JP3847743B2 - Liquid crystal display device manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid crystal display device. More particularly, the present invention relates to a method for manufacturing a liquid crystal display device that can prevent display defects due to interference between a liquid crystal display panel and a backlight unit or a casing, and can keep the brightness of the backlight unit uniform.

  Conventionally, a backlight unit having a light guide plate is provided on the back side of the liquid crystal display panel so that characters and images displayed on the liquid crystal display panel can be clearly seen.

  In the conventional liquid crystal display device shown in FIG. 6, a light guide plate 31 is accommodated in the frame 34 from the front side. Optical sheets such as a diffusion sheet and a reflective sheet (both not shown) are adhered or abutted to the front and rear surfaces of the light guide plate 31, respectively. A liquid crystal display panel 33 is disposed on the front side of the light guide plate 31 so as to be separated from the light guide plate 31 by a predetermined interval with a spacer 37 for cushioning interposed therebetween.

  On the front side of the liquid crystal display panel 33, a frame 35 is disposed so as to be separated from the liquid crystal display panel 33 by a predetermined interval with a spacer 38 for cushioning interposed therebetween. The frame 35 covers the outer surface of the frame 34. The liquid crystal display panel 33 and the light guide plate 31 are positioned in the respective in-plane directions without being wobbled by being held by the frames 34 and 35, and are spaces surrounded by the display surface side housing 39 and the back surface side housing 40. Is housed inside the unit.

  In the liquid crystal display panel 33, a peripheral portion of two flat glass substrates 33a and 33b is sealed by a sealing member 33c to form a space portion, and liquid crystal (not shown) is sealed in the space portion. . When the two glass substrates 33a and 33b are pressure-bonded, first, a thermosetting resin is applied to the peripheral portion of one of the opposing surfaces of the glass substrates 33a and 33b, and then an ultraviolet curable resin or the like is used. Then, the squares of the opposing surfaces of the glass substrates 33a and 33b are temporarily fixed. After that, the glass substrates 33a and 33b are placed on a surface plate heated to about 100 to 180 [deg.] C. and pressed to perform thermocompression bonding.

  In recent years, a liquid crystal display device used for a notebook personal computer or the like is extremely demanded to be thin, and an ultra-thin liquid crystal display device having a thickness of about 5.0 mm has appeared.

  However, in such an ultra-thin liquid crystal display device, a very thin liquid crystal display panel is adopted, and the distance between the liquid crystal display panel and the backlight unit is very narrow (the liquid crystal display in FIG. 6). (See the gap G1 between the display panel 33 and the light guide plate 31). For this reason, when the liquid crystal display panel comes into contact with the backlight unit or the casing, there is a case where a display defect (so-called paddling) due to interference occurs. For example, when the liquid crystal display panel comes into contact with another member, the gap between the substrates in which the liquid crystal is sealed changes, and display defects such as a wavy pattern occur.

  In addition, when the liquid crystal display panel comes into contact with the backlight unit, wrinkles may occur in a sheet such as a diffusion sheet on the front side of the light guide plate that constitutes the backlight unit. If the light is partially dark, there may be a gap or display unevenness may occur.

  The present invention has been made to solve such a problem, and prevents display failure due to interference between the liquid crystal display panel and the backlight unit or the casing, and also keeps the brightness of the backlight unit uniform. An object of the present invention is to provide a method of manufacturing a liquid crystal display device capable of performing

According to the method of manufacturing the liquid crystal display device of the present invention, a liquid crystal display panel and a backlight unit disposed on the rear side of the liquid crystal display panel are housed in a casing, and the liquid crystal display panel includes an array substrate, a color filter substrate, and the like. And the liquid crystal display panel has a substantially spherical shape, and is arranged so that the vicinity of the center of the liquid crystal display panel swells outward, between the liquid crystal display panel and the backlight. A method of manufacturing a liquid crystal display device in which spacers are provided,
The array substrate and the color filter substrate are housed in a sealed bag, the inside of the bag is pressure-bonded in a substantially vacuum state, and then the array substrate and the color filter substrate are heated or cooled at different temperatures, respectively. A substantially spherical liquid crystal display panel is manufactured by warping the color filter substrate and the color filter substrate using a temperature difference, and the liquid crystal display panel is disposed so as to swell outside the casing.

