JP2010025988A - Method of manufacturing liquid crystal display device, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method with which the occurrence of display coarseness on a liquid crystal display device employing a PSA system can be prevented. <P>SOLUTION: The method of manufacturing the liquid crystal display device includes a step of preparing a liquid crystal layer 30 containing liquid crystal molecules 31 and a polymerizable composition and a step of forming an alignment control layer 32 by polymerizing the polymerizable composition with a prescribed voltage applied to the liquid crystal layer 30. In the step of forming the alignment control layer 32, a thin-film transistor 13 is switched between turned-on and turned-off states by a scan signal, and an application voltage is supplied from a signal line 15 to a pixel electrode 12 while the thin-film transistor 13 is in the turned-on state, and the application voltage is held in the pixel electrode 12 and substantially the same reference potential is given to the signal line 15 and a counter electrode 22 while the thin-film transistor 13 is in the turned-off state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a PSA type liquid crystal display device.

  In recent years, a thin and light liquid crystal display device has been used as a display device used for a display of a personal computer or a display unit of a portable information terminal device. However, the conventional twist nematic type (TN type) and super twist nematic type (STN type) liquid crystal display devices have a drawback of a narrow viewing angle, and various technical developments have been carried out to solve this problem. It has been broken.

  As a liquid crystal display device with improved viewing angle characteristics, an alignment division type liquid crystal display device having a vertical alignment type liquid crystal layer is known. Such a liquid crystal display device is called a VA (Vertical Alignment) mode liquid crystal display device. As one of VA modes, Patent Document 1 discloses an MVA (Multi-domain Vertical Alignment) mode. In the MVA mode, an alignment regulating structure that regulates the alignment of liquid crystal molecules is provided on each of a pair of substrates opposed via a liquid crystal layer. Specifically, the orientation regulating structure is a protrusion or a slit formed in the electrode. By providing alignment control structures such as protrusions and slits, when a voltage is applied to the liquid crystal layer, multiple regions with different orientations of the liquid crystal molecules are formed. Will improve.

  Patent Document 2 proposes a CPA (Continuous Pinwheel Alignment) mode as another VA mode. In the CPA mode, an opening or notch is formed in one of a pair of electrodes facing each other through a liquid crystal layer, and liquid crystal molecules are radially inclined and aligned using an oblique electric field generated on the opening or notch. To achieve a wide viewing angle.

  Further, Patent Document 3 discloses a technique for stabilizing the radial tilt alignment of liquid crystal molecules in the CPA mode. According to this technique, a radially inclined alignment formed by an alignment regulating structure (an opening or a notch in an electrode that generates an oblique electric field) provided on one substrate is an alignment regulating structure (for example, It is stabilized by the convex part).

On the other hand, a method of forming a polymer structure as an alignment control layer (alignment maintaining layer) for defining the pretilt angle and the pretilt direction of liquid crystal molecules is disclosed in Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and the like. Proposed. This method is called a PSA (Polymer-Sustained Alignment) method. The polymer structure is formed by photopolymerization or thermal polymerization of a polymerizable composition previously mixed in the liquid crystal layer. By providing such a polymer structure in a VA mode liquid crystal display device, stability of alignment and response characteristics can be improved.
Japanese Patent Laid-Open No. 11-242225 JP 2003-43525 A JP 2002-202511 A JP 2002-23199 A JP 2003-149647 A Japanese Patent Laid-Open No. 2003-177408 JP 2003-307720 A

  The process of forming the polymer structure (hereinafter referred to as “PSA process”) is not a state in which the liquid crystal molecules are vertically aligned, but in a state in which the liquid crystal molecules are tilted by applying a predetermined voltage to the liquid crystal layer. Done. In addition, the application of voltage to the liquid crystal layer in the PSA process is performed such that the polarity of the applied voltage is periodically reversed (that is, AC driving is performed) so that the liquid crystal is not polarized.

  As a method of voltage application (AC drive) in the PSA process, (1) a method of oscillating the potential of the counter electrode while fixing the potential of the pixel electrode by turning on a thin film transistor (TFT) provided in each pixel (2) There is a method in which the potential of the counter electrode is oscillated while the TFT is turned off and the pixel electrode is floated (electrically floating).

  First, a specific example of the method (1) will be described with reference to FIG. A CPA mode liquid crystal display device 500 shown in FIG. 9 includes a TFT substrate 510 in which a TFT (not shown) is provided in each pixel, a counter substrate 520 facing the TFT substrate 510, and a vertical alignment provided therebetween. Type liquid crystal layer 530. On the counter substrate 520, a convex portion 523 having an alignment regulating force for the liquid crystal molecules 531 and fixing the alignment center of the liquid crystal domain is provided.

  As shown in FIGS. 9A, 9B, and 9C, the TFT is turned on when a gate-on voltage of +10 V is applied from the scanning wiring 514 to the gate electrode of the TFT, and the pixel electrode 512 is turned on. Is supplied with a potential of 0 V via a signal wiring (not shown). In this state, when the potential of the counter electrode 522 is vibrated to +4 V (FIG. 9A) and −4 V (FIG. 9B), the polarity of the voltage applied to the liquid crystal layer 530 is changed to that of the counter electrode 522. Since it reverses in synchronization with the oscillation of the potential, AC driving can be performed.

Next, a specific example of the method (2) will be described with reference to FIG. As shown in FIGS. 10A, 10B, and 10C, the TFT is turned off by applying a gate-off voltage of −5 V from the scanning wiring 514 to the gate electrode of the TFT. 512 is in a float state (electrically floating state). In this state, when the potential of the counter electrode 522 is vibrated to +8 V (FIG. 10A) and −8 V (FIG. 10B), the potential of the pixel electrode 512 is also vibrated. For example, when the liquid crystal capacitance and the auxiliary capacitance C _S (schematically indicated by circuit symbols in the figure) have the same capacitance value, the potential of the pixel electrode 512 is +4 V (FIG. 10A) and −. Vibrates to 4V (FIG. 10B). Therefore, the polarity of the voltage applied to the liquid crystal layer 530 is periodically reversed, so that AC driving can be performed.

