JP6671182B2 - Liquid crystal display panel manufacturing method - Google Patents

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.

  2. Description of the Related Art In recent years, liquid crystal display devices have attracted attention in displays of televisions and personal computers. Liquid crystal display devices are characterized by their thinness and low power consumption, and are widely used from small devices such as mobile phones to large devices such as televisions. 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 with excellent design has attracted much attention. As a method for achieving a curved shape, as shown in Patent Literature 1, a method is used in which a liquid crystal display panel having a flat shape is once fabricated, and then fixed to a cover glass or a holding material having a curved shape to forcibly bend. ing.

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

JP 2000-293117 A JP 2011-85740 A

  At the corners of the curved liquid crystal display panel, display unevenness occurs due to the stress of the glass generated to keep the panel in the curved shape. In Patent Document 2, the support is formed near the end of the non-curved side of the curved liquid crystal display panel. Therefore, the size of the periphery of the image display area is increased by the size of the support, and the liquid crystal display panel has a narrower frame. 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 having a simple configuration and suppressing display unevenness at a corner portion.

Method of manufacturing a liquid crystal display panel according to the present invention, a liquid crystal by the manufacturing method for the liquid crystal display panel in which the display surface is curved, and a counter substrate of the array substrate and the planar shape of the planar shape are bonded via the liquid crystal A step of forming a display panel and a step of bending the liquid crystal display panel , wherein a first liquid crystal alignment film is provided on a surface of the array substrate facing the opposing substrate, and a first liquid crystal alignment film is provided on the surface of the opposing substrate facing the array substrate. Is provided with a second liquid crystal alignment film, and the display surface is rectangular, and the display surface includes upper left, upper right, lower right, and lower left corners of the display surface when viewed from the front of the display surface. The upper left area, the upper right area, the lower right area, the lower left area, and the upper left area, the upper right area, the lower right area and a central area located at the center of the display surface than the lower left area, in the liquid crystal display panel before bending , the upper left area, the upper right area, bottom right The alignment directions of the first and second liquid crystal alignment films in a region overlapping in plan view with each of the region and the lower left region are compared with the alignment directions of the first and second liquid crystal alignment films in a region overlapping with the central region in plan view. As a result, the alignment direction of at least one of the first and second liquid crystal alignment films is shifted.

In the method of manufacturing a liquid crystal display panel according to the present invention, in the liquid crystal display panel before being curved , the upper left area, the upper right area, and the lower right area are compared with the alignment directions of the first and second liquid crystal alignment films in the central area. The alignment direction of at least one of the first and second liquid crystal alignment films in the region and the lower left region is shifted. Thus, with a simple configuration for adjusting the alignment direction of at least one of the first and second liquid crystal alignment films, display unevenness in the upper left area, upper right area, lower right area, and lower left area of the liquid crystal display panel after being curved. Can be suppressed.

FIG. 2 is a schematic cross-sectional view of the liquid crystal display panel according to Embodiment 1. FIG. 2 is a plan view of the liquid crystal display panel according to Embodiment 1. FIG. 3 is a diagram for explaining stress generated in an opposing substrate and an array substrate of the liquid crystal display panel according to Embodiment 1. FIG. 3 is a plan view showing the alignment directions of first and second liquid crystal alignment films of the liquid crystal display panel according to Embodiment 1. FIG. 2 is a detailed cross-sectional view of the liquid crystal display panel according to Embodiment 1. 5 is a flowchart showing a manufacturing process of the liquid crystal display panel according to Embodiment 1. FIG. 9 is a schematic cross-sectional view of a liquid crystal display panel according to Embodiment 2. FIG. 10 is a plan view showing the alignment directions of first and second liquid crystal alignment films of the liquid crystal display panel according to Embodiment 2.

<First Embodiment>
FIG. 1 is a schematic sectional view of a 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.

  An array substrate 110 based on a transparent glass substrate has TFTs (Thin Film Transistors) as switching elements arranged in a matrix. Further, a color filter and a black matrix which 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 by a sealing material 130 made of resin.

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

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

<Structure 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 bending the planar liquid crystal display panel, corner portions shown in FIG. 2 (regions 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) shown in FIG. Then, stress is generated on the glass substrates (the array substrate 110 and the counter substrate 120). In a conventional liquid crystal display panel having a curved shape, the stress tends to cause display unevenness at a corner portion due to birefringence.

