JPWO2012124501A1 - Liquid crystal display panel and liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal display panel and a liquid crystal display device that can obtain high transmittance and good display quality. The liquid crystal display panel of the present invention is a liquid crystal display panel comprising a first substrate, a second substrate, and a liquid crystal layer, the liquid crystal layer being sandwiched between the first substrate and the second substrate, One substrate is opposed to the second substrate and has a source bus line, a gate bus line, and a first electrode, and the first substrate and the second substrate have a linear alignment control structure on at least one of them. The first electrode has a linear opening, and the linear opening is along the linear alignment regulating structure when the substrate main surface is viewed in plan view. At least a part of the edge of one electrode is a liquid crystal display panel that is inclined with respect to at least one of a source bus line and a gate bus line.

Description

The present invention relates to a liquid crystal display panel and a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display panel and a liquid crystal display device including an electrode having a slit structure for controlling the alignment of liquid crystal.

In recent years, liquid crystal display panels have been widely used for the advantage of thin and light weight for displays of portable information terminals such as personal computers, televisions, car navigation systems, and mobile phones, and are indispensable for various display means. . In a liquid crystal display device having such a liquid crystal display panel, the display method is determined by how the liquid crystals are arranged in the cell. Conventionally, as a display method of a liquid crystal display device, a vertical electric field driving method (vertical electric field mode) and a horizontal electric field driving method (horizontal electric field mode) are known. Specifically, for example, a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode are known as the vertical electric field driving method. As the lateral electric field driving method, for example, an IPS (In-plane Switching) mode, an FFS (Fringe Field Switching) mode, and the like are known.

Liquid crystal display devices using such a display method are produced in large quantities. For example, a TN mode liquid crystal display device is widely used. However, the TN mode liquid crystal display device has room for improvement in that the viewing angle is narrow.

In contrast, an IPS mode liquid crystal display device or an FFS mode liquid crystal display device uses an electrode having a comb-like structure or an electrode provided with a slit, in a direction parallel to the liquid crystal layer (in other words, with respect to the main surface of the substrate). The orientation state of the liquid crystal is switched by applying an electric field in a horizontal direction or a horizontal direction. The lateral electric field driving method has a wide viewing angle in principle and realizes a wide viewing angle (see, for example, Patent Documents 1 to 3).

The VA mode is an advantageous system for obtaining a wide viewing angle characteristic, and its application is expanding. In these various modes, various contrivances have been made to satisfy the viewing angle characteristics and the like. Among them, as one of the recent important technologies in this field, there is an alignment division method that divides a region in a pixel so that the alignment direction of liquid crystal molecules is different in one pixel, thereby improving viewing angle characteristics. be able to. In particular, MVA (Multi-domain Vertical Alignment) mode, which can satisfy such a wide viewing angle characteristic by being subjected to such orientation division, has attracted attention.

As one of the conventional MVA mode liquid crystal display devices, a first substrate and a second substrate disposed opposite to each other, and a vertical alignment sealed between the first substrate and the second substrate Type liquid crystal, a gate bus line provided on the first substrate and supplied with a scanning signal, a data bus line provided on the first substrate and supplied with a display signal, the gate bus line and the A switching element and a pixel electrode formed for each pixel region defined by the data bus line, a control electrode provided in the pixel region of the first substrate and connected to the switching element, and a second substrate A common electrode provided, the pixel electrode is divided into a plurality of subpixel electrodes, and at least some of the subpixel electrodes are capacitively coupled to the control electrode, and the control When a voltage is applied to the electrode, a capacitance formed between the control electrode and a capacitance formed between the control electrode and the common electrode via the liquid crystal A liquid crystal display device to which a voltage according to the ratio is applied is disclosed (for example, see Patent Document 4).

By the way, a thin film transistor (TFT) used for a liquid crystal display device is usually formed by patterning a plurality of electrodes, semiconductors, and insulating films by repeating an exposure process and an etching process, but a large substrate of G4 size (680 mm × 880 mm) or more. On the other hand, scan exposure using a large mask has become the mainstream rather than divided exposure by the stepper method that has been conventionally used due to demands such as throughput.

JP 2000-10110 A JP 2003-280017 A JP 2003-15146 A JP-A-2005-292397

FIG. 23 is a schematic plan view showing electrodes of a liquid crystal display device according to Patent Document 1. FIG. 24 is a photomicrograph of another conventional liquid crystal display device of a lateral electric field drive method, and in transmissive display. A part of the pixel is shown. The liquid crystal display device according to Patent Document 1 is intended to improve the image quality characteristics by preventing the color shift phenomenon in the IPS mode. As shown in FIG. 23, the pixel electrode formed in a comb shape is used. 125 and the common electrode 128 provided with slits are combined to form oblique slits (openings). Accordingly, the alignment state of the liquid crystal can be switched by applying an electric field in a direction parallel to the liquid crystal layer (a direction horizontal to the substrate main surface or a horizontal direction). However, in the region surrounded by the broken line in FIG. 23, the portion along the gate bus line at the edge of the pixel electrode 125 is formed in parallel with the gate bus line, and has a certain width that does not disconnect the pixel electrode 125. The shape of the tip of the slit is determined so as to have it. However, the shape of the pixel electrode appropriately applies an electric field to the liquid crystal molecules to stabilize the alignment of the liquid crystal molecules, and there is room for ingenuity in sufficiently preventing the deterioration of the display quality such as the response speed, the afterimage, and the roughness. there were.

Further, in another conventional liquid crystal display device of the lateral electric field driving method, the shape of the pixel electrode cannot appropriately apply an electric field to the liquid crystal molecules as in the liquid crystal display device according to Patent Document 1. As shown in FIG. 24, the orientation of the liquid crystal molecules may be disturbed.

FIG. 25 is a schematic plan view showing electrodes of the liquid crystal display device according to Patent Document 2. As shown in FIG. With respect to the above points, as shown in FIG. 25, in the liquid crystal display device according to Patent Document 2, a pixel electrode 125 ′ formed in a comb-like shape and a common electrode 128 ′ provided with a slit are combined. Compared with the liquid crystal display device according to 1, the tip of the slit of the pixel electrode is formed in a shape that can appropriately apply an electric field to the liquid crystal molecules and stabilize the alignment of the liquid crystal molecules. However, in the region surrounded by the broken line in FIG. 25, the shape of the tip is inclined from the straight, and the distance of the part where the line (electrode width) and the space (electrode interval) are constant is shortened. There is room for improvement in that the transmittance (transmittance) decreases and the luminance decreases due to the decrease in transmittance. Similarly, the liquid crystal display device described in Patent Document 3 also has room for improvement in order to improve the transmittance and luminance.

The liquid crystal display device according to Patent Document 4 relates to an MVA mode liquid crystal display device, and pixel edges are formed along a gate bus line to which a scanning signal is supplied. However, there was room for improvement in order to improve the transmittance and luminance.

In the above-described scan exposure, there is a possibility that display unevenness (scan unevenness) may occur due to a change in line width depending on the scan direction or an overlay shift. In addition, in both exposure methods of divided exposure and scan exposure by the stepper method, when the exposure is performed in units of blocks, the distance between the source bus line and the pixel electrode differs for each block unit due to the alignment shift, and the block division is different. This causes noticeable display unevenness. In addition, when the finished width of the opening of the electrode is different for each block, block division occurs.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a liquid crystal display panel and a liquid crystal display device capable of obtaining high transmittance and good display quality.

