JP2017129773A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display panel that allows a simple configuration to suppress display unevenness at corner parts.SOLUTION: A liquid crystal display panel 100 comprises an array substrate 110 and opposing substrate 120 that are curved along a display surface 5a. In the array substrate 110 and opposing substrate 120, first and second liquid crystal orientation films 112 and 122 are provided, respectively. The display surface 5a is quadrangular, and when viewed from forwards the display surface 5a, the display surface 5a comprises: a left upper region 8; a right upper region 9; a right lower region 11; a left lower region 10; and a center region 12 that is located at a center of the display surface 5a. At least one of orientation directions of the first and second liquid crystal orientation films 112 and 122 in a region overlapping the left upper region 8, right upper region 9, right lower region 11 and left lower region 10 in a plane view is deviated in comparison with orientation directions of the first and second liquid crystal orientation films 112 and 122 in a region overlapping the center region 12 in the plane view.SELECTED DRAWING: Figure 1

Description

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

  In recent years, liquid crystal display devices have attracted attention in televisions and personal computer displays. Liquid crystal display devices are characterized by thinness and low power consumption, and are widely used from small devices such as mobile phones to large devices such as televisions. One of the fields in which many demands can be expected from consumer use to industrial use. It can be said that it is one.

  Conventionally, a liquid crystal display panel has a flat shape, but recently, a liquid crystal display panel having a curved display surface excellent in design has attracted much attention. As a method of achieving the curved shape, as shown in Patent Document 1, after a flat liquid crystal display panel is once manufactured, it is fixed to a curved cover glass or a holding material and forcedly curved. ing.

  However, since the liquid crystal display panel manufactured by such a method forcibly curves the flat liquid crystal display panel, stress is applied particularly to the corner portion of the liquid crystal display panel. This stress causes display unevenness. The following solutions have been reported for such problems. For example, in Patent Document 2, a method of suppressing stress concentration by forming a support near the end of a non-curved side in a curved liquid crystal display panel has been adopted.

JP 2000-293117 A JP 2011-85740 A

  In the corner portion of the curved liquid crystal display panel, display unevenness due to the stress of the glass generated to keep the panel in a curved shape occurs. In Patent Document 2, since the support is formed near the end of the non-curved side of the curved liquid crystal display panel, the size of the periphery of the image display area is increased by the amount of the support, and the frame of the liquid crystal display panel is formed. It was difficult.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a liquid crystal display panel that suppresses display unevenness in a corner portion with a simple configuration.

  The liquid crystal display panel according to the present invention is a liquid crystal display panel having a curved display surface, and an array substrate that is curved along the display surface, and a counter plate that is curved along the display surface and is disposed to face the array substrate. And a liquid crystal held between the array substrate and the counter substrate, and a surface of the array substrate on the counter substrate side is provided with a first liquid crystal alignment film, and the surface of the counter substrate on the array substrate side Is provided with a second liquid crystal alignment film, the display surface is rectangular, and the display surface is viewed from the front of the display surface in the upper left, upper right, lower right, and lower left corners, respectively. Including an upper left area, an upper right area, a lower right area, a lower left area, and an upper left area, an upper right area, a lower right area, and a central area located at the center of the display surface than the lower left area. The first in the area that overlaps each of the lower and lower left areas in plan view The alignment direction of the second liquid crystal alignment film is at least one of the first and second liquid crystal alignment films as compared to the alignment direction of the first and second liquid crystal alignment films in the region overlapping the central region in plan view. The orientation direction of is shifted.

  In the liquid crystal display panel according to the present invention, the first and second liquid crystals in the upper left region, the upper right region, the lower right region, and the lower left region are compared with the alignment directions of the first and second liquid crystal alignment films in the central region. The alignment direction of at least one of the alignment films is shifted. Accordingly, it is possible to suppress display unevenness in the upper left region, the upper right region, the lower right region, and the lower left region with a simple configuration in which the alignment direction of at least one of the first and second liquid crystal alignment films is adjusted.

3 is a schematic cross-sectional view of the liquid crystal display panel according to Embodiment 1. FIG. 4 is a plan view of the liquid crystal display panel according to Embodiment 1. FIG. FIG. 6 is a diagram for explaining stresses generated in the counter substrate and the array substrate of the liquid crystal display panel according to Embodiment 1. 3 is a plan view showing the alignment directions of the first and second liquid crystal alignment films of the liquid crystal display panel according to Embodiment 1. FIG. 4 is a detailed cross-sectional view of the liquid crystal display panel according to Embodiment 1. FIG. 4 is a flowchart showing a manufacturing process of the liquid crystal display panel according to Embodiment 1. 6 is a schematic cross-sectional view of a liquid crystal display panel according to Embodiment 2. FIG. FIG. 10 is a plan view showing the alignment directions of the first and second liquid crystal alignment films of the liquid crystal display panel according to Embodiment 2.

