 53A and the diffusion plate 53B are arranged so as to face the front surface portion 10A and the back surface portion 10D of the light guide plate 10 provided in the backlight device 50A. Each is arranged. Here, in the backlight device 50D, the diffused light emitted from the surface portion 10A is incident on the diffusion plate 53A disposed opposite to the surface portion 10A, and the diffused light is further diffused by the diffusion plate 53A. Similarly, the diffused light emitted from the back surface portion 10D is incident on the diffusion plate 53B disposed to face the back surface portion 10D, and the diffused light is further diffused by the diffusion plate 53B. As a result, scattered bright spots become unclear, and both the diffusion plate 53A and the diffusion plate 53B become uniform light emitting surfaces.

  Next, the guide lamp 60 according to the backlight device in which the light guide plate 10 of the present embodiment is disposed will be specifically described with reference to FIGS. 10 (a) to 10 (c).

  10 is a perspective view showing a guide lamp 60 according to a backlight device using the light guide plate 10, and FIG. 10 (a) shows a state in which the guide lamp 60 provided with the light guide plate 10 is assembled. 10B is a perspective view showing a state in which the guide display plate 61 is disposed on one surface of the light guide plate 10 and the reflection sheet 52 is disposed on the other surface of the light guide plate 10. 10 (c) is a perspective view showing a state in which the guide display plate 61A and the guide display plate 61B are disposed on both surfaces of the light guide plate 10, respectively. Hereinafter, the guide lamp 60 according to each backlight device illustrated in FIGS. 10A to 10C will be described in order.

  As shown in FIG. 10A, the guide lamp 60 includes a light guide plate 10, an LED unit 51, a guide display plate 61, and the like. Here, in the guide lamp 60 </ b> A shown in FIG. 10B, the LED unit 51 is disposed so as to face the side surface portion 10 </ b> C of the light guide plate 10. In addition, a reflective sheet 52 is disposed so as to face the back surface portion 10D of the light guide plate 10. Further, a guide display plate 61 is disposed so as to face the surface portion 10 </ b> A of the light guide plate 10. The guidance display board 61 uses, for example, a sheet on which a standard guidance graphic symbol is printed on the surface of a milk half-plate. Such a guide light 60A is a single-sided light emitting display device, and corresponds to an applied product related to the backlight device 50C shown in FIG. 9C.

  Similarly, in the guide lamp 60 </ b> B shown in FIG. 10C, the LED unit 51 is disposed so as to face the side surface portion 10 </ b> C of the light guide plate 10. In addition, a guide display plate 61A and a guide display plate 61B are disposed so as to face the front surface portion 10A and the back surface portion 10D of the light guide plate 10, respectively. Each of the guidance display board 61A and the guidance display board 61B uses, for example, a sheet on which a standard guidance graphic symbol or the like is pasted on the surface of a milk half plate. Such a guide light 60B is a display device that emits light from both sides, and corresponds to an application product related to the backlight device 50D shown in FIG.

  As described above, according to the method for manufacturing the light guide plate 10 according to the first embodiment, the ultrasonic processing unit 20 </ b> A of the processing tool 20 is pressed against one main surface of the processing member 5, whereby the main surface of the processing member 5 is pressed. On the other hand, a plurality of reflective dots reflecting the matrix-like processed dots can be formed at a time. In this way, the ultrasonic processing unit 20A provided with matrix-shaped processing dots enables flexible dot processing using an ultrasonic multihorn to manufacture a relatively large-sized light guide plate of a small amount and a wide variety, and The tact for manufacturing can be greatly shortened. Specifically, in the method of manufacturing the light guide plate 10, according to the ultrasonic processing unit 20 </ b> A in which processing dots are provided in a 4 × 4 matrix, only one processing dot is provided in the ultrasonic processing unit 20 </ b> A. Compared with, the manufacturing tact can be shortened to 1/16.

  In addition, according to the light guide plate 10 according to the first embodiment, the position of the back surface concave pattern mark 10E with respect to the front surface concave pattern mark 10B is formed eccentrically in the X and Y directions, thereby reducing the difference in light brightness. Such optical characteristics can be arbitrarily selected. For example, by forming the position of the back surface concave pattern mark 10E with respect to the front surface concave pattern mark 10B so as to be decentered by a half pitch P2 in the X and Y directions, the difference in light brightness in both the X and Y directions can be reduced. .