The present inventor conducted intensive studies on a liquid crystal display panel and a liquid crystal display device capable of obtaining high transmittance and good display quality, and paid attention to the shape of the electrode that greatly affects the alignment of liquid crystal molecules. The idea that the aperture ratio can be improved by providing one or more portions having an oblique component at the edge of the first electrode (for example, a pixel electrode) and the idea of having such an oblique component is as follows. In addition to the edge of the electrode (for example, pixel electrode), it can be applied to the edge of the signal line, the outline of the opening of the black matrix (BM), the edge of the lower layer electrode, or all of them, thereby Further, it has been found that the aperture ratio can be further improved, the influence of the gate electric field can be reduced to stabilize the orientation, and the display quality can be improved by suppressing the roughness. Here, it has been found that when the influence of the gate electric field in the pixel is reduced, the alignment disorder region is less likely to appear in the pixel (alignment stability) with the same BM design. In particular, in the MVA structure, the inventors have found that a liquid crystal display panel capable of improving the aperture ratio and improving alignment disorder can be realized, and conceived that the above problems can be solved brilliantly, and the present invention has been achieved. is there.

That is, the present invention is a liquid crystal display panel comprising a first substrate, a second substrate, and a liquid crystal layer, wherein the liquid crystal layer is sandwiched between the first substrate and the second substrate, and the first substrate Is opposed to the second substrate and has a source bus line, a gate bus line, and a first electrode, and the first substrate and the second substrate have a linear alignment control structure on at least one of them, The first electrode has a linear opening, and the linear opening is along the linear alignment regulating structure when the main surface of the substrate is viewed in plan, and the first electrode At least a part of the edge is a liquid crystal display panel that is inclined with respect to at least one of the source bus line and the gate bus line.

That at least part of the edge of the first electrode is oblique to at least one of the source bus line and the gate bus line means that the edge (outer end) of the first electrode is adjacent to the source bus line. An angle formed between at least a portion and the source bus line is other than 0 °, and / or at least a portion where the edge of the first electrode is adjacent to the gate bus line and the gate bus line. An angle is other than 0 °. The angle formed is preferably 5 ° or more, for example. Moreover, 60 degrees or less are preferable. Further, it is preferable that at least a part of the edge of the first electrode is inclined so as to protrude outward from the center side of the first electrode. In other words, it is preferable that the first electrode has a portion protruding toward one of the pixels adjacent to the pixel on which the first electrode is arranged. Thereby, the transmittance | permeability can be improved suitably. Moreover, it is preferable that the edge of the first electrode does not form a straight line, and a part thereof forms an angle other than 0 ° with respect to at least one of the bus lines.

It is preferable that at least a part of the edge of the first electrode is along a direction perpendicular to the linear opening and the linear alignment control structure. In the technical field of the present invention, at least a part of the edge of the first electrode is along the vertical direction with respect to the linear opening and the linear alignment control structure. The direction of at least a part of the edge of the substrate is approximated to a direction perpendicular to the linear opening and a direction perpendicular to the linear alignment control structure when the main surface of the substrate is viewed in plan ( For example, it is preferably 15 ° or less with respect to the vertical, for example, when the angle formed by the linear alignment control structure and the gate bus line is 45 °, at least a part of the edge of the first electrode and the gate bus The angle formed by the line is more preferably 45 °.) In addition, at least a part of the edge of the first electrode is substantially parallel to a direction perpendicular to the linear opening and / or the linear orientation when the substrate main surface is viewed in plan view. Preferably, it is substantially parallel to the direction perpendicular to the regulating structure. With such a configuration, the transmittance can be further improved while stabilizing the alignment of the liquid crystal molecules.

From the viewpoint of orientation regulation, the linear orientation regulation structure is preferably a rib. The ribs that the first substrate has may be the ribs that the second substrate has. Further, the second substrate has a third electrode (counter electrode), and the linear alignment regulating structure is an opening provided in the third electrode. One. Note that the pixel electrode is usually provided for each pixel. On the other hand, the counter electrode is usually provided over the entire surface of the second substrate. In the form in which the linear alignment regulating structure is an opening provided in the counter electrode, the opening regulates the alignment of liquid crystal molecules together with the linear opening of the first electrode, for example, Pixels in the liquid crystal display panel form four domains. As a more preferable form, when the main surface of the substrate is viewed in plan, the linear opening of the first electrode is along the linear opening of the counter electrode. The opening portion is a portion corresponding to the rib when the rib is arranged instead of the opening portion as the linear alignment regulation structure when the substrate main surface is viewed in plane, in other words, It is provided in a portion overlapping with the rib. For example, the counter electrode is a transparent electrode (for example, ITO [indium tin oxide]), IZO [indium zinc oxide] or the like, and an opening (extraction) can be provided in the transparent electrode. With the form in which the linear alignment regulating structure is an opening provided in the counter electrode of the second substrate, light leakage due to the rib is eliminated, and the contrast ratio (CR) can be improved. Moreover, it is preferable that the second substrate is provided with an alignment regulating structure such as a rib or a slit. In this specification, as a general rule, the “linear alignment-regulating structure” is described as being separate from the linear opening of the first electrode. The opening also usually has a function as an orientation regulating structure.

Further, in the present specification, in the technical field of the present invention, the linear opening is along the linear alignment regulating structure when the substrate main surface is viewed in plan view. Can be said to be along the alignment regulating structure, and here, the linear opening faces the linear alignment regulating structure when the substrate main surface is viewed in plan view. It is arranged and the direction thereof is also similar to the direction of the linear rib (for example, 10 ° or less). Moreover, it is preferable that the linear opening is substantially parallel to the linear alignment regulating structure when the main surface of the substrate is viewed in plan. By forming linear alignment control patterns such as linear openings and linear alignment control structures in this way, liquid crystal molecules near the substrate surface are affected by the alignment film when no voltage is applied. The liquid crystal molecules are aligned in a direction substantially perpendicular to the substrate surface. When a voltage is applied, the liquid crystal molecules are aligned side by side toward the alignment control pattern.

The source bus lines and / or gate bus lines are preferably provided in a straight line in the display area. The term “provided in a straight line” means that the edge of the bus line may not be a straight line as long as the center line of the bus line is substantially a straight line. Since the source bus lines and / or gate bus lines are provided in a straight line in the display region, the total length is shortened, so that the resistance is lowered and the drive voltage of the liquid crystal display device is sufficiently suppressed. can do. In addition, since the total length is shortened, the occurrence rate of disconnection is lowered, and the yield can be made sufficiently high.

Moreover, in this specification, the opening part of a 1st electrode should just be recognized if the inner side edge of a 1st electrode is made into a contour line, and may be opened toward the outer side. . For example, when the first electrode is composed of a main electrode and a sub electrode that are not electrically coupled to each other, the linear opening between the main electrode and the sub electrode is also an opening of the first electrode. . In the present specification, the linear shape may be any shape that can be recognized as extending in one direction, and examples thereof include a V shape and a linear shape.

Further, not only the edge of the first electrode is obliquely arranged as described above, but the edge of the bus line, the black matrix (BM), and the edge of the second electrode are also parallel to the edge of the first electrode. It is suitable that it is formed. This will be described in detail below.

At least one of the source bus line and the gate bus line preferably has at least a part in the longitudinal direction along at least a part of the edge of the first electrode. The phrase “along at least part of the edge of the first electrode” means that the edge of the first electrode in at least one of the source bus line and the gate bus line when the substrate main surface is viewed in plan view. A longitudinal direction of at least a part adjacent to a part approximates a direction of at least a part of the edge of the first electrode (for example, a longitudinal direction of at least one part of the source bus line and the gate bus line, and The angle formed by at least a part of the edge of the first electrode is preferably 15 ° or less, and more preferably 10 ° or less. Thereby, since the edge of a 1st electrode can be separated from the edge of an adjacent bus line, it can suppress that the electric field resulting from this bus line influences a 1st electrode. That is, the capacitance generated between the bus line and the first electrode can be reduced. As a result, the disorder of the alignment of the liquid crystal molecules can be more effectively suppressed, and the occurrence of scan unevenness can be suppressed. In addition, at least one of the source bus line and the gate bus line preferably has at least a part in the longitudinal direction substantially parallel to at least a part of the edge of the first electrode.

