JP5470152B2 - Light guide plate manufacturing apparatus and method - Google Patents

Description

  The present invention relates to a display device in which a plurality of dot-like reflecting portions are formed on the back surface of a light guide plate, and light that is incident on the light guide plate from the end face is reflected to the front side by each dot-like reflecting portion, and in particular, the display device. The present invention relates to a manufacturing apparatus and a manufacturing method of a light guide plate used in the manufacturing process.

  A plurality of dot-like reflecting portions are formed with a desired pattern on the back surface of the transparent light guide plate, and the bright spot pattern by the dot-like reflecting portion is formed on the surface side of the light guide plate by illuminating with an LED or the like from the end face of the light guide plate. A display device for displaying is known. Each dot-like reflecting portion is formed as a wedge-shaped notch (concave portion) having a reflecting surface inclined with respect to the surface in order to reflect light incident from the end face to the surface side. In the manufacturing method of the light guide plate having such a dot-like reflection portion, when using a heat-softening resin such as acrylic or polycarbonate as the material of the light guide plate, the blade portion of the heated processing tool is placed on one surface of the light guide plate. After pushing in and reaching a predetermined depth, a method of pulling out the blade portion was used (Patent Document 1).

International Publication No. 2007/123202

  However, in the above conventional method of manufacturing a light guide plate, when forming a dot-like reflecting portion on the light guide plate, when the heated blade portion is pushed into the light guide plate, the molten resin is the surface of the light guide plate around the blade portion. Therefore, there is a problem in that it rises like a hill around the dot-like reflecting part or adheres to the lower surface of the processing tool around the blade part.

  FIG. 11 is a schematic cross-sectional view for explaining a conventional method of manufacturing a light guide plate. As shown in FIG. 11 (a), the processing tool 13 is provided with a heating part 11 with a built-in heater, and a wedge-shaped blade part 12 protrudes from the lower surface of the heating part 11. The blade portion 12 is provided with an inclined surface 12a for forming a reflecting surface of the dot-like reflecting portion. Then, as shown in FIG. 11A, when forming the dot-like reflecting portion 2, the melted overflow resin 15 is formed by pushing the blade portion 12 heated to the softening temperature or higher of the light guide plate 1 into the light guide plate 1. It rises on the surface 1c of the light guide plate 1. Further, as shown in FIG. 11B, when the heated blade portion 12 is pulled out from the light guide plate 1, the shape of the dot-like reflecting portion 2 is deformed because the light guide plate around the blade portion 12 is softened. However, a favorable shape of the reflecting surface cannot be obtained, resulting in uneven brightness of the dot-like reflecting portion. In particular, the overflow resin 15 that swells up in the shape of a hill around the dot-like reflecting portion 2 impairs the transparency of the light guide plate and deteriorates the appearance. In addition, when the height of the hill is increased, the thickness of the entire light guide plate increases, which is an obstacle when the light guide plate is desired to be accommodated in a small device.

  Further, as shown in FIG. 11C, when the overflow resin 15 is crushed on the lower surface of the heating unit 11, as shown in FIG. 11D, the softened overflow resin 15 is reflected on the lower surface of the heating unit 11 and the dot-like reflection. It adheres to the periphery of the part 2 and impairs the transparency and appearance of the light guide plate. Furthermore, if the overflowing resin 15 adheres to the lower surface of the heating unit 11, it becomes a hindrance when continuously forming a plurality of dot-like reflection parts.

  The present invention has been made in view of the above circumstances, and when forming a dot-like reflecting portion on the light guide plate, the molten resin rises in a hill shape around the notch portion, or the processing tool lower surface around the blade portion It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method of a light guide plate that can be prevented from adhering to the surface.

  In order to achieve the above object, the present invention is a light guide plate manufacturing apparatus that forms a dot-like reflecting portion on the surface of a light guide plate that reflects light incident from an end face to the surface side, and optionally generates ultrasonic waves. And an ultrasonic vibration generating unit capable of being stopped, and a processing tool that is mechanically connected to the ultrasonic vibration generating unit and includes a blade portion for forming the dot-shaped reflecting portion on the light guide plate, and When the blade portion of the processing tool is pushed into the light guide plate by oscillating the ultrasonic vibration generating portion to form a dot-like reflection portion, the blade portion is pushed into the light guide plate and melted by the blade portion. The gist is that a heel portion for crushing the material is provided around the blade portion.