  Similarly, according to the backlight device according to the first embodiment, the light guide plate 10 is used, for example, a single-sided light emission and double-sided light emitting display device such as a guide lamp 60 is based on required optical characteristics. Can be configured.

[Second Embodiment]
Next, configurations of the light guide plate 70 and the light guide plate 80 according to the second embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 is a schematic diagram showing a side surface portion 70C of the light guide plate 70 in which the depths of the front surface concave pattern mark 70B and the back surface concave pattern mark 70E are different. Similarly, FIG. 12 is a schematic diagram showing the side surface portion 80C of the light guide plate 80 in which the depths of the front surface concave pattern mark 80B and the back surface concave pattern mark 80E are different.

  In addition, the light guide plate 70 and the light guide plate 80 of the second embodiment include a front surface concave pattern mark 10B and a back surface concave pattern mark 10E formed on the light guide plate 10 of the first embodiment and having a substantially uniform depth. Differently, the depth of the concave pattern marks on the front surface portion and the back surface portion is different in stages. The other configurations related to the light guide plate 70 and the light guide plate 80 are the same as the configurations of the light guide plate 10 described in the first embodiment. Therefore, in the light guide plate 70 and the light guide plate 80 of the second embodiment, the structure and effect relating to the depth of the concave pattern marks different from the light guide plate 10 of the first embodiment will be specifically described.

  First, in the light guide plate 70 shown in FIG. 11, the depth of the front surface concave pattern mark 70B of the front surface part 70A and the depth of the back surface concave pattern mark 70E of the back surface part 70D are formed so as to increase stepwise. Has been. Specifically, when viewed from the side surface portion 70C, the concave pattern marks on the front and back surfaces on the right side of FIG. 11 are gradually deeper than the depth of the concave pattern marks on the front and back surfaces on the left side in FIG. Thus, a concave pattern mark is formed. Here, when the incident light L3 of the LED light is irradiated from the left side of FIG. 11 of the side surface portion 70C, the light density is high if it is close to the light source due to optical characteristics, and the light density is low if it is far away. By changing the reflection area of the concave pattern trace from small to large, the extraction of diffused light is averaged. Further, when the incident light L4 of the LED light is irradiated from the right side of FIG. 11 of the side surface portion 70C, the diffused light is extracted by changing the reflection area of the concave pattern trace from the right side of FIG. However, it is more on the right side and less on the left side. That is, this concave pattern trace processing is an effective processing method when using one-side light source.

  Next, in the light guide plate 80 shown in FIG. 12, the depth of the front surface concave pattern mark 80 </ b> B of the front surface portion 80 </ b> A and the depth of the back surface concave pattern mark 80 </ b> E of the back surface portion 80 </ b> D proceed to the center of the light guide plate 80. Each of the light guide plates 80 is formed so as to be relatively deep, that is, shallow at the both end surfaces and deep at the center. Here, when the incident light L5 of the LED light is irradiated from the left side of FIG. 12 of the side surface portion 80C, the light density increases from the left side to the right side of FIG. Therefore, the diffused light from the concave pattern trace on the left side of FIG. 12 is averaged by extracting the diffused light by changing the reflection area of the concave pattern trace reaching the center of FIG. 12 from small to large. Similarly, when the incident light L6 of the LED light is irradiated from the right side of FIG. 12 of the side surface portion 80C, the light density is high if the optical characteristic is close to the light source from the right side to the left side of FIG. Therefore, the diffused light from the concave pattern trace on the right side of FIG. 12 is averaged out of the diffused light by changing the reflection area of the left concave pattern trace reaching the center of FIG. 12 from small to large. Therefore, extraction of the entire diffused light is averaged. That is, this concave pattern trace processing is an effective processing method when using both-side light sources.

  As described above, according to the light guide plate 70 and the method for manufacturing the light guide plate 80 according to the second embodiment, the ultrasonic processing unit 20A of the processing tool 20 is pressed deeply or shallowly into one main surface of the processing member 5 stepwise. Thus, a plurality of reflective dots having an arbitrary depth can be formed on one main surface of the processed member 5. According to such a method of manufacturing the light guide plate 70 and the light guide plate 80, it becomes possible to take out diffused light corresponding to a required light emitting surface size, and optimize the manufacture of the light guide plate according to an arbitrary specification. be able to.