At least one of the first substrate and the second substrate has a black matrix, the black matrix has an opening corresponding to the first electrode, and at least a part of a contour line of the opening is It is preferable to extend along at least a part of the edge of the first electrode. The phrase “along at least a part of the edge of the first electrode” means that at least a part of the edge of the first electrode in the outline of the opening of the black matrix when the main surface of the substrate is viewed in plan Is adjacent to the direction of at least part of the edge of the first electrode (for example, at least part of the outline of the opening of the black matrix and at least part of the edge of the first electrode). Is preferably 15 ° or less, and more preferably 10 ° or less. As a result, since the portion where the alignment of the liquid crystal molecules is good is not shielded by the black matrix, it is possible to improve the aperture ratio and the luminance while sufficiently suppressing the deterioration of the display quality such as the afterimage and the response speed.

The first substrate includes a second electrode formed on a side opposite to the liquid crystal layer side of the first electrode, and the second electrode has at least a part of an edge of the first electrode. It is preferable that it is along at least one part. The phrase “along at least part of the edge of the first electrode” is adjacent to at least part of the edge of the first electrode at the edge of the second electrode when the main surface of the substrate is viewed in plan. The direction of the part approximates the direction of at least part of the edge of the first electrode (for example, the angle formed by at least part of the edge of the second electrode and at least part of the edge of the first electrode) It is preferably 15 ° or less, and more preferably 10 ° or less. The shape of the second electrode can be, for example, a planar shape. The second electrode is also referred to as a lower layer electrode in the present specification.

The first substrate preferably has an auxiliary capacitance signal line. Further, it is particularly preferable that the auxiliary capacitance signal line is in contact with the second electrode. Thereby, Cs capacity | capacitance increases and a scan nonuniformity can be reduced.

The liquid crystal layer preferably includes a liquid crystal material that is aligned in the horizontal direction with respect to the main surface of the substrate when a voltage is applied. The liquid crystal layer preferably includes a negative liquid crystal material.

The first electrode is preferably a pixel electrode. The second electrode is preferably a common electrode. By using the first electrode as the pixel electrode and the second electrode as the common electrode, the common electrode can be prevented from overlapping the gate bus line and the source bus line, and the capacity of the gate bus line and the source bus line can be reduced. . As a result, the signal delay of the gate bus line and the source bus line can be suppressed, and the liquid crystal display device of the present invention can be suitably used as a high-definition and / or large-sized liquid crystal display device. In general, liquid crystal display devices are more susceptible to signal delays as they become higher definition and larger.

It is preferable that the linear alignment control structure is not parallel to at least one of the source bus line and the gate bus line. Since the edge of the first electrode has an oblique component with respect to at least one of the source bus line and the gate bus line, the alignment between the linear alignment control structure and the pixel electrode can be controlled more appropriately. Thus, the alignment of the liquid crystal molecules can be sufficiently controlled without providing a portion (for example, a part of the auxiliary rib) parallel to at least one of the source bus line and the gate bus line in the alignment control structure. . Thereby, the aperture ratio (transmittance) can be further improved. When the orientation regulating structure is a rib, an effect of improving the aperture ratio can be exhibited particularly by not providing a part of the auxiliary rib.

As the display mode of the liquid crystal display device of the present invention, a vertical electric field driving method is preferably used. Further, the MVA mode is more preferably used as the display mode of the liquid crystal display device of the present invention.

The pixel electrode is a transparent electrode formed for each pixel region, and is a transparent electrode (for example, ITO, IZO, etc.) connected to a switching element (for example, TFT). The first electrode may be a transparent electrode that undergoes a voltage drop due to a capacitance component, and may be a sub-pixel electrode that is not directly connected to a switching element (for example, TFT). The subpixel electrode will be described later in detail with reference to FIGS. The material of the second electrode can be the same as that of the pixel electrode.

In the liquid crystal display panel of the present invention, in each of the pixels, the members such as the first electrode may be configured as described above. The member is preferably configured as described above.

The present invention is also a liquid crystal display device including the liquid crystal display panel of the present invention. As the liquid crystal display device of the present invention, for example, a personal computer, a television, a car navigation system, a portable information terminal such as a mobile phone, and the like are preferable. In addition, the preferable form of the liquid crystal display panel with which the liquid crystal display device of this invention is provided is the same as the preferable form of the liquid crystal display panel of this invention.

The configuration of the liquid crystal display panel and the liquid crystal display device of the present invention is not particularly limited by other components as long as such components are formed as essential, and the liquid crystal display panel and the liquid crystal display are not limited. Other configurations normally used in the apparatus can be applied as appropriate.

Each form mentioned above may be combined suitably in the range which does not deviate from the gist of the present invention.

According to the present invention, it is possible to obtain a liquid crystal display device capable of obtaining high transmittance and good display quality.

3 is a schematic plan view showing pixels of the liquid crystal display panel according to Embodiment 1. FIG. It is the figure which expanded a part of FIG. It is a cross-sectional schematic diagram of the liquid crystal display panel in the state cut | disconnected by line segment A1-A2 shown in FIG. 6 is a schematic plan view showing pixels of a liquid crystal display panel according to a modification of Embodiment 1. FIG. 6 is a schematic plan view showing pixels of a liquid crystal display panel according to Embodiment 2. FIG. It is the figure which expanded a part of FIG. 10 is a schematic plan view showing pixels of a liquid crystal display panel according to a modification of Embodiment 2. FIG. 6 is a schematic plan view illustrating pixels of a liquid crystal display panel according to Embodiment 3. FIG. It is the figure which expanded a part of FIG. FIG. 10 is a schematic plan view illustrating pixels of a liquid crystal display panel according to a modification example of Embodiment 3. 6 is a schematic plan view illustrating pixels of a liquid crystal display panel according to Embodiment 4. FIG. It is the figure which expanded a part of FIG. FIG. 10 is an enlarged view of a part of pixels of a liquid crystal display panel according to a modification example of Embodiment 4. FIG. 10 is a schematic plan view illustrating pixels of a liquid crystal display panel according to Embodiment 5. FIG. 9 is a schematic plan view showing only an electrode on the CF substrate side according to Embodiment 5. 10 is a schematic plan view schematically showing nine pixels (picture elements) of an electrode on the CF substrate side according to Embodiment 5. FIG. FIG. 10 is a schematic plan view illustrating pixels of a liquid crystal display panel according to Embodiment 6. It is the figure which expanded a part of FIG. It is a disassembled perspective schematic diagram which shows the structure of the liquid crystal display panel in Embodiments 1-6. FIG. 20 is an exploded perspective schematic diagram illustrating a structure of a liquid crystal display device including the liquid crystal display panel illustrated in FIG. 19. It is a plane schematic diagram which shows the pixel of the conventional liquid crystal display panel. It is a plane schematic diagram which shows the pixel of the conventional liquid crystal display panel. 10 is a schematic plan view showing electrodes of a liquid crystal display device according to Patent Document 1. FIG. It is the microscope picture of the conventional liquid crystal display device of a horizontal electric field drive system. 10 is a schematic plan view showing electrodes of a liquid crystal display device according to Patent Document 2. FIG.