  FIG. 3A is a diagram illustrating a direction of a stress generated at a corner portion of the counter substrate 120. FIG. 3B is a diagram showing directions of stresses generated at corners 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 expanding outward with respect to the display surface 5a. On the other hand, stress is generated on the array substrate 110 disposed on the back side of the liquid crystal display panel 100 in a 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 according to the first embodiment. In FIG. 4, the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the central region 12 are the same. In FIG. 4, the arrow indicated by the solid line indicates the alignment direction of the second liquid crystal alignment film 122 of the counter substrate 120. Arrows indicated by broken lines indicate 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, in a 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 opposite to the alignment direction of the second liquid crystal alignment film 122. It is shifted clockwise by the 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 a region overlapping the upper right region 9 of the display surface 5 a in a 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. At an angle θ2. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper right region 9 is shifted clockwise by the angle θ2 from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

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

  Further, as shown in FIG. 4, in a region overlapping the lower left region 10 of the display surface 5 a in plan view, the orientation direction of the first liquid crystal alignment film 112 is more clockwise than the orientation direction of the second liquid crystal alignment film 122. At an angle θ4. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower left region 10 is shifted clockwise by an angle θ4 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 fixed, but the alignment direction of the first liquid crystal alignment film 112 is fixed. 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, the first liquid crystal alignment film 112 is shifted counterclockwise by θ1 with respect 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 clockwise by θ1 with respect to the alignment direction of the first liquid crystal alignment film 112.

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

  Similarly, in the lower right region 11, the first liquid crystal alignment film 112 is shifted counterclockwise by θ3 with respect 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 clockwise by θ3 with respect to the alignment direction of the first liquid crystal alignment film 112.

  Similarly, in the lower left region 10, the first liquid crystal alignment film 112 is shifted clockwise by θ4 with respect 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 θ4 with respect to the alignment direction of the first liquid crystal alignment film 112.

  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, and are, for example, 1 °.

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

  In particular, as the alignment treatment, a photo-alignment treatment capable of obtaining a different alignment direction relatively easily is preferable. In the case of using the optical alignment treatment, instead of a plurality of masks, an optical filter having different transmission characteristics depending on the region (having a characteristic of changing the polarization direction of irradiated light to a different polarization direction depending on the region) is appropriately used. Can be used. Accordingly, it is possible to perform the alignment process collectively by a single alignment process in a plurality of regions having different alignment directions.

<Detailed configuration of liquid crystal display panel>
FIG. 5 is a more detailed cross-sectional view of liquid crystal display panel 100 according to the first embodiment. FIG. 5 is a sectional view taken along line AA in FIG. Note that the cross-sectional view of FIG. 5 is a schematic view and does not reflect the exact size of the components shown. In FIG. 5, the repeated portions of the display pixels are 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. Further, as an operation mode of the liquid crystal display panel 100, a case of a horizontal electric field method suitable for the first and second embodiments will be described as an example.

  As shown in FIG. 5, a cover glass 103 is disposed on the display surface 5a side of the liquid crystal display panel 100. The cover glass 103 is curved at a predetermined curvature. The cover glass 103 is curved in a convex shape on the side opposite to the side on which the counter substrate 120 is arranged. The liquid crystal display panel 100 is attached to the cover glass 103 via the transparent adhesive 104. Here, the liquid crystal display panel 100 is attached in a state of being curved in accordance with the curvature of the cover glass 103. That is, the liquid crystal display panel 100 is curved in a warp 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. When the liquid crystal display panel 100 is attached to the cover glass 103, the liquid crystal display panel 100 is curved at a predetermined curvature in a direction in which the counter substrate 120 is convex. In Embodiment 1, the liquid crystal display panel 100 is curved along the longitudinal direction of the substrate (the array substrate 110 and the counter substrate 120). Note that the direction of the curvature of the liquid crystal display panel 100 is not limited to this, and the liquid crystal display panel 100 may be curved along the short direction of the substrate (the array substrate 110 and the counter substrate 120).

  The above-mentioned array substrate 110 has a first liquid crystal alignment film 112 for aligning the liquid crystal 140 in a region corresponding to the display surface 5a on one surface of a glass substrate 111 which is a transparent substrate. A pixel electrode 113 and a counter electrode, which are a pair of electrodes provided below and apply a voltage for driving the liquid crystal 140 by generating an electric field in a direction parallel to the substrate surface of the array substrate 110 or the counter substrate 120 (the counter electrode is shown (Omitted), a TFT 114 such as a TFT for supplying a voltage to the pixel electrode 113 which is one of the pair of electrodes, an insulating film 115 covering the TFT 114, a gate wiring and a source wiring which are wirings for supplying a signal to the TFT 114 (both not shown). And so on. Further, on the array substrate 110, a terminal 118 for receiving a signal supplied to the TFT 114 from outside is provided outside a region corresponding to the display surface 5a. On the other surface of the glass substrate 111, a polarizing plate 151 is provided.

