JP2005238492A - Sheet pasting device and manufacturing method of liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet pasting device capable of precisely pasting a sheet smaller than a waveguide to the waveguide, and a manufacturing method of a liquid crystal display. <P>SOLUTION: The sheet pasting device is equipped with a liftable sheet placing stand 23 on which a reflective sheet 7 is placed, a waveguide holding stand 21 for supporting the periphery of the waveguide 6, which has the hole part 21a fitted to the sheet placing stand 23 to be placed so as to cover the hole part 21a, in the periphery of the hole part 21a, the waveguide positioning part 22 attached to the waveguide holding stand 21 to position the waveguide 6 and a rising control part 25 for controlling the rising of the waveguide 6 caused by the rising of the sheet placing stand 23. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sheet affixing device that affixes a sheet such as a reflective sheet to a light guide plate. The present invention also relates to a method for manufacturing a liquid crystal display device having a light guide plate having a reflective sheet attached thereto.

  The liquid crystal display device has a light guide plate disposed to face the liquid crystal panel, and a light source is disposed on the side of the light guide plate. The light emitted from the light source enters the light guide plate, and the light that is guided through the light guide plate and exceeds the critical angle is emitted from the emission surface toward the liquid crystal panel. Thereby, light is irradiated to the liquid crystal panel.

  A reflection sheet that reflects light is attached to the back surface of the light guide plate facing the emission surface. Light emitted from the back surface is reflected by a reflection sheet and guided to the emission surface, thereby reducing unnecessary light and improving illumination efficiency.

  FIG. 7 is an external perspective view showing a conventional sheet affixing device that affixes a reflective sheet to a light guide plate. The light guide plate 6 and the reflection sheet 7 are formed in a rectangular shape. The sheet sticking device 20 has a light guide plate holding base 21 on which the reflection sheet 7 and the light guide plate 6 are placed. An L-shaped light guide plate positioning member 22 for positioning the four corners of the reflection sheet 7 and the light guide plate 6 is attached on the light guide plate holding base 21.

In the sheet affixing device 20 having the above configuration, the reflection sheet 7 having a double-sided adhesive tape (not shown) affixed to one end is positioned by the light guide plate positioning member 22 and placed on the light guide plate holder 21. The light guide plate 6 is placed on the reflection sheet 7 by the positioning of the light guide plate positioning member 22 and is pressed by a finger or the like. Thereby, the reflective sheet 7 is stuck on the light guide plate 6 by the double-sided adhesive tape. In addition, by providing and sticking a double-sided adhesive tape to one end of the reflection sheet 7, the reflection sheet 7 can be prevented from being bent due to temperature and humidity.
JP 2000-284699 A (2nd page-5th page, Fig. 7)

  However, according to the conventional sheet pasting device 20, the reflective sheet 7 and the light guide plate 6 are positioned by the same light guide plate positioning member 22. Therefore, when the reflection sheet 7 protrudes from the light guide plate 6 due to positioning accuracy or when the reflection sheet 7 expands greatly due to temperature or humidity, the end portion of the reflection sheet 7 is accommodated in the housing that houses the light guide plate 6 and the reflection sheet 7. Touch. At this time, there is a problem that the reflecting sheet 7 is bent and light is not reflected in a predetermined direction, and the illumination efficiency is lowered.

  In order to solve this problem, it is conceivable to make the size of the reflection sheet 7 smaller than that of the light guide plate 6. Patent Document 1 discloses an example in which a step is provided in a positioning portion of members having different sizes. However, since the reflective sheet 7 is thin, there is a problem that when the step is deep, it cannot be applied without being sufficiently loaded, and when the step is shallow, there is a problem that the reflective sheet 7 gets over the step and is displaced. The same problem occurs when other sheets such as a diffusion sheet and a lens sheet are attached to the light guide plate.

  An object of this invention is to provide the manufacturing method of the sheet sticking apparatus and liquid crystal display device which can stick a sheet | seat smaller than a light guide plate to a light guide plate accurately.

  In order to achieve the above object, a sheet sticking apparatus according to the present invention includes a sheet placing table on which a sheet can be moved up and down, and a hole portion that fits into the sheet placing table and covers the hole portion. A light guide plate holding base that supports the light guide plate placed around the hole, a light guide plate positioning portion that is disposed on the light guide plate holding base and positions the light guide plate, and a light guide plate formed by raising the sheet mounting base And a rise restricting section that regulates the rise of the

  According to this configuration, a sheet such as a reflective sheet having a double-sided adhesive tape or the like attached thereto is positioned on the inner wall of the hole portion of the light guide plate holding base and placed on the lowered sheet placing base. A light guide plate is placed on the light guide plate holding base so as to cover the hole portion by positioning the light guide plate positioning portion. When the sheet mounting table is raised, the double-sided adhesive tape or the like provided on the sheet comes into contact with the light guide plate, and the light guide plate comes into contact with the rise restricting portion. And a sheet | seat and a light-guide plate are clamped by the sheet mounting base and a raise control part, and a sheet | seat is affixed on a light-guide plate.