<Embodiment 1>
FIG. 1 is a schematic cross-sectional view of the liquid crystal display panel 100 according to the first embodiment. FIG. 2 is a plan view of the liquid crystal display panel 100 as viewed from the display surface side. FIG. 1 is a cross section taken along line AA in FIG.

  The liquid crystal display panel 100 is a liquid crystal display panel 100 having a curved display surface 5a. The liquid crystal display panel 100 includes an array substrate 110, a counter substrate 120, and a liquid crystal 140. The array substrate 110 and the counter substrate 120 are curved along the display surface 5a.

  On the array substrate 110 having a transparent glass substrate as a base, TFTs (Thin Film Transistors) as switching elements are arranged in a matrix. In addition, a color filter and a black matrix that is a light shielding film are arranged on the counter substrate 120 having a transparent glass substrate as a base. The liquid crystal 140 is held between the array substrate 110 and the counter substrate 120. The periphery of the liquid crystal 140 is sealed with a sealing material 130 made of resin.

  The first liquid crystal alignment film 112 is provided on the surface of the array substrate 110 on the counter substrate 120 side. A second liquid crystal alignment film 122 is provided on the surface of the counter substrate 120 on the array substrate 110 side.

  A curved backlight 7 is disposed on the back side of the array substrate 110 (the side opposite to the display surface 5a). A curved cover glass 5 for protecting the liquid crystal display panel is disposed on the display surface 5 a side of the counter substrate 120. The counter substrate 120 and the cover glass 103 are attached by a transparent adhesive material 104.

<Configuration of liquid crystal alignment film>
The stress generated in the curved liquid crystal display panel 100 will be described with reference to FIG. In the liquid crystal display panel 100, by curving the flat liquid crystal display panel, the corner portion shown in FIG. 2 (the upper left region 8, the upper right region 9, the lower right region 11, and the lower left region 10 overlaps in plan view). Stress is generated in the glass substrate (array substrate 110 and counter substrate 120). In the conventional curved liquid crystal display panel, this stress tends to cause display unevenness due to birefringence in the corner portion.

  FIG. 3A is a diagram showing the direction of stress generated in the corner portion of the counter substrate 120. FIG. 3B is a diagram showing the direction of stress generated in the corner portion of the array substrate 110. Stress is generated in the counter substrate 120 disposed on the front surface side of the liquid crystal display panel 100 in a direction in which the counter substrate 120 expands outward with respect to the display surface 5a. On the other hand, stress is generated in the array substrate 110 disposed on the back side of the liquid crystal display panel 100 in the direction of contracting inward with respect to the display surface 5a.

  FIG. 4 is a schematic diagram showing the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the counter substrate 120 and the array substrate 110 in the first embodiment. In FIG. 4, the alignment directions of the first and second liquid crystal alignment films 112 and 122 are the same in the central region 12. In FIG. 4, an arrow indicated by a solid line indicates the alignment direction of the second liquid crystal alignment film 122 of the counter substrate 120. An arrow indicated by a broken line indicates the alignment direction of the first liquid crystal alignment film 112 of the array substrate 110. In FIG. 4, it is assumed that the alignment direction of the second liquid crystal alignment film 122 is constant in the display surface 5a regardless of the region.

  In this case, as shown in FIG. 4, the alignment direction of the first liquid crystal alignment film 112 is opposite to the alignment direction of the second liquid crystal alignment film 122 in the region overlapping the upper left region 8 of the display surface 5a in plan view. It is shifted clockwise by an angle θ1. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper left region 8 is shifted counterclockwise by the angle θ1 from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  Further, as shown in FIG. 4, in the region overlapping the upper right region 9 of the display surface 5 a in plan view, the alignment direction of the first liquid crystal alignment film 112 is more clockwise than the alignment direction of the second liquid crystal alignment film 122. Is shifted by an angle θ2. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper right region 9 is shifted by an angle θ2 clockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  As shown in FIG. 4, the alignment direction of the first liquid crystal alignment film 112 is opposite to the alignment direction of the second liquid crystal alignment film 122 in a region overlapping the lower right region 11 of the display surface 5 a in plan view. It is shifted clockwise by an angle θ3. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower right region 11 is shifted by an angle θ3 counterclockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  Further, as shown in FIG. 4, in the region overlapping the lower left region 10 of the display surface 5 a in plan view, the alignment direction of the first liquid crystal alignment film 112 is more clockwise than the alignment direction of the second liquid crystal alignment film 122. Is shifted by an angle θ4. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower left region 10 is shifted by an angle θ4 clockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  In FIG. 4, the alignment direction of the first liquid crystal alignment film 112 is changed while the alignment direction of the second liquid crystal alignment film 122 is constant, but the alignment direction of the first liquid crystal alignment film 112 is constant. The alignment direction of the second liquid crystal alignment film 122 may be changed. Even in this case, the relative twist direction between the first and second liquid crystal alignment films 112 and 122 in each region shown in FIG. 4 does not change. For example, in the upper left region 8, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted counterclockwise by θ1. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted by θ1 in the clockwise direction when the alignment direction of the first liquid crystal alignment film 112 is used as a reference.

