JP2009092884A - Liquid crystal display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display having a display surface of a curved surface shape by using glass as a substrate material which constitutes the liquid crystal display. <P>SOLUTION: The liquid crystal display is provided with a liquid crystal display panel 10 wherein a liquid crystal layer 13 is provided between an active matrix substrate 11 and a counter substrate 12. Both the active matrix substrate 11 and the counter substrate 12 are formed by using substrates made of glass, a transparent film 17 (a first film) is stuck onto the front surface 10a side of the liquid crystal display panel and a reflection plate 15 (a second film) with a polarizing film is stuck onto a rear surface 10b side. The surfaces of the liquid crystal display panel 10 are curved by utilizing stress difference generated between the front surface 10a and the rear surface 10b by temperature change caused by difference between thermal expansion coefficients of the transparent film 17 and the reflection plate 15 with the polarizing film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device having a panel with a curved display surface and a method for manufacturing the same.

  In recent years, a liquid crystal display device having a curved display surface has been proposed as the use of the liquid crystal display device in various applications is expanding. In such a liquid crystal display device having a curved display surface, a resin substrate is generally used as a substrate serving as a base for an active matrix substrate (TFT substrate) and a color filter (CF) substrate.

  For example, Patent Document 1 discloses a technique in which two resin substrates constituting a liquid crystal display device have different thermal expansion coefficients to form a display surface in a curved shape.

In Patent Document 2, a pair of plastic substrates constituting a liquid crystal display device is made of a polyurethane polymer, and the plastic substrate has a shape memory function or a shape recovery function at the glass transition temperature of the polyurethane polymer. A liquid crystal display device is disclosed. With this configuration, it is said that the curved surface shape can be maintained without continuously applying external force.
JP 7-301789 A (published November 14, 1995) Japanese Patent Laid-Open No. 7-140451 (released on June 2, 1995)

  However, when the substrate itself that becomes the foundation of the TFT substrate and the CF substrate is manufactured from a resin substrate (plastic substrate), the following problems occur.

  That is, the liquid crystal display device using a resin substrate as described above has a heat resistance temperature sufficient for forming a TFT substrate and a CF substrate since the heat resistant temperature of the substrate is lower than that of a glass substrate. It is difficult to make a substrate using it.

  Therefore, when a TFT substrate and a CF substrate are formed by applying low-temperature heat as compared with the case where a glass substrate is used, there arises a problem that the patterning accuracy is lowered. In addition, the resin substrate is softer and easier to bend than the glass substrate, and the large thermal expansion coefficient also causes a decrease in patterning accuracy. In addition, since a high-temperature thermal process cannot be applied, there is a problem that the materials that can be used are limited and the manufacturing cost is increased.

  In addition, as in the above-mentioned Patent Documents 1 and 2, when a panel is formed by using a material having a different coefficient of thermal expansion and a material as a substrate material between the CF substrate and the TFT substrate, the CF substrate and the TFT substrate are separated in the manufacturing process. Since the resin substrates are warped differently, it is very difficult to bond the two substrates together. For this reason, problems such as a decrease in manufacturing yield, an increase in manufacturing cost, and a decrease in panel reliability also occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device having a curved display surface using glass as a substrate material constituting the liquid crystal display device. .

  In order to solve the above-described problems, a liquid crystal display device according to the present invention is a liquid crystal display device including a liquid crystal display panel in which a liquid crystal layer is provided between an active matrix substrate and a counter substrate. The matrix substrate and the counter substrate are both formed of a glass substrate, and a film is attached to at least one of the active matrix substrate and the counter substrate on the side opposite to the side where the liquid crystal layer is provided. The thermal expansion coefficient of the film is different from the thermal expansion coefficient of the material constituting the surface of the liquid crystal display panel opposite to the surface on which the film is attached. The display panel has a curved surface.

  Unlike the conventional liquid crystal display device having a curved display surface, the liquid crystal display device of the present invention uses glass having excellent heat resistance as a substrate material. Therefore, when pattern formation or the like is performed on the active matrix substrate and the counter substrate, a sufficient temperature can be applied, and the pattern accuracy can be prevented from being lowered.