  According to the present invention, a display defect (paddling) due to interference between the liquid crystal display panel and the backlight unit or the casing is provided by arranging the liquid crystal display panel having a substantially spherical shape so as to bulge out near the center. Can be prevented.

  In addition, since there is no interference between the liquid crystal display panel and the backlight unit or the casing, the sheets such as the diffusion sheet are not wrinkled, so that the brightness of the backlight unit can be kept uniform.

  Next, the manufacturing method of the liquid crystal display device of the present invention will be described in detail with reference to the drawings.

  The liquid crystal display device according to the present embodiment shown in FIGS. 1 and 2 is configured so that the liquid crystal display panel 3 does not cause display defects (paddling) due to interference with other components such as a backlight unit. It is a substantially spherical shape.

  As shown in FIG. 1, the light guide plate 1 is accommodated in the frame 4 from the front side. Optical sheets such as a diffusion sheet and a reflective sheet (both not shown) are attached or abutted to the front surface and the rear surface of the light guide plate 1, respectively. On the front side of the light guide plate 1, a liquid crystal display panel 3 is disposed at a predetermined distance from the light guide plate 1 with a spacer 7 for a cushion interposed therebetween.

  In the liquid crystal display panel 3, a peripheral portion is formed by sealing the peripheral portions of the array substrate 3a and the color filter substrate 3b, which are two glass substrates having substantially spherical shapes, with a sealing member 3c, and liquid crystal ( (Not shown) is enclosed. Here, the array substrate 3a is a substrate on which a circuit such as a TFT array is formed on at least a part of the substrate surface, and the color filter substrate 3b is a substrate on which a color filter is formed on at least a part of the substrate surface. It is.

  Since the liquid crystal display panel 3 has a substantially spherical shape, the liquid crystal display panel 3 is disposed so that the vicinity of the central portion P of the liquid crystal display panel 3 swells outward. Accordingly, since the distance from the light guide plate 1 (see the gap G2 between the liquid crystal display panel 3 and the light guide plate 1 in FIG. 1) is the largest in the central portion P, the distance from the backlight unit such as the light guide plate 1 and the casing, etc. Interference can be reliably prevented. Moreover, since the peripheral edge portion of the liquid crystal display panel 3 is substantially the same plane, the liquid crystal display panel 3 can be easily disposed on the metal frame 4 or the like without gaps, as in the conventional liquid crystal display device.

  The vicinity of the central portion P of the liquid crystal display panel 3 swells outward by about 0.2 mm or less (preferably about 0.05 mm or less) in order to prevent interference with the backlight (specifically, the light guide plate 1). Is preferred.

  Further, a frame 5 is disposed on the front side of the liquid crystal display panel 3 so as to be separated from the liquid crystal display panel 3 by a predetermined interval with a spacer 8 for a cushion interposed therebetween. The frame 5 covers the outer surface of the frame 4. The liquid crystal display panel 3 and the light guide plate 1 are held by the frames 4 and 5 to be positioned without wobbling in the respective in-plane directions, and are surrounded by the display surface side housing 9 and the back surface side housing 10. Is housed inside the unit.

  The liquid crystal display device shown in FIG. 1 is manufactured by the following manufacturing method.

  First, as shown in FIG. 3, as a first manufacturing method, the array substrate 3 a and the color filter substrate 3 b are pressed onto a pressure plate (surface plate) 21 bulged near the center. A substantially spherical liquid crystal display panel 3 is manufactured by thermocompression bonding. After that, if the liquid crystal display panel 3 together with the light guide plate 1 and the spacers 7 and 8 is arranged so as to swell outside the casing comprising the housings 9 and 10 shown in FIG. 1, the liquid crystal display device of FIG. 1 is manufactured. be able to. When the liquid crystal display panel 3 is deformed into a substantially spherical shape by the pressure plate 21, the peripheral edge of the liquid crystal display panel 3 is set to be substantially the same plane.

