JP2010156784A - Liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the unevenness of cell thickness in a curved liquid crystal display apparatus. <P>SOLUTION: The liquid crystal display apparatus 50 includes: a first substrate 10, which is brittle; a second substrate 20, which is disposed opposite the first substrate 10 and brittle; and a liquid crystal layer 15, disposed between the first and second substrates 10 and 20. The first and second substrates 10 and 20 are deformed into a curved face so that the first substrate 10 faces outward. The entire curved periphery of the second substrate 20 is provided with a cover member 45 that has the shape of a curved face. The curvature of the second substrate 20 side surface of the cover member 45 is equal to that of the cover member 45 side surface of the second substrate 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a curved liquid crystal display device having a curved display surface.

  In recent years, liquid crystal display devices using a liquid crystal display panel have been proposed with a novel curved design in which the display surface of the liquid crystal display panel is curved (see, for example, Patent Documents 1 to 3).

For example, in Patent Document 1, spacers arranged between an array substrate and a counter substrate are dispersedly arranged so that a distribution density of a central portion or a contact area per unit area is larger than a peripheral portion in a bending direction. A liquid crystal display device is disclosed. According to this, it is possible to relieve the stress applied to the central portion, and for this reason, the interval between the liquid crystal panels in the central portion of the liquid crystal panel can be maintained at a predetermined value, thereby preventing display unevenness. It is possible to prevent the generation of bubbles by displacing the spacer in the peripheral part that is sparse with respect to the central part following the volume change of the liquid crystal member accompanying the temperature change. It is described that a liquid crystal display device with good quality can be obtained.
JP 2004-126197 A JP 2004-69627 A JP 2007-272107 A

  FIG. 6 is an explanatory view for explaining a method of manufacturing a conventional curved liquid crystal display device, and FIG. 7 is a side view schematically showing a liquid crystal display device 150 manufactured by the conventional manufacturing method. .

  For example, as shown in FIG. 6, a conventional curved liquid crystal display device is disposed so as to face a TFT (Thin Film Transistor) substrate 110 having a polarizing plate 131a attached to the lower surface thereof and the TFT substrate 110. A flat liquid crystal display panel 130 including a CF (Color Filter) substrate 120 having a polarizing plate 131b attached thereto, a curved lower case plate 145a having a concave surface, and a curved upper case plate having a convex surface. The liquid crystal display panel 130 is produced by being deformed into a curved surface by being sandwiched between 145b and 145b.

  Here, since the liquid crystal display panel 130 deformed into a curved surface is once formed into a flat shape, the lengths of the display surfaces for displaying images of the TFT substrate 110 and the CF substrate 120 in the bending direction are the same. Designed. Therefore, when the liquid crystal display panel 130 is deformed into a curved surface, for example, the CF substrate 120 on the inner side has a larger curvature than the TFT substrate 10 on the outer side, and as shown in FIG. In addition, the CF substrate 120 bends (sags) inward at the portion X in the figure, and there is a risk that uneven cell thickness may occur in the liquid crystal display panel 130 (liquid crystal display device 150).

  The present invention has been made in view of this point, and an object thereof is to suppress the occurrence of cell thickness unevenness in a curved liquid crystal display device.

  In order to achieve the above object, according to the present invention, the curvature of the surface on the second substrate side of the cover member provided on the entire peripheral surface of the second substrate is the same as the curvature of the surface on the cover member side of the second substrate. It is what I did.

  Specifically, a liquid crystal display device according to the present invention includes a brittle first substrate, a brittle second substrate disposed opposite to the first substrate, and the first substrate and the second substrate. A liquid crystal layer provided on the peripheral surface of the second substrate, wherein the first substrate and the second substrate are deformed into a curved shape so that the first substrate faces outward. The curved cover member is provided on the entire surface, and the curvature of the surface of the cover member on the second substrate side is the same as the curvature of the surface of the second substrate on the cover member side. .

  According to the above configuration, the cover member is provided on the entire peripheral surface of the second substrate, and the curvature of the surface of the cover member on the second substrate side is the same as the curvature of the surface of the second substrate on the cover member side. When the first substrate and the second substrate are deformed into curved surfaces, the inward bending of the second substrate disposed on the inward side is suppressed. As a result, even when the first substrate and the second substrate are deformed into a curved surface shape, the distance between the first substrate and the second substrate is kept constant. Occurrence is suppressed.

