JP2009003049A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of displaying a high-quality image with high contrast even in a bent state. <P>SOLUTION: The liquid crystal display device includes: first and second transparent insulating substrates 110, 210; a liquid crystal 30 sealed between the first and second transparent insulating substrates 110, 210; first and second polarizer plate 120, 220 arranged outside the first and second transparent insulating substrates 110, 210; a first stress relaxing layer 510 held between the first transparent insulating substrate 110 and the first polarizer plate 120 and relaxing the stress generated in the first polarizer plate 120 when being bent; and a second stress-relieving layer 520 held between the second transparent insulating substrate 210 and the second polarizer plate 220 and relieving the stress generated in the second polarizer plate 220 when being bent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device capable of displaying even in a curved state and a manufacturing method thereof.

  A flat display device typified by a liquid crystal display device is used in various fields by taking advantage of light weight, thinness, and low power consumption. In particular, liquid crystal display devices are widely used in portable information devices typified by personal computers. In recent years, liquid crystal display devices have been widely used for TV applications and are about to replace conventional cathode ray tubes. In addition, it solves the problems such as viewing angle and contrast limitations that are problematic in liquid crystal display devices and the difficulty of following high-speed response for moving images, making it an LCD with a wide viewing angle, high contrast, and high-speed response. An electroluminescent EL display device using a light-emitting body such as an EL element in the pixel display portion, which takes advantage of the unique feature, is also being used as a next-generation thin panel device.

  In recent years, such display devices have been required to be thin in order to reduce weight. Further, further thinning is required so that display is possible even in a curved state. In order to satisfy these requirements, it is conceivable to use a thin glass substrate. However, using a glass substrate of less than 0.5 mm makes it difficult to transport due to problems such as bending of the substrate due to its own weight. It becomes a cause of reducing the yield, and it becomes a cause that a situation where the whole part is easily broken is not generated even in a slight impact during the manufacturing process. Although it is conceivable to use a plastic film substrate in place of the glass substrate, the plastic film substrate has a heat-resistant temperature of 200 ° C. and is subject to restrictions such as a film forming temperature, so that it is difficult to put it to practical use.

  On the other hand, a manufacturing method has been proposed in which manufacturing is performed using a relatively thick glass substrate at the beginning of manufacturing, and the glass substrate is thinned by etching the outer surface of the substrate during the manufacturing (for example, Patent Document 1). According to this manufacturing method, the glass substrate is formed thinner than 0.15 mm by etching, and can be curved with a curvature radius of 200 mm.

  18 to 24 are diagrams illustrating the configuration of the above-described conventional liquid crystal display device. 18 is a plan view of a conventional liquid crystal display device, FIG. 19 is an enlarged view of one pixel portion of FIG. 18, FIG. 20 is a sectional view taken along line XX of FIG. 19, and FIG. FIG. 18 is a YY sectional view of 18.

  As shown in FIGS. 18 and 21, the conventional liquid crystal display device includes an array substrate 100 on which active elements such as TFT (Thin Film Transistor) portions, electrodes and wirings are formed, and a color for displaying common electrodes and images. And a color filter substrate 200 on which a filter is formed. The substrates 100 and 200 are bonded to each other with a gap of 5 to 10 μm, for example, by a sealing material 40, and the liquid crystal 30 is sealed in the gap so that the sealing material 40 does not leak outside. Yes.

  The array substrate 100 includes a transparent insulating substrate 110 such as a glass plate and a polarizing plate 120 bonded to the outer main surface of the transparent insulating substrate 110 with an adhesive layer 130. On the inner main surface of the array substrate 100, an active element portion 140 including a TFT portion, a pixel portion, and a capacitor, and a lead-out wiring portion 141 for transmitting an electric signal to the active element portion 140 are formed. A part of the lead wiring portion 141 constitutes the electric signal input terminal portion 103 (FIG. 18).

  The color filter substrate 200 includes a transparent insulating substrate 210 such as a glass plate, and a polarizing plate 220 bonded to the outer main surface of the transparent insulating substrate 210 with an adhesive layer 230. On the inner main surface of the color filter substrate 200, a filter electrode portion 240 including the filter layer 6 (FIG. 20) and the common electrode 13 (FIG. 20) is formed.

  In an area occupying most of the surface area of the liquid crystal display device, a pixel area 204 constituting an image is provided as shown in FIG. 18, and a large number of pixel portions are formed in a matrix in the pixel area 204. Has been. For example, when the screen size is 14 inches (diagonal length is about 36 cm) and the display standard is VGA (Video Graphic Array), the pixel area 204 has about 920,000 pixel portions in a matrix (≈640 × 480 × 3). Are formed). Further, an electric signal input terminal portion 103 for inputting electric signals to a large number of pixel portions is formed around the array substrate 100.

  As shown in FIGS. 19 and 20, each pixel unit includes a gate electrode 1, a gate wiring 21 (FIG. 19) connected to the gate electrode 1, a lower auxiliary capacitance electrode 20, and an inner main surface of the array substrate 100. On the semiconductor active layer 4, a gate insulating film 3 formed on each of these portions 1, 21, 20, a semiconductor active layer 4 made of an amorphous silicon film formed on the gate electrode 1 via the gate insulating film 3, The formed ohmic contact layer 5 made of an n + amorphous silicon layer, a source electrode 7 processed by a metal thin film, a drain electrode 8 processed by a metal thin film, an interlayer insulating film 9 made of a passivation film, and an interlayer A contact hole 10 penetrating the insulating film 9, a transparent pixel portion electrode 11 made of a transparent conductive film such as ITO, and an upper auxiliary capacitance electrode integrally formed with the transparent pixel portion electrode 11 And it is configured to include and. Among these components, the TFT portion is configured by the range P1, the pixel portion is configured by the range P2, and the capacitance is configured by the range P3.