  However, according to the study of the present inventor, when the PSA process is performed while applying a voltage to the liquid crystal layer 530 by the above methods (1) and (2), the display is rough for the following reason. It was found that the display quality deteriorates.

  FIG. 11 is a view of the liquid crystal molecules 531 in one pixel that are inclined and aligned in the PSA process, as viewed from the upper surface side of the liquid crystal display device. FIG. 11A shows an ideal tilted alignment state of the liquid crystal molecules 531, and FIGS. 11B and 11C show tilted alignments that can cause roughness in display by the above methods (1) and (2). The state is schematically represented. In these drawings, in order to represent the tilted alignment of the liquid crystal molecules 531, each liquid crystal molecule 531 is illustrated so that the portion close to the counter electrode 522 looks larger (the end of the liquid crystal molecule 531 closer to the counter electrode 522). The part is indicated by a circle).

  In the PSA process, it is ideal that the liquid crystal molecules 531 in one pixel are uniformly radially inclined with respect to the convex portion 523 as shown in FIG. Therefore, wide viewing angle display with little display unevenness is realized. However, when AC driving is performed by the above methods (1) and (2), as shown in FIGS. 9 and 10, the counter electrode 522 is always supplied with a potential other than 0 V, whereas the signal wiring 516 and Since the potential of the auxiliary capacitor wiring 518 is maintained at 0 V, the liquid crystal molecules 531 positioned on these wirings are also tilted. Here, since the signal wiring 516 and the auxiliary capacitance wiring 518 extend along the boundary between two adjacent pixels, the liquid crystal molecules 531 on these wirings have an alignment regulating force in opposite directions from both pixels. Acts almost evenly (that is, the alignment regulating force from both pixels is offset). Therefore, the liquid crystal molecules 531 on these wirings are not shown in FIG. 11B and FIG. 11C (the liquid crystal molecules 531 on the auxiliary capacitance wiring 518 are not shown), and the signal wiring 516. And, it is oriented in the direction along the direction in which the storage capacitor line 518 extends.

  11B shows a state in which all the liquid crystal molecules 531 on the pair of signal wirings 516 are inclined downward along the signal wiring 516, and FIG. 11C shows the state above one of the pair of signal wirings 516. The liquid crystal molecules 531 are inclined downward, and the liquid crystal molecules 531 on the other signal wiring 516 are oriented upward in the drawing. In any case, the alignment direction of the liquid crystal molecules 531 in the vicinity of the signal wiring 516 (regions indicated by a and b in the figure) is disturbed by the tilted orientation of the liquid crystal molecules 531 on the signal wiring 516, and FIG. The ideal inclined alignment state shown in a) cannot be obtained. Although not shown, the liquid crystal molecules 531 on one signal line 516 are inclined in the opposite direction with respect to one point on the signal line 516 (for example, upward and downward inclined alignments in the figure). May occur, and the boundary may move. Even in such a case, the orientation of the liquid crystal molecules 531 in the pixel is disturbed, and an ideal inclined orientation state cannot be obtained.

  When the PSA process is performed in such a disordered tilted orientation, liquid crystal molecules that are oriented at the time of display are also disturbed by the formed polymer structure. As a result, the orientation state varies from pixel to pixel. As a result, roughness in the display (non-uniform luminance) occurs.

  Further, in the above method (2), the PSA process is performed after the TFT is turned off and the pixel electrode 512 is floated. For this reason, for example, when some DC voltage is applied to the pixel electrode 512 in the initial stage of manufacture, an AC voltage is applied in a state where the DC voltage is superimposed in the PSA process, and a polymer with a voltage different from the desired voltage is applied. There is a problem that will be done. In addition, when AC driving is performed in a state where a negative DC voltage is superimposed on the pixel electrode 512, the potential of the pixel electrode 512 may be lower than the off-potential of the scanning wiring 514. Polymerization may occur with an applied voltage that is conductive and completely different from the desired voltage. In a liquid crystal display device that has been made into a PSA by such an applied voltage, an abnormal alignment of liquid crystal molecules occurs during display, and display quality deteriorates.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a manufacturing method capable of reducing display roughness and providing a high-quality display for a PSA type liquid crystal display device. It is in.

  A method of manufacturing a liquid crystal display device according to the present invention includes a pixel electrode disposed in each of a plurality of pixels, a thin film transistor electrically connected to the pixel electrode, a scanning wiring for supplying a scanning signal to the thin film transistor, A first substrate having a signal wiring for supplying a display signal to the thin film transistor; a second substrate having a counter electrode facing the pixel electrode; and a liquid crystal layer provided between the first substrate and the second substrate; A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer, and the liquid crystal layer is disposed between the vertical alignment film and the liquid crystal layer. A method of manufacturing a liquid crystal display device in which an alignment control layer for defining the alignment direction of the liquid crystal molecules contained is formed, the liquid crystal layer including a liquid crystal material and a polymerizable composition being prepared. Forming the alignment control layer by polymerizing a polymerizable composition in the liquid crystal layer in a state where a predetermined voltage is applied to the liquid crystal layer, and forming the alignment control layer. The thin film transistor is switched on and off by the scanning signal, and when the thin film transistor is in an on state, an applied voltage is supplied from the signal wiring to the pixel electrode, and when the thin film transistor is in an off state, the application is applied to the pixel electrode While holding the voltage, a reference potential substantially the same as that of the counter electrode is applied to the signal wiring.

  In one embodiment, in the step of forming the alignment control layer, a positive potential and a negative potential are alternately applied to the signal wiring in synchronization with the scanning signal, whereby a positive voltage and a negative potential are applied to the pixel electrode. The voltage is held alternately.

  In one embodiment, in the step of forming the alignment control layer, a first potential for turning on the thin film transistor and a second potential for turning off the thin film transistor are alternately applied to the scanning wiring, and the potential of the scanning wiring is formed. Is the second potential, the signal wiring potential and the counter electrode potential are made substantially equal.

  In one embodiment, the potential of the counter electrode is kept substantially constant at the reference potential during the step of forming the alignment control layer.

  In one embodiment, the reference potential is approximately 0 V (volt) or ground potential.