Embodiments will be described below, and the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited only to these embodiments. In the second and subsequent embodiments, members and portions that exhibit the same functions as those of the above-described embodiments are shown in the drawings in the same manner, and descriptions and descriptions of symbols and the like are omitted as appropriate.

In this specification, a pixel refers to a region in which driving is controlled by one switching element (for example, a thin film transistor [TFT]). In other words, it is the smallest unit that can realize a function necessary for display, and usually refers to an area in the display area in which driving is controlled by one switching element for display. In the embodiment, a substrate having a thin film transistor [TFT] is called a TFT substrate, and a substrate having a color filter (CF) facing the TFT substrate is called a CF substrate. In this specification, a pixel electrode connected to the drain electrode through a contact hole is referred to as a main pixel electrode, and a pixel electrode not directly connected to the drain electrode is referred to as a sub-pixel electrode. In this specification, the oblique component is also referred to as a portion having an angle other than 0 °.

Embodiment 1
FIG. 1 is a schematic plan view showing pixels of the liquid crystal display panel according to the first embodiment, and more precisely shows one pixel in the display region and its periphery. FIG. 2 is an enlarged view of a part of FIG. The electrode edge of the liquid crystal display panel according to the first embodiment (the edge of the main pixel electrode 15a) has at least one oblique component at a position adjacent to the gate bus line. Here, the pixel electrode edges are not all linear in the vicinity of the gate bus line 16, and at least a part (within the oval portion indicated by a broken line in FIG. 2) is oblique to the gate bus line 16. Be placed. In other words, the angle formed by at least a part of the pixel edge and the gate bus line 16 is other than 0 °. Specifically, in FIG. 2, the oval portion indicated by a solid line has a linear shape, but the oval portion indicated by a broken line is inclined with respect to the gate bus line 16. The angle formed by at least part of the pixel edge and the gate bus line 16 that is a signal line adjacent to at least part of the pixel edge is preferably 5 ° or more. Moreover, 60 degrees or less are preferable. Note that at least a part of the pixel edge adjacent to the source bus line 19 may be disposed obliquely with respect to the source bus line 19. The preferable range of the angle formed by at least part of the pixel edge and the source bus line 19 that is a signal line adjacent to at least part of the pixel edge is the same as described above.

A part of the pixel electrode edge (edge of the main pixel electrode 15a) is along the vertical direction with respect to the linear rib 33 and the linear opening 61 of the pixel electrode when the substrate main surface is viewed in plan. . The angles formed by at least a part of the pixel electrode edges with respect to the direction perpendicular to the linear rib 33 and the linear opening 61 of the pixel electrode are each preferably 15 ° or less. More preferably, it is 10 ° or less, and more preferably substantially 0 °. That is, as shown in FIGS. 1 and 2, a part of the edge of the main pixel electrode 15a is parallel to the vertical direction with respect to the linear rib 33 and the vertical direction with respect to the linear opening 61 of the pixel electrode. The form is further preferred. In the linear alignment control protrusion, the portion of the pixel that is normally disposed at an angle of 45 ° with respect to the bus line is also referred to as a rib, and is disposed horizontally on the pixel electrode edge portion in the vicinity of the pixel electrode edge. The part which is called is also called an auxiliary rib.

According to the liquid crystal display panel of Embodiment 1, since the pixel electrode edge partially has an oblique component, an opening that can appropriately apply a voltage to the liquid crystal molecules can be widened in the vicinity thereof. As a result, the transmittance can be improved.

The liquid crystal display panel according to Embodiment 1 has a structure (MVA structure) used for an MVA mode liquid crystal display device. The pixel electrode has an opening (slit) 61. In other words, there is an opening (slit) 61 between the main pixel electrode 15a and the sub-pixel electrode 15b. Further, the CF substrate has ribs 33.

In FIG. 1, the lower layer electrode 18 is provided below the main pixel electrode 15a and the sub pixel electrode 15b, but the lower layer electrode 18 may not be provided. When the lower layer electrode 18 is provided, the lower layer electrode 18 is configured to be in direct contact with the upper surface of the auxiliary capacitance signal line 24 so as to directly supply the potential of the auxiliary capacitance signal line 24. The presence of such a lower layer electrode 18 is preferable in that the Cs capacity is increased and the structure is strong against scan unevenness. In addition, when the lower layer electrode 18 is provided, the alignment of the liquid crystal is controlled by the main pixel electrode 15 a, the sub pixel electrode 15 b, and the lower layer electrode 18.

The liquid crystal display panel according to Embodiment 1 includes a sub-pixel electrode 15b (sub-pixel electrode structure). As shown in FIG. 1, a main pixel electrode 15a and a sub-pixel electrode 15b are provided in a region partitioned by a source bus line 19 and a gate bus line 16. The partitioned area corresponds to a pixel. Both the source bus line 19 and the gate bus line 16 are formed linearly in the display area. The main pixel electrode 15a is connected to the drain electrode 52 through the contact hole 71, and a signal from the TFT 30 is directly input, whereas the sub-pixel electrode 15b is not connected to any electrode, and the TFT 30 The signal is not input directly. When a potential is applied to the drain electrode 52, the potential of the subpixel electrode 15b changes due to a field effect caused by an insulator between the drain electrode 52 and the subpixel electrode 15b. That is, when a signal is input from the TFT 30, the main pixel electrode 15a and the sub pixel electrode 15b have different potentials. In the liquid crystal display panel shown in FIG. 1, a rib 33 formed in a V shape is provided at a position facing the main pixel electrode 15a, and the region whose orientation is controlled by the main pixel electrode 15a is divided into four. Thereby, the viewing angle of the liquid crystal display panel can be widened. In addition, the region whose orientation is controlled by the sub-pixel electrode 15b is also divided into four as in the case of the main pixel electrode 15a. However, the main pixel electrode 15a and the sub-pixel electrode 15b have different potentials as described above. The controlled area (domain) is divided into eight. Accordingly, the first electrode including the main pixel electrode 15a and the sub pixel electrode 15b is preferable in that a liquid crystal display panel having a very wide viewing angle can be obtained. Further, since the voltage-transmittance curves (VT curves) in these regions are different, in the liquid crystal display panel including the sub-pixel electrode 15b as in the first embodiment, the VT curve of the entire pixel. Therefore, even if at least one of the line width change, the overlay deviation, the alignment deviation, and the difference in the finished width of the opening of the electrode is slightly generated, a large difference in the transmittance for each pixel does not occur. As a result, display unevenness such as scan unevenness and block division in the liquid crystal display panel can be suppressed. This effect is also exerted to some extent on the basis of the MVA structure even in the embodiment relating to the non-subpixel electrode structure.

The main pixel electrode 15a and the sub-pixel electrode 15b are formed by forming a transparent conductive film such as ITO by sputtering and patterning the transparent conductive film. Similarly, the lower layer electrode 18 is formed of a transparent conductive film such as ITO. The lower layer electrode 18 is disposed so as to overlap the main pixel electrode 15a and the sub pixel electrode 15b when the main surface of the substrate is viewed in plan. These are formed in an appropriate shape according to the shape of the pixel. A transparent electrode such as IZO other than ITO may be used.

In FIG. 1, at least a part of the edge of the main pixel electrode 15a is disposed obliquely with respect to the bus line, but at least a part of the edge of the sub-pixel electrode 15b is disposed obliquely with respect to the bus line. Form may be sufficient. Further, although the main pixel electrode 15a is disposed outside the sub pixel electrode 15b, the sub pixel electrode may be disposed outside the main pixel electrode. Furthermore, the pixels in the first embodiment are vertically long pixels, but may be horizontally long pixels (a structure in which the length of the scanning signal line in one pixel is longer than that of the video signal line).

