KR101731842B1 - Array substrate and display apparatus having the same - Google Patents

Abstract

In an array substrate and a display device having the same, a pixel electrode includes slit portions formed in different directions for respective domains in order to control the efficiency of liquid crystal behavior. The pixel electrode can be divided into a main pixel region and a sub pixel region having domains. At least a part of the slit portion is formed so as to intersect with the alignment direction of the liquid crystal in a staggered manner. Alternatively, a part of the slit part may be cut off from the supporting electrode part supporting the slit part. Alternatively, the area of the domains may be different or the angle of the slit may be varied by 45 degrees. The secondary efficiency and the tertiary efficiency of the liquid crystal are controlled to improve the lateral visibility of the display device.

Description

[0001] ARRAY SUBSTRATE AND DISPLAY APPARATUS HAVING THE SAME [0002]

The present invention relates to an array substrate and a display device having the same. And more particularly, to an array substrate in which a slit is formed in an electrode to control a liquid crystal and a display device having the same.

2. Description of the Related Art In general, a liquid crystal display device is one of the most widely used flat panel display devices. The liquid crystal display device is composed of two display panels having field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal layer sandwiched therebetween. A voltage is applied to the electric field generating electrode to generate an electric field in the liquid crystal layer, thereby determining the orientation of the liquid crystal molecules in the liquid crystal layer and controlling the polarization of incident light to display an image.

Among them, VA (vertical alignment) mode liquid crystal display devices arranged so that the long axes of the liquid crystal molecules are perpendicular to the upper and lower display plates in a state in which no electric field is applied have a large contrast ratio, A patterned vertically aligned (PVA) mode liquid crystal display device in which a cutout is formed in the electric field generating electrode of the liquid crystal display device of the vertical alignment mode has been developed.

On the other hand, a micro-slit mode or an SVA mode has been disclosed to reduce the slit portion which is an obstacle to the aperture ratio enhancement. In the micro-slit mode, a micro slit portion is formed only in the lower electrode among the field generating electrodes facing each other to impart directionality to the liquid crystal, and the upper electrode is formed as a flat plate having no cut portion.

However, the display devices of the SVA mode and the PVA mode also have many problems that the control of the liquid crystal is not uniform and must be improved in terms of side viewability.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an array substrate for improving lateral visibility by controlling the control efficiency of liquid crystal according to gradation.

Further, embodiments of the present invention provide a display device including the array substrate.

According to an aspect of the present invention, an array substrate includes a lower substrate, a switching device, and a pixel electrode. In the lower substrate, unit pixel regions divided into a plurality of domains are defined. The switching element is formed on the lower substrate and transmits a pixel signal. The pixel electrode is formed to be electrically connected to the switching element in the unit pixel region and includes slits. At least a part of the slit part is formed to extend in different directions for each of the domains so as to intersect with the alignment direction of the liquid crystal applied with an electric field in a staggered manner.

According to an aspect of the present invention, there is provided a display device including the array substrate, the counter substrate, and a liquid crystal layer. The counter substrate includes an upper substrate facing the lower substrate, and a common electrode facing the pixel electrode. The liquid crystal layer is located between the array substrate and the counter substrate, and the orientation is arranged in the alignment direction when an electric field is applied.

According to another aspect of the present invention, an array substrate includes a lower substrate, a switching device, and a pixel electrode. In the lower substrate, unit pixel regions divided into a plurality of domains are defined. The switching element is formed on the lower substrate and transmits a pixel signal. The pixel electrode is formed in the unit pixel region and includes a first supporting electrode portion, first slits, and second slits. The first support electrode portion extends along the boundaries of the domains. The first slits extend in different directions for each of the domains and are connected to the first support electrode unit. The second slit portion is disposed between the first slit portions and the end portion is cut off from the first support electrode portion.

According to another aspect of the present invention, there is provided a display device including the array substrate, the counter substrate, and a liquid crystal layer. The counter substrate includes an upper substrate facing the lower substrate, and a common electrode facing the pixel electrode. The liquid crystal layer is positioned between the array substrate and the counter substrate, and when the electric field is applied, the reaction speed is slower than the other portions at the end of the second slit portion.