  In one embodiment, the alignment control layer is configured so that liquid crystal molecules on the pixel electrode are perpendicular to the surface of the first substrate when no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal molecules on the signal wiring are maintained so as to be substantially perpendicular to the surface of the first substrate.

  In one embodiment, each of the plurality of pixels includes a liquid crystal capacitor formed by the pixel electrode, the liquid crystal layer, and the counter electrode, an auxiliary capacitor electrode electrically connected to the pixel electrode, an insulating layer, And an auxiliary capacitance formed by an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer, and the auxiliary capacitance counter electrode is electrically connected to an auxiliary capacitance wiring, and the orientation control During the step of forming the layer, the potential of the storage capacitor line is kept substantially the same as the potential of the counter electrode.

  In one embodiment, the alignment control layer is configured so that liquid crystal molecules on the pixel electrode are perpendicular to the surface of the first substrate when no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal molecules on the storage capacitor line are maintained so as to be substantially perpendicular to the surface of the first substrate.

  In one embodiment, the polymerizable composition has photopolymerizability, and the step of forming the alignment control layer is performed by irradiating the liquid crystal layer with light.

  Another manufacturing method of the liquid crystal display device according to the present invention includes a pixel electrode disposed in each of a plurality of pixels, a thin film transistor electrically connected to the pixel electrode, a scanning wiring for supplying a scanning signal to the thin film transistor, A first substrate having a signal line for supplying a display signal to the thin film transistor and a storage capacitor line, a second substrate having a counter electrode facing the pixel electrode, and between the first substrate and the second substrate And each of the plurality of pixels includes an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary electrode facing the auxiliary capacitance electrode through the insulating layer An auxiliary capacitor formed by a capacitor counter electrode, wherein the first substrate has an auxiliary capacitor wiring electrically connected to the auxiliary capacitor counter electrode; A vertical alignment film is formed between at least one of the second substrates and the liquid crystal layer, and an alignment direction of liquid crystal molecules contained in the liquid crystal layer is defined between the vertical alignment film and the liquid crystal layer. A method of manufacturing a liquid crystal display device in which an alignment control layer is formed, the step of preparing the liquid crystal layer containing a liquid crystal material and a polymerizable composition, and a state in which a predetermined voltage is applied to the liquid crystal layer Forming the alignment control layer by polymerizing a polymerizable composition in the liquid crystal layer, and in the step of forming the alignment control layer, the thin film transistor is switched on and off by the scanning signal. When the thin film transistor is in an ON state, an applied voltage is supplied from the signal wiring to the pixel electrode and the step of forming the orientation control layer is performed. It kept substantially the same potential as the potential of counter electrode.

  The liquid crystal display device according to the present invention includes a pixel electrode disposed in each of a plurality of pixels, a thin film transistor electrically connected to the pixel electrode, a scanning line for supplying a scanning signal to the thin film transistor, and a display on the thin film transistor. A first substrate having a signal wiring for supplying a signal; a second substrate having a counter electrode facing the pixel electrode; and a liquid crystal layer provided between the first substrate and the second substrate. A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer, and the liquid crystal contained in the liquid crystal layer is between the vertical alignment film and the liquid crystal layer. An alignment control layer for defining the alignment direction of molecules is formed, and in a state where no voltage is applied between the pixel electrode and the counter electrode, a liquid crystal component on the pixel electrode is formed. Is maintained in a state inclined from the direction perpendicular to the plane of the first substrate by the orientation control layer, the liquid crystal molecules on said signal lines is maintained substantially perpendicular to the plane of the first substrate.

  In one embodiment, the alignment control layer is configured so that liquid crystal molecules on the pixel electrode are perpendicular to the surface of the first substrate when no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal molecules on the signal wiring are maintained substantially perpendicular to the surface of the first substrate.

  In one embodiment, each of the plurality of pixels is formed by an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer The first substrate has a storage capacitor wire electrically connected to the storage capacitor counter electrode, and no voltage is applied between the pixel electrode and the counter electrode. In the state, the liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate.

  In one embodiment, the alignment control layer is configured so that liquid crystal molecules on the pixel electrode are perpendicular to the surface of the first substrate when no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate.

  Another liquid crystal display device according to the present invention includes a pixel electrode disposed in each of a plurality of pixels, a thin film transistor electrically connected to the pixel electrode, a scanning wiring for supplying a scanning signal to the thin film transistor, and the thin film transistor A first substrate having a signal wiring for supplying a display signal to the second substrate, a second substrate having a counter electrode facing the pixel electrode, a liquid crystal layer provided between the first substrate and the second substrate, Each of the plurality of pixels is formed by an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer The first substrate has an auxiliary capacitance wiring electrically connected to the auxiliary capacitance counter electrode, and at least one of the first substrate and the second substrate. A vertical alignment film is formed between the liquid crystal layer and an alignment control layer for defining the alignment direction of the liquid crystal molecules contained in the liquid crystal layer between the vertical alignment film and the liquid crystal layer. In the state where no voltage is applied between the pixel electrode and the counter electrode, the liquid crystal molecules on the pixel electrode are formed by the alignment control layer from a direction perpendicular to the surface of the first substrate. The tilted state is maintained, and the liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate.

  In one embodiment, the alignment control layer is configured so that liquid crystal molecules on the pixel electrode are perpendicular to the surface of the first substrate when no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate.

  According to the present invention, in the process of forming the alignment control layer of the PSA liquid crystal display device, the potential of the pixel electrode is held at the potential given from the signal wiring, and thus a desired voltage is applied to the liquid crystal layer. Thus, the orientation control layer is formed. At this time, since substantially the same reference potential as that of the counter electrode is applied to the signal wiring or the auxiliary capacitance wiring, the liquid crystal molecules on the signal wiring or the auxiliary capacitance wiring are aligned substantially perpendicularly to the substrate surface. Accordingly, since the disorder of the alignment of the liquid crystal molecules on the pixel electrode during the formation of the alignment control layer is reduced, an ideal alignment control function can be given to the alignment control layer. Thereby, the alignment disorder of the liquid crystal molecules in each pixel at the time of display is reduced, and variations in luminance characteristics from pixel to pixel are reduced, so that display roughness is reduced.