The source bus line 19 and the gate bus line 16 are formed in a straight line, so that the source bus line 19 or the gate bus line 16 is formed in a V shape as compared with the case where the source bus line 19 or the gate bus line 16 is formed in a V shape. Since the total length is shortened, the resistance can be lowered. That is, the drive voltage can be prevented from rising. Moreover, since the probability of disconnection can be lowered by shortening the total length, the yield is improved.

FIG. 3 is a schematic cross-sectional view of the liquid crystal display panel in a state cut along line A1-A2 shown in FIG.
In the liquid crystal display panel of Embodiment 1, a TFT substrate 10 having a plurality of TFTs 30 arranged in a matrix and a CF substrate 25 as a counter substrate bonded to the TFT substrate 10 are bonded together by a sealing material. A liquid crystal layer 23 containing liquid crystal molecules (negative liquid crystal material) having negative dielectric anisotropy is sealed between the TFT substrate 10 and the CF substrate 25.

The TFT substrate 10 has a transparent glass substrate 11 (corresponding to the first substrate). On the glass substrate 11, a first wiring layer (gate bus line 16, gate electrode 53 and auxiliary capacitance signal line 24), Second electrode (lower layer electrode 18), gate insulating film 59, semiconductor layer (n ⁺ ) 58, second wiring layer (source bus line 19, source electrode 51 and drain electrode 52), insulating layer 57, contact hole, first The electrodes (main pixel electrode 15a and subpixel electrode 15b) and the alignment film 55 are formed in this order. Note that the source bus line 19, the source electrode 51 and the drain electrode 52, and the gate bus line 16 and the gate electrode 53 are electrically insulated by a gate insulating film 59. The semiconductor layer 58 is formed on the gate electrode 53 with the gate insulating film 59 interposed therebetween. The source electrode 51 and the drain electrode 52 can be electrically connected through the semiconductor layer 58.

The CF substrate 25 has a transparent glass substrate 21 (corresponding to the second substrate), and a black matrix 20 is provided on the glass substrate 21. The black matrix 20 is formed so as to shield the source bus line 19, the TFT 30, the gate bus line 16, and the peripheral areas of the TFT substrate 10. Further, a color layer 26 is provided on the glass substrate 21. In the color layer 26, three types of colored layers of R (red), G (green), and B (blue) are alternatively arranged for each pixel based on a predetermined pixel arrangement. In addition to the RGB combination, C (cyan), M (magenta), and Y (yellow) complementary colors may be used as constituents of the colored layer, or a combination of four or more colors (for example, RGBY). May be used. An alignment film 56 is provided at the interface between the CF substrate 25 and the liquid crystal layer 23. Furthermore, columnar spacers (not shown) formed so as to extend toward the opposing TFT substrate 10 are formed on the alignment film 56. Note that the black matrix 20 may be formed on the TFT substrate 10. A polarizing plate 35 is provided on the side of the TFT substrate 10 opposite to the liquid crystal layer 23, and a polarizing plate 36 is provided on the side of the CF substrate 25 opposite to the liquid crystal layer 23.

FIG. 4 is a schematic plan view illustrating pixels of a liquid crystal display panel according to a modification of the first embodiment. As shown in FIG. 1, the liquid crystal display panel according to the first embodiment includes the main pixel electrode 15a and the sub-pixel electrode 15b for each pixel region, but the liquid crystal display panel according to the modification of the first embodiment. Comprises only one pixel electrode 15 'for each pixel region (no subpixel electrode structure). In the modification of the first embodiment, the opening 61 ′ of the pixel electrode 15 ′ is not open to the outside. Also in the modification of the first embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and an effect based on the characteristics can be obtained. The preferable form of the modification of Embodiment 1 is the same as the preferable form of Embodiment 1 mentioned above.

Embodiment 2
FIG. 5 is a schematic plan view showing pixels of the liquid crystal display panel according to the second embodiment, and more precisely shows one pixel and its periphery. FIG. 6 is an enlarged view of a part of FIG. In the liquid crystal display panel of the first embodiment, the edge of the gate bus line 16 and the edge of the lower layer electrode 18 are formed in a straight line, but in the liquid crystal display panel of the second embodiment, FIG. 5 and FIG. As shown in the oval portion indicated by a broken line in FIG. 2, the edge of the gate bus line 116 and the edge of the lower layer electrode 118 each include a portion formed along the oblique component of the main pixel electrode 115 a. In other words, where the pixel electrode edge has an angle other than 0 ° with respect to the gate bus line 116, the edge of the gate bus line 16 and the edge of the lower layer electrode are also along the pixel electrode edge. It is preferable that the edge of the gate bus line 16 and the edge of the lower layer electrode are formed substantially parallel to the pixel electrode edge. Other than that, the liquid crystal display panel of the second embodiment is the same as the liquid crystal display panel of the first embodiment.

According to the liquid crystal display panel of the second embodiment, the gate bus line 16 extends along the pixel electrode edge (the edge of the gate bus line 16 includes an oblique component), whereby the edge of the main pixel electrode 115a is connected to the gate bus line 116. Therefore, it is possible to further suppress the influence of the electric field caused by the gate bus line 116 on the main pixel electrode 115a. That is, the capacitance generated between the gate bus line 116 and the main pixel electrode 115a can be further reduced. As a result, the disorder of the alignment of the liquid crystal molecules can be further effectively suppressed, and the display quality can be improved by reducing the roughness. Further, the occurrence of scan unevenness can be further suppressed. The angle formed by at least part of the pixel electrode edge (diagonal component) and at least part of the edge of the gate bus line (diagonal component) is preferably 15 ° or less. More preferably, it is 10 ° or less, and more preferably substantially 0 °. That is, it is preferable that at least part of the pixel electrode edge (diagonal component) and at least part of the edge of the gate bus line (diagonal component) are substantially parallel.

In the second embodiment, the gate bus line 116 is formed along the diagonal component of the pixel electrode edge. However, the source bus line 119 is used as the diagonal component of the pixel electrode edge (for example, the edge of the sub-pixel electrode 115b). When adjacent to each other, the edge of the source bus line 119 may include a portion formed along an oblique component of the pixel electrode edge. As a result, the capacitance generated between the source bus line 119 and the pixel electrode (for example, the sub-pixel electrode 115b) can be reduced.

Further, when the lower layer electrode 118 is along the edge of the pixel electrode, the overlapping area with the pixel electrode increases, and the Cs capacity increases. As a result, since the storage capacity increases, the structure is resistant to scan unevenness.

In the second embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and an effect based on the characteristics can be obtained.

FIG. 7 is a schematic plan view illustrating pixels of a liquid crystal display panel according to a modification of the second embodiment. As shown in FIG. 5, the liquid crystal display panel according to the second embodiment includes the main pixel electrode 115 a and the sub-pixel electrode 115 b for each pixel region, but the liquid crystal display panel according to the modification of the second embodiment. Comprises only one pixel electrode 115 ′ for each pixel region (no subpixel electrode structure). In the modification of the second embodiment, the opening 161 ′ of the pixel electrode 115 ′ is not open to the outside. Also in the modification of the second embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and the diagonal component of the lower electrode edge and the diagonal component of the scanning signal line edge are different. The second embodiment has the same characteristics as the oblique component of the lower layer electrode edge and the oblique component of the scanning signal line edge in the second embodiment, and an effect based on the feature can be obtained. The preferable form of the modification of Embodiment 2 is the same as the preferable form of Embodiment 2 mentioned above.