  The above-described 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 provided below the second alignment film 122, and a light-shielding layer 125 ( Black matrix). As illustrated, an overcoat layer 123 made of a transparent resin film may be provided below the second alignment film 122 so as to cover the color filter 124 and the light-shielding layer 125 and flatten the surface of the counter substrate 120. . Further, a polarizing plate 152 is provided on the other surface of the glass substrate 121.

  Note that the orientation directions of the first and second orientation films 112 and 122 are, as described above in detail with reference to FIG.

  The glass substrate 121 serving as a base of the counter substrate 120 and the glass substrate 111 serving as a base of the array substrate 110 have a thickness of about 0.2 mm so as to have flexibility. If the liquid crystal display panel 100 is of a transmission type within the range of a substrate having flexibility, instead of the glass substrates 111 and 112, a transparent material of a transparent material such as transparent plastic or quartz may be used. A substrate may be used. When the liquid crystal display panel 100 is of a reflection type, one of the substrates is not necessarily a transparent substrate such as a silicon substrate.

  Further, the array substrate 110 and the counter substrate 120 are bonded together via a spacer (not shown) for keeping a distance between the sealing material 4 and the substrate at a constant distance. As the spacer, a granular spacer dispersed on a 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) for generating a driving signal and the like 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 arranged 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 stuck together via a transparent adhesive 104. 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) having a display surface 5a opened or made of a member 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 drive 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 drive voltage is At the same time, the direction of the molecules of the liquid crystal 140 changes. Then, light emitted from the backlight is transmitted or blocked to the observer side via the array substrate 110, the liquid crystal 140, and the counter substrate 120, so that an image is displayed on the display surface 5a of the liquid crystal display panel 100.

  FIG. 5 is an example of the configuration of the liquid crystal display panel 100, and another configuration may be used. In the above, the operation mode of the liquid crystal display panel 100 has been described as a horizontal electric field method in which an electric field is applied to the liquid crystal 140 in a horizontal direction between the pixel electrode 113 and the common electrode provided on the array substrate 110. A TN (Twisted Nematic) mode or the like in which an electric field is applied to the liquid crystal 140 between the array substrate 110 and the counter substrate 120 may be provided. 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 mounted on the control board 135. However, the driving IC may be directly disposed on the terminal 118 and the terminal of the driving IC may be directly connected to the terminal 118. In the sealing material 130, an inlet for injecting liquid crystal is not shown, but when a vacuum injection method of injecting the liquid crystal from the inlet is used as the liquid crystal injection method, the inlet and the inlet may be omitted. A sealing agent for sealing is formed. In the case of using a drop-injection method in which liquid crystals are arranged in the form of droplets and a substrate is bonded and injected in a vacuum, the injection port and the sealant can be omitted.

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

<Production method>
FIG. 6 is a flowchart showing a manufacturing process of the liquid crystal display panel 100 according to the first embodiment. The method of manufacturing 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 a TFT 114, a pixel electrode 113, a terminal 118, and the like on one surface of a glass substrate 111 by repeatedly performing a pattern forming process such as film formation, patterning by photolithography, and etching. You.

  Similarly, the counter substrate 120 is manufactured by forming a color filter 124 and a light shielding layer 125 on one surface of the glass substrate 121. At least before each substrate is bonded, it is manufactured as an uncurved planar substrate.

  Subsequently, in a substrate cleaning step, the array substrate 110 on which the TFT 114, the pixel electrode 113, and the like are formed is cleaned (Step S1). Next, in a liquid crystal alignment film material application step, an organic film made of polyimide as 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 baked by 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 has been applied to form a first alignment film 112 (Step S3). 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 processing as in steps S1 to S3.

  As described above, the alignment processing in step S3 has different transmission characteristics depending on each of the central region 12, and the corner region (upper left region 8, upper right region 9, lower right region 11, lower left region 10). Photo-alignment treatment is performed through the provided mask and optical filter to obtain an alignment film having a desired alignment direction in each region.