  Further, according to the present invention, the liquid crystal molecules on the signal wiring or the auxiliary capacitance wiring are aligned almost perpendicularly to the substrate surface when no voltage is applied, so that the liquid crystal molecules on the pixel electrode can be given a pre-tilt with little disturbance. It becomes. Thereby, the alignment disorder of the liquid crystal molecules at the time of display is reduced, and uniform luminance characteristics can be given to each pixel, so that display roughness is reduced.

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

  1, 2 and 3 show a CPA mode liquid crystal display device 100 according to the present embodiment. FIG. 1 is a plan view schematically showing a region corresponding to one pixel of the liquid crystal display device 100. FIG. 2 is a cross-sectional view taken along line 2A-2A ′ in FIG. 1 and shows a state in which no voltage is applied to the liquid crystal layer (a state in which a voltage less than the threshold voltage is applied). . FIG. 3 shows an equivalent circuit of one pixel of the liquid crystal display device 100.

  The liquid crystal display device 100 includes a liquid crystal display panel 100a and includes a plurality of pixels arranged in a matrix. The liquid crystal display panel 100 a includes an active matrix substrate (first substrate) 10, a counter substrate (second substrate) 20 facing the active matrix substrate 10, and a vertical provided between the active matrix substrate 10 and the counter substrate 20. And an alignment type liquid crystal layer 30.

  The active matrix substrate 10 includes a pixel electrode 12 disposed in each pixel, a thin film transistor (TFT) 13 electrically connected to the pixel electrode 12, and a scanning wiring (gate bus line) for supplying a scanning signal to the TFT 13 serving as a switching element. 14 and a signal wiring (source bus line) 15 for supplying a display signal to the TFT 13. The pixel electrode 12, the TFT 13, the scanning wiring 14, and the signal wiring 15 are provided on a transparent substrate (for example, a glass substrate or a plastic substrate) 11. On the transparent substrate 11, auxiliary capacitance wiring 16 is also provided.

  The pixel electrode 12 has a plurality of sub-pixel electrodes 12a. In the present embodiment, the pixel electrode 12 having two sub-pixel electrodes 12a is illustrated, but the number of sub-pixel electrodes 12a included in one pixel electrode 12 is not limited to this. Further, the shape of each sub-pixel electrode 12a is not limited to a substantially rectangular shape as illustrated, but a shape having high rotational symmetry (a substantially rectangular shape having a substantially square, a substantially circular shape, or an arcuate corner). Etc.) are preferably used.

  The counter substrate 20 includes a counter electrode 22 that faces the pixel electrode 12. The counter electrode 22 is provided on a transparent substrate 21 (for example, a glass substrate or a plastic substrate). While the pixel electrode 12 is disposed in each of the plurality of pixels, the counter electrode 22 is typically formed as one transparent conductive film that faces all the pixel electrodes 12. Although not shown here, typically, a color filter is provided between the transparent substrate 21 and the counter electrode 22. Therefore, the counter substrate 20 is also called a color filter substrate.

As shown in FIG. 3, each pixel has a liquid crystal capacitor C _LC formed by the pixel electrode 12 and the counter electrode 22 and a liquid crystal layer 30 positioned therebetween. Each pixel has an auxiliary capacitor C _S electrically connected to the liquid crystal capacitor C _LC in parallel. The auxiliary capacitance C _S is formed by the auxiliary capacitance electrode 17 electrically connected to the pixel electrode 12, the insulating layer 18, and the auxiliary capacitance counter electrode 19 that faces the auxiliary capacitance electrode 17 through the insulating layer 18. Various known configurations can be used as the specific configuration of the auxiliary capacitor C _S including the auxiliary capacitor electrode 17 and the auxiliary capacitor counter electrode 19. For example, the auxiliary capacitance electrode 17 is formed by patterning the same metal layer as the signal wiring 15 and arranged so as to overlap the auxiliary capacitance wiring 16, and the portion of the auxiliary capacitance wiring 16 overlapping the auxiliary capacitance electrode 17 is set as the auxiliary capacitance counter electrode. 19 can be used.

  As shown in FIG. 2, a vertical alignment film 33 is provided on the surface of the active matrix substrate 10 on the liquid crystal layer 30 side, and an alignment control layer (alignment maintaining layer) is provided on the surface of the vertical alignment film 33 on the liquid crystal layer 30 side. A polymer structure 32 which is a layer). Such a vertical alignment film 33 is also provided on the surface of the counter substrate 20 on the liquid crystal layer 30 side, and a polymer structure 32 that is an alignment control layer is also provided on the surface of the vertical alignment film 33 on the liquid crystal layer 30 side. However, the illustration is omitted here. Typically, a retardation plate and a polarizing plate are provided outside the active matrix substrate 10 and the counter substrate 20, respectively.

  The vertically aligned liquid crystal layer 30 includes liquid crystal molecules 31 having negative dielectric anisotropy, and further includes a chiral agent as necessary. The liquid crystal molecules 31 in the liquid crystal layer 30 are aligned substantially perpendicular to the surface of the vertical alignment film 33 when no voltage is applied to the liquid crystal layer 30. However, in this embodiment, since the polymer structure 32 is provided by a method described later, the liquid crystal molecules 31 are not aligned strictly perpendicular to the surface of the vertical alignment film 33.

  4 and 5 show the alignment state of the liquid crystal molecules 31 when a predetermined voltage (a voltage equal to or higher than the threshold voltage) is applied between the pixel electrode 12 and the counter electrode 22. When a predetermined voltage is applied between the pixel electrode 12 and the counter electrode 22, a liquid crystal domain is formed on each sub-pixel electrode 12a as shown in FIGS. Within the liquid crystal domain, the liquid crystal molecules 31 have a radially inclined orientation (radially inclined orientation).

  A liquid crystal domain having a radially inclined orientation is formed for each sub-pixel electrode 12a because the sub-pixel electrode 12a has an outer edge close to an independent island, and an oblique electric field generated at an edge portion of the sub-pixel electrode 12a. This is because the alignment regulating force acts on the liquid crystal molecules 31. The electric field generated at the edge portion of the sub-pixel electrode 12a is inclined toward the center of the sub-pixel electrode 12a, and acts to tilt and align the liquid crystal molecules 31 radially.