  Furthermore, in the liquid crystal display device of the present invention, the front surface of the liquid crystal display panel (the surface opposite to the side where the liquid crystal layer of the counter substrate is provided) or the back surface (the side opposite to the side where the liquid crystal layer of the active matrix substrate is provided). The thermal expansion coefficient of the film disposed on at least one of the side surfaces) and the heat of the material of the member (eg, glass substrate, polarizing plate, reflector, etc.) disposed on the surface opposite to the film Due to the difference in expansion coefficient, the liquid crystal display panel is bent using a stress difference generated between the front surface and the back surface due to a change in temperature. By utilizing such a stress difference, it is possible to apply a force uniformly to the entire panel.

  Therefore, according to said structure, it can also prevent that a glass-made board | substrate is broken by force concentrating locally. Therefore, it is possible to avoid deterioration in manufacturing yield.

  In addition, according to the above configuration, since the same material can be used for each glass substrate serving as the base of the active matrix substrate and the counter substrate, the method of warping the substrate differs in the manufacturing process of each substrate. The problem that it is difficult to bond the two substrates together can be solved.

  In the liquid crystal display device of the present invention, the total thickness of the two glass substrates is preferably 0.1 mm or more and 0.8 mm or less.

  According to said structure, when the sum total of the thickness of two glass substrates is 0.8 mm or less, the temperature at the time of sticking a film to a liquid crystal display panel is 100 degreeC which does not generate | occur | produce a phase transition in liquid crystal material Even if it is below, the liquid crystal display panel which has sufficient curvature (namely, curvature radius R = 2000 mm or less) at the time of finishing can be obtained.

  Further, by setting the thickness of the glass substrate to about 0.05 mm per sheet, the bending stress can be reduced, and the yield when applying curvature is improved. However, if the thickness of one sheet is thinner than this, the manufacturing yield when the glass is made thinner is deteriorated. Therefore, the lower limit value of the thickness of one glass substrate is preferably 0.05 mm. From this, the total thickness of the two glass substrates is preferably 0.1 mm or more.

  In the liquid crystal display device of the present invention, the active matrix substrate and the counter substrate are each attached with a film on the side opposite to the side on which the liquid crystal layer is provided, and are attached to the counter substrate. The first film and the second film attached to the active matrix substrate may have different coefficients of thermal expansion.

  According to the above configuration, the liquid crystal can have a desired curvature by utilizing a stress difference generated by a change in temperature due to a difference in thermal expansion coefficient between the first film and the second film. The surface of the display panel can be curved more easily.

  In the liquid crystal display device of the present invention, one of the first film and the second film is a transparent film, and the other is a polarizing plate, a retardation plate, a reflecting plate, and a light scattering plate. It may be selected from a group.

  According to the above configuration, a liquid crystal display device having a curved surface is easily produced by a difference in thermal expansion coefficient between the transparent film and any one of a polarizing plate, a retardation plate, a reflecting plate, and a light scattering plate. be able to.

  In the liquid crystal display device of the present invention, the transparent film is preferably selected from the group consisting of polycarbonate, polyarylate, and polyethylene terephthalate.

According to the above configuration, polycarbonate, polyarylate, and polyethylene terephthalate all have a high coefficient of thermal expansion of 5.0 × 10 ⁻⁵ / ° C. or higher, so that a polarizing plate, a retardation plate, a reflector, and light scattering The difference in coefficient of thermal expansion from the other film selected from any one of the plates can be made sufficiently large. Thereby, a liquid crystal display panel can be easily curved by the change of temperature.

  In the liquid crystal display device of the present invention, the liquid crystal display panel may be disposed in a housing formed of a material whose shape changes when heat is applied.

  Conventionally, in order to manufacture a curved liquid crystal display device, if an attempt is made to hold a liquid crystal display panel using a glass substrate in a curved housing, the liquid crystal display panel is stressed and fixed to the housing in a bent state. There was a need to do. For this reason, there is a problem in that a non-uniform force is easily applied to the liquid crystal display panel, the panel is broken during the manufacturing process, and the incidence of defective products is increased.

  According to the above configuration, the casing for housing the liquid crystal display panel is formed of a material whose shape changes when heat is applied, so that the entire apparatus including the casing is curved. It can be easily manufactured. In other words, the liquid crystal display panel using a glass substrate is curved without being broken during the manufacturing process by fixing the liquid crystal display panel inside the housing in a heated state and then returning it to room temperature. Can be easily manufactured.

  In the liquid crystal display device of the present invention, the material may be a bimetal material.