  Similarly, in the upper right region 9, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted by θ2 in the clockwise direction. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted counterclockwise by θ2 when the alignment direction of the first liquid crystal alignment film 112 is used as a reference.

  Similarly, in the lower right region 11, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted counterclockwise by θ3. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted clockwise by θ 3 when the alignment direction of the first liquid crystal alignment film 112 is used as a reference.

  Similarly, in the lower left region 10, the first liquid crystal alignment film 112 is shifted clockwise by θ4 with reference to the alignment direction of the second liquid crystal alignment film 122. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted counterclockwise by θ 4 with reference to the alignment direction of the first liquid crystal alignment film 112.

  Note that the angles θ1, θ2, θ3, and θ4 in FIG. 4 vary depending on the thickness of the array substrate 110 and the counter substrate 120, the degree of curvature, and the like, but are, for example, 1 °.

  A method for adjusting the alignment direction with respect to the second liquid crystal alignment film 122 in the counter substrate 120 and the first liquid crystal alignment film 112 in the array substrate 110 will be described. For example, when an alignment film is formed by performing a predetermined alignment process on the alignment film material formed on the counter substrate 120, a plurality of masks each having an opening for the central region 12 or the corner portion. It is possible to adjust by performing an alignment process through the two and performing alignment processes in different alignment directions between these regions.

  In particular, the alignment treatment is preferably a photo-alignment treatment in which different alignment directions can be obtained relatively easily. When using photo-alignment treatment, instead of multiple masks, use optical filters that have different transmission characteristics depending on the area (having characteristics that change the polarization direction of the irradiated light in different areas depending on the area). Can be used. Thereby, in a plurality of regions having different alignment directions, it is possible to perform the alignment process collectively by one alignment process.

<Detailed configuration of LCD panel>
FIG. 5 is a more detailed cross-sectional view of the liquid crystal display panel 100 according to the first embodiment. FIG. 5 is a cross-sectional view taken along line AA in FIG. Note that the cross-sectional view of FIG. 5 is schematic and does not reflect the exact size of the components shown. In FIG. 5, the repeated portion of the display pixel is omitted and the film configuration is partially simplified. Here, a liquid crystal display panel 100 that operates using a TFT as a switching element will be described as an example. The operation mode of the liquid crystal display panel 100 will be described by taking the case of the horizontal electric field method suitable for the first and second embodiments as an example.

  As shown in FIG. 5, a cover glass 103 is disposed on the display surface 5 a side of the liquid crystal display panel 100. The cover glass 103 is curved with a predetermined curvature. The cover glass 103 is curved in a convex shape on the side opposite to the side where the counter substrate 120 is disposed. The liquid crystal display panel 100 is affixed to the cover glass 103 via a transparent adhesive material 104. Here, the liquid crystal display panel 100 is attached in a curved state in accordance with the curvature of the cover glass 103. That is, the liquid crystal display panel 100 is curved in a warping direction in which the counter substrate 120 side is convex.

  As described above, the liquid crystal display panel 100 includes the array substrate 110, the counter substrate 120, and the liquid crystal 140. The liquid crystal display panel 100 is curved with a predetermined curvature in a direction in which the counter substrate 120 is convex in a state of being attached to the cover glass 103. In the first embodiment, the liquid crystal display panel 100 is curved along the longitudinal direction of the substrates (the array substrate 110 and the counter substrate 120). The bending direction of the liquid crystal display panel 100 is not limited to this, and the liquid crystal display panel 100 may be bent along the short direction of the substrates (the array substrate 110 and the counter substrate 120).

  The array substrate 110 described above includes a first liquid crystal alignment film 112 that aligns the liquid crystal 140 in a region corresponding to the display surface 5a on one surface of the glass substrate 111, which is a transparent substrate, and the first liquid crystal alignment film 112. A pixel electrode 113 and a counter electrode (the counter electrode is shown in the figure), which are a pair of electrodes that are provided in the lower portion and generate an electric field in a direction parallel to the substrate surface of the array substrate 110 or the counter substrate 120 and apply a voltage for driving the liquid crystal 140. (Omitted), a TFT 114 such as a TFT that supplies a voltage to the pixel electrode 113 that is one of the pair of electrodes, an insulating film 115 that covers the TFT 114, and a gate wiring and a source wiring that are wiring for supplying a signal to the TFT 114 (both not shown) Etc. Further, on the array substrate 110, a terminal 118 for receiving a signal supplied to the TFT 114 from the outside is provided outside the region corresponding to the display surface 5a. A polarizing plate 151 is provided on the other surface of the glass substrate 111.