According to another aspect of the present invention, an array substrate includes a lower substrate, a switching element, a first pixel electrode, and a second pixel electrode. A main pixel region having a plurality of domains and unit pixel regions divided into sub pixel regions are defined in the lower substrate. The switching element is formed on the lower substrate and transmits a pixel signal. The first pixel electrode is formed in the main pixel region and has first slit portions. The first slit part forms a first angle with the first direction and is formed in different directions for each of the domains. The second pixel electrode is formed in the sub pixel region and has second slit portions. The second slit part forms a second angle with the first direction and is formed in different directions for each of a plurality of domains. The sub-pixel region has an area of a lower-side domain that is in contact with the main pixel region and an area of an upper-side domain that are different from each other.

According to another aspect of the present invention, there is provided a display device including the array substrate, the counter substrate, and a liquid crystal layer. The counter substrate includes an upper substrate facing the lower substrate, and a common electrode facing the pixel electrode. And the liquid crystal layer is positioned between the array substrate and the counter substrate.

According to an aspect of the present invention, there is provided an array substrate including a gate line extending in a first direction and a data line extending in a second direction intersecting the first direction, Pixel region including a first sub pixel region and a second sub pixel region which are defined by the gate line and the data line and have a larger area than the first sub pixel region and the first sub pixel region, A first pixel electrode arranged in the pixel region and including a first support electrode portion and a plurality of first branch portions extending from the first support electrode portion and spaced apart from each other by a predetermined distance to define a micro-slit portion, Pixel regions, and extending from the second supporting electrode portion and the second supporting electrode portion, A second pixel electrode including a plurality of second branches defining a first pixel electrode and a second pixel electrode, and a storage supporter disposed between the first pixel electrode and the second pixel electrode and extending in a direction parallel to the gate line, And a storage branch that extends in a direction parallel to the data line and is disposed between the first pixel electrode and the data line.

In one embodiment of the present invention, the array substrate includes a first switching element disposed in the first sub-pixel region and electrically connected to the gate line, the data line, and the first pixel electrode, And a second switching element disposed adjacent to the gate line, the data line, and the second pixel electrode, the second switching element being adjacent to the gate line, the data line, and the second pixel electrode.

According to an embodiment of the present invention, the second pixel electrode may further include a connection electrode electrically connecting the second branch portion and the second switching element. The connection electrodes may extend in a direction parallel to the data lines and overlap the data lines.

In one embodiment of the present invention, the first supporting electrode part may have a cross shape.

In one embodiment of the present invention, the first branch portion may include a first zigzag portion disposed at a central portion of the first sub pixel region and extending in a zigzag form, and a second zigzag portion extending from the first zigzag portion to an outer edge of the first sub pixel region As shown in FIG.

In one embodiment of the present invention, the second support electrode portion may have a cross shape.

In one embodiment of the present invention, the second branch portion may include a second zigzag portion disposed in a central portion of the second sub pixel region and extending in a zigzag form, and a second zigzag portion extending from the second zigzag portion in an outer And a second straight line extending straightly up to the first straight line.

According to the above-described array substrate and display device, the secondary efficiency of the liquid crystal at the low gradation and the secondary efficiency of the liquid crystal at the low gradation are improved, thereby improving side visibility. Thus, the display quality of the display device is improved.