  According to said structure, a housing | casing can also be curved like a liquid crystal display panel by changing temperature.

  In the liquid crystal display device of the present invention, the material may be a shape memory alloy material.

  According to said structure, a housing | casing can also be curved like a liquid crystal display panel by changing temperature.

  In order to solve the above problems, a manufacturing method of a liquid crystal display device according to the present invention includes a liquid crystal display panel in which a liquid crystal layer is provided between an active matrix substrate and a counter substrate. The substrates are both formed of a glass substrate material, and a film is attached to at least one of the active matrix substrate and the counter substrate on the side opposite to the side where the liquid crystal layer is provided, A method of manufacturing a liquid crystal display device, wherein the thermal expansion coefficient of the film is different from the thermal expansion coefficient of the material constituting the surface of the liquid crystal display panel opposite to the surface to which the film is attached. In the heated state, the film is attached to at least one of the active matrix substrate and the counter substrate, and the heated state is released. By Rukoto, by utilizing the stress difference generated between the material constituting the film and the surface of the opposite side, it is characterized by comprising the step of curving the surface of the liquid crystal display panel.

  In the method for manufacturing a liquid crystal display device of the present invention, the front surface (the surface opposite to the side where the liquid crystal layer of the counter substrate is provided) or the back surface (the side where the liquid crystal layer of the active matrix substrate is provided) The coefficient of thermal expansion of the film disposed on at least one of the opposite surfaces) and the material of the member (for example, glass substrate, polarizing plate, reflector, etc.) disposed on the surface opposite to the film Due to the difference in thermal expansion coefficient, the liquid crystal display panel is bent using a stress difference generated between the front surface and the back surface due to a change in temperature. By utilizing such a stress difference, it is possible to apply a force uniformly to the entire panel.

  Therefore, according to said method, it can prevent that a glass-made board | substrate breaks because force concentrates locally. Therefore, it is possible to avoid deterioration in manufacturing yield.

  In the method for manufacturing a liquid crystal display device of the present invention, the liquid crystal display device further includes a housing formed of a material whose shape changes by applying heat, and heating is performed after the step of attaching the film. It is preferable that the method further includes a step of placing the liquid crystal display panel in the housing in the maintained state, and the heating state is released after the step.

  According to the above method, when manufacturing a liquid crystal display device in which the liquid crystal display panel is housed in the housing, the liquid crystal display panel is fixed inside the housing with heat applied, and then returned to room temperature. By performing the process, the liquid crystal display panel using the glass substrate can be disposed in the housing without being broken during the manufacturing, and a curved liquid crystal display device can be easily manufactured.

  In the liquid crystal display device of the present invention, as described above, the active matrix substrate and the counter substrate are both formed of a glass substrate, and at least one of the active matrix substrate and the counter substrate includes the liquid crystal layer. A film is affixed to the side opposite to the side where the film is provided, and the coefficient of thermal expansion of the film constitutes the surface of the liquid crystal display panel on the side opposite to the surface to which the film is affixed. The surface of the liquid crystal display panel is curved due to the difference in thermal expansion coefficient of the material.

  The method for manufacturing a liquid crystal display device of the present invention is a method for manufacturing a liquid crystal display device having the above-described configuration, and the film is attached to at least one of the active matrix substrate and the counter substrate in a heated state. And a step of curving the surface of the liquid crystal display panel by utilizing a stress difference generated between the film and the material constituting the surface on the opposite side by releasing the heating state. Is included.

  Therefore, according to the present invention, since glass having excellent heat resistance is used as a substrate material, a sufficient temperature can be applied when patterning or the like is performed on the active matrix substrate and the counter substrate. The effect that it can prevent that falls is produced. Further, according to the present invention, the panel is bent by utilizing the difference in stress generated between the front and back surfaces of the panel due to a change in temperature, so that the glass substrate breaks due to local concentration of force. This can be prevented. Therefore, it is possible to avoid deterioration in manufacturing yield.

[Embodiment 1]
One embodiment of the present invention is described below with reference to FIGS. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. This is just an example.

  In this embodiment, a reflective liquid crystal display device that performs display by reflecting external light with a reflecting plate will be described as an example. The liquid crystal display device according to the present embodiment is a liquid crystal display having a curved surface formed using an active matrix substrate (TFT substrate) and a color filter substrate (CF substrate) manufactured using a glass substrate. Device.