  Subsequently, in a sealant applying step for forming the sealant 130, a resin serving as the sealant 4 is applied to one surface of the TFT substrate 110 or the counter substrate 120 (step S4). In addition, a thermosetting resin such as an epoxy-based adhesive or an ultraviolet-curable resin can be used for the sealing material 4. When a drop injection method is used as a liquid crystal injection step to be performed later, an ultraviolet-curable resin is used. It is desirable to use In the first embodiment, a dispenser method suitable for combination with the drop-injection method is used for the sealing material application step. Specifically, using a seal dispenser device, a resin serving as the sealing material 4 is discharged from a nozzle as a paste and applied to one surface of the array substrate 110 or the counter substrate 120 as a paste. This resin is applied so as to surround the display area 1 of the liquid crystal display panel 100 to form the sealing material 4.

  Next, a transfer material application step (Step S5), a spacer dispersion step (Step S6), and the like are performed. In the transfer material application step, a resin mixed with conductive particles, a silver paste, or the like is arranged on one surface of the array substrate 110 or the counter substrate 120 in order to make the substrates conductive. In the spacer spraying step, spacers for keeping the distance between the substrates constant on one surface of the array substrate 110 or the counter substrate 120 are sprayed by a wet method or a dry method. Note that the transfer material application step can also serve as the seal material 130 forming step by mixing conductive particles in the seal material 130 for bonding the substrates. Further, the spacer dispersing step can be omitted by forming a projecting column spacer for determining the distance between the substrates on one surface of the array substrate 110 or the counter substrate 120 in advance.

  The liquid crystal 140 is dropped (step S7) on the array substrate 110 and the counter substrate 120 prepared as described above by a drop injection method. 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 with respect to the array substrate 110 and the opposing substrate bonded as described above. This step is performed by, for example, applying heat in accordance with the material of the sealing material 130 or irradiating ultraviolet rays. In the first embodiment, the curing treatment of the sealant 130 is performed by ultraviolet irradiation suitable for combination with the drop injection method.

  Next, a thinning polishing process is performed (step S9). In the thinning polishing step, the glass substrates 111 and 112 are ground to a thickness of about 0.2 mm. This is to make the liquid crystal display panel 100 flexible and to facilitate bending. Polishing is performed by, for example, grinding the surfaces of the glass substrates 111 and 121 by chemical polishing using a chemical solution or physical polishing by 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, the 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 assembly 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 104. At this time, the liquid crystal display panel 100 is attached in a curved state in accordance with the curvature of the cover glass 103. Then, the liquid crystal display device 100 is completed by incorporating the liquid crystal display panel 100 attached to the cover glass 103 into a housing (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, an array substrate 110 curved along the display surface 5a, and an array substrate curved along the display surface 5a. A counter substrate 120 disposed opposite to the first substrate 110; and a liquid crystal 140 held between the array substrate 110 and the counter substrate 120. 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, and the display surface 5a has a rectangular shape, and the display surface 5a is When viewed from the front, the upper left area 8, upper right area 9, lower right area 11, lower left area 10 including the upper left, upper right, lower right, and lower left corners of the display surface 5a, and the upper left area 8, upper right area 9, Lower right area 1 And a central region 12 located at the center of the display surface 5a with respect to the lower left region 10. The first and second regions in the upper left region 8, the upper right region 9, the lower right region 11, and the lower left region 10 overlap in plan view. The alignment directions of the second liquid crystal alignment films 112 and 122 are compared with the alignment directions of the first and second liquid crystal alignment films 112 and 122 in a 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 opposing 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 occurs. Therefore, in the first embodiment, at least one of the first and second liquid crystal alignment films 112 and 122 in the corner portion is compared with the first and second liquid crystal alignment films 112 and 122 in the central region 12. Is shifted. This makes it possible to correct the above-described birefringence and suppress display unevenness at the corners. As described above, the liquid crystal display panel 100 according to the first embodiment can suppress display unevenness in a corner portion with a simple configuration for adjusting 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 being sandwiched.

  Further, 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 in the second liquid crystal alignment film 122 is a fixed direction in the display surface 5a, and the upper left region 8 The orientation direction of the first liquid crystal alignment film 112 in a region overlapping each of the lower right region 11 in plan view is the first liquid crystal orientation in a region overlapping 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 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. Therefore, the alignment direction of the first liquid crystal alignment film 112 in a region overlapping the central region 12 in a plan view is shifted clockwise 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 in 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 when viewed from the front of the display surface 5a. 12 is shifted clockwise from the alignment direction of the second liquid crystal alignment film 122 in a region overlapping in a plan view, and the second liquid crystal alignment film 122 in a region overlapping each of the upper right region 9 and the lower left region 10 in a plan view. Is, when viewed from the front of the display surface 5a, shifted counterclockwise from the alignment direction of the second liquid crystal alignment film 122 in a region overlapping the central region 12 in plan view.