1 is a plan view of one pixel of the array substrate according to the first embodiment.
FIG. 2 is a cross-sectional view of the display device having the array substrate shown in FIG. 1 taken along line II '.
3 is a plan view of the pixel electrode shown in FIG.
4 is a plan view of one pixel of a display device having a chevron structure.
5 is a graph of voltage-transmittance for the display device described in Figs. 1 and 2 and the display device described in Fig.
FIG. 6 is a grayscale-transmittance graph obtained by converting the graph shown in FIG. 5 into standardized grayscales.
FIG. 7 is a graph showing the secondary efficiencies and the tertiary efficiencies observed from the front of the display device described in FIGS. 1 and 2 and the display device illustrated in FIG.
FIG. 8 is a graph showing the secondary efficiency and the tertiary efficiency measured at the right side at 60 degrees with respect to the display device described in FIGS. 1 and 2 and the display device illustrated in FIG.
9 is a plan view of the pixel electrode of the array substrate according to the second embodiment.
10 is a plan view of the pixel electrode of the array substrate according to the third embodiment.
11 is a plan view of a pixel electrode of an array substrate according to a fourth embodiment.
12A is an enlarged plan view of the fifth region shown in FIG.
12B, 12C and 12D are plan views showing the openings as modifications.
FIG. 13 is a graph showing the secondary efficiency with respect to the display device having the pixel electrode shown in FIG. 11 and the display device shown in FIG.
14 is a plan view of a pixel electrode of an array substrate according to a fifth embodiment.
15 is a plan view of the pixel electrode of the array substrate according to the sixth embodiment.
16 is a plan view of the pixel electrode of the array substrate according to the seventh embodiment.
17 is a plan view of one pixel of the array substrate according to the eighth embodiment.
18 is a diagram showing the orientation of the liquid crystal and the areas of the domains in the main pixel region.
FIG. 19 is a grayscale-transmittance graph observed along the direction in which the main pixel region shown in FIG. 18 is observed.
20 is a diagram showing the orientation of the liquid crystal in the main pixel region.
21 is a grayscale-transmittance graph observed along the direction in which the main pixel region shown in Fig. 20 is observed.
22 is a graph showing the visibility index when the pixels shown in FIG. 17 are observed at an azimuth angle of 60 degrees at each azimuth angle.
23 is a plan view of one pixel of the display device according to the ninth embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged from the actual size in order to clarify the present invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

1 is a plan view of one pixel of the array substrate 101 according to the first embodiment. 2 is a cross-sectional view of the display device 100 having the array substrate 101 shown in FIG. 1 taken along line I-I '.

Various techniques for improving image quality are applied to the liquid crystal display device 100. For example, in the liquid crystal display device 100, a plurality of pixel electrodes 160 and 170 to which pixel voltages of different levels are applied are arranged in a unit pixel region. In addition, the pixel electrodes 160 and 170 are formed with micro-slit portions 165 and 175 for improving the viewing angle by varying the alignment direction of the liquid crystal.

1 and 2, the display device of the present embodiment includes an array substrate 101, an opposing substrate 201, and a liquid crystal layer 103 interposed therebetween.

The array substrate 101 of the present embodiment includes a lower substrate 110, a gate line 111, a gate insulating film 121, an active layer 125, a data line 131, first and second switching elements TFT01 and TFT02 A passivation film 151, an organic insulating film 153, first and second pixel electrodes 160 and 170, and a lower alignment layer 181. The array substrate 101 described above is an example, and the array substrate 101 may be any substrate that forms a micro-slit (hereinafter referred to as a slit portion) on a pixel electrode.

A gate metal is deposited on the lower substrate 110 made of glass or plastic and etched so that the gate lines 111 are formed to be parallel to each other in the first direction D01. A gate insulating layer 121 covering the gate lines 111 is formed.

A semiconductor layer and a source metal layer are sequentially formed on the gate insulating layer 121 and etched to form data lines 131, a source electrode 132, a channel layer 131, And the drain electrode 135 are formed. The data lines 131 extend substantially in the second direction D02 perpendicular to the first direction D01 on the gate insulating layer 121. [

The gate lines 111 and the data lines 131 intersect with each other to define a substantially rectangular area and the first and second pixel electrodes 160 and 170 are formed in the rectangular area. Therefore, the rectangular region is defined as the unit pixel region. Alternatively, the shape of the unit pixel region may be changed into various shapes such as a Z-shape.

The gate electrode 112, the gate insulating layer 121, the channel layer 131, the source electrode 132 and the drain electrode 135 are connected to the first and second switching elements TFT01 , TFT02).

The passivation film 151 covering the data line 131 is formed and the organic insulating film 153 is formed on the passivation film 151. A contact hole is formed in the organic insulating layer 153 and the passivation layer 151 to expose a part of the drain electrode 135. The organic insulating film may be omitted.

3 is a plan view of the pixel electrode shown in FIG.