  The counter substrate 120 includes a second alignment film 122 that aligns the liquid crystal 140 on one surface of a glass substrate 121 that is a transparent substrate, a color filter 124 and a light shielding layer 125 (under the second alignment film 122). Black matrix). As shown in the figure, an overcoat layer 123 made of a transparent resin film may be provided under the second alignment film 122 so as to cover the color filter 124 and the light shielding layer 125 and to flatten the surface of the counter substrate 120. . A polarizing plate 152 is provided on the other surface of the glass substrate 121.

  Note that the alignment directions of the first and second alignment films 112 and 122 are different from each other in the corner portions as described in detail with reference to FIG.

  Further, the glass substrate 121 serving as the base of the counter substrate 120 and the glass substrate 111 serving as the base of the array substrate 110 have a thickness of about 0.2 mm so as to be flexible. Further, if the liquid crystal display panel 100 is a transmissive type within the range of a flexible substrate, instead of the glass substrates 111 and 112, a transparent material such as transparent plastic or quartz, which is a transparent material, is transparent. A substrate may be used. In the case where the liquid crystal display panel 100 is of a reflective type, one of the substrates is not necessarily a transparent substrate such as a silicon substrate.

  The array substrate 110 and the counter substrate 120 are bonded to each other via a sealant 4 and a spacer (not shown) that keeps the distance between the substrates constant. As the spacer, a granular spacer dispersed on the substrate may be used, or a columnar spacer formed by patterning a resin on one of the substrates may be used.

  A control board 153 equipped with a driving IC (Integrated Circuit) that generates a driving signal is electrically connected to the terminal 118 via an FFC (Flexible Flat Cable) 154.

  Further, as described above, the cover glass 103 having a curved shape having a curved surface with a desired curvature is disposed on the display surface 5a side of the liquid crystal display panel 100. The cover glass 103 and the liquid crystal display panel 100 are pasted through a transparent adhesive material 104. Further, on the back side of the liquid crystal display panel 100, a curved backlight 7 (see FIG. 1) serving as a light source is provided via an optical sheet (not shown) having a function of adjusting light from the backlight 7. Be placed. The liquid crystal display panel 100 is housed together with the cover glass 103 and the backlight 7 in a housing (not shown) formed of a member that is open on the display surface 5a side or capable of transmitting light.

  The liquid crystal display panel 100 operates as follows. For example, when an electric signal is input from the control substrate 153, a predetermined driving voltage that generates an electric field in a direction parallel to the substrate surface of the array substrate 110 or the counter substrate 120 is applied between the pixel electrode 113 and the common electrode, and the driving voltage is added. At the same time, the direction of the molecules of the liquid crystal 140 changes. Then, the light emitted from the backlight is transmitted or blocked to the viewer side through the array substrate 110, the liquid crystal 140, and the counter substrate 120, whereby an image is displayed on the display surface 5a of the liquid crystal display panel 100.

  FIG. 5 shows an example of the configuration of the liquid crystal display panel 100, and other configurations may be used. The operation mode of the liquid crystal display panel 100 has been described as a lateral electric field method in which an electric field is applied to the liquid crystal 140 in the lateral direction between the pixel electrode 113, but the common electrode provided on the array substrate 110 is a counter substrate. A TN (Twisted Nematic) mode in which an electric field is applied to the liquid crystal 140 between the array substrate 110 and the counter substrate 120 may be used. The driving method may be a simple matrix or an active matrix. In the above description, the liquid crystal display panel 100 is described as a transmissive type, but a reflective type or a transflective type having both of them may be used.

  Further, here, the driving IC is connected to the terminal 118 in a state of being placed on the control board 135, but it may be arranged directly on the terminal 118 so that the terminal of the driving IC is directly connected to the terminal 118. In addition, in the sealing material 130, an injection port for injecting liquid crystal is not shown. However, when a vacuum injection method in which the liquid crystal is injected from the injection port is used as a liquid crystal injection method, the injection port and the injection port are provided. A sealant for sealing is formed. In addition, in the case of using a dropping injection method in which liquid crystals are arranged in the form of droplets and the substrates are bonded together and injected in a vacuum, the injection port and the sealing agent can be omitted.

  Further, the cover glass 103 may be a glass substrate having a curved shape and a certain degree of strength, a resin substrate (plastic substrate), or a touch panel substrate having a curved shape.

<Manufacturing method>
FIG. 6 is a flowchart showing manufacturing steps of the liquid crystal display panel 100 according to the first embodiment. The manufacturing method of the array substrate 110 and the counter substrate 120 will be briefly described because a general method is used. The array substrate 110 is manufactured by forming the TFT 114, the pixel electrode 113, the terminal 118, and the like on one surface of the glass substrate 111 by repeatedly using a pattern formation process such as film formation, patterning by photolithography, and etching. The

  Similarly, the counter substrate 120 is manufactured by forming the color filter 124 and the light shielding layer 125 on one surface of the glass substrate 121. Any substrate is manufactured as an uncurved flat substrate until at least before being bonded.