  In this liquid crystal display device, light from a light source is irradiated from the direction of arrow A in FIG. Then, the irradiated light is transmitted through the array substrate 100, adjusted by the liquid crystal 30, transmitted through the color filter substrate 200, and displayed in color on the pixel area 204.

JP 2004-046115 A

  In the above liquid crystal display device, for example, when each of the transparent insulating substrates 110 and 210 is a glass substrate and the thickness thereof is about 0.15 mm, when the stress is applied, the above liquid crystal display device is reduced to a curvature of about 200 mm. Can be bent without breaking. That is, if an electric signal is applied to the liquid crystal display device in a curved state as shown in FIG. 22, an image can be projected in the curved state. FIG. 22 is a cross-sectional view in the case where the color filter substrate 200 is curved in a convex shape.

  The problems associated with the curved liquid crystal display device will be described with reference to FIGS. FIG. 23 is a plan view of the array-side polarizing plate 120 and the color filter-side polarizing plate 220 when the liquid crystal display device is not curved (flat state). Reference numeral 121 in the drawing indicates a component such as iodine that constitutes the array-side polarizing plate 120 and has a polarization effect, and an arrow 121a indicates a polarization direction in a state where the liquid crystal display device is not curved. Similarly, reference numeral 221 indicates a component such as iodine that constitutes the color filter side polarizing plate 220 and has a polarization effect, and an arrow 221a indicates the polarization direction in a state where the liquid crystal display device is not curved.

  When the liquid crystal 30 is a TN (Twisted Nematic) type liquid crystal, the polarization directions 121a and 221a are set to be orthogonal to each other. In this case, the light from the light source enters the array substrate 100 from the direction A in FIGS. 21 and 23, and only the polarized component in the direction of the arrow 121a passes through the array substrate 100 and passes through the liquid crystal 30. At that time, when the TFT portion of the liquid crystal display device is in the OFF state, the polarization component is rotated by 90 ° by the liquid crystal 30, is polarized in the direction of the arrow 221 a, and enters the color filter side substrate 200. Since the polarization direction of the incident polarization component coincides with the polarization direction 221a of the color filter side polarizing plate 220, it passes through the color filter substrate 200 and emits light from the pixel surface. On the other hand, when the TFT portion of the liquid crystal display device is in the on state, the polarization component is not rotated by the liquid crystal 30 and therefore does not coincide with the polarization direction 221a of the color filter side polarizing plate 220, and thus transmits through the color filter substrate 200. No light is emitted from the pixel surface.

  As described above, when the narrow angle (right angle) between the two polarization directions 121a and 221a and the rotation amount (90 °) of the polarization component by the liquid crystal 30 coincide with each other, a high-contrast and high-quality image is displayed. be able to.

  FIG. 24 is a plan view of the array-side polarizing plate 120 and the color filter-side polarizing plate 220 in the curved state of the liquid crystal display device (FIG. 22). In this curved state, the array side polarizing plate 120 is contracted in the bending direction by a compressive stress as indicated by reference numeral 120b, and the color filter side polarizing plate 220 is extended in the bending direction by a tensile stress as indicated by reference numeral 220b. As a result, the polarization direction of the array-side polarizing plate 120 is polarized in the direction of the arrow 121b, the polarization direction of the array-side polarizing plate 120 is polarized in the direction of the arrow 221b, and the polarization directions 121b and 221b are not orthogonal to each other.

  In such a case (that is, when the narrow angle (in this case, non-right angle) of the two polarization directions 121b and 221b does not coincide with the rotation amount (90 °) of the polarization component by the liquid crystal 30), the TFT portion is turned on. In the state, the pixel surface cannot be made to emit light sufficiently, and when the TFT portion is in the off state, the pixel surface cannot emit light sufficiently. That is, a high-quality image with high contrast cannot be displayed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a liquid crystal display device capable of displaying a high-contrast and high-quality image even in a curved state, and a manufacturing method thereof.

  In order to solve the above-described problem, a first aspect of the present invention includes first and second transparent insulating substrates, and a liquid crystal sealed between the first and second transparent insulating substrates, First and second polarizing plates respectively disposed outside the first and second transparent insulating substrates, and disposed between the first transparent insulating substrate and the first polarizing plate. And disposed between the first stress relaxation layer that relaxes the stress generated in the first polarizing plate during bending, the second transparent insulating substrate, and the second polarizing plate, And a second stress relaxation layer that relieves stress generated in the second polarizing plate.

  According to the first aspect of the present invention, the first stress relaxation layer is disposed between the first transparent insulating substrate and the first polarizing plate, and the second transparent insulating substrate and the second transparent insulating substrate are disposed. Since the second stress relaxation layer is disposed between the polarizing plates, the stress relaxation layers can relieve the stress generated in each polarizing plate when the liquid crystal display device is bent. A high-quality image with high contrast can be displayed.

Embodiment 1 FIG.
As shown in FIG. 1, the liquid crystal display device according to this embodiment includes an array substrate 100 on which active elements such as TFT (Thin Film Transistor) sections, electrodes and wirings are formed, and a common electrode and an image for displaying images. And a color filter substrate 200 on which a color filter is formed. The substrates 100 and 200 are bonded to each other with a gap of 5 to 10 μm, for example, by a sealing material 40, and the liquid crystal 30 is sealed in these gaps so as not to leak to the outside by the sealing material 40. Yes. Hereinafter, parts corresponding to those of the conventional liquid crystal display device are denoted by the same reference numerals, and differences from the conventional liquid crystal display device will be described.