  In the present embodiment, the counter substrate 20 is provided with a convex portion 23 for stabilizing the radial tilt alignment. The convex portion 23 is disposed in a region corresponding to the center of the liquid crystal domain (that is, a region corresponding to the center of each sub-pixel electrode 12a). The convex part 23 is formed from a transparent dielectric material (for example, resin). Note that the protrusions 23 are not necessarily provided, and some or all of the plurality of protrusions 23 provided in each pixel may be omitted. Further, instead of the convex portion 23, another alignment regulating structure (for example, an opening formed in the counter electrode 22) may be provided.

  Further, the liquid crystal layer 30 of the liquid crystal display device 100 includes a polymer structure 32 for defining the alignment direction of the liquid crystal molecules 31 as schematically shown in FIG. In the polymer structure 32, a vertical alignment film 33 is obtained by previously mixing a polymerizable composition (polymerizable monomer or oligomer) into the liquid crystal material constituting the liquid crystal layer 30 and photopolymerizing the polymerizable composition. Formed on top. The polymer structure 32 has an alignment regulating force for orienting the liquid crystal molecules 31, and the liquid crystal molecules 31 around the polymer structure 32 are aligned in the same direction as the tilt direction at the time of voltage application even when no voltage is applied ( Pretilt). That is, by forming the polymer structure 32, the pretilt azimuth of the liquid crystal molecules 31 is regulated so as to match the radial tilt alignment at the time of voltage application even when no voltage is applied. Therefore, alignment stability and response characteristics are improved.

  In the present embodiment, in a state where no voltage is applied between the pixel electrode 12 and the counter electrode 22, the liquid crystal molecules 31 on the pixel electrode 12 are separated from the active matrix substrate 10 ( Alternatively, it is maintained in an inclined state with respect to a direction perpendicular to the surface of the pixel electrode 12). However, the liquid crystal molecules on the signal wiring 15 and the auxiliary capacitance wiring 16 are maintained substantially perpendicular to the surface of the active matrix substrate 10 by the polymer structure 32 on these wirings. Accordingly, the pretilt of the liquid crystal molecules 31 on the pixel electrode is less disturbed by the liquid crystal molecules 31 on these wirings. Therefore, the alignment disorder of the liquid crystal molecules at the time of display is reduced, and uniform luminance characteristics can be given to each pixel.

  Next, a method for manufacturing the liquid crystal display device 100 according to the present embodiment will be described with reference to FIGS.

  First, as shown in FIG. 6A, a liquid crystal display panel 100a including a polymerizable composition in the liquid crystal layer 30 is prepared. Each of the active matrix substrate 10 and the counter substrate 20 can be formed using various known methods. As the polymerizable composition, various materials (for example, materials disclosed in Patent Document 7) used for forming a PSA-type polymer structure can be used.

  Next, as shown in FIG. 6B, the polymer composition is polymerized by polymerizing the polymerizable composition in the liquid crystal layer 30 in a state where a predetermined voltage is applied to the liquid crystal layer 30 of the liquid crystal display panel 100a. 32 is formed. Typically, the polymerizable composition has photopolymerizability, and the polymerization is performed by irradiating the liquid crystal layer 30 with light (specifically, ultraviolet light). The irradiation intensity and irradiation time of light are appropriately set according to the polymerizable composition used. In addition, when the polymerizable composition has thermal polymerizability, the polymerization may be performed by heating. In the manufacturing method in this embodiment, the method of applying a voltage to the liquid crystal layer 30 in this step (PSA process) is different from the conventional method. This will be specifically described below.

  First, in the manufacturing method of the present embodiment, an oscillating voltage as shown in FIG. 7C is applied to the signal wiring 15 in the PSA process. That is, positive and negative (for example, ± 4 V) potentials are periodically applied to the signal wiring 15 periodically with reference to 0 V (or ground potential (GND)). Further, as shown in FIG. 7A, a gate-on voltage (first potential) synchronized with positive and negative potentials applied to the signal wiring 15 and a gate-off voltage (first potential) are applied to the gate electrodes of the scanning wiring 14 to the TFT 13. 2 potential) are applied alternately.

  The gate on voltage is, for example, 10V, and the gate off voltage is, for example, -5V. The application time of one gate-on voltage is 1 mSec, for example, and the application time of one gate-off voltage is longer than the application time of the gate-on voltage, for example, 10 mSec. The application time of the gate-off voltage is preferably at least three times the application time of the gate-on voltage.

  This is because, as will be described later, in order to keep the liquid crystal layer on the signal wiring 15 vertical, it is necessary to reduce the ratio of the time during which the voltage is applied between the signal wiring 15 and the counter electrode 22. It is. When the applied voltage to the signal wiring 15 is ± 4 V, the effective voltage to the liquid crystal layer on the signal wiring 15 is, for example, when the ratio of the time during which the voltage is applied and the time during which the voltage is not applied is 1: 3. Since this is approximately ± 1 V, which is lower than the threshold voltage of the liquid crystal alignment, it is possible to avoid an undesirable state in which the liquid crystal molecules on the signal line are inclined. When shortening the processing time by increasing the driving voltage of the signal wiring 15, the ratio of the off time is further increased and the time during which no voltage is applied to the liquid crystal molecules on the signal wiring 15 is simultaneously increased. Is preferred.

  The thin film transistor 13 is switched on and off in accordance with the scanning signal of the scanning wiring 14 composed of such gate on voltage and gate off voltage. In the PSA process, the potentials of the auxiliary capacitance line 16 and the counter electrode 22 are 0 V (or GND) as shown in FIG.

  When a gate-on voltage is applied to the gate electrode and the thin film transistor 13 is turned on, a positive applied voltage is supplied from the signal wiring 15 to the pixel electrode 12, and the potential of the pixel electrode 12 is the same as that of the signal wiring 15 (for example, + 4V). It becomes. Thereafter, while the gate-off voltage is applied to the gate electrode and the thin film transistor 13 is in the off state, a positive applied voltage (for example, +4 V) is held at the pixel electrode 12. At this time, 0 V (GND) which is substantially the same reference potential as the counter electrode 22 is applied to the signal wiring 15.