  Subsequently, in the substrate cleaning process, the array substrate 110 on which the TFT 114, the pixel electrode 113, and the like are formed is cleaned (step S1). Next, in the liquid crystal alignment film material application step, an organic film made of polyimide, which is a material of the first alignment film 112, is applied to one surface of the array substrate 110 by, for example, a printing method, and is baked using a hot plate or the like. Dry (step S2). Thereafter, an alignment process is performed on the array substrate 110 to which the alignment film material is applied to form a first alignment film 112 (step S3). In addition, the second alignment film 122 is also formed on the counter substrate 120 on which the color filter 124 and the like are formed by performing cleaning, application of an organic film, and alignment treatment as in Steps S1 to S3.

  Further, as described above, the alignment process in step S3 has different transmission characteristics depending on the central area 12 and the corner areas (upper left area 8, upper right area 9, lower right area 11, lower left area 10). A photo-alignment process is performed through the mask and the optical filter, and an alignment film having a desired alignment direction is obtained in each region.

  Subsequently, in a sealing material application process for forming the sealing material 130, a resin application process for the sealing material 4 is performed on one surface of the TFT substrate 110 or the counter substrate 120 (step S 4). Further, for the sealing material 4, for example, a thermosetting resin such as an epoxy-based adhesive or an ultraviolet curable resin can be used. When a dropping injection method is used as a liquid crystal injection process to be performed later, an ultraviolet curable resin is used. It is desirable to use For this sealing material application process, in the first embodiment, a dispenser method suitable for combination with the dropping injection method is used. Specifically, a seal dispenser device is used to apply and apply a resin as a sealant 4 as a paste from one side of the array substrate 110 or the counter substrate 120 from a nozzle. This resin is applied so as to surround the display region 1 of the liquid crystal display panel 100 to form the seal material 4.

  Next, a transfer material application process (step S5), a spacer spraying process (step S6), and the like are performed. In the transfer material application step, a resin mixed with conductive particles, silver paste, or the like is disposed on one surface of the array substrate 110 or the counter substrate 120 in order to conduct electricity between the substrates. In the spacer spraying step, a spacer that keeps the distance between the substrates constant on one surface of the array substrate 110 or the counter substrate 120 is sprayed by a wet method or a dry method. Note that the transfer material application process can be combined with the process of forming the seal material 130 by, for example, mixing conductive particles in the seal material 130 for bonding the substrates together. Further, the spacer spraying step can be omitted by forming a protruding column spacer for determining the distance between the substrates in advance on one surface of the array substrate 110 or the counter substrate 120.

  The liquid crystal 140 is dropped (step S7) by the dropping injection method on the array substrate 110 and the counter substrate 120 that have been prepared as described above. Then, the liquid crystal 140 is sealed by bonding the array substrate 110 and the counter substrate 120 (step S8).

  The sealing material 130 is cured on the array substrate 110 and the counter substrate bonded together as described above. This step is performed, for example, by applying heat according to the material of the sealing material 130 or by irradiating ultraviolet rays. In the first embodiment, the sealing material 130 is cured by ultraviolet irradiation suitable for combination with the dropping injection method.

  Next, a thinning polishing process is performed (step S9). In the thinning polishing step, the glass substrates 111 and 112 are cut to a thickness of about 0.2 mm. This is to make the liquid crystal display panel 100 flexible and facilitate bending. Polishing is performed, for example, by scraping the surfaces of the glass substrates 111 and 121 by chemical polishing using a chemical solution or physical polishing rubbing with an abrasive. Next, in the cell dividing step, the bonded substrates are divided into individual cells corresponding to the individual liquid crystal display panels 100 (step S10).

  Subsequently, in the polarizing plate attaching step, polarizing plates 151 and 152 are attached to the glass substrates 111 and 121, respectively (step S11). Subsequently, in the control board mounting step, the liquid crystal display panel 100 is completed by mounting the control board 153 (step S12).

  Further, finally, in the housing assembling step (cover glass bonding), the flexible liquid crystal display panel 100 created as described above is bonded to the cover glass 103 via the transparent adhesive material 104. At this time, the attachment is performed in a state where the liquid crystal display panel 100 is curved in accordance with the curvature of the cover glass 103. And the liquid crystal display device is completed by incorporating the liquid crystal display panel 100 affixed to the cover glass 103 in a housing | casing (step S13).

<Effect>
The liquid crystal display panel 100 according to the first embodiment is a liquid crystal display panel 100 having a curved display surface 5a. The array substrate 110 is curved along the display surface 5a, and is curved along the display surface 5a. 110, and a liquid crystal 140 held between the array substrate 110 and the counter substrate 120. The surface of the array substrate 110 on the counter substrate 120 side has a first substrate A liquid crystal alignment film 112 is provided, a second liquid crystal alignment film 122 is provided on the surface of the counter substrate 120 on the array substrate 110 side, the display surface 5a is rectangular, and the display surface 5a is the display surface 5a. , The upper left area 8, the upper right area 9, the lower right area 11, the lower left area 10 and the upper left area 8, the upper right area 9, respectively including the upper left, upper right, lower right, and lower left corners of the display surface 5a. Lower right area 1 And a central region 12 located in the center of the display surface 5a rather than the lower left region 10, and the first region in the region overlapping the upper left region 8, the upper right region 9, the lower right region 11, and the lower left region 10 in plan view, The alignment directions of the second liquid crystal alignment films 112 and 122 are the first and second alignment directions compared to the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the region overlapping the central region 12 in plan view. The alignment direction of at least one of the liquid crystal alignment films 112 and 122 is shifted.