  The array substrate 100 includes a transparent insulating substrate 110 (first transparent insulating substrate) such as a glass plate, and a glass plate disposed on the outer principal surface side of the transparent insulating substrate 110 via a stress relaxation layer 510. The transparent insulating auxiliary substrate 511 (first auxiliary substrate) and the polarizing plate 120 (first polarizing plate) bonded to the outer main surface of the auxiliary substrate 511 by the adhesive layer 130 are provided. On the inner main surface of the array substrate 100, an active element portion 140 including a TFT portion, a pixel portion, and a capacitor, and a lead-out wiring portion 141 for transmitting an electric signal to the active element portion 140 are formed. In this embodiment, the auxiliary substrate 511 is disposed on the inner main surface of the polarizing plate 120, but may be disposed on the outer main surface of the polarizing plate 120.

  The auxiliary substrate 511 is for maintaining the strength when the polarizing plate 120 is relatively soft.

  The stress relaxation layer 510 is a layer in which the transparent insulating substrate 110 and the auxiliary substrate 511 are bonded to each other so as to be relatively displaceable in the principal surface direction. For example, the refractive index is approximately the same as those of the substrates 110 and 511. It is formed by the liquid which has.

  The stress relaxation layer 510 relaxes the stress generated in the polarizing plate 120 when the array substrate 100 is curved by bonding the substrates 110 and 510 so as to be relatively displaceable in the main surface direction as described above. Work. The stress relaxation layer 510 is formed of a liquid as described above, and functions to prevent bubbles from entering between the substrates 110 and 511 when the substrates 110 and 511 are bonded to each other. In addition, the stress relaxation layer 510 has the same refractive index as that of each of the substrates 110 and 511 as described above, thereby reducing image degradation due to multiple reflection of light source light between the polarizing plate 120 and the auxiliary substrate 511. It works to prevent.

  The color filter substrate 200 includes a transparent insulating substrate 210 (second transparent insulating substrate) such as a glass plate, and a stress relaxation layer 520 (second stress relaxation layer) on the outer main surface of the transparent insulating substrate 210. A transparent insulating auxiliary substrate 521 (second auxiliary substrate) such as a glass plate disposed via the polarizing plate 220 and a polarizing plate 220 (second auxiliary substrate) bonded to the outer main surface of the auxiliary substrate 521 by an adhesive layer 230. Polarizing plate). On the inner main surface of the color filter substrate 200, a filter electrode portion 240 including a filter layer and a common electrode is formed. In this embodiment, the auxiliary substrate 521 is disposed on the inner main surface of the polarizing plate 220, but may be disposed on the outer main surface of the polarizing plate 220.

  The auxiliary substrate 521 is for maintaining the strength when the polarizing plate 220 is relatively soft.

  The stress relaxation layer 520 is to bond the transparent insulating substrate 210 and the auxiliary substrate 521 to each other so as to be relatively displaceable in the main surface direction. For example, the stress relaxation layer 520 has a refractive index comparable to those of the substrates 210 and 521. It is formed by the liquid which has.

  The stress relaxation layer 520 relaxes the stress generated in the polarizing plate 220 when the color filter substrate 200 is curved by bonding the substrates 210 and 520 so as to be relatively displaceable in the principal surface direction as described above. To work. The stress relaxation layer 520 is formed of a liquid as described above, and functions to prevent bubbles from entering between the substrates 210 and 521 when the substrates 210 and 521 are bonded to each other. Further, the stress relaxation layer 520 has the same refractive index as that of the substrates 210 and 521 as described above, so that image degradation due to multiple reflection of light source light between the polarizing plate 220 and the auxiliary substrate 521 is prevented. It works to prevent.

  In addition, a synthetic oil such as Cargill standard refraction liquid (manufactured by Moritex Co., Ltd.) can be used for the liquid material having the same refractive index as that of the transparent insulating substrates 110 and 210 and the auxiliary substrates 511 and 521. In this synthetic oil, since the refractive index can be selected in the range of 1.30 to 2.11, it can sufficiently cope with a glass plate (refractive index of about 1.5).

  The auxiliary substrates 511 and 521 are suitably glass plates or acrylic plates having a thickness of about 0.05 mm to 0.10 mm.

  In this liquid crystal display device, when the liquid crystal display device is bent as shown in FIG. 9, the stress generated in the array-side polarizing plate 120 is caused by the array-side stress relaxation layer 510 to be relative to the main surface direction between the substrates 110 and 511. The stress generated by the color filter side polarizing plate 220 is relaxed by allowing the displacement, and the color filter side stress relaxation layer 520 allows the relative displacement in the principal surface direction between the substrates 210 and 521 to be allowed. As a result, the polarization directions 121c and 221c of the polarizing plates 120 and 220 are kept orthogonal to each other as shown in FIG. That is, the narrow angle (right angle) of the polarization directions 121c and 221c of the polarizing plates 120 and 220 coincides with the rotation amount (90 °) of the polarization component by the liquid crystal 30, and thus, for example, the TFT portion of the liquid crystal display device When is turned on, the pixel surface is not emitted by the light source light. On the other hand, when the TFT portion of the liquid crystal display device is turned off, the pixel surface is emitted by the light source light, and a high-quality image with high contrast is displayed. Is done.

  According to the liquid crystal display device configured as described above, the array-side stress relaxation layer 510 is disposed between the array-side transparent insulating substrate 110 and the array-side polarizing plate 120, and the color filter-side transparent insulating substrate 210. Since the color filter side stress relaxation layer 520 is disposed between the color filter side polarizing plate 220 and the color filter side polarizing plate 220, the stress relaxation layers 510 and 520 cause the polarizing plates 120 and 220 to be attached to the liquid crystal display device when the liquid crystal display device is curved. The generated stress can be relieved, so that a high-quality image with high contrast can be displayed even in a curved state.