  When the thin film transistor 13 is next turned on, a negative applied voltage (for example, −4 V) is applied from the signal wiring 15 to the pixel electrode 12, and after that, while the thin film transistor 13 is turned off, the pixel electrode 12 is Hold negative applied voltage. At this time, 0 V (GND) which is substantially the same reference potential as the counter electrode 22 is applied to the signal wiring 15.

  By repeating ON / OFF of the thin film transistor 13 in this way, as shown in FIG. 7D, a positive voltage and a negative voltage are alternately and periodically held in the pixel electrode 12. That is, an oscillating voltage that periodically changes is supplied to the pixel electrode 12. During this time, since the potential of the counter electrode 22 is maintained at 0V, the liquid crystal layer 30 has a periodic oscillating voltage (for example, + 4V and −4) according to the potential of the pixel electrode 12, as shown in FIG. An oscillating voltage that varies between 4V) is applied.

  Thus, the liquid crystal display device 100 including the polymer structure 32 as shown in FIG. 2 is obtained. According to the manufacturing method of the present embodiment, in the process of forming the polymer structure 32 (PSA process), the liquid crystal molecules 31 are activated between the pixel electrode 12 and the counter electrode 22 when the thin film transistor 13 is off. A potential difference for alignment in a direction inclined from the direction perpendicular to the surface of the matrix substrate 10 is given, but the potential difference between the signal wiring 15 and the counter electrode 22 is substantially zero, so that the liquid crystal on the signal wiring 15 The molecules 31 are oriented substantially perpendicular to the surface of the active matrix substrate 10. Further, since the potential of the auxiliary capacitance line 16 is maintained at substantially the same potential as the potential of the counter electrode 22 while the polymer structure 32 is formed, the liquid crystal molecules 31 on the auxiliary capacitance line 16 are also active matrix substrate 10. It is oriented almost perpendicularly to the plane.

  The polymer structure 32 formed in this manner allows the liquid crystal molecules 31 on the pixel electrode 12 to be placed on the surface of the active matrix substrate 10 when no voltage is applied between the pixel electrode 12 and the counter electrode 22. The liquid crystal molecules 31 on the signal line 15 and the auxiliary capacity line 16 are maintained substantially perpendicular to the surface of the active matrix substrate 10 while maintaining the state inclined from the vertical direction.

  In the process of forming the polymer structure 32, as described above, the liquid crystal molecules 31 on the signal wiring 15 and the auxiliary capacitance wiring 16 are substantially vertically aligned. The alignment disorder of the liquid crystal molecules 31 in the vicinity as shown in FIGS. 11B and 11C is reduced, and the alignment disorder of the liquid crystal molecules 31 in the vicinity of the auxiliary capacitance wiring 16 is also reduced. Therefore, an alignment state close to the ideal inclined alignment state as shown in FIG. 11A in which the disorder of the alignment of the liquid crystal molecules 31 on the pixel electrode 12 is reduced can be obtained. Further, when display is performed by the liquid crystal display device 100 having the polymer structure 32 formed as described above, the alignment restriction force of the polymer structure 32 gives the liquid crystal molecules 31 a less disturbing alignment, so that each pixel It is possible to perform display with more uniform orientation and less roughness.

  In addition, in one cycle of ON / OFF of the thin film transistor 13, by setting the OFF state time longer, the liquid crystal molecules 31 on the signal wiring 15 are aligned more vertically and an alignment state with less disturbance is obtained. Can do. Therefore, it is preferable to set the ON time of the thin film transistor 13 to a shorter time in a time sufficient for applying a desired voltage from the signal wiring 15 to the pixel electrode 12.

  This voltage application time is determined by the time constant of the wiring of the signal input system necessary for PSA processing. For example, when processing the whole mother glass, it is desirable to take a long application time, for example, a long time such as 1 msec. Is selected. When a large number of input systems can be taken and the time constant for each system is low, for example, about several tens of microseconds may be used. Further, the time during which the thin film transistor 13 is turned off is set with a limit that the pixel can maintain a sufficient voltage over the period, and depends on the intensity of irradiation light during the PSA process. It is preferably shorter than 16.7 msec, which is the charge retention time at the time.

  8A and 8B, when the PSA process is performed by the voltage application method (reference example) shown in FIGS. 9 and 10, and the PSA process is performed by the voltage application method of this embodiment. The case and the micrograph of the state which inclined-aligned the liquid crystal molecule are shown. The two polarizing plates are arranged in a crossed Nicol state (a state in which the polarization axes are orthogonal to each other). In this arrangement, a region where the liquid crystal molecules are aligned perpendicular to the substrate and a region where the liquid crystal molecules are aligned in an orientation parallel or perpendicular to the polarization axis of the polarizing plate are observed as black. On the other hand, the region where the liquid crystal molecules are aligned in the direction inclined with respect to the polarization axis is observed brightly, and the region where the liquid crystal molecules are aligned in the direction forming an angle of 45 ° with respect to the polarization axis is the most. Observed brightly.

  When the PSA process is performed by the voltage application method shown in FIGS. 9 and 10, as shown in FIG. 8A, some liquid crystal domains (portions surrounded by solid lines in the figure) The distribution of bright areas is different from other liquid crystal domains. This indicates that variation occurs in the liquid crystal alignment state for each pixel.

  On the other hand, when the PSA process is performed by the voltage application method of the present embodiment, as shown in FIG. 8B, bright areas are distributed in substantially the same manner in a plurality of liquid crystal domains. This indicates that the liquid crystal alignment state for each pixel is substantially uniform. As described above, according to the manufacturing method of the present embodiment, the occurrence of display roughness is prevented in the PSA type liquid crystal display device.