  Here, the curvature of the surface of the cover member on the second substrate side is the same as the curvature of the surface of the second substrate on the cover member side means that the curvature radius of the surface of the cover member on the second substrate side is second. It is within a range of ± 5 mm of the curvature radius of the surface of the substrate on the cover member side, and the curvature of the surface of the cover member on the second substrate side is substantially the same as the curvature of the surface of the second substrate on the cover member side. Contains.

  The thermal expansion coefficient of the cover member may be the same as the thermal expansion coefficient of the first substrate and the second substrate.

  According to the above configuration, since the thermal expansion coefficient of the cover member is the same as the thermal expansion coefficient of the first substrate and the second substrate, even if the temperature of the environment where the liquid crystal display device is installed rises, The elongation is the same as that of the first substrate and the second substrate. Thereby, since generation | occurrence | production of the tensile stress of the bending direction of a 1st board | substrate and a 2nd board | substrate is suppressed, the crack by the thermal expansion of a 1st board | substrate and a 2nd board | substrate is suppressed.

  The cover member, the first substrate, and the second substrate may be made of glass.

  According to the above configuration, since the cover member, the first substrate, and the second substrate are made of glass, the thermal expansion coefficient of the cover member is specifically the same as the thermal expansion coefficient of the first substrate and the second substrate.

  The cover member and the peripheral surface of the second substrate may be bonded to each other via an adhesive layer having transparency.

  According to the above configuration, since the adhesive layer having transparency is interposed between the cover member and the peripheral surface of the second substrate, the cover member is bonded to the peripheral surface of the second substrate, and the cover member Deterioration of display quality via the screen is suppressed.

  According to the present invention, the curvature of the surface on the second substrate side of the cover member provided on the entire peripheral surface of the second substrate is the same as the curvature of the surface on the cover member side of the second substrate. In the display device, the occurrence of uneven cell thickness can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment.

  FIG. 1 is a cross-sectional view of the liquid crystal display device 50 of the present embodiment.

  As shown in FIG. 1, the liquid crystal display device 50 includes a liquid crystal display panel 30 that is deformed into a curved surface so that the display surface D is curved, and a pair of polarized lights that are respectively attached to the upper and lower surfaces of the liquid crystal display panel 30. Plates 31b and 31a, a curved backlight unit 40 provided on the lower side of the liquid crystal display panel 30 via a polarizing plate 31a, a bezel 41 provided on the lower side of the backlight unit 40, and a liquid crystal display panel 30 is provided with a curved cover member 45 provided via a polarizing plate 31 b and an adhesive layer 35.

  The liquid crystal display panel 30 includes a TFT substrate 10 provided as a brittle first substrate, a CF substrate 20 disposed opposite the TFT substrate 10 and provided as a brittle second substrate, the TFT substrate 10, A liquid crystal layer 15 provided between the CF substrates 20 and a sealing material 16 for adhering the TFT substrate 10 and the CF substrate 20 to each other and enclosing the liquid crystal layer 15 between the substrates 10 and 20 are provided. The TFT substrate 10 and the CF substrate 20 are curved so that the TFT substrate 10 faces outward. Here, the size of the liquid crystal display panel 30 is, for example, type 2 (length 40 mm × width 55 mm, thickness 0.2 mm × 2), and its curvature radius is 50 mm to 400 mm.

  The TFT substrate 10 includes, for example, a plurality of gate lines (not shown) provided so as to extend in parallel with each other on a glass substrate, a gate insulating film (not shown) provided so as to cover each gate line, and a gate A plurality of source lines (not shown) provided on the insulating film so as to extend in parallel to each other in a direction orthogonal to each gate line, and a plurality of TFTs provided for each gate line and each intersection of the source lines. (Not shown), a plurality of pixel electrodes (not shown) provided in a matrix on an interlayer insulating film (not shown) covering each TFT and each source line, and covering each pixel electrode An alignment film (not shown) is provided. Here, as shown in FIG. 1, an end portion along one edge of the TFT substrate 10 that protrudes from the CF substrate 20 constitutes a terminal region, and the terminal region includes, for example, a backlight. An FPC (Flexible Printed Circuit) 32 for connection to the unit 40 or the like is attached.