Embodiment 3
FIG. 8 is a schematic plan view illustrating pixels of the liquid crystal display panel according to the third embodiment. FIG. 8 shows one pixel and its periphery. FIG. 9 is an enlarged view of a part of FIG. In the liquid crystal display panels of Embodiments 1 and 2, the black matrix (BM) is formed in a rectangular shape. However, in the liquid crystal display panel of Embodiment 3, BM corresponds to the pixel electrode as shown in FIG. An opening is provided, and at least a part of the outline of the opening is along at least a part (an oblique component) of the edge of the pixel electrode. In other words, the pixel electrode edge portion, the lower layer electrode, the gate bus line, and the BM have at least one oblique component. Otherwise, the liquid crystal display panel of the third embodiment is the same as the liquid crystal display panel of the second embodiment.

According to the liquid crystal display panel of the third embodiment, at least a part of the outline of the BM opening extends along the pixel electrode edge (the outline of the BM opening is obliquely adjacent to the diagonal component of the pixel electrode edge). By including a component), an opening area can be increased and an aperture ratio can be improved. The angle formed by at least part of the pixel electrode edge (oblique component) and at least part of the outline of the BM opening (oblique component) is preferably 15 ° or less. More preferably, it is 10 ° or less, and more preferably substantially 0 °. That is, it is preferable that at least a part of the pixel electrode edge (oblique component) and at least a part of the outline of the BM opening (oblique component) are substantially parallel.

Also in the third embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and the diagonal component of the lower layer electrode and the diagonal component of the gate bus line are the same as those in the second embodiment. It has the same characteristics as the diagonal component of the lower layer electrode and the diagonal component of the gate bus line, and an effect based on the characteristics can be obtained. The preferable form of Embodiment 3 is the same as the preferable form of Embodiment 1 and Embodiment 2 mentioned above.

It is preferable that all of the gate bus line, the BM, and the lower layer electrode are specified as described above, but any one or a combination of any two of these may be used. This is a preferred form of the present invention.

FIG. 10 is a schematic plan view illustrating pixels of a liquid crystal display panel according to a modification of the third embodiment. As shown in FIG. 8, the liquid crystal display panel according to the third embodiment includes the main pixel electrode 215a and the sub-pixel electrode 215b for each pixel region, but the liquid crystal display panel according to the modification of the third embodiment. Includes only one pixel electrode 215 ′ for each pixel region (no subpixel electrode structure). In the modification of the third embodiment, the opening 261 ′ of the pixel electrode 215 ′ is not open to the outside. Also in the modification of the third embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and the diagonal component of the lower electrode edge and the diagonal component of the scanning signal line edge are different. The diagonal component of the lower layer electrode edge and the diagonal component of the scanning signal line edge in the second embodiment have the same characteristics, and the diagonal component of the outline of the BM opening in the modification of the third embodiment is the BM in the third embodiment. It has the same characteristic as the oblique component of the contour line of the opening, and an effect based on the characteristic can be obtained. The preferable form of the modification of Embodiment 3 is the same as the preferable form of Embodiment 3 mentioned above.

Embodiment 4
FIG. 11 is a schematic plan view illustrating pixels of the liquid crystal display panel according to the fourth embodiment. FIG. 12 is an enlarged view of a part of FIG. In the liquid crystal display panels of the first to third embodiments, diagonal components such as pixel electrodes exist in a portion (rectangular portion) surrounded by a solid line in FIG. 12, and extend from a rib to a portion (elliptical portion) surrounded by a broken line. The auxiliary rib is provided in parallel with the edge of the pixel electrode, in other words, in parallel with the gate bus line. However, the liquid crystal display panel according to the fourth embodiment is shown by a broken line as shown in FIGS. An auxiliary rib parallel to the edge other than the diagonal component of the edge of the pixel electrode (in other words, an auxiliary rib parallel to the gate bus line) where the diagonal component of the pixel electrode edge exists in the enclosed part (ellipse part) Is not provided. In the fourth embodiment, as shown in FIG. 12, the tip of the rib 33a protrudes from the pixel electrode edge when the main surface of the substrate is viewed in plan. When a misalignment (alignment misalignment between the TFT substrate and the CF substrate) occurs, the form in which the tip of the rib 33a protrudes from the pixel electrode edge is a structure advantageous for alignment. In other words, even when the alignment deviation between the TFT substrate and the CF substrate occurs, the influence on the alignment of the liquid crystal molecules due to the deviation of the positional relationship between the pixel electrode of the TFT substrate and the rib 33a of the CF substrate is affected. It can be smaller. Specifically, the alignment is regulated by the pixel electrode and the rib. For example, when an alignment shift between the TFT substrate and the CF substrate occurs, the rib is retracted into the pixel, and the rib for regulating the orientation is not provided. In some cases, the alignment of liquid crystal molecules may be affected, but such an effect can be sufficiently prevented. Otherwise, the liquid crystal display panel of the fourth embodiment is the same as the liquid crystal display panel of the first embodiment. By providing an oblique component such as a pixel electrode in a portion surrounded by a broken line, liquid crystal molecules between the rib and the pixel electrode can be controlled more appropriately, and parallel to the gate bus line and / or the source bus line. It is also possible to use a rib (for example, the rib 33a) in which no auxiliary rib extends. Thus, by not providing the auxiliary rib parallel to at least one of the gate bus line and the source line, the aperture ratio can be further improved.

The oblique component such as the edge of the pixel electrode is preferably in the vicinity of the portion where the conventional auxiliary rib has been disposed, so that no auxiliary rib is provided in the vicinity of the oblique component (near the portion indicated by reference numeral 35). However, the liquid crystal molecules can be suitably controlled. Such an auxiliary rib is disposed near the edge of the first electrode so as to surround the opening of the first electrode together with the rib when the substrate main surface is viewed in plan as shown in FIG. The orientation of molecules is suitably controlled.

Also in the fourth embodiment, the diagonal component of the pixel electrode edge has at least the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and the preferred embodiment also has the diagonal component of the pixel electrode edge in the first embodiment. It is the same as that of a preferable form.

In FIG. 11 and FIG. 12, the oblique components as shown in the second and third embodiments are not shown in the lower layer electrode, the gate bus line, and the BM, but the liquid crystal display panel according to the fourth embodiment also has the second embodiment. 3, an oblique component may be provided in one or all of the lower layer electrode, the gate bus line, and the BM, and this form is preferable. Moreover, the preferable form of the said diagonal component and the preferable form of another part and a member are the same as the preferable form in Embodiment 2 and Embodiment 3 mentioned above.
11 and 12, the TFT is provided on the right side of the source bus line. However, the TFT may be provided on the left side of the source bus line. In this structure, interference between the TFT and the pixel electrode is prevented. It can be made sufficiently small.
FIG. 11 shows a liquid crystal display panel including a main pixel electrode and a sub-pixel electrode for each pixel region. However, the opening of the pixel electrode is not opened to the outside, and the liquid crystal display panel is A structure having only one pixel electrode for each pixel region (no sub-pixel electrode structure) may be used.

FIG. 13 is an enlarged view of a part of pixels of a liquid crystal display panel according to a modification of the fourth embodiment. 12 shows a form in which the tip of the rib protrudes from the pixel electrode edge, but in FIG. 13, the tip of the rib 33a ′ does not protrude from the pixel electrode edge, and the pixel electrode edge and the tip of the rib 33a ′ are substantially the same. Forms that are identical in nature. Such a form may be sufficient and the effect of this invention can fully be exhibited.