  Note that the potential applied to the scanning wiring 14 in the PSA process (that is, the voltage applied to the gate electrode of the TFT 13) does not generate an electric field that greatly disturbs the liquid crystal alignment, and the TFT 13 is switched on and off. It is sufficient that the potential is sufficient, and the value is not limited to the exemplified values. Further, the potential applied to the signal wiring 15, the pixel electrode 12, the counter electrode 22, and the auxiliary capacitance wiring 16 may be any potential that is appropriate for obtaining a desired liquid crystal alignment state, and is limited to the above values. is not.

  In the present embodiment, the polymer structure 32 is formed to have a function of maintaining the liquid crystal molecules 31 on the signal wiring 15 and the auxiliary capacitance wiring 16 substantially perpendicular to the surface of the active matrix substrate 10. However, a manufacturing method for forming the polymer structure 32 so that the liquid crystal molecules 31 on either the signal wiring 15 or the auxiliary capacitance wiring 16 are maintained substantially perpendicular to the substrate surface, and such a polymer structure 32 is provided. The liquid crystal display device provided is also included in the present invention.

  Further, although the CPA mode liquid crystal display device 100 is used in this embodiment, the present invention is not limited to this. The present invention relates to a liquid crystal display device that includes a vertical alignment type liquid crystal layer, and in which a plurality of regions in which liquid crystal molecules are inclined in different directions when a voltage is applied to the liquid crystal layer (that is, alignment division type). It can be used widely, and for example, it is also suitably used for an MVA mode liquid crystal display device.

  According to the present invention, there is provided a manufacturing method capable of preventing the occurrence of display roughness in a PSA liquid crystal display device. The liquid crystal display device manufactured by the manufacturing method of the present invention is suitably used as a liquid crystal display device from a small size to a large size such as a mobile phone, a PDA, a notebook PC, a monitor, and a television receiver.

It is a figure which shows typically the liquid crystal display device 100 in suitable embodiment of this invention, and is a top view which shows the area | region corresponding to one pixel. It is a figure which shows typically the liquid crystal display device 100 in suitable embodiment of this invention, and is sectional drawing along the 2A-2A 'line | wire in FIG. It is a figure which shows typically the liquid crystal display device 100 in suitable embodiment of this invention, and is an equivalent circuit schematic which shows the area | region corresponding to one pixel. 4 is a plan view schematically showing the alignment state of liquid crystal molecules when a voltage is applied to a liquid crystal layer in the liquid crystal display device 100. FIG. 5 is a cross-sectional view schematically showing an alignment state of liquid crystal molecules when a voltage is applied to a liquid crystal layer in the liquid crystal display device 100, and is a cross-sectional view taken along line 5A-5A 'in FIG. (A) And (b) is process sectional drawing which shows the manufacturing process of the liquid crystal display device 100 typically. 4 is a diagram showing potentials applied to the scanning wiring, the auxiliary capacitance wiring 16, the counter electrode 22, the signal wiring 15, the pixel electrode 12, and the liquid crystal layer 30 in the manufacturing process of the liquid crystal display device 100. FIG. (A) is a microscope picture which shows the orientation state at the time of performing a PSA process by the voltage application method of a reference example, (b) is a PSA process by the voltage application method in suitable embodiment of this invention. It is a microscope picture which shows the orientation state at the time of performing. It is a figure for demonstrating the 1st example (method (1)) of the method of applying a voltage to a liquid-crystal layer in a PSA process. It is a figure for demonstrating the 2nd example (method (2)) of the method of applying a voltage to a liquid crystal layer in a PSA process. (A) is a diagram schematically showing an ideal alignment state of liquid crystal, and (b) and (c) are diagrams schematically showing an alignment state including alignment disorder.

Explanation of symbols

10 Active matrix substrate (first substrate)
DESCRIPTION OF SYMBOLS 11 Transparent substrate 12 Pixel electrode 12a Sub pixel electrode 13 Thin film transistor (TFT)
14 scanning wiring 15 signal wiring 16 auxiliary capacitance wiring 17 auxiliary capacitance electrode 18 insulating layer 19 auxiliary capacitance counter electrode 20 counter substrate (second substrate)
21 Transparent substrate 22 Counter electrode 23 Projection 30 Liquid crystal layer 31 Liquid crystal molecule 32 Polymer structure (alignment control layer)
33 Vertical alignment film 100a Liquid crystal display panel 100 Liquid crystal display device

Claims (16)