  Further, the gutter of the light guide plate manufacturing apparatus of the present invention is characterized in that the surface in contact with the molten material is a mirror surface or a surface having a specified surface roughness.

  The present invention also provides an ultrasonic vibration generating unit capable of arbitrarily oscillating and stopping ultrasonic waves, and a blade portion for mechanically connecting to the ultrasonic vibration generating unit to form a dot-like reflecting portion on a light guide plate A light guide plate manufacturing method comprising: forming a dot-like reflecting portion on a surface of a light guide plate that reflects light incident from an end surface to the surface side by a manufacturing apparatus comprising: A first step of pushing the blade portion, to which ultrasonic vibration is applied by the portion, to a desired position of the light guide plate to a predetermined depth, and stopping the oscillation of the ultrasonic vibration generating portion, The gist includes a second step of curing the light guide plate and a third step of extracting the blade portion from the light guide plate.

  Moreover, the manufacturing method of the light-guide plate of this invention repeats from the said 1st process to a 3rd process in multiple different desired positions of the said light-guide plate in multiple times, The several said dot shape on the said light-guide plate. The gist of the invention is that it further includes a fourth step of forming a desired pattern by the reflecting portion.

  According to the present invention, since the molten material is crushed by the collar portion of the processing tool, there is an effect that the molten material does not rise around the formed dot-shaped reflection portion and the transparency of the light guide plate is not impaired. .

  Further, according to the present invention, the molten material does not swell around the formed dot-shaped reflecting portion, the increase in the thickness of the light guide plate is suppressed, and does not become an obstacle when the light guide plate is placed in a small device. There is an effect.

  Further, according to the present invention, after the blade portion of the processing tool to which ultrasonic vibration is applied is pushed into the light guide plate, the ultrasonic vibration is stopped and the melted portion of the light guide plate is cured, and then the blade portion of the processing tool is guided. Since it is pulled out from the optical plate, the shape of the blade portion and the shape of the lower surface of the collar portion are accurately transferred to the light guide plate, and there is an effect that a dot-shaped reflecting portion having an accurate shape can be formed.

  Further, according to the present invention, since the molten material does not adhere to the processing tool, there is an effect that a plurality of dot-like reflecting portions can be continuously formed on the light guide plate.

It is a perspective view which shows the example of the display apparatus using the light-guide plate by the manufacturing apparatus of the light-guide plate of this invention. It is sectional drawing of the display apparatus shown in FIG. It is a principal part expanded sectional view of the display apparatus shown in FIG. It is a top view which shows the dot-shaped reflection part of the display apparatus shown in FIG. It is a perspective view which shows the outline of the manufacturing apparatus of the light-guide plate of this invention. It is a principal part front view of the manufacturing apparatus of the light-guide plate of this invention. (A) It is a front view of an example of the processing tool used for the manufacturing apparatus of the light-guide plate of this invention, (b) It is a side view. (A) The front view of the other example of the processing tool used for the manufacturing apparatus of the light-guide plate of this invention, (b) It is a side view. (A) The figure explaining formation of the dot-shaped reflection part by ultrasonic processing using the manufacturing apparatus of the light-guide plate of this invention, (b) The figure explaining extraction of the processing tool after an ultrasonic oscillation stop, (c) It is a top view of the dot-shaped reflection part formed with the manufacturing apparatus of the light-guide plate of this invention. It is a flowchart which shows the manufacturing method of the light-guide plate of this invention. (A) The figure explaining overflow resin by the manufacturing method of the conventional light-guide plate, (b) The figure explaining the deformation | transformation of the dot-shaped reflection part shape by the manufacturing method of the conventional light-guide plate, (c) Manufacture of the conventional light-guide plate The figure explaining overflow resin by a method, (d) It is a figure explaining adhesion to the processing tool of overflow resin by the manufacturing method of the conventional light-guide plate.