Embodiment 5
FIG. 14 is a schematic plan view showing pixels of the liquid crystal display panel according to the fifth embodiment. The liquid crystal display panels of Embodiments 1 to 4 have ribs and auxiliary ribs on the counter substrate. However, in the liquid crystal display panel according to Embodiment 5, the counter substrate has no ribs and auxiliary ribs. Has a planar ITO electrode, and the ITO electrode is a portion surrounded by an alternate long and short dash line (that is, a portion corresponding to the rib in Embodiments 1 to 4 when the substrate main surface is viewed in plan view, in other words, A portion overlapping the rib) has an opening. With such an opening, the alignment of liquid crystal molecules is preferably regulated, and four domains can be formed in a pixel. As described above, by using the openings of the ITO electrodes provided on the counter substrate instead of the ribs and the auxiliary ribs as the alignment control structure, light leakage due to the ribs or the like is eliminated, so that the contrast ratio is improved.

Also in the fifth embodiment, the diagonal component of the pixel electrode edge has the same characteristics as the diagonal component of the pixel electrode edge in the first embodiment, and its preferable form is also a preferable form of the diagonal component of the pixel electrode edge in the first embodiment. It is the same.

In FIG. 14, the lower layer electrode, the gate bus line, and the black matrix (BM) do not show the oblique components as shown in the second and third embodiments, but the liquid crystal display panel according to the fifth embodiment also has the embodiment. Similar to 2, 3, one or all of the lower layer electrode, the gate bus line, and the BM may be provided with an oblique component, which is preferable. Moreover, the preferable form of the said diagonal component, the other part, and the preferable form of a member are the same as the preferable form in Embodiment 2 and Embodiment 3 mentioned above.

Further, FIG. 14 shows a liquid crystal display panel having a main pixel electrode and a sub-pixel electrode for each pixel region, but the opening of the pixel electrode is not opened to the outside, and the liquid crystal display panel is A structure having only one pixel electrode for each pixel region (no sub-pixel electrode structure) may be used.

FIG. 15 is a schematic plan view showing only the electrode on the CF substrate side according to the fifth embodiment. FIG. 16 is a schematic plan view schematically showing nine pixels (picture elements) of the electrode on the CF substrate side according to the fifth embodiment. FIG. 15 shows only the electrode on the CF substrate side for one pixel corresponding to FIG. The dashed-dotted line of FIG.15 and FIG.16 shows the opening part of a counter electrode similarly to FIG. The electrode on the CF substrate side in the fifth embodiment is formed over the entire surface of the second substrate. In the portions corresponding to the ribs in the first to fourth embodiments, the electrode on the CF substrate side is notched.

Embodiment 6
FIG. 17 is a schematic plan view illustrating pixels of the liquid crystal display panel according to the sixth embodiment. FIG. 17 shows one pixel and its periphery. FIG. 18 is an enlarged view of a part of FIG. In the liquid crystal display panel of Embodiment 6, at least a part of the edge of the pixel electrode 315 is inclined with respect to the gate bus line 316 at a position adjacent to the gate bus line 316 (where the pixel electrode edge has an oblique component). ) Are present (in the sixth embodiment, there are two locations per edge of the pixel electrode 315 adjacent to the gate bus line 316). Thereby, the transmittance can be further improved. When the pixel pitch is widened, a configuration in which a diagonal component is present instead of one in this way is particularly suitable. For example, since a design in which a plurality of oblique components exist with a pixel pitch of 85 μm or shorter on the short side is possible, the present invention applies a configuration in which a plurality of diagonal components exist in pixels with a pixel pitch of 85 μm or longer on the short side. It is preferable.

The edge of the pixel electrode 315 of the liquid crystal display panel according to Embodiment 6 has at least one oblique component at a location adjacent to the gate bus line 316. Here, the pixel electrode edges are not all linear in the vicinity of the gate bus line 316, and at least a part (in the circle indicated by the solid line in FIG. 18) is arranged obliquely with respect to the gate bus line 316. Is done. In other words, the angle formed by at least part of the pixel edge and the gate bus line 316 is other than 0 °. The angle formed by at least part of the edge of the pixel electrode 315 and the gate bus line 316 that is a signal line adjacent to at least part of the edge of the pixel electrode 315 is preferably 5 ° or more. Moreover, 60 degrees or less are preferable. Note that at least a part of the pixel edge adjacent to the source bus line 19 may be disposed obliquely with respect to the source bus line 19. The preferable range of the angle formed by at least part of the pixel edge and the source bus line 19 that is a signal line adjacent to at least part of the pixel edge is the same as described above.

The liquid crystal display panel according to Embodiment 6 has a structure (MVA structure) used for an MVA mode liquid crystal display device. The pixel electrode has an opening (slit) 361. In other words, the pixel electrode 315 has an opening (slit) 361. Further, the CF substrate has a rib 333.

In FIG. 17, a lower layer electrode (not shown) is provided below the pixel electrode 315, but the lower layer electrode may not be provided. When the lower electrode is provided, the lower electrode is configured to be in contact with the upper surface of the auxiliary capacitance signal line 324 so that the lower electrode directly supplies the potential of the auxiliary capacitance signal line 324. The presence of such a lower layer electrode is preferable in that the Cs capacity increases and the structure is strong against scan unevenness. Note that in the case where a lower electrode is provided, the alignment of liquid crystal is controlled by the pixel electrode 315 and the lower electrode.

As shown in FIG. 17, the liquid crystal display panel according to Embodiment 6 includes a pixel electrode 315 in a region partitioned by a source bus line 319 and a gate bus line 316. The partitioned area corresponds to a pixel. Both the source bus line 319 and the gate bus line 316 are formed linearly in the display area. The pixel electrode 315 is connected to the drain electrode through a contact hole (not shown), and a signal from the TFT is directly input thereto.

The pixel electrode 315 is formed by forming a transparent conductive film such as ITO by sputtering and patterning the transparent conductive film. Similarly, the lower layer electrode is formed of a transparent conductive film such as ITO. The lower layer electrode is disposed so as to overlap with the pixel electrode 315 when the main surface of the substrate is viewed in plan. These are formed in an appropriate shape according to the shape of the pixel.

In FIG. 17, at least a part of the edge of the pixel electrode 315 is disposed obliquely with respect to the bus line. However, when the pixel electrode is composed of the main pixel electrode and the sub-pixel electrode, the edge of the main pixel electrode is At least a part and at least a part of the edge of the sub-pixel electrode may be arranged obliquely with respect to the bus line. For example, there may be a form in which there is one oblique component per edge of the main pixel electrode and one edge per edge of the sub pixel electrode. The pixels in the sixth embodiment are vertically long pixels, but may be horizontally long pixels (a structure in which the length of a scanning signal line in one pixel is longer than that of a video signal line).

Note that, by forming the source bus line 319 and the gate bus line 316 in a straight line, the source bus line 319 or the gate bus line 316 is compared with the source bus line 319 or the gate bus line 316 formed in a V shape. Since the total length is shortened, the resistance can be lowered. That is, the drive voltage can be prevented from rising. Moreover, since the probability of disconnection can be lowered by shortening the total length, the yield is improved.

In the liquid crystal display panel of Embodiment 6, a TFT substrate having a plurality of TFTs arranged in a matrix and a CF substrate as a counter substrate bonded to the TFT substrate are bonded together by a sealing material. A liquid crystal layer 23 containing liquid crystal molecules (negative liquid crystal material) having negative dielectric anisotropy is sealed between the TFT substrate and the CF substrate.

The TFT substrate has a transparent glass substrate (corresponding to the first substrate), and on the glass substrate, a first wiring layer (gate bus line 316, gate electrode and auxiliary capacitance signal line 324), second electrode ( Lower layer electrode), gate insulating film, semiconductor layer (n ⁺ ), second wiring layer (source bus line 319, source electrode and drain electrode), insulating layer, contact hole, first electrode (pixel electrode 315), and orientation Films are formed in this order. Note that the source bus line 319, the source electrode and the drain electrode, and the gate bus line 316 and the gate electrode are electrically insulated by a gate insulating film. The semiconductor layer is formed on the gate electrode via the gate insulating film. The source electrode and the drain electrode can be electrically connected through the semiconductor layer.