  The CF substrate 20 includes, for example, a black matrix (not shown) provided in a frame shape on the glass substrate and in a lattice shape in the frame, and a red layer, a green layer, and a black layer provided between the lattices of the black matrix, respectively. A color filter layer (not shown) including a blue layer, a common electrode (not shown) provided so as to cover the black matrix and the color filter layer, and an alignment film (not shown) provided so as to cover the common electrode And.

  The liquid crystal layer 15 is made of a nematic liquid crystal material having electro-optical characteristics.

  As shown in FIG. 1, the backlight unit 40 includes a light guide plate (not shown) made of a transparent resin such as an acrylic resin curved in one direction, and an LED provided along an uncurved edge of the light guide plate. Lamp (not shown) such as (Light Emitting Diode), a resin-made reflective sheet (not shown) such as white PET (Polyethylene Terephthalate) film provided on the outer peripheral surface of the light guide plate, and the inner peripheral surface of the light guide plate A diffusion sheet (not shown) made of a resin such as an acrylic resin and a prism sheet (not shown) are provided.

  The bezel 41 is configured to have a concave cross section with acrylic resin or the like so as to accommodate the backlight unit 40 therein.

The cover member 45 is a glass substrate formed into a curved surface so as to have a predetermined curvature. Here, the curvature of the surface of the cover member 45 on the CF substrate 20 side is, for example, a radius of curvature of 50 mm to 400 mm, and is set to be the same as the curvature of the surface of the CF substrate 20 on the cover member 45 side. Here, the curvature of the surface of the cover member 45 on the CF substrate 20 side is the same as the curvature of the surface of the CF substrate 20 on the cover member 45 side means that the curvature radius of the surface of the cover member 45 on the CF substrate 20 side is CF. The curvature of the surface of the cover member 45 on the side of the cover member 45 is within ± 5 mm, and the curvature of the surface of the cover member 45 on the side of the CF substrate 20 is substantially the same as the curvature of the surface of the CF substrate 20 on the side of the cover member 45. Including being. Further, the thermal expansion coefficient of the cover member 45 is approximately the same as the thermal expansion coefficient of 40 to 60 × 10 ⁻⁷ / K of the alkali-free glass substrate constituting the TFT substrate 10 and the CF substrate 20.

The adhesive layer 35 is made of an epoxy-based or acrylic UV-curing adhesive that is colorless and transparent after curing and has a predetermined adhesive strength. Here, for example, when a glass substrate having a length of 40 mm, a width of 55 mm, and a thickness of 0.2 mm is deformed to have a radius of curvature of 50 mm to 400 mm, the repulsive force to return to the original shape (planar shape) is 1.8 × 10 ^−. since the ^{3 N / mm 2 ~1.4 × 10} -2 N / mm 2, the adhesive strength of the adhesive used may be any 1.4 × ¹⁰ -2 N / mm ² or more. A double-sided tape can also be used as the adhesive layer 35 as long as it has a predetermined adhesive strength and transparency.

  In the liquid crystal display device 50 configured as described above, one pixel is formed for each pixel electrode of the TFT substrate 10 and each colored layer of the CF substrate 20, and a voltage of a predetermined magnitude is applied to the liquid crystal layer 15 in each pixel. As a result, the alignment state of the liquid crystal layer 15 is changed and the transmittance of light incident on the liquid crystal display panel 30 from the backlight unit 40 is adjusted to display an image.

  Next, a method for manufacturing the liquid crystal display device 50 of the present embodiment will be described with reference to FIGS. Here, the manufacturing method of this embodiment includes a liquid crystal display panel manufacturing process, a panel deformation process, and an adhesive curing process. FIG. 2 is an explanatory diagram for explaining the panel deformation step, and FIG. 3 is an explanatory diagram for explaining the adhesive curing step. 4 is a side view of the liquid crystal display panel 30 attached to the cover member 45, and FIG. 5 is a perspective view thereof.

<Liquid crystal display panel manufacturing process>
First, for example, on a large glass substrate having a thickness of about 0.7 mm, by using a well-known method, a TFT substrate constituent portion including gate lines, source lines, TFTs, and pixel electrodes is formed in a matrix, A TFT mother substrate (not shown) is produced. On the TFT mother substrate, an alignment film is formed by performing a rubbing process after forming a polyimide resin film so as to cover each TFT substrate component.

  In addition, for example, a CF substrate constituent portion including a black matrix, a color filter layer, and a common electrode is formed in a matrix shape on a large glass substrate having a thickness of about 0.7 mm using a known method. A mother substrate (not shown) is produced. Note that a polyimide resin film is formed on the CF mother substrate so as to cover each common electrode, and then an alignment film is formed by performing a rubbing process.