  Embodiments of the present invention will be described below with reference to the drawings. First, a display device using a light guide plate manufactured using the light guide plate manufacturing apparatus of the present invention will be described.

  1 to 4 show an example of a display device 10 using a light guide plate 1 manufactured using the light guide plate manufacturing apparatus of the present invention. 1 is a perspective view schematically showing the display device 10, FIG. 2 is a cross-sectional view of the display device 10, FIG. 3 is an enlarged cross-sectional view of the main part of the display device 10, and FIG. FIG. 4 is a plan view of a dot-like reflecting unit 2.

  The display device 10 includes a light guide plate 1 and a light source 6 provided on an end surface 1 a of the light guide plate 1. As the light source 6, a light emitting diode (LED), a laser diode (LD), an organic electroluminescence (organic EL), a cold cathode fluorescent tube (CCFL), or the like can be used. The light source 6 is preferably formed so as to extend along the extending direction of the light guide plate 1. In the illustrated example, the light source 6 is formed so as to extend along the end surface 1 a on one side of the substantially rectangular light guide plate 1. As the light source 6, for example, a plurality of LEDs arranged in a direction along the end face 1a can be used. The color of the light emitted from the light source 6 can be exemplified by white, red, yellow, green, blue, and the like, and can be appropriately selected according to the pattern formed by the dot-like reflecting portions 2 formed on the light guide plate 1. The light source 6 can also be provided on one and the other end surfaces of the light guide plate 1.

  The light guide plate 1 may be a transparent material, and a plate made of a synthetic resin such as an acrylic resin, a polycarbonate resin, a silicone resin, or a cyclopolyolefin resin is used. Among them, an acrylic resin is used from the viewpoints of transparency and ease of processing. A plate is preferred.

  The thickness of the light guide plate 1 can be set to 0.5 mm to 10 mm, for example. It is preferable that the light guide plate 1 has a light transmittance that allows the background to be seen through. The light guide plate 1 has a substantially rectangular shape in plan view as shown in the figure, but the light guide plate 1 has a shape that functions as an end face 1a, a front face 1b, and a back face 1c. If it can form, it will not be limited to the shape of illustration. In the present invention, the term “transparent” means that the reflected light from the dot-like reflecting portion 2 has a light transmittance that can be visually recognized.

  On the back surface 1 c of the light guide plate 1, a display unit 3 including one or a plurality of dot-like reflection units 2 is formed. As shown in FIGS. 3 and 4, the dot-like reflecting portion 2 is a notch formed in the back surface 1 c, and a reflecting surface 2 a that reflects the light emitted from the light source 6 and incident from the end surface 1 a to the surface 1 b side. Have The dot-like reflecting portion 2 is shaped so that the light from the light source 6 strikes the reflecting surface 2a.

  In the illustrated example, the shape of the dot-like reflecting portion 2 in plan view is substantially rectangular (see FIG. 4), and the cross-sectional shape along the incident direction of light from the light source 6 of the dot-like reflecting portion 2 is the end face 1a. It forms a triangle with the reflecting surface 2a formed on the side as a hypotenuse (see FIG. 3).

  The dot-like reflection part 2 may be any structure as long as it is formed on the light guide plate 1 and reflects the light from the light source 6 toward the surface 1b, and its configuration is not limited to the example shown in the drawing. The shape of the dot-like reflecting portion 2 in plan view may be, for example, a polygon such as a trapezoid, a triangle, and a pentagon, a circle, or a shape obtained by cutting a part of a circle.