  When thermocompression bonding is performed using the pressure plate (surface plate) 21, first, a thermosetting resin is applied to the peripheral edge of one of the opposing surfaces of the array substrate 3a and the color filter substrate 3b, and then ultraviolet rays are applied. The squares of the opposing surfaces of the substrates 3a and 3b are temporarily fixed using a cured resin or the like. After that, the substrates 3a and 3b are placed on a pressure plate (surface plate) 21 protruding upward and heated to about 100 to 180 ° C., and are subjected to thermocompression bonding.

  The crimping plate 21 is a member protruding upward, and is preferably made of a material such as stainless steel so that high-precision control can be performed. Furthermore, the protrusion A (see FIG. 3) of the crimping plate 21 is preferably about 50 to 200 μm. Further, in the case of the liquid crystal display panel 3 having a 12.1 inch size (rectangular shape having a length of about 200 mm and a width of about 275 mm), the protrusion A is preferably about 20 to 200 μm.

  In the first manufacturing method shown in FIG. 3, the substantially spherical liquid crystal display panel 3 shown in FIG. 3 can be obtained by using an ultraviolet curable resin instead of thermocompression bonding without applying heat. Can do.

  Next, as a second manufacturing method, as shown in FIG. 4, the array substrate 3 a and the color filter substrate 3 b are placed on a flat plate-like pressure plate 22, and a penetration formed on the pressure plate 22. The liquid crystal display panel 3 having a substantially spherical shape is manufactured by pressing the pin 23 by pressing it upward through the hole 22a. After that, if the liquid crystal display panel 3 together with the light guide plate 1 and the spacers 7 and 8 is arranged so as to swell outside the casing comprising the housings 9 and 10 shown in FIG. 1, the liquid crystal display device of FIG. 1 is manufactured. be able to. When the liquid crystal display panel 3 is deformed into a substantially spherical shape by the crimping plate 22, the periphery of the liquid crystal display panel 3 is set to be substantially on the same plane.

  In the example shown in FIG. 4, since the graphite substrate 24 is interposed between the pin 23 and the liquid crystal display panel 3, the concentrated load due to the pin 23 is caused by the graphite substrate 24 pushed upward by the pin 23. Accordingly, the liquid crystal display panel 3 having a substantially spherical shape can be obtained.

  Even if the liquid crystal display panel 3 is pushed up using a plate instead of a pin, the liquid crystal display panel 3 can be formed into a substantially spherical shape as described above.

  In the 2nd manufacturing method shown by FIG. 4, both the thermocompression bonding and the crimping | compression-bonding which does not apply the heat | fever using an ultraviolet curable resin are employable.

  Further, as a third manufacturing method, as shown in FIG. 5, a bag 25 in which the array substrate 3a and the color filter substrate 3b are sealed by a sealing member 3c, specifically a thin stainless plate 25a, 25b and an O-ring 25c are housed in a bag 25, and the bag 25 is crimped by utilizing the contraction force of the bag 25 in a state where the air in the bag 25 is evacuated through the discharge port 25d. Thereafter, the array substrate 3a and the color filter substrate 3b are warped downward by their own weights, thereby producing the liquid crystal display panel 3. At this time, as shown in FIG. 5B, the periphery of the liquid crystal display panel 3 is supported by a rectangular ring-shaped protrusion 26 so that the vicinity of the center of the liquid crystal display panel 3 is warped in a substantially spherical shape. Can do. After that, if the liquid crystal display panel 3 together with the light guide plate 1 and the spacers 7 and 8 is arranged so as to swell outside the casing comprising the housings 9 and 10 shown in FIG. 1, the liquid crystal display device of FIG. 1 is manufactured. be able to. In addition, when the liquid crystal display panel 3 is deformed into a substantially spherical shape by the protrusions 26, the periphery of the liquid crystal display panel 3 is set to be substantially the same plane.