  In the sheet sticking device having the above-described configuration, the light guide plate and the hole are formed in a rectangular shape, and the distance between the peripheral edge of the hole and the inner edge of the light guide plate positioning portion is 0.2 to 0.5 mm. It is characterized by that. According to this structure, a sheet | seat is affixed in the center with 0.2-0.5 mm circumference | surroundings with respect to a light-guide plate.

  According to the present invention, in the sheet affixing device having the above-described configuration, a plurality of guide pins protruding from the sheet mounting table, and a lifting slider that has a guide groove whose one wall surface is an inclined surface and slides on the guide pin. It is characterized by having prepared. According to this configuration, when the elevation slider is moved in a plane, the guide pin that comes into contact with the bottom surface of the guide groove slides on the inclined surface. Thereby, a sheet mounting base raises with a guide pin.

The present invention also includes a light source, a light guide plate that guides light incident from the light source and emits the light from an exit surface, a reflection sheet that is attached to a surface of the light guide plate that faces the exit surface, and the guide. In a method of manufacturing a liquid crystal display device, comprising: a liquid crystal panel disposed opposite to the light exit surface of the light plate; and the light source, the light guide plate, and a housing that covers the liquid crystal panel.
A sheet mounting table that can be moved up and down on which the reflection sheet is mounted, and a light guide plate that has a hole portion that fits into the sheet mounting table and covers the hole portion is supported around the hole portion. A light guide plate holding base, a light guide plate positioning portion arranged on the light guide plate holding base for positioning the light guide plate, and a rise restricting portion for restricting the rise of the light guide plate due to the rise of the sheet placing table. A sheet sticking device
The reflective sheet with the adhesive tape attached is placed on the sheet placement table, the light guide plate is placed on the light guide plate holding table, the sheet placement table is raised, and the reflection sheet is attached to the light guide plate. It is characterized by wearing.

  According to the present invention, in the method of manufacturing a liquid crystal display device having the above-described configuration, the light guide plate and the hole are formed in a rectangular shape, and the distance between the peripheral edge of the hole and the inner edge of the light guide plate positioning portion is 0.2 to 0.2. It is characterized by 0.5 mm.

  Further, the present invention provides the method for manufacturing a liquid crystal display device having the above configuration, wherein the sheet sticking device has a plurality of guide pins protruding from the sheet mounting table and a guide groove whose one wall surface is an inclined surface. It is characterized by comprising a guide pin and a sliding slider that slides.

  According to the present invention, the sheet is placed on the vertically movable sheet placing table that fits into the hole, and the sheet placing table is raised and stuck to the light guide plate. Therefore, a sheet smaller than the light guide plate is placed in the center of the light guide plate. Can be positioned and attached with high accuracy.

  According to the present invention, since the distance between the peripheral edge of the hole and the inner edge of the light guide plate positioning portion is 0.2 to 0.5 mm, the light guide plate can be reliably supported around the hole. Can be easily mounted. Further, it is not necessary to make the light guide plate larger than necessary with respect to the sheet, and the light guide plate can be made small, and the light guide plate can be easily disposed between the rise restricting portion and the periphery of the hole portion.

  In addition, according to the present invention, since the plurality of guide pins protruding from the sheet mounting table and the elevating slider that slides with the guide pins having a guide groove having one inclined wall surface, the sheet mounting table can be easily provided. Can be moved up and down.

  Embodiments of the present invention will be described below with reference to the drawings. For convenience of explanation, the same parts as those of the conventional example shown in FIG. FIG. 1 is an exploded perspective view showing a liquid crystal display device according to an embodiment. In the liquid crystal display device 1, a frame 9 made of a resin molded product is fitted in a back case 14 made of a resin molded product.

  An upper concave portion 9a having a rectangular shape in plan view is formed on the upper surface of the frame 9, and a lower concave portion 9b having a rectangular shape in plan view is formed on the rear surface. The upper concave portion 9a and the lower concave portion 9b are partitioned by a partition plate 9c having a through hole 9d. The partition plate 9c is formed with a plurality of light source insertion holes 9e on the side.

  A plurality of light sources 8 made of LEDs are inserted into the light source insertion hole 9e. Each light source 8 is connected to an FPC 8a that transmits and receives signals. The liquid crystal panel 2 is fitted into the upper recess 9a. A polarizing plate 10 is attached to the surface of the liquid crystal panel 2, and an FPC 2a that transmits and receives signals is connected.