  Therefore, in the liquid crystal display panel 100 in which the display surface 5a is curved in a convex shape, the first and second liquid crystal alignments are performed as described above at the corners (upper left area 8, upper right area 9, lower right area 11, lower left area 10). By displacing the orientation direction of one of the films 112 and 122, it is possible to suppress display unevenness at a corner portion.

  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.

  Therefore, in the liquid crystal display panel 100 in the operation mode of the horizontal electric field system in which the first and second liquid crystal alignment films 112 and 122 are required to have the same alignment direction, it is possible to suppress display unevenness in a corner portion. It is.

  When the liquid crystal display panel 100 is in an operation mode (for example, a 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 central region 12 and the flat surface are different from each other. It is sufficient that the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the overlapping regions are different from each other by 90 °.

<Embodiment 2>
FIG. 7 is a schematic sectional view of the liquid crystal display panel 200 according to the second embodiment. The liquid crystal display panel 100 of the first embodiment has a convex shape with respect to the display surface 5a. On the other hand, the liquid crystal display panel 200 of the second embodiment is concavely curved 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. The other configuration is the same as that of the first embodiment, and the description is omitted. In the second embodiment, liquid crystal display panel 200 is curved along the longitudinal direction of the substrate (array substrate 110 and counter substrate 120). Note that the direction of curvature of the liquid crystal display panel 200 is not limited to this, and the liquid crystal display panel 200 may be curved along the lateral direction of the substrate (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 according to the second embodiment. In FIG. 8, the alignment directions of the first and second liquid crystal alignment films 112 and 122 in the central region 12 are the same. In FIG. 8, the arrow indicated by the solid line indicates the alignment direction of the second liquid crystal alignment film 122 of the counter substrate 120. Arrows indicated by broken lines indicate 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 a region overlapping the upper left region 8 of the display surface 5a in plan view, the orientation direction of the first liquid crystal alignment film 112 is more clockwise than the orientation direction of the second liquid crystal alignment film 122. It is shifted around by angle θ1 9. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper left region 8 is shifted clockwise 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. 8, in a region overlapping the upper right region 9 of the display surface 5a in plan view, the orientation direction of the first liquid crystal alignment film 112 is more counterclockwise than the orientation direction of the second liquid crystal alignment film 122. It is shifted around by angle θ2. That is, the alignment direction of the first liquid crystal alignment film 112 in the upper right region 9 is shifted counterclockwise by the angle θ2 from the alignment direction of the first liquid crystal alignment film 112 in the central region 12.

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

  Further, as shown in FIG. 8, in a region overlapping the lower left region 10 of the display surface 5a in plan view, the orientation direction of the first liquid crystal alignment film 112 is more counterclockwise than the orientation direction of the second liquid crystal alignment film 122. It is shifted around by an angle θ4. That is, the alignment direction of the first liquid crystal alignment film 112 in the lower left area 10 is shifted counterclockwise by an angle θ4 from the alignment direction of the first liquid crystal alignment film 112 in the central area 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 fixed, but the alignment direction of the first liquid crystal alignment film 112 is changed. 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, the first liquid crystal alignment film 112 is shifted clockwise by θ1 with respect 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 θ1 with respect to the alignment direction of the first liquid crystal alignment film 112.

  Similarly, in the upper right region 9, the first liquid crystal alignment film 112 is shifted counterclockwise by θ2 with respect 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 clockwise by θ2 with respect to the alignment direction of the first liquid crystal alignment film 112.

  Similarly, in the lower right region 11, the first liquid crystal alignment film 112 is shifted clockwise by θ3 based on 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 θ3 with respect to the alignment direction of the first liquid crystal alignment film 112.

  Similarly, in the lower left region 10, the first liquid crystal alignment film 112 is shifted counterclockwise by θ4 with respect 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 clockwise by θ4 with respect to the alignment direction of the first liquid crystal alignment film 112.

  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, and are, for example, 1 °.

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

  Therefore, in the liquid crystal display panel 200 in which the display surface 5a is concavely curved, the first and second liquid crystal alignment films are formed as described above in the corner portions (upper left region 8, upper right region 9, lower right region 11, lower left region 10). By displacing one of the orientation directions of 112 and 122, it is possible to suppress display unevenness in a corner portion.