Referring to FIGS. 1, 2 and 3, a transparent conductive material layer such as indium tin oxide (ITO) or indium tin oxide (IZO) is deposited on the organic insulating layer 153. The conductive material layer is in contact with the drain electrode 135 through the contact hole. The first and second pixel electrodes 160 and 170 are formed by etching the conductive material layer.

The first and second pixel electrodes 160 and 170 include support electrode portions 163 and 167 and micro slit portions 165 and 175 to obtain the plurality of domains. The support electrodes 163 and 167 are arranged like a rod in a cross shape in the row direction D1 and the column direction D2. The micro slit portions 165 and 175 are formed in the first diagonal direction D3 and the second diagonal direction D3 which are 45 degrees from the supporting electrodes 163 and 167 in the row direction D1 and the column direction D2, And extend in the diagonal direction D4, respectively, and the directions may be formed differently for each domain. The supporting electrode and the micro slit portions 165 and 175 will be described in detail later.

A lower alignment layer 171 covering the first and second pixel electrodes 160 and 170 is formed. The lower alignment layer 171 may be formed by, for example, a blend of a cinnamate series photo-reactive polymer and a polyimide series polymer, On the electrodes 160 and 170, and cured.

The long axes of the liquid crystals are arranged in parallel to the extending direction of the micro slit portions (165, 175). As a result, a plurality of domains are formed and the viewing angle of the display device 100 is improved. The lower polarizer may be attached to the back surface of the lower base substrate 110 and the micro slits 165 and 175 formed on the first and second pixel electrodes 160 and 170 may be attached to the lower polarizer For example, in the first oblique direction D3 and the second oblique direction D4, which form approximately 45 degrees or 135 degrees.

The counter substrate 201 may include an upper substrate 210, a light shielding pattern 221, a color filter pattern 231, an overcoat layer 241, a common electrode 251, and an upper alignment layer 261.

The light shielding pattern 221 is formed on the upper base substrate 211 corresponding to the gate line 111, the data line 131, the first and second switching elements TFT01 and TFT02, 210). Therefore, the color filter pattern 231 is formed in the unit pixel region that is not shielded. The color filter pattern 231 may include, for example, a red filter, a green filter, and a blue filter. The red filter, the green filter, and the blue filter in the row direction D1.

The overcoat layer 241 covers the color filter pattern 231 and the light shielding pattern 221 and the common electrode 251 is formed of the same material as the first and second pixel electrodes 160 and 170 And is formed on the overcoat layer 241. Unlike the first and second pixel electrodes 160 and 170, the common electrode 251 corresponding to the unit pixel region is not formed with slits or cutouts, and the common electrode 251 is formed as a flat plate . The liquid crystal cell type in which the micro-slit portions 165 and 175 are formed on the first and second pixel electrodes 160 and 170 and the common electrode 251 is formed on the flat plate is referred to as SVA Also called mode.

The upper alignment layer is formed on the common electrode with the same material as the lower alignment layer.

An upper polarizer may be attached to the upper surface of the counter substrate 201 and a polarization axis of the upper polarizer may be disposed substantially perpendicular to a polarization axis of the lower polarizer.

Before the electric field is applied by the first and second pixel electrodes 160 and 170 and the common electrode 251, the liquid crystal layer 103 is aligned in the longitudinal direction of the liquid crystal 181 (hereinafter referred to as liquid crystal orientation) May be oriented in a direction orthogonal to the array substrate 101 and the counter substrate 201.

1 to 3, in the present embodiment, the slits 165 and 175 extend in a zigzag shape near the center of the cross-shaped support electrode, and the remainder are straight lines Respectively. The zigzag portion extending in the zigzag and the straight portion extending in the straight line are respectively defined. The pitch of the zigzag portion may be, for example, about 10 to 20 μm. The pitch may be changed to be different from the range appropriately according to the size of the pixel. The zigzag portion extends in zigzags while being bent at +15 to -15 degrees about the 45-degree direction. The angles of inclination of the zigzag portions may be appropriately changed in accordance with the size of the pixels.

The zigzag portion adjusts the third efficiency of the liquid crystal to be described later. The third efficiency means the efficiency in which the direction of the liquid crystal is aligned in the 45-degree direction by the electric field applied by the first and second pixel electrodes and the common electrode.