  The aspect ratio (aspect ratio) (average value) of the dot-like reflecting portions 2 when viewed in plan is preferably in the range of 10: 1 to 1: 1, and more preferably in the range of 5: 1 to 1: 1. . The aspect ratio refers to the ratio of the long side to the short side (long side: short side) of the rectangle having the smallest area that is inscribed by the dot-like reflecting portion 2 in plan view. If the aspect ratio is too large, the shape of the light from the dot-like reflecting portion 2 is recognized as a linear shape instead of a dot shape, resulting in a decrease in visibility. As shown in FIG. 4, the aspect ratio refers to the ratio of long side to short side (long side: short side) when the shape of the dot-like reflecting unit 2 in plan view is a rectangle. When β1> β2, β1: β2, and when β1 <β2, β2: β1. When the shape of the dot-like reflecting portion 2 in plan view is a figure other than a rectangle, the ratio of the long side to the short side of the rectangle with the smallest area that is inscribed in the plan view (long side: short side). Say.

  If the angle of inclination of the reflecting surface 2b with respect to the surface 1b of the light guide plate 1 (angle α shown in FIG. 3) is too small, the angle of inclination of the emitted light also increases, and the dot-like reflecting portion 2 when the display device 101 is viewed from the front. Visibility is reduced. If the inclination angle α is too large, the incident angle of light exceeds the critical angle and the proportion of light transmitted through the reflecting surface 2a increases, so that the light reflectance decreases and the light utilization efficiency decreases. For this reason, the inclination angle α of the reflecting surface 2a is preferably 45 degrees or more and 60 degrees or less, and more preferably 50 degrees or more and 55 degrees or less. By setting the tilt angle in the above range, the reflection efficiency of light can be increased, and the reflected light can be emitted at an angle close to perpendicular to the surface 1b, so that the visibility of the dot-like reflecting portion 2 can be enhanced.

  In the illustrated example, the reflecting surface 2a is flat, but at least a part of the reflecting surface may be curved. If the reflection surface is a curved surface, the emission angle of the reflected light may extend over a wide range. In this case, the dot-like reflection unit 2 can be viewed from a wide range.

  The surface roughness (maximum height Ry) of the reflecting surface 2a (JIS B 0601-1994) is 1 μm or less, preferably 0.1 μm or less. By setting the surface roughness within this range, the reflectance of light on the reflecting surface 2 can be increased.

  In FIG. 3, the height of the dot-like reflecting portion 2 indicated by the height γ is too small, the visibility of the dot-like reflecting portion 2 is lowered, and if the height is too large, the transparency of the display device 10 is not preferable. Therefore, the average value of the height γ of the dot-like reflecting portion 2 is preferably 0.1 mm to 5 mm, and more preferably 0.5 mm to 3 mm. In addition, the ratio (average value) of the height of the dot-like reflecting portion 2 to the thickness of the light guide plate 1 is preferably 1/10 to 1/1, and more preferably 1/5 to 2/3.

  If the area of the reflecting surface 2b of all the dot-like reflecting parts 2 is constant, the intensity of the reflected light at the dot-like reflecting part 2 located far from the light source 6 as compared with the reflected light at the dot-like reflecting part 2 close to the light source 6 Tend to be lower. For this reason, it is preferable to make the intensity of the reflected light of the dot-like reflecting portion 2 uniform by increasing the area of the reflecting surface 2b as the distance from the light source 6 increases.

  As shown in FIG. 3, in the display device 10, the light from the light source 6 can be incident on the light guide plate 1 from the end surface 1 a, reflected on the reflecting surface 2 a of the dot-like reflecting portion 2, and emitted from the surface 1 b side. . When the display device 10 is viewed from the front surface 1b side, the dot-like reflecting portion 2 is observed as a dot-like bright spot.

  Next, a manufacturing apparatus and a manufacturing method for manufacturing the light guide plate 1 of the display device 10 will be described with reference to FIGS. FIG. 5 is a perspective view showing an outline of an embodiment of the manufacturing apparatus, and FIG. 6 is an enlarged view of a main part of the manufacturing apparatus. Fig.7 (a) is a front view which shows an example of the processing tool with which a manufacturing apparatus is mounted | worn, (b) is the same side view. Fig.8 (a) is a front view which shows the other example of the processing tool with which a manufacturing apparatus is mounted | worn, (b) is the same side view. 9A and 9B are diagrams for explaining a method of manufacturing the light guide plate. FIG. 9A is a schematic cross-sectional view showing a state where the processing tool is pushed in while applying ultrasonic vibration to the blade portion, and FIG. 9B is an ultrasonic vibration. 7 is a schematic cross-sectional view showing a state in which the processing tool is pulled out after the light guide plate is cured and (c) a plan view showing the shape of the dot-like reflecting portion 2 after processing and the overflow resin 16 around it. FIG. 10 is a flowchart showing the manufacturing method.