  A rectangular light guide plate 6 is fitted into the lower recess 9b. Light emitted from the light source 8 is guided to the light guide plate 6, and light exceeding the critical angle is emitted from the emission surface 6a. The light emitted from the light guide plate 6 illuminates the liquid crystal panel 2 through the through hole 9d. A diffusion sheet 5 and a lens sheet 4 are disposed on the upper surface side of the light guide plate 6.

  The diffusion sheet 5 diffuses the light emitted from the light guide plate 6 to form uniform light. The lens sheet 4 condenses the light transmitted through the diffusion sheet 5 at a predetermined interval, and regulates the visual range of the liquid crystal panel 2 that can visually recognize the display image. On the back side of the light guide plate 6, a reflective sheet 7 is attached with a double-sided adhesive tape (not shown).

  The reflection sheet 7 reflects the light emitted beyond the critical angle from the back surface of the light guide plate 6 and guides it in the direction of the emission surface 6a. Thereby, the illumination efficiency of the liquid crystal display device 1 is improved. The double-sided pressure-sensitive adhesive tape is provided at one end of the light guide plate 6 to prevent the reflection sheet 7 from being bent due to temperature and humidity.

  2 to 4 show a sheet sticking device for sticking the reflection sheet 7 to the light guide plate 6. 2 is a top view, FIG. 3 is a front view, and FIG. 4 is a side sectional view. The sheet sticking apparatus 20 has a light guide plate holding base 21 on which the light guide plate 6 is placed. The light guide plate holding base 21 is formed with a rectangular hole 21a at substantially the center. A U-shaped light guide plate positioning member 22 for positioning the light guide plate 6 is attached before and after the hole 21a. You may provide the L-shaped light guide plate positioning member 22 which supports the four corners of the light guide plate 6 in four places.

  The end face of the peripheral edge of the hole 21a and the end face of the inner edge of the light guide plate positioning member 22 are separated by a distance L, and the light guide plate 6 can be placed on the light guide plate holding base 21 so as to cover the hole 21a. ing. Further, a rising restricting portion 25 that overhangs in the hole portion 21 a is attached to one of the light guide plate positioning members 22.

  By setting the distance L to 0.2 mm or more, the light guide plate 6 can be reliably supported around the hole 21a, and the light guide plate 6 can be easily placed. Further, by making the distance L 0.5 mm or less, the light guide plate 6 does not need to be made larger than necessary with respect to the reflection sheet 7, and the light guide plate 6 can be made smaller. The light guide plate 6 can be easily arranged between the periphery of the hole 21a.

  A rectangular sheet placement table 23 is fitted in the hole 21a so as to be movable in the vertical direction. On the back surface of the sheet mounting table 23, four pins protrude from the front, rear, left and right. A lift slider 24 is disposed below the sheet placement table 23. The elevating slider 24 is slidable in the front-rear direction as indicated by an arrow A (see FIG. 3). The elevating slider 24 has groove portions 24a formed at two positions on the front and rear sides. The wall surface in front of the groove 24a is an inclined surface 24b.

  The sheet mounting table 23 is supported by a pin 23 a contacting the upper surface of the lift slider 24. When the elevating slider 24 is moved back and forth, the pin 23 a slides on the upper surface of the elevating slider 24. When the elevating slider 24 is moved forward from the state of FIG. 4, the pin 23a is disposed in the groove 24a via the inclined surface 24b, and the sheet placing table 23 is lowered. When the elevating slider 24 is moved backward from this state, the pin 23a is pushed up to the inclined surface 24b, and the sheet placing table 23 is raised. Therefore, the lifting slider 24 and the pin 23a constitute lifting means for lifting the sheet placing table 23 as indicated by the arrow B.

  In the sheet sticking apparatus 20 having the above-described configuration, the reflective sheet 7 having a double-sided adhesive tape (not shown) attached to one end thereof is placed on the sheet placing table 23 while the sheet placing table 23 is lowered. At this time, the side where the double-sided pressure-sensitive adhesive tape of the reflective sheet 7 is attached is disposed on the side where the rising restricting portion 25 is provided, and the reflective sheet 7 is positioned by the hole 21 a of the light guide plate holding base 21.

  Next, the light guide plate 6 is placed on the light guide plate holding base 21 so as to cover the hole 21a. The light guide plate 6 is positioned by the light guide plate positioning member 22 and supported around the hole 21a. When the sheet mounting table 23 is raised, the double-sided adhesive tape and the reflection sheet 7 come into contact with the light guide plate 6 and the light guide plate 6 is lifted.