  FIG. 1 shows a cross-sectional configuration of a liquid crystal display panel 10 provided in the liquid crystal display device according to the present embodiment.

  As shown in FIG. 1, a liquid crystal display panel 10 includes a liquid crystal layer 13 between an active matrix substrate (TFT substrate) 11 and a color filter (CF) substrate (counter substrate) 12 disposed to face the active matrix substrate (TFT substrate) 11. Has a sandwiched structure.

  The TFT substrate 11 is a glass substrate (glass substrate) on which scanning matrixes, grid-like matrix wiring made up of signal lines, switching elements (TFT elements) provided for each pixel, pixel electrodes, and the like are formed. is there. The color filter substrate 12 has a structure in which a common electrode, a color filter layer, and the like are formed on a glass substrate. As the detailed structures of the TFT substrate 11 and the color filter substrate 12, a conventionally known structure can be applied, and the description thereof is omitted.

  The liquid crystal layer 13 has a structure in which a liquid crystal material is sealed between two substrates by a sealing material 14. In the liquid crystal layer 13, a spacer (not shown) for maintaining a distance between the TFT substrate 11 and the CF substrate 12 is disposed.

  A reflective plate 15 with a polarizing film (second film) is attached to the outside of the TFT substrate 11 (the side opposite to the side where the liquid crystal layer 13 is provided). On the other hand, a polarizing plate 16 is attached to the outside of the CF substrate 12 (the side opposite to the side on which the liquid crystal layer 13 is provided), and a transparent film (first film) 17 is further provided on the outside thereof. Is pasted.

In the present embodiment, the transparent film 17 is made of polycarbonate, the coefficient of thermal expansion is 6.9 × 10 ⁻⁵ / ° C., and the thickness is about 0.1 mm. Moreover, the thermal expansion coefficient of the reflecting plate 15 with a polarizing film and the polarizing plate 16 is 2.0 * 10 < ^-5 > / degreeC, and both these thickness is about 0.15 mm.

  Thus, in this Embodiment, the thermal expansion coefficient of the transparent film 17 (1st film) arrange | positioned at the surface 10a side of the liquid crystal display panel 10, and the reflecting plate with a polarizing film arrange | positioned at the back surface 10b side 15 (second film) has a different coefficient of thermal expansion.

  Thereby, using the difference in stress generated between the front surface 10a side and the back surface 10b side due to a change in temperature, the liquid crystal display panel 10 has a front surface (image display surface) 10a as shown in FIG. It has a shape curved toward the back surface (surface opposite to the image display surface) 10b from the end toward the center. That is, the surface of the liquid crystal display panel 10 has a curved surface that is smoothly recessed.

  Then, the manufacturing method of the liquid crystal display panel 10 concerning this Embodiment is demonstrated. In addition, about the manufacturing method of the TFT substrate 11 and the CF substrate 12, it can implement using a conventionally well-known patterning method. The step of encapsulating the liquid crystal material between the TFT substrate 11 and the CF substrate 12 can also be performed using a conventionally known encapsulating method. Therefore, description of these processes is omitted here, and the process of attaching each film to a panel in which a liquid crystal material is sealed will be described below with reference to FIGS.

  FIG. 2 shows that the polarizing plate 16 and the transparent film 17 are attached to the CF substrate 12 while being heated to a high temperature (about 80 ° C.) in the manufacturing process of the liquid crystal display panel 10, and the reflective plate 15 with a polarizing film is attached to the TFT substrate. FIG.

  FIG. 1 is a diagram illustrating a state in which the heating state illustrated in FIG. 2 is canceled and the liquid crystal display panel 10 is returned to a practical temperature (about 25 ° C.) (that is, the liquid crystal display panel 10 is completed).

  First, a thermostat (not shown) capable of temperature adjustment is prepared, and the inside of the thermostat is set to about 80 ° C. In this thermostatic chamber, a liquid crystal display panel in which a liquid crystal material is sealed is placed between the TFT substrate 11 and the CF substrate 12, and the work of attaching the reflecting plate 15 with a polarizing film and the polarizing plate 16 to the front and back surfaces, respectively, is performed. .

  Here, the thickness of the glass substrate which is the base of the TFT substrate 11 and the CF substrate 12 is both 0.25 mm, and the combined thickness (total thickness) of the two substrates is 0.5 mm. . The thicknesses of the polarizing plate 16 and the reflecting plate 15 with the polarizing film are both about 0.15 mm, and the sizes are both about 300 × 150 mm.