Embodiment 2. FIG.
This embodiment is a method of manufacturing the liquid crystal display device according to the first embodiment. Hereinafter, a case where a plurality of (for example, four) liquid crystal display devices are manufactured together will be described.

  First, as shown in FIGS. 2 and 3, for example, a rectangular array substrate main material 111 and, for example, a rectangular color filter substrate main material 211 are prepared. Each of these substrate main materials 111 and 211 is formed of a glass plate having a thickness of 0.5 to 1.0 mm, for example. On the upper surface of the array substrate main material 111, the active element portion 140 and the lead-out wiring portion 141 of each liquid crystal display device are formed by a fine processing technique. Further, a filter electrode portion 240 of each liquid crystal display device is formed on the lower surface of the color filter substrate main material 211 by a fine processing technique.

  Next, the sealing material 40 is applied around the active element portions 140 on the array substrate main material 111 in a rectangular frame shape, for example. Further, the dummy seal material 41 is applied in a frame shape over the periphery of the array substrate main material 111. For the sealing material 40 and the dummy sealing material 41, a thermosetting type epoxy adhesive that is cured by heating or a photocurable type adhesive that is cured by irradiating light such as ultraviolet rays is used.

  Next, the liquid crystal material 31 is dropped on each active element part 140 surrounded by each sealing material 40.

  Thereafter, as shown in FIG. 4, the array substrate main material 111 and the color filter substrate main material 211 are positioned with respect to each other, and the sealing materials 40 and 41 are bonded together as an adhesive. Then, the sealing materials 40 and 41 are cured, and the substrate main materials 111 and 211 are bonded and fixed to each other. In this state, the liquid crystal material 31 is sandwiched between the substrate main materials 111 and 211 and spreads in the sealing material 40 to become the liquid crystal 30.

  After that, as shown in FIG. 5, the array substrate main material 111 and the color filter substrate main material 211 are thinned by a chemical mechanical polishing method or a chemical etching method. By these methods, it is possible to reduce the thickness of the main substrates 111 and 211 to about 0.1 mm.

  After that, the array substrate main material 111 and the color filter substrate main material 211 are cut along the dotted line B in FIG. 6, and the array-side transparent insulating substrate 110 (first first) for each liquid crystal display device as shown in FIG. (Transparent insulation) and color filter side transparent insulation substrate 210 (second transparent insulation). Hereinafter, the one divided for each liquid crystal display device as shown in FIG.

  Next, as shown in FIG. 8, the array-side polarizing plate 120 (first polarizing plate) is disposed on one main surface (here, the lower surface) of the array-side auxiliary substrate 511 (first auxiliary substrate) via the adhesive layer 130. The color filter side polarizing plate 220 (second polarizing plate) is disposed on one main surface (here, the upper surface) of the color filter side auxiliary substrate 521 (second transparent insulating substrate) via the adhesive layer 230. Prepare the arranged ones.

  Then, a liquid material 513 serving as a stress relaxation layer is applied to the upper surface of the array side auxiliary substrate 511, and the array side auxiliary substrate is interposed through the liquid material 513 so that air does not enter between the substrates 110 and 511. The upper surface of 511 is attached to the lower surface of the array-side transparent insulating substrate 110 of the liquid crystal plate 600. Similarly, a liquid material 523 serving as a stress relaxation layer is applied to the upper surface of the color filter side transparent insulating substrate 210 of the liquid crystal plate 600, and air is not interposed between the substrates 210 and 521 through the liquid material 523. Then, the lower surface of the color filter side auxiliary substrate 521 is attached to the upper surface of the color filter side transparent insulating substrate 210 of the liquid crystal plate 600. The liquid bodies 513 and 523 are liquid bodies (equal refractive index liquid) having a refractive index comparable to that of glass or acrylic resin, and those having moderate viscosity are suitable.

  FIG. 1 shows a state in which the auxiliary substrates 511 and 512 are disposed on the transparent insulating substrates 110 and 210 of the liquid crystal plate 600 through the liquid bodies 513 and 523 by the bonding. . In this state, the array-side liquid material 513 is sandwiched and spread between the substrates 110 and 511 to form an array-side stress relaxation layer 510 (first stress relaxation layer). Similarly, the color filter-side liquid material 523 is The color filter side stress relaxation layer 520 (second stress relaxation layer) is formed by being sandwiched between the substrates 210 and 521 and expanded.

  In this way, the liquid crystal display device according to Embodiment 1 is manufactured. After this, a control printed circuit board and a backlight are attached and housed in a housing to be a finished product. Examples of the step of bending the liquid crystal display device by applying stress include a step of attaching a backlight and a step of housing in a housing.

  According to the manufacturing method of the liquid crystal display device described above, the array-side polarizing plate 120 is disposed outside the array-side transparent insulating substrate 110 via the array-side stress relaxation layer 510, and the color filter-side transparent insulating property is provided. Since the color filter side polarizing plate 220 is disposed outside the substrate 210 via the color filter side stress relaxation layer 520, the liquid crystal display device according to claim 1 (liquid crystal capable of displaying a high-contrast and high-quality image even in a curved state). Display device).

  In addition, an array side auxiliary substrate 511 is disposed on one main surface (here, the upper surface) of the array side polarizing plate 120, and a color filter side auxiliary substrate 521 is provided on one main surface (here, the lower surface) of the color filter side polarizing plate 220. Therefore, even when each of the polarizing plates 120 and 220 is relatively soft, a liquid crystal display device that maintains its strength can be manufactured.