  In addition, embodiment described below is a manufacturing apparatus of the system which moves a processing tool within XY plane in order to manufacture a comparatively large light-guide plate. However, when a relatively small light guide plate is manufactured, a manufacturing apparatus that moves the table on which the light guide plate material is placed in the XY directions is preferable.

  As shown in FIG. 5, the manufacturing apparatus 51 is configured on a table 53 on which a light guide plate material to be processed is placed. In order to increase rigidity with respect to the upper axis (X axis) of the single axis stage, the lower axis (Y axis) has a gantry type configuration using two parallel linear guideways 55 and 56. The linear guide way 55 is provided with a linear motor 57 as a Y-axis drive source. Stoppers 59a, 59b, 59c, and 59d are provided at both ends of the linear guideways 55 and 56, respectively. The linear guideways 55 and 56 are provided so that the sliders 61 and 63 are straddled, respectively, and can slide on the linear guideways 55 and 56 in the Y-axis direction.

  The sliders 61 and 63 are connected by a beam member 65. The beam member 65 is provided with two linear guideways 67 and 69 in parallel. Stoppers 71a, 71b, 71c, 71d are provided at both ends of the linear guideways 67, 69, respectively. The linear guide way 69 is provided with a linear motor 73 as an X-axis drive source. Further, a Z-axis base 75 is provided so as to straddle the linear guideways 67 and 69, and the Z-axis base 75 is slidable in the X direction. Thus, the Z-axis base 75 can be driven in the X-axis direction and the Y-axis direction by the linear motors 73 and 57, respectively. The driving amounts of the X axis and the Y axis are controlled by an NC program which will be described later.

  Further, the Z-axis base 75 is provided with a tilt base 77 that can rotate in the XZ plane with respect to the Z-axis base 75. An upper end portion of the tilt base 77 is formed in an arc shape, and an angle scale 78 indicating a rotation angle is written therein. The angle scale 78 is written up to 40 ° to the left and right in the drawing, for example, centering on 0 ° indicating the upright position of the tilt base 77. A plate 79 having a reference scale is fixed to the Z-axis base 75 at a position facing the angle scale 78. The user of the manufacturing apparatus 51 fixes the tilt base 77 to the Z-axis base 75 in a state where the angle scale 78 is aligned with the reference scale and the angle at which the Z-axis is desired to be tilted. The Z ′ axis inclined in the XZ plane can be realized. The tilt base 77 can be rotated and fixed with respect to the Z-axis base 75 by using a motor and a speed reduction mechanism or manually.

  The tilt base 77 is provided with a Z-axis carrier 81 via a Z-axis drive unit 80 which is a linear motion mechanism such as a linear motor or a ball screw. The drive amount of the Z-axis drive unit 80 is controlled by an NC program described later. An ultrasonic vibration generator 85 is fixed to the Z-axis carrier 81 by a bracket 87 and screws 89a to 89d. The ultrasonic vibration generating unit 85 includes an ultrasonic transducer that converts high-frequency power supplied from the cable 86 into ultrasonic vibration. The ultrasonic vibration generating unit 85 can be supplied with high frequency power of several tens of kHz and several tens of W, for example, from a high frequency power generating unit (not shown). The magnitude of the high-frequency power required for the ultrasonic vibration generating unit 85 is larger as the softening point temperature of the light guide plate material is higher, and is larger as the size of the dot-like reflecting part to be processed is larger. The magnitude of the power is preferably adjustable. The lower end of the ultrasonic vibration generating unit 85 is a horn unit 91, and the processing tool 21 can be fixed with a screw 93.

  The processing tool 21 is formed with a blade portion 22 that is pushed into the light guide plate and a flange portion 23 that presses the molten resin extruded from the light guide plate by the blade portion 22 against the surface of the light guide plate. The blade portion 22 is provided with a slope 22a for forming a reflection surface of the dot-like reflection portion.