In this embodiment, when the low voltage driving is performed, the third efficiency of the liquid crystal is reduced by the zigzag portion. When a high voltage is applied to the first and second pixel electrodes 160 and 170, All of the liquid crystals on the zigzag portion are aligned in the direction of 45 degrees which is the extending direction of the slit portions 165 and 175. [ Thus, the third-order efficiency of the liquid crystal can be controlled in the low-voltage driving and the high-voltage driving while substantially reducing the transmittance reduction effect.

4 is a plan view of one pixel of a display device 400 having a chevron structure.

Referring to FIG. 4, in the cubic display device 400, the first slits are formed in the pixel electrode in a direction forming 45 degrees with respect to the first direction D01 and the second direction D02. The first slits are formed symmetrically with respect to a center line of the unit pixel region. The pixel electrodes are divided into a high pixel and a low pixel by the first slits. This structure may be referred to as S-PVA mode. The high pixel has a substantially V shape. And the second slit portions 551 located between the first slit portions are formed in the 45-degree direction in the common electrode. The cubic display device 400 is known to have excellent lateral visibility.

5 is a graph of voltage-transmittance for the display device 100 described in Figs. 1 and 2 and the display device 400 described in Fig. FIG. 6 is a grayscale-transmittance graph obtained by converting the graph shown in FIG. 5 into standardized grayscales.

In FIGS. 5 and 6, the abscissa indicates the voltage applied to the first and second pixel electrodes 160 and 170 and the high and low pixels, and the corresponding gray scale. The vertical axis indicates the transmittance of the pixel. 5, a graph G11 is a V-T graph observed from the front of the display device 100 of the SVA mode of the present embodiment, and a graph G12 is a V-T graph of the display device 100 of the SVA mode observed at a right viewing angle of 60 degrees. Graph G13 is a V-T graph observed at a right-side viewing angle of 60 degrees when the slit portions 165 and 175 are formed entirely without a zigzag portion, unlike the present embodiment. A display device in which the slit portions 165 and 175 are all formed in a straight line without a zigzag portion is defined as a linear display device. A graph G21 is a VT graph observed from the front of the S-PVA mode display device 400 shown in FIG. 4, and a graph G22 is a VT graph obtained by observing the S-PVA mode display device 400 at a right 60 degree viewing angle .

In FIG. 6, the graphs G31, G32, G33, G41 and G42 respectively show the front gradation-transmittance (GT) graph, the right 60 degree GT graph, the right 60 degree GT graph in the straight SVA mode, And a right-side 60-degree GT graph.

Referring to FIG. 5, it can be seen that the SVA mode of the present embodiment is significantly improved from the viewpoint of transmittance in contrast to the S-PVA mode. On the other hand, the S-PVA mode, that is, the conventional Chevron structure, has a feature in which the frontal and lateral V-T graphs similarly increase. On the other hand, the linear SVA structure shows a reversal phenomenon at about 3.8 V front and side V-T graphs. Referring to FIG. 6, in the linear display device, the side gamma is higher in the low gray level than in the cubic mode, and the side inversion phenomenon is observed in the high gray level higher than 50 gray.

Therefore, it can be seen that the linear display device is reduced in terms of visibility compared to the S-PVA. On the other hand, in the display device 100 of the present embodiment, the inversion phenomenon disappears in the front and side V-T graphs due to the zigzag portion, thereby improving the visibility index.

FIG. 7 is a graph showing the secondary efficiencies and the tertiary efficiencies observed from the front with respect to the display device 100 described in FIGS. 1 and 2 and the display device 400 illustrated in FIG. FIG. 8 is a graph showing the secondary efficiencies and the tertiary efficiencies observed at the right side of the display device 100 illustrated in FIGS. 1 and 2 and the display device 400 illustrated in FIG.

In FIG. 7, the graphs G51, G52, G53, G61, and G62 are graphs of the secondary efficiency graph, the tertiary efficiency graph, the frontal tertiary efficiency graph of the linear SVA mode, The frontal secondary efficiency graph and the tertiary efficiency graph are shown.