  In the liquid crystal display panel in which the array substrate 110 and the counter substrate 120 are curved, birefringence occurs due to stress applied to the glass substrate in the corner portions (upper left region 8, upper right region 9, lower right region 11, lower left region 10). Display unevenness. Therefore, in the first embodiment, at least one of the first and second liquid crystal alignment films 112 and 122 at the corner portion is compared with the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the central region 12. The orientation direction of is shifted. Thereby, it is possible to correct the above-described birefringence and suppress display unevenness in the corner portion. As described above, the liquid crystal display panel 100 according to the first embodiment can suppress display unevenness in the corner portion with a simple configuration that adjusts the alignment direction of the liquid crystal alignment film. That is, in the first embodiment, it is not necessary to add a new member or increase the size of the member, and it does not prevent the liquid crystal display panel 100 from becoming a framed frame.

  In the liquid crystal display panel 100 according to the first embodiment, the display surface 5a is curved in a convex shape, and the alignment direction of the second liquid crystal alignment film 122 is a constant direction in the display surface 5a, and the upper left region 8 The alignment direction of the first liquid crystal alignment film 112 in the region overlapping with each of the lower right region 11 in plan view is the first liquid crystal alignment in the region overlapping with the central region 12 in plan view when viewed from the front of the display surface 5a. The alignment direction of the first liquid crystal alignment film 112 in a region that is offset counterclockwise from the alignment direction of the film 112 and overlaps each of the upper right region 9 and the lower left region 10 in plan view is viewed from the front of the display surface 5a. The first liquid crystal alignment film 112 is shifted in the clockwise direction from the alignment direction of the first liquid crystal alignment film 112 in the region overlapping the central region 12 in plan view, or the alignment direction of the first liquid crystal alignment film 112 is The alignment direction of the second liquid crystal alignment film 122 in a certain direction within the display surface 5a and overlapping each of the upper left 8 region and the lower right region 11 in plan view is the central region as viewed from the front of the display surface 5a. 12 is shifted in the clockwise direction from the alignment direction of the second liquid crystal alignment film 122 in the region overlapping in plan view, and the second liquid crystal alignment film 122 in the region overlapping with each of the upper right region 9 and lower left region 10 in plan view. The alignment direction is deviated counterclockwise from the alignment direction of the second liquid crystal alignment film 122 in a region overlapping the central region 12 in plan view when viewed from the front of the display surface 5a.

  Therefore, in the liquid crystal display panel 100 with the display surface 5a curved in a convex shape, the first and second liquid crystal alignments are performed as described above in the corner portions (upper left region 8, upper right region 9, lower right region 11, lower left region 10). By shifting one of the orientation directions of the films 112 and 122, display unevenness in a corner portion can be suppressed.

  In the liquid crystal display panel 100 according to the first embodiment, the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the region overlapping the central region 12 in plan view are the same direction.

  Therefore, in the liquid crystal display panel 100 in the operation mode of the horizontal electric field method that requires the alignment directions of the first and second liquid crystal alignment films 112 and 122 to be the same, display unevenness in the corner portion can be suppressed. It is.

  When the liquid crystal display panel 100 is in an operation mode (for example, TN mode) in which the alignment directions of the first and second liquid crystal alignment films 112 and 122 are required to be different from each other by 90 °, the liquid crystal display panel 100 is flat with the central region 12. The alignment directions of the first and second liquid crystal alignment films 112 and 122 in the overlapping region may be different from each other by 90 °.

<Embodiment 2>
FIG. 7 is a schematic cross-sectional view of the liquid crystal display panel 200 according to the second embodiment. The liquid crystal display panel 100 of Embodiment 1 was curved in a convex shape with respect to the display surface 5a. On the other hand, the liquid crystal display panel 200 of Embodiment 2 is curved in a concave shape with respect to the display surface 5a. The second embodiment is different from the first embodiment in the alignment directions of the first and second liquid crystal alignment films 112 and 122. Since other configurations are the same as those of the first embodiment, description thereof is omitted. In the second embodiment, the liquid crystal display panel 200 is curved along the longitudinal direction of the substrates (the array substrate 110 and the counter substrate 120). The bending direction of the liquid crystal display panel 200 is not limited to this, and the liquid crystal display panel 200 may be bent along the short direction of the substrates (the array substrate 110 and the counter substrate 120).