  Subsequently, for example, using a dispenser, the sealing material 16 is drawn in a frame shape on each CF substrate constituent portion of the CF mother substrate.

  Thereafter, a liquid crystal material is dropped on a region surrounded by the sealing material 16 on the CF mother substrate on which the sealing material 16 is drawn.

  Further, the CF mother substrate onto which the liquid crystal material is dropped and the TFT mother substrate are bonded together under reduced pressure, and then released to the atmospheric pressure to pressurize the outer surfaces of the TFT mother substrate and the CF mother substrate. A bonded body is prepared.

  Subsequently, after curing each sealing material 16 sandwiched between large bonded bodies, each glass substrate constituting the TFT mother substrate and the CF mother substrate is subjected to chemical polishing treatment (chemical etching treatment). Each plate is thinned to about 05 mm to 0.3 mm.

  Then, on the outer surface of the thinned TFT substrate, for example, the cutting edge of the disc-shaped cutting blade is brought into contact with the periphery of each TFT substrate constituting portion while the cutting edge is rolled. As a result, a linear crack is formed, and the crack is grown in the thickness direction, whereby the TFT mother substrate is divided into each TFT substrate constituent portion, and the TFT substrate 10 (see FIG. 2) is manufactured. . Here, the cutting edge of the cutting blade is made of, for example, cemented carbide such as tungsten carbide, sintered diamond, or the like.

  Subsequently, after reversing the front and back of the bonded body from which the TFT mother substrate has been divided, on the outer surface of the CF mother substrate, for example, while contacting the cutting edge of the cutting blade along the periphery of each CF substrate component By rolling the cutting blade, a linear crack is formed, and the crack is grown in the thickness direction, so that the CF mother substrate is divided into each CF substrate component, and the CF substrate 20 (See FIG. 2).

  As described above, the planar liquid crystal display panel 30 (see FIG. 2) is manufactured. Thereafter, after polarizing plates 31a and 31b are respectively attached to the surface of the TFT substrate 10 and the surface of the CF substrate 20 of the liquid crystal display panel 30, an FPC 32 is attached to the end of the liquid crystal display panel 30 via an ACF (Anisotropic Conductive Film). Implement.

<Panel deformation process>
First, as shown in FIG. 2, after a cylinder is cut vertically on a sticking table 60 and a transparent resin sticking jig 70 having a cut surface as a bottom surface is placed, the sticking jig 70 is placed. The cover member 45 described above is installed on the peripheral surface.

  Subsequently, as shown in FIG. 2, the adhesive 35 a is uniformly applied to the peripheral surface of the cover member 45 installed in the sticking jig 70 by, for example, brushing or dropping with a dispenser and subsequent spreading with a blade. .

  Further, as shown in FIG. 2, a flat liquid crystal display panel 30 in which polarizing plates 31a and 31b are attached to one end of a cover member 45 coated with an adhesive 35a in the liquid crystal display panel manufacturing process. After bringing one end into contact with each other, the liquid crystal display panel 30 is deformed along the peripheral surface of the cover member 45 by rolling the sticking roll 65 along the surface of the liquid crystal display panel 30 (polarizing plate 31a). Let

<Adhesive curing process>
As shown in FIG. 3, the surface of the liquid crystal display panel 30 (polarizing plate 31a) is shown in the figure with respect to the adhesive 35a disposed between the liquid crystal display panel 30 deformed in the panel deformation step and the cover member 45. The adhesive 35a is cured by irradiating UV light L from the lower side in the figure while pressing from the upper side. Thereby, the adhesive layer 35 is formed between the liquid crystal display panel 30 and the cover member 45, and the cover member 45 is attached to the peripheral surface of the liquid crystal display panel 30 as shown in FIGS. 4 and 5.

  After that, as shown in FIG. 1, the liquid crystal display panel 30 with the cover member 45 attached is incorporated into the bezel 41 in which the backlight unit 40 is accommodated.

  As described above, the liquid crystal display device 50 of the present embodiment can be manufactured.