In FIG. 8, the graphs G71, G72, G73, G81, and G82 show the secondary efficiency graph, the tertiary efficiency graph, the right 60-degree tertiary efficiency graph in the linear SVA mode, The right side 60-degree secondary efficiency graph and the tertiary efficiency graph of the display device 400 are shown.

Referring to FIG. 7, it can be seen that the increasing slope of the secondary efficiency of the SVA mode of the present embodiment is very rapid, which is very high compared to the cubic display device 400. However, the linear SVA mode and the cubic mode do not show any particular difference in the third efficiency. In the linear SVA mode, it can be seen that the third-order efficiency increases very rapidly at a low gradation and is very small at an intermediate gradation. It is preferable that the third efficiency increase rate with respect to gradation is constant in terms of visibility. Therefore, in the linear SVA mode, it is preferable that the third efficiency graph is reduced at a low gray level. On the other hand, in the SVA mode of the present embodiment, as described above, the third order efficiency is lowered at a low gray scale due to the zigzag portion. As a result, it can be confirmed that the gradient of the graph of the tertiary efficiency is relatively constant as a whole. This improves the visibility of the display apparatus 100 of the present embodiment.

8, in the graph of the secondary and tertiary efficiencies for each gradation at 60 degrees on the right side, the slope of the secondary efficiency of the SVA mode display device 100 of this embodiment rises rapidly similar to the front, From the above, it can be seen that an inflection point is formed. On the other hand, in the case of the third efficiency in the side, the third efficiency graph is closer to the straight shape in the SVA mode of the present embodiment as compared with the linear SVA mode and the chevron mode. Therefore, the display device 100 of the present embodiment has improved visibility as compared with the linear SVA mode and the Chevron mode.

9 is a plan view of the pixel electrode of the array substrate according to the second embodiment.

9, the array substrate and the display device of this embodiment are substantially the same as the array substrate 101 and the display device 100 described in Figs. 1 to 8 except that the positions where the zigzag portions of the slit portions are formed are changed Do. Therefore, redundant description is omitted.

In this embodiment, the support electrode portions are formed in the main pixel region and the sub pixel region in a substantially columnar shape. The first slit portion and the second slit portion each include a straight portion and a zigzag portion. The rectilinear section extends straight from the support electrode section at the center of the main pixel region and the center of the sub pixel region. The zigzag portion extends in the zigzag shape from the straight portion to the outer edge of the unit pixel region.

The third-order efficiency reduction effect and the side-view visibility improvement effect at the low gradation due to the zigzag portion are substantially the same as those described in Figs. 1 to 8.

10 is a plan view of the pixel electrode of the array substrate according to the third embodiment.

10, the array substrate and the display device of this embodiment are substantially the same as the array substrate 101 and the display device 100 described in Figs. 1 to 8 except that the whole slit portion is formed in a zigzag shape Do. Therefore, redundant description is omitted.

In this embodiment, the support electrode portions are formed in the main pixel region and the sub pixel region in a substantially columnar shape. The first slit portion and the second slit portion are formed in a zigzag shape as a whole. It is preferable that the zigzag angle be made smaller than that of the first and second embodiments because the area where the zigzag is formed increases.

The third-order efficiency reduction effect and the side-view visibility improvement effect at the low gradation due to the zigzag portion are substantially the same as those described in Figs. 1 to 8.

11 is a plan view of a pixel electrode of an array substrate according to a fourth embodiment.

11, the array substrate and the display device of this embodiment are similar to the array substrate 101 described in Figs. 1 to 3 except that the shape of the pixel electrode is changed and the visibility is improved by controlling the secondary efficiency. And the display device 100 are substantially the same. Therefore, redundant description is omitted.

In the present embodiment, the pixel electrode is divided into four domains. The pixel electrode includes a supporting electrode portion, a first slit portion, and a second slit portion. The supporting electrode part includes a first supporting electrode part and a second supporting electrode part. The first supporting electrode portion is disposed at the outer periphery of the unit pixel region. The second support electrode portion is disposed along a boundary where the domains contact with each other, and is arranged in a substantially cross shape.