Next, the transparent film 17 (made of polycarbonate: coefficient of thermal expansion: 6.9 × 10 ⁻⁵ / ° C.) having a thickness of about 0.1 mm is further pasted on the polarizing plate 16.

  Then, after leaving in this heated state (about 80 ° C.) for about 10 minutes, it is taken out and returned to room temperature (about 25 ° C.), whereby a curved liquid crystal display panel 10 is obtained as shown in FIG. At this time, when the radius of curvature of the surface 10a of the liquid crystal display panel 10 was measured, R = about 1500 mm.

Such bending is mainly due to the temperature of the transparent film 17 being stretched, while the polarizing plate 16 and the reflecting plate 15 with a polarizing film are also slightly stretched. This is because 0 × 10 ⁻⁵ / ° C. is small compared to the transparent film 17, and thus the influence of temperature change is small. Thus, since the thermal expansion coefficient of the transparent film 17 arrange | positioned at the surface 10a side of the liquid crystal display panel 10 differs from the thermal expansion coefficient of the reflecting plate 15 with a polarizing film arrange | positioned at the back surface 10b side, the above-mentioned When the heating state is released, a stress difference occurs between the two. In the present invention, the liquid crystal display panel 10 is bent using this stress difference.

  That is, by returning the liquid crystal display panel 10 in the constant temperature layer at 80 ° C. to room temperature (25 ° C.), the polarizing plate 15 with the polarizing film disposed on the back surface 10 b side is hardly reduced in value, but on the front surface 10 a side. When the arranged transparent film 17 is contracted, the liquid crystal display panel 10 is subjected to a bending force so that the central portion of the surface 10a is recessed.

〔Example〕
Here, the result of having verified the preferable thickness of the glass substrate used for preparation of the liquid crystal display panel 10 is shown.

  The thickness of the glass substrate used for manufacturing the TFT substrate 11 and the CF substrate 12 constituting the liquid crystal display panel 10 is 1.0 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm. Seven types of 0.4 mm substrates were prepared. The thickness of a glass substrate here means the total thickness of each glass substrate used for a TFT substrate and a CF substrate.

  A TFT substrate and a CF substrate were prepared using a glass substrate of each thickness, the TFT substrate and the CF substrate were bonded together, and a liquid crystal material was sealed between them to prepare a liquid crystal display panel. After affixing a transparent film 17 (made of polycarbonate) having a thickness of 0.1 mm to the liquid crystal display panel 10 in a state where the temperature of the thermostatic chamber was changed from 40 ° C. to 130 ° C., the liquid crystal display panel 10 was allowed to stand at each temperature for 10 minutes. The curvature radius R (mm) after returning to normal temperature (25 degreeC) was measured. The result is shown in FIG.

  In addition, the size of the glass substrate used here is about 300 mm × 150 mm, and the size of each attached film (transparent film, reflector, polarizing plate, etc.) is substantially the same as this.

  In a liquid crystal display panel, if the radius of curvature R is 2000 mm or more, it is difficult to determine that the object is bent visually. Therefore, the radius of curvature R is preferably 2000 mm or less. Moreover, since the thermal phase transition temperature of the liquid crystal material used for a general liquid crystal display panel is about 80 to 100 ° C., when the liquid crystal display panel is set to 100 ° C. or higher, the liquid crystal material becomes a complete liquid. Therefore, the temperature applied to the liquid crystal display panel is desirably 100 ° C. or lower.

  However, as shown in FIG. 3, when the total thickness of the glass substrates constituting the liquid crystal display panel is 0.9 mm or more, the curvature radius R is 2000 mm unless the heating temperature at the time of attaching the film is 100 ° C. or more. It was confirmed that it was not the following.

  From this, it was confirmed that the total thickness of the two glass substrates is preferably 0.8 mm or less. As a result, a curved liquid crystal display panel can be produced even when the heating temperature when performing the operation of attaching each film (transparent film, reflector, etc.) to the liquid crystal display panel is 100 ° C. or lower.

  The plate thickness of the glass substrate is preferably 0.05 mm or more per sheet.