  The Z-axis carrier 81 is provided with a contact sensor 95. The contact sensor 95 is a sensor that detects that the lower end portion of the contact lever 97 that is slidable in the Z-axis direction is in contact with the light guide plate. Inside the contact sensor 95, for example, a position sensor using a photo interrupter is provided. When the lower end portion of the contact lever 97 comes into contact with the light guide plate, a hole provided in the center portion of the contact lever 97 causes light in the photo interrupter to pass. Intermittent state changes to detect contact. An adjuster 99 using a micrometer is provided to adjust the offset of the contact sensor 95.

  Fig.7 (a) is a front view which shows an example of the processing tool 21, FIG.7 (b) is the side view. A wedge-shaped blade portion 22 and a flange portion 23 having a flat lower surface 23 a are formed at the distal end portion of the processing tool 21. The blade portion 22 has a shape corresponding to the dot-like reflection portion formed on the light guide plate, and the blade portion 22 forms a dot-like reflection portion on the light guide plate when the blade portion 22 that ultrasonically vibrates is pushed into the light guide plate. To do. And the inclined surface 22a of the blade part 22 forms the reflective surface of a dot-shaped reflective part.

  Here, since the shape of the blade portion 22 is increased by several degrees without making the other surface of the inclined surface 22a perpendicular to the lower surface 23a, the blade portion 22 can be easily pulled out from the light guide plate after processing.

  As shown in FIG. 9A, when the blade portion 22 that is ultrasonically vibrated is pushed into the light guide plate 1, the overflow resin 16 overflows on the light guide plate surface 1 c around the blade portion 22. Performs the action of crushing the overflow resin 16. The shape of the overflow resin 16 in plan view is as shown in FIG. Thereby, the overflowing resin 16 does not swell around the dot-like reflecting portion 2 of the light guide plate, and the transparency of the light guide plate is not impaired. In addition, since the overflow resin 16 is crushed by the flange 23, the overflow resin 16 does not rise around the dot-like reflection portion 2, the increase in the thickness of the light guide plate is suppressed, and the light guide plate is accommodated in a small device. The case will not be an obstacle.

  The surface roughness (maximum height Ry) (JIS B 0601) of the lower surface 23a of the flange 23 is, for example, mirror-finished to 0.1 μm or less. Accordingly, as shown in FIG. 9B, when the ultrasonic vibration is stopped and the temperature of the blade portion 22 and the surrounding light guide plate becomes equal to or lower than the softening point temperature of the light guide plate material, the processing tool 21 is used. Is pulled out from the light guide plate 1, the surface 16 a of the overflow resin 16 that has been in contact with the lower surface 23 a of the flange 23 becomes smooth because the surface roughness of the lower surface 23 a of the flange 23 is transferred, and the transparency of the light guide plate Will not be damaged.

  Fig.8 (a) is a front view which shows the other example of the processing tool 21, FIG.8 (b) is the side view. As in FIG. 7, a wedge-shaped blade portion 22 and a flange portion 23 having a flat lower surface 23 a are formed at the distal end portion of the processing tool 21. The blade portion 22 has a shape corresponding to the dot-like reflection portion formed on the light guide plate, and the blade portion 22 forms a dot-like reflection portion on the light guide plate when the blade portion 22 that ultrasonically vibrates is pushed into the light guide plate. To do. And the inclined surface 22a of the blade part 22 forms the reflective surface of a dot-shaped reflective part. The bottom surface 23a of the flange 23 may be a concave surface as shown in FIG. 9 or a flat surface as shown in FIGS.

  Next, a manufacturing method using the light guide plate manufacturing apparatus 51 will be described with reference to the flowchart of FIG. In the description of this flowchart, an example in which a light guide plate is manufactured by cooperation between an operator and the manufacturing apparatus 51 is shown. However, a robot apparatus that handles a plate-shaped light guide plate material can be introduced to be fully automated.