  FIG. 8 is a schematic diagram showing the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the counter substrate 120 and the array substrate 110 in the second embodiment. In FIG. 8, the alignment directions of the first and second liquid crystal alignment films 112 and 122 are the same in the central region 12. In FIG. 8, an arrow indicated by a solid line indicates the alignment direction of the second liquid crystal alignment film 122 of the counter substrate 120. An arrow indicated by a broken line indicates the alignment direction of the first liquid crystal alignment film 112 of the array substrate 110. In FIG. 8, it is assumed that the alignment direction of the second liquid crystal alignment film 122 is constant in the display surface 5a regardless of the region.

  In this case, as shown in FIG. 8, in the region overlapping the upper left region 8 of the display surface 5a in plan view, the alignment direction of the first liquid crystal alignment film 112 is more clockwise than the alignment direction of the second liquid crystal alignment film 122. The angle is shifted by an angle θ19. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper left region 8 is shifted by an angle θ1 clockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  Further, as shown in FIG. 8, in the region overlapping the upper right region 9 of the display surface 5 a in plan view, the alignment direction of the first liquid crystal alignment film 112 is counterclockwise than the alignment direction of the second liquid crystal alignment film 122. The angle is shifted by an angle θ2. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper right region 9 is shifted by an angle θ2 counterclockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  Further, as shown in FIG. 8, in the region overlapping the lower right region 11 of the display surface 5a in plan view, the alignment direction of the first liquid crystal alignment film 112 is more clockwise than the alignment direction of the second liquid crystal alignment film 122. The angle is shifted by an angle θ3. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower right region 11 is shifted by an angle θ3 clockwise from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  Further, as shown in FIG. 8, in the region overlapping the lower left region 10 of the display surface 5a in plan view, the alignment direction of the first liquid crystal alignment film 112 is counterclockwise than the alignment direction of the second liquid crystal alignment film 122. The angle θ4 is shifted around. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower left region 10 is shifted counterclockwise by the angle θ4 from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

  In FIG. 8, the alignment direction of the first liquid crystal alignment film 112 is changed while the alignment direction of the second liquid crystal alignment film 122 is constant, but the alignment direction of the first liquid crystal alignment film 112 is constant. The alignment direction of the second liquid crystal alignment film 122 may be changed. Even in this case, the relative twist direction between the first and second liquid crystal alignment films 112 and 122 in each region shown in FIG. 8 does not change. For example, in the upper left region 8, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted clockwise by θ1. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted counterclockwise by θ1 when the alignment direction of the first liquid crystal alignment film 112 is used as a reference.

  Similarly, in the upper right region 9, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted counterclockwise by θ2. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted by θ2 in the clockwise direction with reference to the alignment direction of the first liquid crystal alignment film 112.

  Similarly, in the lower right region 11, when the alignment direction of the second liquid crystal alignment film 122 is used as a reference, the first liquid crystal alignment film 112 is shifted by θ3 in the clockwise direction. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted counterclockwise by θ3 when the alignment direction of the first liquid crystal alignment film 112 is used as a reference.

  Similarly, in the lower left region 10, the first liquid crystal alignment film 112 is shifted by θ4 counterclockwise when the alignment direction of the second liquid crystal alignment film 122 is used as a reference. In other words, in the upper left region 8, the second liquid crystal alignment film 122 is shifted by θ 4 in the clockwise direction with reference to the alignment direction of the first liquid crystal alignment film 112.

  Note that the angles θ1, θ2, θ3, and θ4 in FIG. 8 vary depending on the thickness of the array substrate 110 and the counter substrate 120, the degree of curvature, and the like, but are, for example, 1 °.

<Effect>
In the liquid crystal display panel 200 according to the second embodiment, the display surface 5a is curved in a concave shape, and the alignment direction in the second liquid crystal alignment film 122 is a fixed direction in the display surface 5a, and the upper left region 8 and the lower right region The alignment direction of the first liquid crystal alignment film 112 in a region overlapping with each of the regions 11 in plan view is that of the first liquid crystal alignment film 112 in the region overlapping with the central region 12 in plan view when viewed from the front of the display surface 5a. The alignment direction of the first liquid crystal alignment film 112 in a region that is shifted clockwise from the alignment direction and overlaps each of the upper right region 9 and the lower left region 10 in plan view is the central region as viewed from the front of the display surface 5a. 12 is shifted counterclockwise from the alignment direction of the first liquid crystal alignment film 112 in a region overlapping with 12 in a plan view, or the alignment direction in the first liquid crystal alignment film 112 is the display surface. The alignment direction of the second liquid crystal alignment film 122 in a certain direction within a and overlapping with each of the upper left region 8 and the lower right region 11 in plan view is the same as the central region 12 when viewed from the front of the display surface 5a. The second liquid crystal alignment film 122 is shifted in the counterclockwise direction from the alignment direction of the second liquid crystal alignment film 122 in the region overlapping in plan view, and the second liquid crystal alignment film 122 in the region overlapping with each of the upper right region 9 and lower left region 10 in plan view. The alignment direction is shifted clockwise from the alignment direction of the second liquid crystal alignment film 122 in a region overlapping the central region 12 in plan view as viewed from the front of the display surface 5a.