Embodiment 3 FIG.
As shown in FIG. 12, in the liquid crystal display device according to the first embodiment, an array side transparent insulating substrate 110 (first transparent insulating substrate) and an array side auxiliary substrate 511 (first auxiliary substrate) are provided. The adhesive layer 514 is partially bonded and fixed, and the color filter side transparent insulating substrate 210 (second transparent insulating substrate) and the color filter side auxiliary substrate 521 (second auxiliary substrate) are partially bonded by the adhesive layer 524. Alternatively, it may be bonded and fixed. In FIG. 12, by providing an adhesive layer 514 on one side of the periphery of the array-side transparent insulating substrate 110, the substrates 110 and 511 are partially bonded and fixed. Similarly, the periphery of the color filter-side transparent insulating substrate 210 By providing the adhesive layer 524 on one side, the substrates 210 and 521 are partially bonded and fixed.

  In this way, the substrates 110 and 511 on the array side are partially fixed to each other by the adhesive layer 514, and the substrates 210 and 521 on the color filter side are partially fixed to each other by the adhesive layer 524. As described above, the liquid crystal display device can be curved by applying stress without the relative arrangement of the polarizing plates 120 and 220 and the transparent insulating substrates 110 and 210 being greatly shifted.

Embodiment 4 FIG.
This embodiment is a method of manufacturing a liquid crystal display device according to the third embodiment.

  As shown in FIG. 7, a liquid crystal plate 600 is prepared as in the second embodiment.

  Next, as shown in FIG. 11, the array-side polarizing plate 120 (first polarizing plate) is arranged on one main surface (here, the lower surface) of the array-side auxiliary substrate 511 (first auxiliary substrate) via the adhesive layer 130. The color filter side polarizing plate 220 (second polarizing plate) is disposed on one main surface (here, the upper surface) of the color filter side auxiliary substrate 521 (second auxiliary substrate) via the adhesive layer 230. Prepare what you did. Then, an adhesive layer 514 is partially formed on the upper surface of the array-side auxiliary substrate 511 (for example, one side edge of the upper surface), and partially on the lower surface of the color filter-side auxiliary substrate 521 (for example, one side edge of the lower surface). ) Is formed with an adhesive layer 524.

  Thereafter, as in the second embodiment, a liquid material 513 serving as a stress relaxation layer is applied to the upper surface of the array side auxiliary substrate 511, and the liquid material 513 is formed so that air does not enter between the substrates 110 and 511. Further, the upper surface of the array side auxiliary substrate 511 is attached to the lower surface of the array side transparent insulating substrate 110 of the liquid crystal plate 600 through the adhesive layer 514. Similarly, a liquid material 523 serving as a stress relieving layer is applied to the upper surface of the color filter side transparent insulating substrate 210 of the liquid crystal plate 600, and the liquid material 523 and the above-described liquid are prevented so that air does not enter between the substrates 210 and 521. The lower surface of the color filter side auxiliary substrate 521 is attached to the upper surface of the color filter side transparent insulating substrate 210 of the liquid crystal plate 600 through the adhesive layer 524.

  FIG. 12 shows a state in which the auxiliary substrates 511 and 512 are disposed on the transparent insulating substrates 110 and 210 of the liquid crystal plate 600 through the liquid bodies 513 and 523 and the adhesive layers 514 and 524 by the above-described sticking. Is shown. In this state, the array-side liquid material 513 is sandwiched and spread between the substrates 110 and 511 to form an array-side stress relaxation layer 510 (first stress relaxation layer). Similarly, the color filter-side liquid material 523 is The color filter side stress relaxation layer 520 (second stress relaxation layer) is formed by being sandwiched between the substrates 210 and 521 and expanded. Further, the substrates 110 and 511 are partially bonded and fixed to each other by an adhesive layer 514 (for example, at one side of the periphery of the upper surface of the substrate 511). Similarly, the substrates 210 and 521 are bonded by the adhesive layer 524. They are bonded and fixed partially to each other (for example, at one side of the periphery of the lower surface of the substrate 521). In this way, the liquid crystal display device according to Embodiment 3 is manufactured.

  According to the method for manufacturing a liquid crystal display device described above, the array-side transparent insulating substrate 110 side and the array-side polarizing plate 120 side are partially fixed to each other by the adhesive layer 514, and the aller filter-side transparent insulating substrate is used. Since the 210 side and the color filter side polarizing plate 220 side are partially fixed to each other by the adhesive layer 524, the liquid crystal display device according to claim 3 (the relative relationship between the polarizing plates 120 and 220 and the transparent insulating substrates 110 and 210). A liquid crystal display device that can be bent by applying stress without significantly shifting the arrangement can be manufactured.

  Although the first to fourth embodiments have been described on the assumption that the polarizing plates 120 and 240 have low strength and the auxiliary substrates 511 and 521 are provided in order to maintain the strength, If there is sufficient strength, the auxiliary substrates 511 and 521 (and thus the adhesive layers 130 and 230) may be omitted.

Embodiment 5. FIG.
In the liquid crystal display devices according to Embodiments 1 and 3, it is possible to change the shape again after being bent once. However, depending on the intended use, there is a case where it is not necessary to change the shape after bending once (that is, when it is desired to fix the curved state after bending). For example, the display device for advertisement in harmony with the surrounding design and functions, and the case where it is used for an instrument display of an automobile or the like can be mentioned.

  In this embodiment, a method of manufacturing a liquid crystal display device that can fix the curved shape after bending is provided.