The first slit portion and the second slit portion extend in a direction forming approximately 45 degrees intersecting the first direction D01 and the second direction D02 in each domain, Respectively. The first slit portion is connected to the first supporting electrode portion and the second supporting electrode portion. The second slit part is connected to the first supporting electrode part and is separated from the second supporting electrode part. The first slit portion and the second slit portion are alternately arranged.

Therefore, an opening portion having a width larger than that of the other portion is formed on the outer periphery of the unit pixel region because the end portion of the second slit portion is spaced apart from the second supporting electrode portion.

12A is an enlarged plan view of the fifth region shown in FIG. 12B, 12C and 12D are plan views showing the openings as modifications. FIG. 13 is a graph showing the secondary efficiency of the display device having the pixel electrode shown in FIG. 11 and the display device 400 described in FIG.

12B, 12C and 12D show modified examples for narrowing the width of the opening formed by cutting the end of the first slit part from the second supporting electrode part. When the width of the opening is too wide, the liquid crystal is not controlled, so that the width of the opening is preferably narrowed as shown in Figs. 12B, 12C and 12D.

13, the horizontal axis represents the azimuth angle of the liquid crystal, and the vertical axis represents the ratio of the liquid crystal present at the azimuth angle. Referring to FIG. 13, it can be seen that the second efficiency graph of the cubon display device 400 is narrower and wider than the second efficiency graph of the display device 100 of the present embodiment. It was analyzed that the secondary efficiency of the liquid crystal was decreased in the middle gradation due to the opening.

The secondary efficiency means an efficiency in which the liquid crystal shifts vertically to horizontally by an electric field formed between the pixel electrode and the common electrode. The opening weakens the liquid crystal control force so that the liquid crystal is controlled not to be completely black nor completely white.

Referring to FIG. 7 and FIG. 8, a graph G54 showing the front secondary efficiency and a graph G74 showing the secondary secondary efficiency of the display device 100 of the present embodiment show that the secondary efficiency .

 That is, it can be seen that the second-order efficiency graph is closer to the straight line having a relatively constant slope in the curve in which the slope changes rapidly, and is close to the second efficiency in the cubic mode. Therefore, it can be confirmed that the lateral visibility of the display device is improved by bringing the secondary efficiency closer to a linear shape.

14 is a plan view of a pixel electrode of an array substrate according to a fifth embodiment.

Referring to Fig. 14, the array substrate and display device of this embodiment are substantially the same as the array substrate and display device described in Figs. 11 to 13 except that the positions where the openings are formed are changed. Therefore, redundant description is omitted.

In this embodiment, the second slit portion is cut from the first supporting electrode portion that divides the unit pixel region into four domains. Therefore, the two first slits 1376 adjacent to the second slit portion, the opening surrounded by the first supporting electrode portion and the second slit portion are arranged in a substantially columnar shape in the unit pixel region . The effect of reducing the secondary efficiency in the intermediate gradation by the opening and the effect of improving the side visibility by the opening are substantially the same as those described in Figs. Therefore, redundant description is omitted.

15 is a plan view of the pixel electrode of the array substrate according to the sixth embodiment.

15, the array substrate and the display device of this embodiment are substantially the same as the array substrate and the display device described in Figs. 11 to 13 except that zigzag portions are further formed in the first slit portion and the second slit portion Do. Therefore, redundant description is omitted.

In the present embodiment, the first slit portion and the second slit portion are formed in a zigzag shape near the center of the unit pixel region and are connected to the first supporting electrode portion. And the second slit portion is cut away from the second supporting electrode portion disposed on the outer periphery of the unit pixel region.

The effect of reducing the secondary efficiency in the intermediate gradation due to the opening and the effect of improving the side viewability thereof are substantially the same as those described in Figs. Therefore, redundant description is omitted. In addition, the third-order efficiency reduction effect and the side view visibility improvement effect at the low gradation by the zigzag portion are substantially the same as those described in Figs. 1 to 8. Therefore, the array substrate and the display device of this embodiment reduce the third efficiency of the liquid crystal at a low gray level and reduce the secondary efficiency of the liquid crystal at an intermediate gray level, thereby improving side visibility.

16 is a plan view of the pixel electrode of the array substrate according to the seventh embodiment.