A pixel electrode disposed in each of the plurality of pixels; a thin film transistor electrically connected to the pixel electrode; a scanning wiring for supplying a scanning signal to the thin film transistor; and a signal wiring for supplying a display signal to the thin film transistor A first substrate;
A second substrate having a counter electrode facing the pixel electrode;
A liquid crystal layer provided between the first substrate and the second substrate,
A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer;
A method of manufacturing a liquid crystal display device in which an alignment control layer for defining an alignment direction of liquid crystal molecules contained in the liquid crystal layer is formed between the vertical alignment film and the liquid crystal layer,
Preparing the liquid crystal layer containing a liquid crystal material and a polymerizable composition;
Forming the alignment control layer by polymerizing a polymerizable composition in the liquid crystal layer in a state where a predetermined voltage is applied to the liquid crystal layer, and
In the step of forming the alignment control layer, the thin film transistor is turned on and off by the scanning signal. When the thin film transistor is in an on state, an applied voltage is supplied from the signal wiring to the pixel electrode, and the thin film transistor is turned off. A method of manufacturing a liquid crystal display device, wherein the applied voltage is held in the pixel electrode and a reference potential substantially the same as that of the counter electrode is applied to the signal line when in the state.   In the step of forming the alignment control layer, a positive voltage and a negative voltage are alternately applied to the signal wiring in synchronization with the scanning signal, so that a positive voltage and a negative voltage are alternately held in the pixel electrode. The manufacturing method according to claim 1. In the step of forming the alignment control layer, a first potential for turning on the thin film transistor and a second potential for turning off the thin film transistor are alternately applied to the scanning wiring,
The manufacturing method according to claim 1, wherein when the potential of the scanning wiring is the second potential, the potential of the signal wiring and the potential of the counter electrode are made substantially equal.   The manufacturing method according to claim 1, wherein the potential of the counter electrode is kept substantially constant at the reference potential during the step of forming the orientation control layer.   The manufacturing method according to claim 1, wherein the reference potential is approximately 0 V (volt) or a ground potential.   In a state where no voltage is applied between the pixel electrode and the counter electrode, the alignment control layer inclines liquid crystal molecules on the pixel electrode from a direction perpendicular to the surface of the first substrate. 6. The manufacturing method according to claim 1, wherein the method is formed so as to have a function of maintaining and maintaining liquid crystal molecules on the signal wiring substantially perpendicular to the surface of the first substrate. Each of the plurality of pixels is
A liquid crystal capacitor formed by the pixel electrode, the liquid crystal layer, and the counter electrode;
An auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance formed by an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer,
The auxiliary capacity counter electrode is electrically connected to an auxiliary capacity wiring,
The manufacturing method according to claim 1, wherein a potential of the auxiliary capacitance wiring is maintained at a potential substantially the same as a potential of the counter electrode during the step of forming the orientation control layer.   In a state where no voltage is applied between the pixel electrode and the counter electrode, the alignment control layer inclines liquid crystal molecules on the pixel electrode from a direction perpendicular to the surface of the first substrate. The manufacturing method according to claim 7, wherein the method is formed so as to have a function of maintaining and maintaining liquid crystal molecules on the storage capacitor line substantially perpendicular to the surface of the first substrate. The polymerizable composition has photopolymerizability,
The manufacturing method according to claim 1, wherein the step of forming the alignment control layer is performed by irradiating the liquid crystal layer with light. A pixel electrode disposed in each of the plurality of pixels, a thin film transistor electrically connected to the pixel electrode, a scanning wiring for supplying a scanning signal to the thin film transistor, a signal wiring for supplying a display signal to the thin film transistor, and an auxiliary A first substrate having capacitive wiring;
A second substrate having a counter electrode facing the pixel electrode;
A liquid crystal layer provided between the first substrate and the second substrate,
Each of the plurality of pixels has an auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer. Have
The first substrate has a storage capacitor line electrically connected to the storage capacitor counter electrode;
A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer;
A method of manufacturing a liquid crystal display device in which an alignment control layer for defining an alignment direction of liquid crystal molecules contained in the liquid crystal layer is formed between the vertical alignment film and the liquid crystal layer,
Preparing the liquid crystal layer containing a liquid crystal material and a polymerizable composition;
Forming the alignment control layer by polymerizing a polymerizable composition in the liquid crystal layer in a state where a predetermined voltage is applied to the liquid crystal layer, and
In the step of forming the alignment control layer, the thin film transistor is turned on and off by the scanning signal, and when the thin film transistor is in an on state, an applied voltage is supplied from the signal wiring to the pixel electrode,
The manufacturing method in which the potential of the auxiliary capacitance wiring is maintained at substantially the same potential as the potential of the counter electrode during the step of forming the orientation control layer. A pixel electrode disposed in each of the plurality of pixels; a thin film transistor electrically connected to the pixel electrode; a scanning wiring for supplying a scanning signal to the thin film transistor; and a signal wiring for supplying a display signal to the thin film transistor A first substrate;
A second substrate having a counter electrode facing the pixel electrode;
A liquid crystal layer provided between the first substrate and the second substrate,
A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer;
An alignment control layer for defining an alignment direction of liquid crystal molecules contained in the liquid crystal layer is formed between the vertical alignment film and the liquid crystal layer,
In a state where no voltage is applied between the pixel electrode and the counter electrode, the liquid crystal molecules on the pixel electrode are maintained in an inclined state from a direction perpendicular to the surface of the first substrate by the alignment control layer. And the liquid crystal molecules on the signal lines are maintained substantially perpendicular to the surface of the first substrate.   In a state where no voltage is applied between the pixel electrode and the counter electrode, the alignment control layer inclines liquid crystal molecules on the pixel electrode from a direction perpendicular to the surface of the first substrate. The liquid crystal display device according to claim 11, wherein the liquid crystal display device has a function of maintaining and maintaining liquid crystal molecules on the signal wiring substantially perpendicular to the surface of the first substrate. Each of the plurality of pixels has an auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer. Have
The first substrate has a storage capacitor line electrically connected to the storage capacitor counter electrode;
The liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate in a state where no voltage is applied between the pixel electrode and the counter electrode. A liquid crystal display device according to 1.   In a state where no voltage is applied between the pixel electrode and the counter electrode, the alignment control layer inclines liquid crystal molecules on the pixel electrode from a direction perpendicular to the surface of the first substrate. The liquid crystal display device according to claim 13, wherein the liquid crystal display device has a function of maintaining and maintaining liquid crystal molecules on the storage capacitor line substantially perpendicular to the surface of the first substrate. A pixel electrode disposed in each of the plurality of pixels; a thin film transistor electrically connected to the pixel electrode; a scanning wiring for supplying a scanning signal to the thin film transistor; and a signal wiring for supplying a display signal to the thin film transistor A first substrate;
A second substrate having a counter electrode facing the pixel electrode;
A liquid crystal layer provided between the first substrate and the second substrate,
Each of the plurality of pixels has an auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the pixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via the insulating layer. Have
The first substrate has a storage capacitor line electrically connected to the storage capacitor counter electrode;
A vertical alignment film is formed between at least one of the first substrate and the second substrate and the liquid crystal layer;
An alignment control layer for defining an alignment direction of liquid crystal molecules contained in the liquid crystal layer is formed between the vertical alignment film and the liquid crystal layer,
In a state where no voltage is applied between the pixel electrode and the counter electrode, the liquid crystal molecules on the pixel electrode are maintained in an inclined state from a direction perpendicular to the surface of the first substrate by the alignment control layer. The liquid crystal display device, wherein the liquid crystal molecules on the storage capacitor line are maintained substantially perpendicular to the surface of the first substrate.   The alignment control layer is in a state in which the liquid crystal molecules on the pixel electrode are tilted from a direction perpendicular to the surface of the first substrate in a state where no voltage is applied between the pixel electrode and the counter electrode. The liquid crystal display device according to claim 15, wherein the liquid crystal display device has a function of maintaining and maintaining liquid crystal molecules on the storage capacitor line substantially perpendicular to the surface of the first substrate.

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