  In the 3rd manufacturing method shown by FIG. 5, both the thermocompression bonding and the crimping | compression-bonding which does not apply the heat | fever using an ultraviolet curable resin are employable.

  Further, as the fourth manufacturing method, the bag 25 (see FIG. 5) and the pin 23 (see FIG. 4) may be used in combination. Specifically, the array substrate 3a and the color filter substrate 3b are accommodated in a sealed bag 25, and the inside of the bag 25 is pressure-bonded in a substantially vacuum state, and then the array substrate 3a and the color filter substrate are used using the pins 23. The liquid crystal display device shown in FIG. 1 can be manufactured by manufacturing the liquid crystal display panel 3 by warping 3b upward and arranging the liquid crystal display panel 3 so as to swell outside the casing. When the liquid crystal display panel 3 is deformed into a substantially spherical shape using the pins 23, the periphery of the liquid crystal display panel 3 is set to be substantially the same plane.

  Further, as a fifth method, the array substrate 3a and the color filter substrate 3b are stored in a sealed bag 25 (see FIG. 5), and the bag 25 is pressure-bonded in a substantially vacuum state, and then the array substrate 3a. The color filter substrate 3b is heated or cooled at different temperatures, and the array substrate 3a and the color filter substrate 3b are warped using a temperature difference, whereby the substantially spherical liquid crystal display panel 3 is manufactured. For example, the array substrate 3a may be heated to about 120 to 180 ° C., and the color filter substrate 3b may be heated to about 100 to 160 ° C. After that, if the liquid crystal display panel 3 together with the light guide plate 1 and the spacers 7 and 8 is arranged so as to swell outside the casing comprising the housings 9 and 10 shown in FIG. 1, the liquid crystal display device of FIG. 1 is manufactured. be able to. Note that when the liquid crystal display panel 3 is deformed into a substantially spherical shape due to a temperature difference between the two substrates, the periphery of the liquid crystal display panel 3 is set to be substantially in the same plane.

  In the above manufacturing method, the array substrate 3a is on the lower side, the color filter substrate 3b is on the upper side, and the color filter substrate 3b is on the outer side. However, the present invention is not limited to this, The opposite arrangement may be possible, and in that case, the arrangement may be reversed. That is, the array substrate 3a is warped so that the array substrate 3a is on the upper side, the color filter substrate 3b is on the lower side, and the array substrate 3a is on the outer side.

1 is a cross-sectional explanatory view showing a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is an explanatory perspective view of the liquid crystal display panel of FIG. It is process cross-sectional explanatory drawing which shows the manufacturing method of the liquid crystal display device concerning a reference example. It is process cross-sectional explanatory drawing which shows the manufacturing method of the liquid crystal display device concerning a reference example. It is process cross-sectional explanatory drawing which shows the manufacturing method of the liquid crystal display device concerning a reference example. It is sectional drawing of the conventional liquid crystal display device.

Explanation of symbols

1 Light guide plate 3 LCD panel

Claims (1)

A liquid crystal display panel and a backlight unit disposed on the rear side of the liquid crystal display panel are housed in a casing, and the liquid crystal display panel is bonded with an array substrate and a color filter substrate, and the liquid crystal display A liquid crystal display device in which a panel has a substantially spherical shape, a central portion of the liquid crystal display panel is disposed so as to bulge outward, and a spacer is disposed between the liquid crystal display panel and the backlight. The manufacturing method of
The array substrate and the color filter substrate are housed in a sealed bag, the inside of the bag is pressure-bonded in a substantially vacuum state, and then the array substrate and the color filter substrate are heated or cooled at different temperatures, respectively. And a color filter substrate are warped using a temperature difference to produce a substantially spherical liquid crystal display panel, and the liquid crystal display panel is disposed so as to swell outside the casing.

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