  First, in step (hereinafter, step is abbreviated as S) 10, the operator causes the manufacturing apparatus 51 to read an NC program for processing the light guide plate. It is assumed that the manufacturing apparatus 51 that has read the NC program waits until a manufacturing start button on an operation panel (not shown) is pressed. This NC program, for example, controls the general X-axis, Y-axis, and Z-axis positions of a well-known XYZ 3-axis NC machine, and controls on / off of high-frequency power supplied to the ultrasonic vibration generator. This is an NC program comprising auxiliary commands such as a command to wait, a time wait command, and loop control. The NC program is created by a general-purpose CAD system provided separately from the manufacturing apparatus, and is read into the manufacturing apparatus 51 via a communication line or a portable storage medium.

  In this embodiment, the processing tool 21 is pushed into the light guide plate from an oblique direction by tilting the Z axis of the manufacturing apparatus 51 in the ZX plane. Therefore, it is necessary to note that the X coordinate at which the blade portion 22 of the processing tool 21 acts on the light guide plate is shifted depending on the angle θ in which the Z axis is inclined and the displacement amount z of the Z axis. This amount of deviation can be compensated by correcting the X coordinate of the NC program or shifting the positioning position for setting the light guide plate material on the table 53 in accordance with sin θ and the amount of displacement z. The Z axis on the NC program is a Z ′ axis obtained by tilting the Z axis by an angle θ in the XZ plane in the real space.

  Next, in S12, the worker places and fixes the material of the light guide plate such as an acrylic plate on the table 53 of the manufacturing apparatus 51, for example. Although not shown, the table 53 is provided with, for example, a positioning plate for positioning by positioning the end face of the light guide plate to be placed and a clamp for fixing the positioned light guide plate.

  Next, the worker presses a button for starting production from an operation panel (not shown). Then, in S14, the manufacturing apparatus 51 recognizes the start of manufacturing, the determination in S14 is YES, and the process proceeds to S16. In S16, the manufacturing apparatus 51 reads the XY coordinates of the first machining position from the NC program, drives the X-axis linear motor 73 and the Y-axis linear motor 57, and moves the Z-axis base 75 to the read XY coordinate position. Let

  Next, in S18, the manufacturing apparatus 51 drives the Z-axis drive unit 80 to move the Z-axis carrier 81 until the tip of the contact sensor 97 contacts the light guide plate. Next, in S <b> 20, the manufacturing apparatus 51 turns on the high-frequency power supplied to the ultrasonic vibration generation unit 85 and starts ultrasonic vibration. The ultrasonic vibration generated by the ultrasonic vibration generating unit 85 is transmitted to the blade unit 22 via the horn 91 and the processing tool 21. Next, in S22, the manufacturing apparatus 51 drives the Z-axis drive unit 80 in the −Z direction in a state where the blade unit 22 is ultrasonically oscillated, and pushes the blade unit 22 into the light guide plate to a predetermined depth. In the portion where the blade portion 22 and the light guide plate that are ultrasonically vibrated contact each other, the ultrasonic energy is converted into heat energy, and the temperature of the blade portion 22 and the portion of the light guide plate in contact with the blade portion 22 rises and melts. The melted portion is pushed out by the blade portion 22 and overflows to the surface of the light guide plate around the blade portion 22. FIG. 9A shows a state where the blade portion 22 is pushed to a predetermined depth. The overflow resin 16 overflowing on the surface of the light guide plate is crushed by the flange portion 23 provided on the processing tool 21 and has a low height.

  Next, in S <b> 24, the manufacturing apparatus 51 turns off the high-frequency power supplied to the ultrasonic vibration generating unit 85 and stops the ultrasonic vibration. By stopping the ultrasonic vibration, there is no ultrasonic energy converted into thermal energy, so heat supply is stopped, and the temperature of the blade 22 and the surrounding light guide plate begins to decrease.