The CF substrate has a transparent glass substrate (corresponding to the second substrate), and a black matrix is provided on the glass substrate. The black matrix is formed so as to shield the source bus line 319, the TFT, the gate bus line 316, and the surrounding area of the TFT substrate. Furthermore, a color layer is provided on the glass substrate. In the color layer, three types of colored layers of R (red), G (green), and B (blue) are alternatively arranged for each pixel based on a predetermined pixel arrangement. In addition to the RGB combination, C (cyan), M (magenta), and Y (yellow) complementary colors may be used as constituents of the colored layer, or a combination of four or more colors (for example, RGBY). May be used. An alignment film is provided at the interface between the CF substrate and the liquid crystal layer. The surface of the alignment film is rubbed and defines the alignment direction of the nearby liquid crystal molecules. Furthermore, columnar spacers (not shown) formed so as to extend toward the opposing TFT substrate are formed on the alignment film. Note that the black matrix may be formed on the TFT substrate. A polarizing plate is provided on the side opposite to the liquid crystal layer of the TFT substrate, and a polarizing plate is provided on the side opposite to the liquid crystal layer of the CF substrate.

The sixth embodiment is an example in which only the pixel electrode edge has an oblique component, but similarly to the second and third embodiments, the lower layer electrode, the scanning signal line, and the BM may have corresponding patterns in the same manner. Such a form is preferable in that the same effect as in the second and third embodiments can be exhibited.

In the first to sixth embodiments, the lower layer electrode is formed on the side opposite to the liquid crystal layer of the pixel electrode. That is, the pixel electrode corresponds to the first electrode and the lower layer electrode corresponds to the second electrode. Conversely, the lower layer electrode corresponds to the first electrode and the pixel electrode corresponds to the second electrode. In other words, the edge of the lower layer electrode may have an oblique component.

FIG. 19 is an exploded perspective schematic view showing the structure of the liquid crystal display panel in the first to sixth embodiments. As shown in FIG. 19, the CF side substrate 25 and the TFT substrate 10 of the liquid crystal display panel 100 sandwich the liquid crystal layer 23. Also, a liquid crystal display panel 200 with a backlight is provided with a backlight 73 on the back surface of the liquid crystal display panel 100. The light of the backlight 73 passes through the polarizing plate 35, the TFT substrate 10, the liquid crystal layer 23, the CF side substrate 25, and the polarizing plate 36 in this order, and the passage / non-transmission of light is controlled by controlling the orientation of the liquid crystal. .

20 is an exploded perspective schematic view showing the structure of a liquid crystal display device 900 including the liquid crystal display panel shown in FIG. As shown in FIG. 19, the backlit liquid crystal display panel 200 is fixed on a fixed panel 400 and sealed by a front cabinet 300 and a rear cabinet 500. Then, the rear cabinet 500 and the upper stand 700 are fixed via a metal fitting 600. Further, the upper stand 700 and the lower stand 800 are fitted together.

The liquid crystal display panel according to the above-described embodiment is suitably used for an MVA mode liquid crystal display device. Moreover, each form in embodiment mentioned above may be combined suitably in the range which does not deviate from the summary of this invention.

21 and 22 are schematic plan views showing pixels of a conventional liquid crystal display panel.
In the liquid crystal display panel shown in FIG. 21, unlike the first embodiment, the pixel electrode edge does not have an oblique component. Other than that, the configuration is the same as that shown in the first embodiment (sub-pixel electrode structure). Note that the liquid crystal display panel shown in FIG. 22 is the same as the modification of Embodiment 1 except that the pixel electrode edge does not have an oblique component (sub-pixel electrode structure). Such a conventional liquid crystal display panel cannot sufficiently increase the aperture ratio unlike the liquid crystal display panel according to the present invention.

Each form in embodiment mentioned above may be combined suitably in the range which does not deviate from the summary of this invention.

The present application claims priority based on the Paris Convention or the laws and regulations in the country to which the transition is based on Japanese Patent Application No. 2011-054536 filed on March 11, 2011. The contents of the application are hereby incorporated by reference in their entirety.

10: TFT substrate 11, 21: Glass substrate 15 ', 115', 215 ', 315, 415': Pixel electrode 15a, 115a, 215a, 415a: Main pixel electrode 15b, 115b, 215b, 415b: Sub pixel electrode 16, 116, 216, 316, 416: gate bus lines 18, 118, 218, 418: lower layer electrodes 19, 119, 219, 319, 419: source bus lines 20, 120, 220, 420: black matrix 23: liquid crystal layer 24, 124, 224, 324, 424: auxiliary capacitance signal line 25: CF substrate 26: color layer 30: TFT
33, 33a, 33a ′, 133, 233, 333, 433: ribs 35, 36: polarizing plate 51: source electrodes 52, 152, 252, 452: drain electrode 53: gate electrode 55, 56: alignment film 57: insulating layer 58: Semiconductor layer (n ⁺ )
59: Gate insulating films 61, 61 ′, 161, 161 ′, 261, 261 ′, 361, 461, 461 ′: Openings 71, 171, 271, 471: Contact holes 73: Backlight 100: Liquid crystal display panel 125, 125 ': pixel electrodes 128 formed in a comb shape, 128': common electrode 200 provided with slits: liquid crystal display panel with backlight 300: front cabinet 400: fixed panel 500: rear cabinet 600: metal fitting 700: Upper stand 800: Lower stand 900: Liquid crystal display device

Claims (11)

A liquid crystal display panel comprising a first substrate, a second substrate, and a liquid crystal layer,
The liquid crystal layer is sandwiched between a first substrate and a second substrate,
The first substrate is opposed to the second substrate and has a source bus line, a gate bus line, and a first electrode,
The first substrate and the second substrate have at least one linear alignment control structure,
The first electrode has a linear opening, and the linear opening is along the linear alignment regulating structure when the substrate main surface is viewed in plan view,
At least a part of the edge of the first electrode is inclined with respect to at least one of a source bus line and a gate bus line. 2. The liquid crystal display panel according to claim 1, wherein at least a part of an edge of the first electrode extends along a direction perpendicular to the linear opening and the linear alignment regulating structure. . The at least one of the source bus line and the gate bus line has at least a part in a longitudinal direction along at least a part of an edge of the first electrode. LCD display panel. At least one of the first substrate and the second substrate has a black matrix,
The black matrix has an opening corresponding to the first electrode, and at least a part of a contour line of the opening is along at least a part of an edge of the first electrode. Item 4. A liquid crystal display panel according to any one of Items 1 to 3. The first substrate has a second electrode formed on a side opposite to the liquid crystal layer side of the first electrode,
The liquid crystal display panel according to claim 1, wherein at least part of the edge of the second electrode is along at least part of the edge of the first electrode. The liquid crystal display panel according to claim 1, wherein the liquid crystal layer includes a liquid crystal material that is aligned in a horizontal direction with respect to the main surface of the substrate when a voltage is applied. The liquid crystal display panel according to claim 1, wherein the first electrode is a pixel electrode. The liquid crystal display panel according to claim 1, wherein the linear alignment regulation structure is not parallel to at least one of a source bus line and a gate bus line. The liquid crystal display panel according to claim 1, wherein the linear alignment regulating structure is a rib. The second substrate has a third electrode;
The liquid crystal display panel according to claim 1, wherein the linear alignment regulating structure is an opening provided in the third electrode. A liquid crystal display device comprising the liquid crystal display panel according to claim 1.

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