  By setting the thickness of the glass substrate to about 0.05 mm per sheet, the bending stress can be reduced, and the yield when imparting curvature is improved. However, if the thickness of one sheet is thinner than this, the manufacturing yield when the glass is made thinner is deteriorated. For this reason, the lower limit value of the thickness of the glass substrate is preferably 0.05 mm.

  Therefore, the total thickness of the two glass substrates constituting the liquid crystal display panel is preferably 0.1 mm or more and 0.8 mm or less.

  Further, as shown in FIG. 3, the curvature of the liquid crystal display panel tends to change greatly when the heating temperature at the time of attaching the film is set to 60 ° C. or higher. On the other hand, at a temperature of 60 ° C. or lower, the change in curvature due to the temperature change is small. That is, when the temperature is about 60 ° C. or lower, the curvature of the liquid crystal display panel does not change much. From this, it is preferable that the heating temperature when performing the operation of attaching each film to the liquid crystal display panel is 60 ° C. or higher and 100 ° C. or lower.

  In addition, since the curvature of the liquid crystal display panel does not change much when the temperature is about 60 ° C. or less as described above, the liquid crystal display panel itself is entirely in the practical use temperature range (usually 20 to 30 ° C.) The curved shape can be stably maintained.

  Moreover, if the transparent film 17 made of polycarbonate is pasted, the panel can be formed by the difference in coefficient of thermal expansion between the transparent film and the glass substrate disposed on the opposite side without using the reflector 15 with polarizing film or the polarizing plate 16. Since it can be curved, a liquid crystal display device that is curved as a whole can be obtained.

  As described above, unlike a conventional liquid crystal display device having a curved display surface, a liquid crystal display device provided with the liquid crystal display panel of the present embodiment is a glass having excellent heat resistance as a substrate material. Is used. Therefore, a sufficient temperature can be applied when pattern formation or the like is performed on the TFT substrate and the CF substrate, and the pattern accuracy can be prevented from being lowered.

  Furthermore, in this Embodiment, the thermal expansion coefficient of the transparent film (2nd film) arrange | positioned at the surface side of a liquid crystal display panel, and the reflecting plate with a polarizing film (1st film) arrange | positioned at the back side Due to the difference in thermal expansion coefficient, the liquid crystal display panel is bent by utilizing the difference in stress generated between the two films due to a change in temperature. By utilizing such a stress difference, it is possible to apply a force uniformly to the entire panel. For this reason, it is possible to prevent the glass substrate from being broken by locally concentrating the force. Therefore, it is possible to avoid deterioration in manufacturing yield.

  In addition, since the same material can be used for the glass substrate that is the foundation of the TFT substrate and the CF substrate, the method of warping the substrates differs in the manufacturing process of each substrate, making it difficult to bond the two substrates together. The problem of becoming can also be solved.

  Further, by selecting the type of transparent film to be attached based on the coefficient of thermal expansion, the panel surface can be curved so as to have a desired radius of curvature.

  In the above-described embodiment, the transparent film 17 is attached to the surface 10a side of the liquid crystal display panel 10 and curved in a direction in which the surface 10a is recessed. However, the present invention is not necessarily limited to such a configuration. . That is, a configuration in which the liquid crystal display panel 10 is curved to the opposite side to the above by attaching the transparent film 17 to the back surface 10b side of the liquid crystal display panel 10 in a heated state and then returning to room temperature (that is, the front surface 10a is The shape curved so as to rise toward the center portion is also included in the scope of the present invention.

  Further, in the above-described embodiment, the polarizing plate 16 and the transparent film 17 are attached to the liquid crystal display panel 10 on the CF substrate 12 side, and the polarizing plate-attached reflective plate 15 is attached to the TFT substrate 11 side of the liquid crystal display panel 10. However, the present invention is not limited to such a configuration. For example, the transparent film 17 and the polarizing plate 16 pasted only on the front surface 10a of the liquid crystal display panel 10 are curved, and then the polarizing plate with the polarizing film 15 is pasted on the back surface 10b of the liquid crystal display panel 10. Also good.

  In the above embodiment, the liquid crystal display panel 10 in which the liquid crystal material is encapsulated is curved. However, the liquid crystal display panel 10 before the liquid crystal material is encapsulated (that is, the TFT substrate and the CF substrate are bonded together). The liquid crystal material may be encapsulated after the curved panel) is curved.