  As shown in FIG. 13, a liquid crystal plate 600 is prepared as in the second embodiment. For example, an adhesive layer 515 that can function as a stress relaxation layer (first stress relaxation layer) is formed on the upper surface of the polarizing plate 120 (first polarizing plate), and air does not enter between the substrates 120 and 110. Similarly, the polarizing plate 120 is attached to the lower surface of the array-side transparent insulating substrate 110 (first transparent insulating substrate) of the liquid crystal plate 600 through the adhesive layer 515. Similarly, for example, an adhesive layer 525 that can function as a stress relaxation layer (second stress relaxation layer) is formed on the lower surface of the polarizing plate 220 (second polarizing plate), and air enters between the substrates 210 and 220. Thus, the polarizing plate 220 is attached to the upper surface of the color filter side transparent insulating substrate 210 (second transparent insulating substrate) of the liquid crystal plate 600 through the adhesive layer 525. For the adhesive layers 515 and 525, a thermosetting or photo-curing adhesive is used.

  FIG. 14 shows a state in which the polarizing plates 120 and 220 are disposed on the transparent insulating substrates 110 and 210 of the liquid crystal plate 600 through the adhesive layers 515 and 525 by the above-described bonding. In this state, the adhesive layers 515 and 525 are not yet cured, and function as stress relaxation layers as in the first embodiment. In this state, the liquid crystal display device is bent into a desired shape as shown in FIG. 15, for example, and the adhesive layers 515 and 525 are cured while the shape is maintained, and the bent shape is fixed.

  According to the manufacturing method of the liquid crystal display device configured as described above, the polarizing plate 120, the polarizing plate 120, the transparent insulating substrate 110, 210 of the liquid crystal plate 600 through the thermosetting or photocurable adhesive layers 515, 525. 220 is disposed and the liquid crystal display device is curved into a desired shape, and then the adhesive layers 515 and 525 are cured to fix the curved shape, so that a high-contrast and high-quality image can be obtained even in a curved state. A liquid crystal display device that can display and can fix the curved state after bending can be manufactured.

  Note that this embodiment includes not only a method for manufacturing a liquid crystal display device but also a liquid crystal display device.

  This embodiment corresponds to the case where a thermosetting or photocurable adhesive is used as the stress relaxation layer in the first and second embodiments.

Embodiment 6 FIG.
In the fifth embodiment, when the viscosity of the adhesive layer 515 (525) is low (FIG. 14), when the liquid crystal display device is bent, the polarizing plate 120 (220) and the transparent insulating substrate 110 (210) are relative to each other. Arrangement may be greatly shifted. This embodiment provides a method of manufacturing a liquid crystal display device that overcomes such problems.

  First, as shown in FIG. 13, a liquid crystal plate 600 is prepared as in the fifth embodiment. Then, for example, an adhesive layer 515 that can function as a stress relaxation layer (first stress relaxation layer) is formed on the upper surface of the polarizing plate 120, and the adhesive layer 515 prevents air from entering between the substrates 120 and 110. Then, the polarizing plate 120 is attached to the lower surface of the array-side transparent insulating substrate 110 of the liquid crystal plate 600. Similarly, for example, an adhesive layer 525 that can function as a stress relaxation layer (second stress relaxation layer) is formed on the lower surface of the polarizing plate 220, and the adhesive layer prevents air from entering between the substrates 210 and 525. The polarizing plate 220 is attached to the upper surface of the color filter side transparent insulating substrate 210 of the liquid crystal plate 600 through 525. For the adhesive layers 515 and 525, as in the fifth embodiment, a thermosetting or photocurable adhesive is used.

  FIG. 14 shows a state in which the polarizing plates 120 and 220 are disposed on the transparent insulating substrates 110 and 210 of the liquid crystal plate 600 through the adhesive layers 515 and 525 by the above-described bonding. In this state, the adhesive layers 515 and 525 are not yet cured, and function as a stress relaxation layer as in the first embodiment.

  Then, in this state, as shown in FIG. 16, a portion 515a (525a) of the adhesive layer 515 (525) (for example, a portion on one side of the peripheral edge of the upper surface of the polarizing plate 120 (220)) is partially cured to provide transparent insulation. The polarizing plate 120 (220) is partially bonded and fixed to the conductive substrate 110 (210). Thus, while maintaining the function of the adhesive layer 515 (525) as the stress relaxation layer (first stress relaxation layer (second stress relaxation layer)), the polarizing plate 120 (220) and the transparent insulating substrate 110 ( 210) can be prevented from greatly deviating. In this state, the liquid crystal display device is bent into a desired shape as shown in FIG. 17, for example, and the remaining portions of the adhesive layers 515 and 525 are cured while the shape is maintained, and the curved shape is fixed.

  According to the method of manufacturing a liquid crystal display device configured as described above, the array side transparent insulating substrate 110 side and the array side polarizing plate 120 side are partially set by partially curing the array side adhesive layer 515. The color filter side adhesive layer 525 is partially cured, and the color filter side transparent insulating substrate 210 side and the color filter side polarizing plate 220 side are partially adhered and fixed to each other. The liquid crystal display device is curved into a desired shape, and the remaining portions of the adhesive layers 515 and 525 are cured while maintaining the curved state, so that the adhesive layers 514 and 524 are not provided as in the fifth embodiment. In addition, it is possible to manufacture a liquid crystal display device capable of displaying a high-contrast and high-quality image even in a curved state and fixing the curved state after bending.