  Next, in S <b> 26, the manufacturing apparatus 51 stands by until cooling is completed to a temperature at which the temperature of the blade 22 and the surrounding light guide plate is lower than the softening point of the light guide plate. In the determination of the completion of cooling, it can be determined that the cooling is completed after a certain time has elapsed. In this embodiment, it is determined that the cooling is completed when a predetermined time (for example, 1 second to several seconds) elapses. Since this predetermined time is affected by the ambient temperature and tends to become longer as the temperature rises, the predetermined time may be set with a margin, and the measured value of the ambient temperature is reflected in the predetermined time. Also good. Further, a temperature sensor that detects the temperature of the blade portion 22 may be provided, and the completion of cooling may be determined by comparing the detected value of the temperature sensor and the softening point temperature of the light guide plate. When the cooling is completed, the overflow resin 16 is cured, and the surface of the overflow resin 16 becomes a smooth surface by transferring the mirror surface shape of the bottom surface 23a of the flange 23.

  If it is determined that the cooling is completed in S26, then in S28, the manufacturing apparatus 51 drives the Z-axis drive unit 80 in the + Z direction and pulls out the blade unit 22 from the light guide plate. Thereby, the dot-shaped reflection part 2 according to the shape of the blade part 22 is formed in the light guide plate 1. FIG. 9B is a schematic cross-sectional view showing this state.

  Next, in S30, the manufacturing apparatus 51 determines whether or not there is a next processing point. If there is a next processing point, the manufacturing apparatus 51 returns to S16 and repeats the operation of forming a dot-like reflecting portion at the next processing point. It is. In this way, a desired pattern can be formed on the light guide plate 1 by the plurality of dot-like reflecting portions 2.

  If it is determined in S30 that there is no next processing point, the manufacturing apparatus 51 displays the end of processing on the operation panel in S32. Next, in S34, the operator sees the display of the end of processing on the operation panel, takes out the light guide plate from the table 53, and ends the production of one light guide plate. If the next light guide plate is manufactured, the operator can manufacture the light guide plate in the same manner as the first sheet by repeating the process from S12 in which the light guide plate is set on the table 53.

  As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims.

21 Processing tool 22 Blade part 23 Gutter part 23a Lower surface 51 Light guide plate manufacturing apparatus 85 Ultrasonic vibration generating part

Claims (4)

A light guide plate manufacturing apparatus that forms a dot-like reflecting portion on the surface of a light guide plate that reflects light incident from an end surface to the surface side,
An ultrasonic vibration generator capable of arbitrarily oscillating and stopping ultrasonic waves; and
A processing tool that is mechanically connected to the ultrasonic vibration generating portion and includes a blade portion for forming the dot-like reflecting portion on the light guide plate, and
When forming the dot-like reflecting portion by oscillating the ultrasonic vibration generating portion and pushing the blade portion of the processing tool into the light guide plate, the blade portion was pushed into the light guide plate and pushed out by the blade portion. An apparatus for manufacturing a light guide plate, wherein a flange portion for crushing a molten material is provided around the blade portion.   The light guide plate manufacturing apparatus according to claim 1, wherein a surface of the flange portion that contacts the molten material is a mirror surface or a surface having a specified surface roughness. An ultrasonic vibration generating unit capable of arbitrarily oscillating and stopping ultrasonic waves, and a processing tool having a blade portion for mechanically connecting to the ultrasonic vibration generating unit and forming a dot-like reflecting portion on the light guide plate; A light guide plate manufacturing method for forming, on the surface of the light guide plate, a dot-like reflecting portion that reflects light incident from the end face to the surface side,
A first step of pushing the blade portion, to which ultrasonic vibration is applied by the ultrasonic vibration generator, into a desired position of the light guide plate to a predetermined depth;
A second step of stopping the oscillation of the ultrasonic vibration generating unit and curing the light guide plate around the blade unit;
A third step of pulling out the blade portion from the light guide plate;
Equipped with a,
In the first step, the blade portion is pushed into the light guide plate by a flange provided around the blade portion, and the molten material pushed out by the blade portion is crushed. .   A fourth pattern is formed on the light guide plate by a plurality of dot-like reflecting portions by repeating the first to third steps a plurality of times at different desired positions on the light guide plate. The method for manufacturing a light guide plate according to claim 3, further comprising a step.

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