[Embodiment 2]
Subsequently, a second embodiment of the present invention will be described below.
In this embodiment, the liquid crystal display device 30 having a configuration in which the liquid crystal display panel 10 described in Embodiment 1 is housed in a housing 31 (also referred to as a bezel) is shown in FIGS. The description will be given with reference.

  FIG. 5 is a diagram showing the shape of the liquid crystal display device 30 in a state of being heated to a high temperature (about 80 ° C.) during the manufacturing process of the liquid crystal display device 30. FIG. 4 is a diagram showing a state where the heating state is canceled and the liquid crystal display device 30 is returned to a practical temperature (about 25 ° C.) (that is, the liquid crystal display panel 10 is completed).

  As shown in FIG. 4, in the liquid crystal display device 30 of the present embodiment, the liquid crystal display panel 10 is arranged in a housing 31 formed of a material whose shape changes when heat is applied. About the liquid crystal display panel 10, since the thing of the structure similar to what was demonstrated in Embodiment 1 can be used, the description is abbreviate | omitted.

  The casing 31 is flat when the temperature is 80 ° C. (see FIG. 5), and is bent at a room temperature (about 25 ° C.) as shown in FIG. 4, or a shape memory alloy material ( For example, it is made of a Ni—Ti-based shape memory alloy). The casing 31 and the liquid crystal display panel 10 are bonded by an adhesive resin 32. Specifically, the side surface inside the casing 31 and the end of the TFT substrate 11 of the liquid crystal display panel 10 are connected by an adhesive resin 32.

  As shown in FIG. 4, the liquid crystal display device 30 according to the present embodiment includes a liquid crystal display panel 10 and a housing 31 that houses the liquid crystal display panel 10 in a normal state (that is, a state at room temperature). Both are curved.

  Then, the manufacturing method of the liquid crystal display device 30 concerning this Embodiment is demonstrated.

  First, a thermostat (not shown) capable of temperature adjustment is prepared in the same manner as in the first embodiment, and the inside of the thermostat is set to about 80 ° C. In this thermostatic chamber, a liquid crystal display panel in which a liquid crystal material is sealed is placed between the TFT substrate 11 and the CF substrate 12, and the work of attaching the reflecting plate 15 with a polarizing film and the polarizing plate 16 to the front and back surfaces, respectively, is performed. . Then, an operation of attaching a transparent film 17 having a thickness of about 0.1 mm on the polarizing plate 16 is performed.

  Next, in the same constant temperature bath at 80 ° C., the liquid crystal display panel 10 to which each film is attached is placed in the housing 31 and fixed with an adhesive resin 32 or the like, and in this state (about 80 ° C.) Leave for 10 minutes. Thereafter, the liquid crystal display device 30 is taken out of the thermostat and returned to room temperature (about 25 ° C.). Thereby, as shown in FIG. 4, the liquid crystal display device 30 contained in the curved casing 31 is obtained.

  Here, as the material of the casing 31, a material adjusted so as to be flat at a high temperature and to have the curvature shown in FIG. 3 at a normal temperature (about 25 ° C.) is used. Specific examples of the material to be used include, for example, Fuji Metal 5020 for a bimetal material, and an alloy such as a Ni—Ti material for a shape memory alloy material.

  In the first and second embodiments, a glass substrate having a total thickness of 0.5 mm and one side of 0.25 mm is used. However, the present invention is not limited to this. In the present invention, any combination of glass thicknesses may be used as long as the total thickness (total thickness) of the glass substrate on the TFT substrate side and the glass substrate on the CF substrate side is 0.8 mm or less. The glass substrates may have different thicknesses such that the glass substrate is 0.1 mm and the TFT substrate side glass substrate is 0.4 mm.

  Further, the size of the liquid crystal display panel is not limited to the size described in the above embodiment, and may be any size.

Moreover, in said embodiment, although the film made from a polycarbonate was used as the transparent film 17, this invention is not limited to this. Examples of transparent film materials other than polycarbonate include polyarylate (thermal expansion coefficient: 6.2 × 10 ⁻⁵ / ° C.) and polyethylene terephthalate (thermal expansion coefficient: 5.5 × 10 ⁻⁵ / ° C.). Examples thereof include a film having a high expansion coefficient.

  In each of the above embodiments, the reflective liquid crystal display device has been described as an example. However, the present invention is not limited to such a configuration. The present invention can also be applied to a transmissive liquid crystal display device provided with a backlight on the back surface. In this case, if a backlight that can be curved is installed on the TFT substrate side, a liquid crystal display device that is curved as a whole can be realized.