  In the fifth and sixth embodiments, the case where the adhesive layers 515 and 525 are formed on the entire surfaces of the bright insulating substrates 110 and 210 has been described. However, when the transmittance of the adhesive layers 515 and 525 is low, high display performance is achieved. In this case, the adhesive layers 515 and 525 are formed only on the periphery of the bright insulating substrates 110 and 210 as in the case of the adhesive layers 514 and 524 of the third and fourth embodiments. Liquid bodies 513 and 523 may be dispersed in the center (pixel area) of 110 and 210. Even in this case, the same effect as in the fifth and sixth embodiments can be obtained.

  Furthermore, if bubbles do not enter between the transparent insulating substrates 110 and 210 and the polarizing plates 120 and 220 and the image quality is not deteriorated, the liquid materials 513 and 523 need not be sprayed. .

  9, 10, 15, and 17, the lengths of the polarizing plates 120 and 220 in the bending direction and the lengths of the transparent insulating substrates 110 and 210 in the bending direction coincide with each other when the liquid crystal display device is bent. If the transparent insulating substrates 110 and 210 are covered with the polarizing plates 120 and 220 (that is, the ends of the transparent insulating substrates 110 and 210 are covered with the polarizing plates 120 and 220), Even if a crack or the like occurs in the cut portion of 110 or 210, the transparent insulating substrate 110 or 210 can be prevented from cracking due to the crack or the like. That is, on the convex side of the curved state of the liquid crystal display device, the length of the polarizing plate 220 in the curved direction is formed longer than the length of the transparent insulating substrate 210 in the curved direction, and on the concave side of the curved state of the liquid crystal display device, The length of the polarizing plate 120 in the bending direction is shorter than the length of the transparent insulating substrate 110 in the bending direction.

  In the first to sixth embodiments, the curved liquid crystal display device has been described. However, in a flat liquid crystal display device, the display area is warped due to a difference in shrinkage between the transparent insulating substrates 110 and 210 and the polarizing plates 120 and 220. When this occurs, it may be applied as means for preventing the warpage. In that case, warping of the display area is prevented by the stress relaxation layer, and a flat liquid crystal display device can be realized. In addition, an example in which a transparent insulating substrate is used as the auxiliary substrates 511 and 521 is shown. However, in the case where screen charging affects the image quality, a conductive layer is formed on the conductive substrate or the transparent insulating substrate. A thing may be used. Further, as the auxiliary substrate, a substrate having a function such as an electrostatic induction touch panel by forming a metal film or a transparent conductive film may be used. Furthermore, although the present invention has been shown as a means for eliminating the deterioration of image quality due to expansion and contraction of the polarizing plate, the height of the gap between the substrates (100 and 200) due to the stress generated between the polarizing plate and the transparent insulating substrate. It is also effective in eliminating image quality degradation due to misalignment.

  In the fifth and sixth embodiments, as in the first to fourth embodiments, auxiliary substrates 511 and 521 for maintaining the strength may be disposed on one main surface of the polarizing plates 120 and 240.

FIG. 3 is a schematic cross-sectional view of a flat state of the liquid crystal display device according to the first embodiment and a schematic cross-sectional view of the flat state of the liquid crystal display device manufactured by the method for manufacturing a liquid crystal display device according to the second embodiment. FIG. 10 is an exploded perspective view of a color filter substrate main material 211 and an array substrate main material 111 in the method for manufacturing a liquid crystal display device according to the second embodiment. FIG. 10 is an exploded cross-sectional schematic diagram of a color filter substrate main material 211 and an array substrate main material 111 in the method for manufacturing a liquid crystal display device according to Embodiment 2. FIG. 10 is a schematic cross-sectional view of a color filter substrate main material 211 and an array substrate main material 111 in a mutually bonded state in the method for manufacturing a liquid crystal display device according to the second embodiment. FIG. 10 is a diagram illustrating a process of thinning the color filter substrate main material 211 and the array substrate main material 111 in the method for manufacturing the liquid crystal display device according to the second embodiment. FIG. 10 is a diagram illustrating a process of cutting the color filter substrate main material 211 and the array substrate main material 111 for each liquid crystal display device in the method for manufacturing a liquid crystal display device according to the second embodiment. 6 is a diagram showing a state (liquid crystal plate 600) in which a liquid crystal 30 is sealed between transparent insulating substrates 110 and 210 in the method for manufacturing a liquid crystal display device according to Embodiments 2 and 4. FIG. FIG. 11 is a diagram illustrating a process of applying liquid bodies 513 and 523 to liquid crystal plate 600 and disposing polarizing plates 120 and 220 in the method for manufacturing a liquid crystal display device according to Embodiment 2. FIG. 3 is a schematic cross-sectional view of the liquid crystal display device according to Embodiment 1 in a curved state. 10 is a schematic cross-sectional view of a liquid crystal display device according to Embodiment 3 in a curved state. FIG. FIG. 10 is a diagram for explaining a process of disposing polarizing plates 120 and 220 on a liquid crystal plate 600 through liquid bodies 513 and 523 and adhesive layers 514 and 524 in the method for manufacturing a liquid crystal display device according to Embodiment 4. FIG. 6 is a schematic cross-sectional view of a liquid crystal display device manufactured by the method for manufacturing a liquid crystal display device according to Embodiment 4, and a schematic cross-sectional view of the liquid crystal display device according to Embodiment 3 in a flat state. FIG. 11 is a diagram illustrating a process of disposing polarizing plates 120 and 220 on liquid crystal plate 600 with adhesive layers 515 and 525 in the method for manufacturing a liquid crystal display device according to Embodiments 5 and 6. 7 is a schematic cross-sectional view of a liquid crystal display device manufactured by the method for manufacturing a liquid crystal display device according to Embodiments 5 and 6, in a flat state. FIG. 10 is a schematic cross-sectional view of a liquid crystal display device manufactured by the method for manufacturing a liquid crystal display device according to Embodiment 5 in a curved state. FIG. 16 is a diagram showing a state in which portions 515a and 525a of adhesive layers 515 and 525 are partially cured in the method for manufacturing a liquid crystal display device according to Embodiment 6. FIG. 25 is a diagram showing a state where the entire adhesive layers 515 and 525 are cured in a curved state in the method for manufacturing a liquid crystal display device according to the sixth embodiment. It is a top view of the conventional liquid crystal display device. It is a top view for 1 pixel of the conventional liquid crystal display device. It is XX sectional drawing of FIG. It is YY sectional drawing of FIG. It is the cross-sectional schematic of the curved state of the conventional liquid crystal display device. It is a figure explaining the conventional problem. It is another figure explaining the conventional problem.