  As shown in FIG. 4, when the light guide plate 6 comes into contact with the rise restricting portion 25, the light guide plate 6, the double-sided adhesive tape and the reflection sheet 7 are sandwiched and pressed by the sheet placing table 23 and the rise restricting portion 25. Thereby, the reflective sheet 7 is stuck to the light guide plate 6 by the double-sided adhesive tape.

  According to the present embodiment, the reflective sheet 7 is placed on the vertically movable sheet placing table 23 that fits into the hole 21 a of the light guide plate holding table 21, and the sheet placing table 23 is raised and attached to the light guide plate 6. Therefore, the reflective sheet 7 smaller than the light guide plate 6 can be accurately positioned and adhered to the center of the light guide plate 6. Therefore, the reflection sheet 7 does not protrude from the light guide plate 6 due to a pasting error, and the reflection sheet 7 does not come into contact with the housing including the frame 9 and the back case 14 even if it expands due to temperature and humidity. For this reason, it is possible to prevent the reflection sheet 7 from being bent and to prevent a decrease in illumination efficiency.

  Even when other sheets such as the diffusion sheet 5 and the lens sheet 4 are attached to the light guide plate 6, a sheet smaller than the light guide plate 6 can be attached with high accuracy by using the sheet attaching device 20.

These are the disassembled perspective views which show the liquid crystal display device of embodiment of this invention. These are top views which show the sheet sticking apparatus which sticks the light-guide plate and reflective sheet of the liquid crystal display device of embodiment of this invention. These are front views which show the sheet | seat sticking apparatus which sticks the light-guide plate and reflective sheet of the liquid crystal display device of embodiment of this invention. These are side surface sectional drawings which show the sheet sticking apparatus which sticks the light-guide plate and reflective sheet of the liquid crystal display device of embodiment of this invention. These are perspective views which show the sheet sticking apparatus which sticks the light-guide plate and reflection sheet of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal panel 4 Lens sheet 5 Diffusion sheet 6 Light guide plate 7 Reflection sheet 8 Light source 9 Frame 14 Back case 20 Sheet sticking device 21 Light guide plate holding base 21a Hole part 22 Light guide plate positioning part 23 Sheet mounting base 23a Pin 24 Elevating slider 24a Groove 24b Inclined surface

Claims (6)

  A sheet placing table capable of moving up and down on which the sheet is placed, and a light guide plate that has a hole portion that fits into the sheet placing table and covers the hole portion and supports the light guide plate around the hole portion. An optical plate holding table, a light guide plate positioning unit that is disposed on the light guide plate holding table and positions the light guide plate, and an ascending restriction unit that regulates the rise of the light guide plate due to the rising of the sheet mounting table. Sheet pasting device.   2. The sheet according to claim 1, wherein the light guide plate and the hole are formed in a rectangular shape, and a distance between a peripheral edge of the hole and an inner edge of the light guide plate positioning portion is 0.2 to 0.5 mm. Pasting device.   2. The apparatus according to claim 1, further comprising: a plurality of guide pins projecting from the sheet mounting table; and an elevating slider that slides on the guide pins with a guide groove having one inclined wall surface. The sheet sticking apparatus according to 2. A light source; a light guide plate that guides light incident from the light source and emits the light from an exit surface; a reflection sheet that is attached to a surface of the light guide plate facing the exit surface; and the exit surface of the light guide plate In a method for manufacturing a liquid crystal display device, comprising: a liquid crystal panel arranged oppositely; and a light source, the light guide plate, and a housing that covers the liquid crystal panel.
A sheet mounting table that can be moved up and down on which the reflection sheet is mounted, and a light guide plate that has a hole portion that fits into the sheet mounting table and covers the hole portion is supported around the hole portion. A light guide plate holding base, a light guide plate positioning portion arranged on the light guide plate holding base for positioning the light guide plate, and a rise restricting portion for restricting the rise of the light guide plate due to the rise of the sheet mounting table. A sheet sticking device is provided,
The reflective sheet with the adhesive tape attached is placed on the sheet placement table, the light guide plate is placed on the light guide plate holding table, the sheet placement table is raised, and the reflection sheet is attached to the light guide plate. A method of manufacturing a liquid crystal display device, characterized by being worn.   The said light guide plate and the said hole part are formed in the rectangle, The distance of the peripheral edge of the said hole part and the inner edge of the said light guide plate positioning part was 0.2-0.5 mm. A method for manufacturing a liquid crystal display device.   The sheet sticking device includes a plurality of guide pins protruding from the sheet mounting table, and a lifting slider having a guide groove having a wall surface formed of an inclined surface and sliding with the guide pin. Item 6. A method for manufacturing a liquid crystal display device according to Item 4 or Item 5.

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