[Third Embodiment]
Next, a configuration of the light guide plate 90 according to the third embodiment will be described with reference to FIG. FIG. 13 is a schematic diagram showing the light guide plate 90 in which the depths of the front surface concave pattern mark 90B and the back surface concave pattern mark 90E are different, and the side surface part of the reflective tape 91 bonded to the light guide plate 90. .

  The light guide plate 90 of the third embodiment is different from the surface portion concave pattern trace 10B and the back surface concave pattern trace 10E of substantially uniform depth formed in the light guide plate 10 of the first embodiment. In addition, the depth of the concave pattern traces on the back surface portion is varied stepwise, and the reflective tape 91 is bonded to one side of the side surface portion of the light guide plate 90. In addition, the structure which concerns on the light-guide plate 90 other than that is the same as that of the light-guide plate 10 described in 1st Embodiment. Therefore, in the light guide plate 90 of the third embodiment, the structure and effect relating to the depth of the concave pattern marks different from the light guide plate 10 of the first embodiment will be specifically described.

  Regarding the structure of the light guide plate 90, the depth of the front surface concave pattern mark 90B on the front surface part 90A and the depth of the back surface concave pattern mark 90E on the back surface part 90D are as follows. '' Is formed so as to become deeper in stages. However, in the side surface portion 90C '' at the right end of FIG. 13, both the depth of the front surface concave pattern mark 90B of the front surface portion 90A and the depth of the back surface concave pattern mark 90E of the back surface portion 90D are formed to be relatively shallow. Has been. Specifically, for example, in the surface portion concave pattern trace 90B of the surface portion 90A shown in FIG. 13, the depth of the concave pattern trace is the shallowest in the concave pattern trace T1, the deepest in the concave pattern trace T5, and the concave The pattern mark T1 <T2 <T3 <T4 <T5.

  Regarding the effect relating to the optical characteristics of the light guide plate 90, when the incident light L7 of LED light is irradiated from the side surface portion 90C ′ on the left side of FIG. Since the reflection area of the concave pattern mark is changed from small to large from the left side of FIG. 13, the extraction of diffused light is averaged at the front surface portion 90A and the back surface portion 90D. Here, the incident light L7 of the LED light is reflected by the side surface portion 90C ″ by the reflective tape 91 bonded to the side surface portion 90C ″ of the light guide plate 90, and the reflected light L8 is generated. Since the reflected light L8 is converted into diffused light by the concave pattern trace, the rate at which the LED light is converted into diffused light increases. Such reflected light L8 affects the diffused light at the concave pattern marks in the vicinity of the side surface portion 90C ″. Therefore, the side surface portion 90C ″ is formed so that both the depth of the front surface concave pattern mark 90B of the front surface portion 90A and the depth of the back surface concave pattern mark 90E of the back surface portion 90D are relatively shallow.

  As described above, according to the method for manufacturing the light guide plate 90 according to the third embodiment, the ultrasonic processing unit 20A of the processing tool 20 is pressed deeply or shallowly into one main surface of the processing member 5 in a stepwise manner. A plurality of reflective dots having an arbitrary depth can be formed on one main surface of the member 5. According to such a method of manufacturing the light guide plate 90, even in the configuration in which the reflective tape 91 is adhered to one side of the side surface portion of the light guide plate 90, it is possible to extract uniform diffused light corresponding to the required light emitting surface size. Thus, it is possible to optimize the manufacture of the light guide plate according to an arbitrary specification.

  In the first to third embodiments described above, the light guide plate has been described as an optical device used in a backlight device related to a guide lamp. However, the present invention is not limited to such a form, and the present invention is not limited thereto. Changes can be made as appropriate without departing from the scope of the invention. Specifically, for example, a light guide plate may be used in a backlight device related to a liquid crystal display. For example, you may comprise a light-guide plate as an illuminating device used for an LED illuminating device. Moreover, LED arrange | positioned in an LED unit is not limited to white LED, For example, it is good also as LED which consists of one color in white, red, blue, and green, or the combination of these LED of each color.