Explanation of symbols

  31 Liquid crystal material, 40 Sealing material, 41 Dummy sealing material, 100 Array substrate, 110, 210 Transparent insulating substrate, 111 Array substrate main material, 120, 220 Polarizing plate, 130, 230 Adhesive layer, 140 Active element part, 141 Drawer Wiring portion, 200 color filter substrate, 211 color filter substrate main material, 240 filter electrode portion, 510, 520 stress relaxation layer, 511, 521 auxiliary substrate, 513, 523 liquid, 514, 524 adhesive layer, 515, 525 adhesive layer .

Claims (15)

First and second transparent insulating substrates;
A liquid crystal sealed between the first and second transparent insulating substrates;
First and second polarizing plates respectively disposed outside the first and second transparent insulating substrates;
A first stress relaxation layer disposed between the first transparent insulating substrate and the first polarizing plate to relieve stress generated in the first polarizing plate during bending;
A second stress relaxation layer disposed between the second transparent insulating substrate and the second polarizing plate to relieve stress generated in the second polarizing plate during bending;
A liquid crystal display device comprising:   The liquid crystal display device according to claim 1, wherein the first and second stress relaxation layers are formed of a liquid material. The first stress relaxation layer is formed of a liquid material having a refractive index comparable to that of the first transparent insulating substrate,
The liquid crystal display device according to claim 1, wherein the second stress relaxation layer is formed of a liquid material having a refractive index comparable to that of the second transparent insulating substrate. The first transparent insulating substrate and the first polarizing plate are partially fixed to each other by an adhesive layer,
The liquid crystal display device according to claim 1, wherein the second transparent insulating substrate and the second polarizing plate are partially fixed to each other by an adhesive layer.   The liquid crystal display device according to claim 1, wherein the first and second stress relaxation layers are formed of a thermosetting or photocurable adhesive. A first auxiliary substrate that holds the strength of the first polarizing plate is disposed on one main surface of the first polarizing plate,
6. The second auxiliary substrate for maintaining the strength of the second polarizing plate is disposed on one main surface of the second polarizing plate. Liquid crystal display device.   When the liquid crystal display device is curved in a convex shape toward the first polarizing plate, the length of the first polarizing plate in the bending direction is longer than the length of the first transparent insulating substrate in the bending direction. The length of the second polarizing plate in the bending direction is shorter than the length of the second transparent insulating substrate in the bending direction. Liquid crystal display device. (A) sealing a liquid crystal between the first and second transparent insulating substrates to form a liquid crystal plate;
(B) A first polarizing plate is disposed outside the first transparent insulating substrate via a first stress relaxation layer, and a second stress relaxation is performed outside the second transparent insulating substrate. Disposing a second polarizing plate through the layer;
A method for manufacturing a liquid crystal display device, comprising:   9. The method of manufacturing a liquid crystal display device according to claim 8, wherein the first and second stress relaxation layers are formed of a liquid material. The first stress relaxation layer is formed of a liquid material having a refractive index comparable to that of the first transparent insulating substrate.
9. The method of manufacturing a liquid crystal display device according to claim 8, wherein the second stress relaxation layer is formed of a liquid material having a refractive index comparable to that of the second transparent insulating substrate.   In the step (b), the first transparent insulating substrate and the first polarizing plate are partially fixed to each other by an adhesive layer, and the second transparent insulating substrate and the second polarizing plate are The method for manufacturing a liquid crystal display device according to claim 8, wherein the liquid crystal display device is partially fixed to each other by an adhesive layer. The first and second stress relaxation layers are formed of a thermosetting or photocurable adhesive,
(C) curving the liquid crystal display device into a desired shape and curing the first and second stress relaxation layers in a state where the curved state is maintained;
The method for manufacturing a liquid crystal display device according to claim 8, further comprising: The first and second stress relaxation layers are formed of a thermosetting or photocurable adhesive,
(C) The first stress relaxation layer is partially cured to partially fix the first transparent insulating substrate and the first polarizing plate to each other, and the second stress relaxation layer. Partially fixing the second transparent insulating substrate and the second polarizing plate to each other, and
(D) curving the liquid crystal display device into a desired shape and curing the remaining portions of the first and second stress relaxation layers in a state where the curved state is maintained;
The method for manufacturing a liquid crystal display device according to claim 8, further comprising:   In the step (b), a first auxiliary substrate that retains the strength of the first polarizing plate is disposed on one main surface of the first polarizing plate, and one main surface of the second polarizing plate. 9. The method of manufacturing a liquid crystal display device according to claim 8, wherein a second auxiliary substrate that maintains the strength of the second polarizing plate is disposed on the surface.   In the step (b), when the liquid crystal display device is convexly curved toward the first polarizing plate, the length of the first polarizing plate in the bending direction is the first transparent insulating substrate. The length in the bending direction of the second polarizing plate is shorter than the length in the bending direction of the second transparent insulating substrate. The manufacturing method of the liquid crystal display device of description.

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