  Therefore, in the liquid crystal display panel 200 with the display surface 5a curved in a concave shape, the first and second liquid crystal alignment films as described above at the corner portions (upper left region 8, upper right region 9, lower right region 11, lower left region 10). By shifting one of the orientation directions 112 and 122, display unevenness in the corner portion can be suppressed.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  103 cover glass, 104 transparent adhesive material, 110 array substrate, 111, 121 glass substrate, 112 first liquid crystal alignment film, 113 pixel electrode, 114 TFT, 115 insulating film, 118 terminal, 120 counter substrate, 122 second liquid crystal Alignment film, 123 Overcoat layer, 124 Color filter, 125 Light-shielding layer, 130 Sealing material, 140 Liquid crystal, 5a Display surface, 7 Backlight, 8 Upper left area, 9 Upper right area, 10 Lower left area, 11 Lower right area, 12 Center Area, 100, 200 Liquid crystal display panel.

Claims (4)

A liquid crystal display panel with a curved display surface,
An array substrate curved along the display surface;
A counter substrate that is curved along the display surface and is disposed to face the array substrate;
Liquid crystal held between the array substrate and the counter substrate;
With
A first liquid crystal alignment film is provided on the surface of the array substrate on the counter substrate side,
On the surface of the counter substrate on the array substrate side, a second liquid crystal alignment film is provided,
The display surface has a quadrangular shape,
The display surface is
When viewed from the front of the display surface, the upper left region, the upper right region, the lower right region, the lower left region including the upper left, upper right, lower right, and lower left corners of the display surface,
A central region located in the center of the display surface than the upper left region, the upper right region, the lower right region, and the lower left region;
With
The alignment directions of the first and second liquid crystal alignment films in the upper left region, the upper right region, the lower right region, and the lower left region in the region overlapping in plan view are in the region overlapping in the plan view with the central region. Compared with the alignment direction of the first and second liquid crystal alignment films, the alignment direction of at least one of the first and second liquid crystal alignment films is shifted.
LCD display panel. The display surface is curved in a convex shape,
In the second liquid crystal alignment film, the alignment direction is a constant direction in the display surface, and the alignment direction of the first liquid crystal alignment film in a region overlapping each of the upper left region and the lower right region in plan view is: When viewed from the front of the display surface, it is deviated counterclockwise from the alignment direction of the first liquid crystal alignment film in a region overlapping the central region in plan view, and is flat with each of the upper right region and the lower left region. The alignment direction of the first liquid crystal alignment film in the region overlapping in view is clockwise from the alignment direction of the first liquid crystal alignment film in the region overlapping with the central region in plan view when viewed from the front of the display surface. Or
Alternatively, in the first liquid crystal alignment film, the alignment direction is a constant direction in the display surface, and the alignment direction of the second liquid crystal alignment film in a region overlapping each of the upper left region and the lower right region in plan view Is shifted clockwise from the alignment direction of the second liquid crystal alignment film in a region overlapping the central region in plan view when viewed from the front of the display surface, and each of the upper right region and the lower left region The alignment direction of the second liquid crystal alignment film in the region overlapping in plan view is opposite to the alignment direction of the second liquid crystal alignment film in the region overlapping with the central region in plan view when viewed from the front of the display surface. Shifted clockwise,
The liquid crystal display panel according to claim 1. The display surface is concavely curved;
In the second liquid crystal alignment film, the alignment direction is a constant direction in the display surface, and the alignment direction of the first liquid crystal alignment film in a region overlapping each of the upper left region and the lower right region in plan view is: When viewed from the front of the display surface, it is shifted clockwise from the alignment direction of the first liquid crystal alignment film in a region overlapping with the central region in plan view, and in plan view with each of the upper right region and the lower left region. The alignment direction of the first liquid crystal alignment film in the region overlapping with the counterclockwise direction is counterclockwise than the alignment direction of the first liquid crystal alignment film in the region overlapping with the central region in plan view as viewed from the front of the display surface. Or
Alternatively, in the first liquid crystal alignment film, the alignment direction is a constant direction in the display surface, and the alignment direction of the second liquid crystal alignment film in a region overlapping each of the upper left region and the lower right region in plan view Is shifted counterclockwise from the alignment direction of the second liquid crystal alignment film in a region overlapping the central region in plan view when viewed from the front of the display surface, and each of the upper right region and the lower left region The alignment direction of the second liquid crystal alignment film in the region overlapping in plan view is larger than the alignment direction of the second liquid crystal alignment film in the region overlapping with the central region in plan view when viewed from the front of the display surface. Shifted clockwise,
The liquid crystal display panel according to claim 1. The alignment directions of the first and second liquid crystal alignment films in the region overlapping the central region in plan view are the same direction.
The liquid crystal display panel as described in any one of Claims 1-3.

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