  In the present invention, each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted within the scope of the invention.

  103 cover glass, 104 transparent adhesive, 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 sealant, 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 method for manufacturing a liquid crystal display panel having a curved display surface,
And a counter substrate of the array substrate and the planar shape of the planar shape, forming a liquid crystal display panel by bonding through a liquid crystal,
Curving the liquid crystal display panel ;
With
A first liquid crystal alignment film is provided on a surface of the array substrate on the counter substrate side,
A second liquid crystal alignment film is provided on a surface of the counter substrate on the array substrate side,
The display surface is a square shape,
The display surface,
Seen from the front of the display surface, upper left, upper right, lower right, upper left region including each of the lower left corner, upper right region, lower right region, lower left region of the display surface,
The upper left area, the upper right area, a central area located at the center of the display surface than the lower right area and the lower left area,
With
In the liquid crystal display panel before being curved, the upper left region, the upper right region, the lower right region, the alignment direction of the first and second liquid crystal alignment films in a region overlapping each of the lower left region in a plan view, An alignment direction of at least one of the first and second liquid crystal alignment films is shifted from an alignment direction of the first and second liquid crystal alignment films in a region overlapping with the central region in plan view;
A method for manufacturing a liquid crystal display panel. In the liquid crystal display panel after being curved , the display surface is convexly curved,
In the liquid crystal display panel before being curved , the alignment direction in the second liquid crystal alignment film is a fixed direction in the display surface, and the second liquid crystal alignment film is in a region overlapping in plan view with each of the upper left region and the lower right region. The alignment direction of the liquid crystal alignment film of No. 1 is counterclockwise shifted from the alignment direction of the first liquid crystal alignment film in a region overlapping the central region in a plan view, as viewed from the front of the display surface, The alignment direction of the first liquid crystal alignment film in a region overlapping each of the upper right region and the lower left region in plan view is the first direction in a region overlapping the central region in plan view when viewed from the front of the display surface. Whether it is shifted clockwise from the alignment direction of the liquid crystal alignment film,
Alternatively, in the liquid crystal display panel before being curved , an alignment direction in the first liquid crystal alignment film is a fixed direction in the display surface, and is in a region overlapping each of the upper left region and the lower right region in plan view. The alignment direction of the second liquid crystal alignment film is clockwise shifted from the alignment direction of the second liquid crystal alignment film in a region overlapping the central region in a plan view when viewed from the front of the display surface, The orientation direction of the second liquid crystal alignment film in a region overlapping each of the upper right region and the lower left region in a plan view is the second direction in a region overlapping the central region in a plan view when viewed from the front of the display surface. Is displaced counterclockwise from the alignment direction of the liquid crystal alignment film,
A method for manufacturing a liquid crystal display panel according to claim 1. In the liquid crystal display panel after being curved, the display surface is concavely curved,
In the liquid crystal display panel before being curved , the alignment direction in the second liquid crystal alignment film is a fixed direction in the display surface, and the second liquid crystal alignment film is in a region overlapping in plan view with each of the upper left region and the lower right region. When viewed from the front of the display surface, the alignment direction of the first liquid crystal alignment film 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. The alignment direction of the first liquid crystal alignment film in a region overlapping each of the region and the lower left region in a plan view is the first liquid crystal in a region overlapping the central region in a plan view when viewed from the front of the display surface. Whether it is shifted counterclockwise from the alignment direction of the alignment film,
Alternatively, in the liquid crystal display panel before being curved , an alignment direction in the first liquid crystal alignment film is a fixed direction in the display surface, and is in a region overlapping each of the upper left region and the lower right region in plan view. When viewed from the front of the display surface, the alignment direction of the second liquid crystal alignment film is shifted counterclockwise from the alignment direction of the second liquid crystal alignment film in a region overlapping the central region in plan view. The orientation direction of the second liquid crystal alignment film in a region overlapping each of the upper right region and the lower left region in plan view is the second direction in a region overlapping the central region in plan view when viewed from the front of the display surface. 2 is clockwise shifted from the alignment direction of the liquid crystal alignment film,
A method for manufacturing a liquid crystal display panel according to claim 1. In the liquid crystal display panel before being curved , the orientation directions of the first and second liquid crystal alignment films in a region overlapping the central region in a plan view are the same direction.
The method for manufacturing a liquid crystal display panel according to claim 1.

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