  According to the present invention, a liquid crystal display device using a glass substrate can be easily bent.

It is sectional drawing which shows the structure of the liquid crystal display panel with which the liquid crystal display device concerning one embodiment of this invention was equipped. FIG. 2 is a cross-sectional view illustrating a configuration in the middle of manufacturing of the liquid crystal display panel illustrated in FIG. 1 and illustrating a configuration in a high temperature state in order to attach a film and a polarizing plate. In the liquid crystal display device of one embodiment of the present invention, it is a graph showing the relationship between the temperature at the time of film sticking and the finished curvature of the liquid crystal display panel when the thickness of the glass substrate is varied. It is sectional drawing which shows the structure of the liquid crystal display device concerning the 2nd Embodiment of this invention. FIG. 4 shows a configuration in the course of manufacturing the liquid crystal display device shown in FIG. 4, in which a film and a polarizing plate are pasted on the liquid crystal display panel, and then the liquid crystal display panel is placed in a high temperature state so as to fit in the housing. FIG.

Explanation of symbols

10 liquid crystal display panel 10a front surface (liquid crystal display panel) 10b back surface (liquid crystal display panel) 11 TFT substrate (active matrix substrate)
12 CF (color filter) substrate (counter substrate)
13 Liquid crystal layer 14 Sealing material 15 Reflector with polarizing film (second film)
16 Polarizing plate 17 Transparent film (first film)
30 Liquid crystal display device 31 Housing 32 Adhesive resin R Curvature radius

Claims (10)

A liquid crystal display device comprising a liquid crystal display panel in which a liquid crystal layer is provided between an active matrix substrate and a counter substrate,
The active matrix substrate and the counter substrate are both formed of a glass substrate,
At least one of the active matrix substrate and the counter substrate has a film attached to the side opposite to the side where the liquid crystal layer is provided,
The coefficient of thermal expansion of the film is different from the coefficient of thermal expansion of the material constituting the surface of the liquid crystal display panel opposite to the surface on which the film is affixed. A liquid crystal display device having a curved surface.   2. The liquid crystal display device according to claim 1, wherein the total thickness of the two glass substrates is 0.1 mm or more and 0.8 mm or less. Each of the active matrix substrate and the counter substrate has a film attached to the side opposite to the side where the liquid crystal layer is provided,
3. The first film affixed to the counter substrate and the second film affixed to the active matrix substrate have different coefficients of thermal expansion. A liquid crystal display device according to 1. Either one of the first film and the second film is a transparent film,
4. The liquid crystal display device according to claim 3, wherein the other one is selected from the group consisting of a polarizing plate, a retardation plate, a reflecting plate, and a light scattering plate.   The liquid crystal display device according to claim 4, wherein the transparent film is selected from the group consisting of polycarbonate, polyarylate, and polyethylene terephthalate.   The liquid crystal display device according to claim 1, wherein the liquid crystal display panel is disposed in a casing formed of a material whose shape changes when heat is applied.   The liquid crystal display device according to claim 6, wherein the material is a bimetal material.   The liquid crystal display device according to claim 6, wherein the material is a shape memory alloy material. A liquid crystal display panel provided with a liquid crystal layer between an active matrix substrate and a counter substrate,
The active matrix substrate and the counter substrate are both formed of a glass substrate material,
At least one of the active matrix substrate and the counter substrate has a film attached to the side opposite to the side where the liquid crystal layer is provided,
This is a method for manufacturing a liquid crystal display device in which the thermal expansion coefficient of the film is different from the thermal expansion coefficient of the material constituting the surface of the liquid crystal display panel opposite to the surface to which the film is attached. And
A process of attaching the film to at least one of the active matrix substrate and the counter substrate in a heated state;
A step of curving the surface of the liquid crystal display panel using a stress difference generated between the film and the material constituting the opposite surface by releasing the heating state;
A method of manufacturing a liquid crystal display device comprising: The liquid crystal display device further includes a housing formed of a material whose shape changes by applying heat,
The method according to claim 9, further comprising a step of arranging the liquid crystal display panel in the housing in a state where heating is maintained after the step of attaching the film, and the heating state is released after the step. The manufacturing method of the liquid crystal display device of description.

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