  As described above, according to the liquid crystal display device 50 of the present embodiment, the cover member 45 is provided on the entire peripheral surface of the CF substrate 20, and the curvature of the surface of the cover member 45 on the CF substrate 20 side is that of the CF substrate 20. Since the curvature is the same as the curvature of the surface on the cover member 45 side, when the TFT substrate 10 and the CF substrate 20 are deformed into a curved shape, the inward bending of the CF substrate 20 disposed on the inner side is suppressed. be able to. As a result, even when the TFT substrate 10 and the CF substrate 20 are deformed into a curved shape, the distance between the TFT substrate 10 and the CF substrate 20 can be kept constant. The occurrence of uneven thickness can be suppressed.

  Further, according to the liquid crystal display device 50 of the present embodiment, the thermal expansion coefficient of the cover member 45 is approximately the same as the thermal expansion coefficients of the TFT substrate 10 and the CF substrate 20, so that the environment in which the liquid crystal display device 50 is installed. Even if the temperature rises, the elongation of the cover member 45 becomes approximately the same as the elongation of the TFT substrate 10 and the CF substrate 20. Thereby, since generation | occurrence | production of the tensile stress of the bending direction of the TFT substrate 10 and CF substrate 20 can be suppressed, the crack by the thermal expansion of the TFT substrate 10 and CF substrate 20 can be suppressed.

  Further, according to the liquid crystal display device 50 of the present embodiment, since the adhesive layer 35 having transparency is interposed between the cover member 45 and the peripheral surface of the CF substrate 20, the cover is provided on the peripheral surface of the CF substrate 20. The member 45 can be bonded via the polarizing plate 31b, and the deterioration of display quality via the cover member 45 can be suppressed.

  In the present embodiment, the liquid crystal display device in which the TFT substrate is disposed outward as the first substrate when the liquid crystal display panel 30 is deformed into a curved surface is illustrated. However, the present invention deforms the liquid crystal display panel into a curved surface. The present invention can also be applied to a liquid crystal display device in which the CF substrate is disposed outward as the first substrate.

  In the present embodiment, an active matrix driving type liquid crystal display device including a TFT as a switching element is illustrated. However, the present invention is an active matrix driving type or passive matrix driving type liquid crystal display including other switching elements. It can also be applied to devices.

  In the present embodiment, a glass substrate is exemplified as the brittle substrate, but the present invention can also be applied to a brittle substrate such as a ceramic substrate or a silicon substrate.

  As described above, in the curved liquid crystal display device manufactured by bonding a pair of glass substrates, the present invention can suppress the occurrence of cell thickness unevenness, and thus a pair of brittle substrates are bonded together. This is useful for a curved display device to be manufactured.

It is sectional drawing of the liquid crystal display device 50 which concerns on embodiment of this invention. 6 is an explanatory diagram for explaining a panel deformation step in the method of manufacturing the liquid crystal display device 50. FIG. 6 is an explanatory diagram for explaining an adhesive curing step in the method for manufacturing the liquid crystal display device 50. FIG. 4 is a side view of the liquid crystal display panel 30 attached to a cover member 45. FIG. 3 is a perspective view of a liquid crystal display panel 30 attached to a cover member 45. FIG. It is explanatory drawing explaining the method to manufacture the conventional curved-surface-shaped liquid crystal display device. It is the side view which showed typically the curved-surface-shaped liquid crystal display device 150 manufactured with the conventional manufacturing method.

Explanation of symbols

10 TFT substrate (first substrate)
15 Liquid crystal layer 20 CF substrate (second substrate)
35 Adhesive layer 45 Cover member 50 Liquid crystal display device

Claims (4)

A brittle first substrate;
A brittle second substrate disposed opposite the first substrate;
A liquid crystal layer provided between the first substrate and the second substrate,
A liquid crystal display device in which the first substrate and the second substrate are deformed into a curved shape so that the first substrate faces outward,
A curved cover member is provided on the entire surface of the second substrate,
2. The liquid crystal display device according to claim 1, wherein the curvature of the surface of the cover member on the second substrate side is the same as the curvature of the surface of the second substrate on the cover member side. The liquid crystal display device according to claim 1,
The liquid crystal display device according to claim 1, wherein a thermal expansion coefficient of the cover member is the same as that of the first substrate and the second substrate. The liquid crystal display device according to claim 2,
The liquid crystal display device, wherein the cover member, the first substrate, and the second substrate are made of glass. The liquid crystal display device according to claim 1,
The cover member and the peripheral surface of the second substrate are bonded to each other through a transparent adhesive layer.

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