5 Processing member 10 Light guide plate 10A Surface portion 10B Surface portion concave pattern mark 10C Side surface portion 10D Back surface portion 10E Back surface portion concave pattern mark 20 Processing tool 20A Ultrasonic processing section 20B Support section 30 Ultrasonic processing apparatus 31 Machine base 32 Worktable 33 Moving mechanism 34 Vacuum pump 35 Ultrasonic oscillator 40 Light guide plate 40A Surface portion 40B Surface portion concave pattern mark 40C Side surface portion 40D Back surface portion 40E Back surface concave pattern mark 50, 50A, 50B, 50C, 50D Backlight device 51 LED unit 52 Reflection Sheet 53, 53A, 53B Diffusion plate 60, 60A, 60B Guide lamp 61, 61A, 61B Guide display plate 70 Light guide plate 70A Surface portion 70B Surface portion concave pattern mark 70C Side surface portion 70D Back surface portion concave pattern mark 80 Light guide plate 80A Surface portion 80B Surface portion concave pattern mark 80C Side surface portion 80D Back Portion 80E Back surface concave pattern mark 90 Light guide plate 90A Surface part 90B Surface part concave pattern mark 90C ', 90C''Side surface part 90D Back surface part 90E Back surface concave pattern mark 91 Reflective tape D Probe H1, H2, H3, H4 Start of processing Reference height P1 Pitch P2 Half pitch L1, L2, L3, L4, L5, L6, L7 Incident light L8 Reflected light T1, T2, T3, T4, T5 Concave pattern trace

Claims (9)

A method of manufacturing a light guide plate for deriving diffused light generated from concave reflective dots formed on one main surface and the other main surface by entering light from a side surface of the light guide plate substrate, from the main surface ,
Provided with a plurality of processing dots arranged in a matrix on the tip surface of the ultrasonic processing horn ,
Wherein said processing dot of the front end surface of the ultrasonic machining horn on the one principal surface and the other main surface of the one main surface and said other main surface is pressed to be the light guide plate substrate of the light guide plate substrate to form the reflective dots reflecting the working dot of the tip surface,
The ultrasonic processing horn is moved relative to the light guide plate substrate in the plane of the one main surface and the other main surface to repeat the formation of the reflective dots, and the one of the light guide plate substrates is repeated. Forming the reflective dots in a predetermined range of the main surface and the other main surface ;
The depth of the reflective dots relative to the light guide plate substrate is set so that the reflective dots do not face each other along two orthogonal directions or any one direction in the plane of the one main surface and the other main surface. A method of manufacturing a light guide plate, wherein the light guide plates are formed in different stages . A method of manufacturing a light guide plate for deriving diffused light generated from concave reflective dots formed on one main surface and the other main surface by entering light from a side surface of the light guide plate substrate, from the main surface,
Provided with a plurality of processing dots arranged in a matrix on the tip surface of the ultrasonic processing horn,
The processing dots on the tip end surface of the ultrasonic processing horn are pressed against the one main surface and the other main surface of the light guide plate substrate, so that the one main surface and the other main surface of the light guide plate substrate are pressed. Forming the reflective dots reflecting the processed dots on the tip surface;
The ultrasonic processing horn is moved relative to the light guide plate substrate in the plane of the one main surface and the other main surface to repeat the formation of the reflective dots, and the one of the light guide plate substrates is repeated. Forming the reflective dots in a predetermined range of the main surface and the other main surface;
The light guide plate substrate so that the reflective dots formed on the one main surface are positioned in the middle of the reflective dots formed on the other main surface along two orthogonal directions within the surface of the one main surface. In contrast, the reflective dots are formed with different depths in stages.
A method of manufacturing a light guide plate characterized by the above. Method for manufacturing a light guide plate according to claim 1 or claim 2, wherein the working dot is quadrangular pyramid. Wherein the at least one direction extending direction of the ridge line of the quadrangular pyramid shape of the processed dots to claim 1 or claim 2, characterized in that it is substantially parallel to the incident direction of light incident from the side surface of the substrate for the light guide plate The manufacturing method of the light-guide plate of description. Method for manufacturing a light guide plate according to claim 1 or claim 2 substrate the light guide plate is characterized in that it is placed on a fixed table with respect to the in-plane direction of the main surface. A light guide plate manufactured by the method for manufacturing a light guide plate according to any one of claims 1 to 5 . A backlight device comprising the light guide plate according to claim 6 . A display plate is disposed on one or both sides of the light guide plate.
The backlight device according to claim 7. An illumination apparatus comprising the light guide plate according to claim 6 .