16, the array substrate and the display device of this embodiment are substantially the same as the array substrate and display device described in Figs. 11 to 13 except that zigzag portions are further formed in the first slit portion and the second slit portion Do. Therefore, redundant description is omitted.

In this embodiment, the first slit portion and the second slit portion are formed in a zigzag shape near the edge of the outer edge of the unit pixel region and are connected to the second supporting electrode portion. And the second slit portion is cut away from the first supporting electrode portion disposed in the unit pixel region.

The effect of reducing the secondary efficiency in the intermediate gradation due to the opening and the effect of improving the side viewability thereof are substantially the same as those described in Figs. Therefore, redundant description is omitted. In addition, the third-order efficiency reduction effect and the side view visibility improvement effect at the low gradation by the zigzag portion are substantially the same as those described in Figs. 1 to 8. Therefore, the array substrate and the display device of this embodiment reduce the third efficiency of the liquid crystal at a low gray level and reduce the secondary efficiency of the liquid crystal at an intermediate gray level, thereby improving side visibility.

17 is a plan view of one pixel of the array substrate according to the eighth embodiment.

Referring to FIG. 17, the array substrate and the display device of the present embodiment have a structure in which the second slit portion is linearly formed, the areas of the domains in the main pixel region are different from each other, the first slit portion in the main pixel region is in the first direction D01, Is substantially the same as the array substrate 101 and the display device 100 described in Figs. 1 to 3 except that the angles are smaller than 45 degrees. Therefore, redundant description is omitted.

18 is a diagram showing the orientation of the liquid crystal and the areas of the domains in the main pixel region. FIG. 19 is a grayscale-transmittance graph observed along the direction in which the main pixel region shown in FIG. 18 is observed.

Referring to FIG. 18, the subdomain in the main pixel region is wider than the upper domain, as shown in FIG.

FIG. 18 schematically shows the area ratio of the domains of the main pixel region. The graph shown in FIG. 19 is a grayscale transmittance graph according to the area ratio of the upper and lower domains. Graph G110 is a G-T graph in which the main pixel region is observed at a viewing angle of 60 degrees at the lower side and the upper side when the area ratio is 5: 5. A graph G111 is a G-T graph in which the main pixel region is observed on the front surface regardless of the area ratio. And a graph G112 is a G-T graph in which the main pixel region is observed at a lower 60-degree viewing angle when the area ratio is 4: 6. And a graph G113 is a G-T graph in which the main pixel region is observed at an angle of view of 60 degrees at the upper side when the area ratio is 4: 6.

As shown in FIG. 18, when the area of the upper two domains is narrowed and the area of the lower two domains is widened, the shapes of the gamma (gamma) curves observed from the upper side and the lower side are different. On the image side, the gamma curve changes to the darker side, and on the lower side it changes to the brighter side.

20 is a diagram showing the orientation of the liquid crystal in the main pixel region. FIG. 21 is a grayscale-transmittance graph observed along the direction in which the main pixel region shown in FIG. 20 is observed.

20, the first slit portion is formed to be rotated by 10 degrees in the first direction D01, that is, in the direction of the polarization axis of the polarizer, so that the orientation of the liquid crystal is also shifted horizontally along the first slit portion As shown in Fig. In FIG. 21, a graph G211 is a G-T graph in which the main pixel region is observed from the front. And a graph G214 is a G-T graph observed at the upper and lower 60 degrees when the angle of the first slit portion is 45 degrees with the polarization axis. And a graph G212 is a G-T graph observed at the upper and lower 60 degrees of the main pixel region shown in FIGS. 17 and 20. FIG. A graph G213 is a G-T graph observed at 60 degrees on the left and right sides of the main pixel region shown in FIGS. 17 and 20. FIG.

Referring to the graphs, if the orientation of the liquid crystal is made smaller than 45 degrees, the shapes of the gamma (gamma) curves observed on the upper and lower sides are different. On the image side, the gamma curve changes to the lighter side, while on the lower side it changes to the darker side.

22 is a graph showing the visibility index when the pixels shown in FIG. 17 are observed at an azimuth angle of 60 degrees at each azimuth angle.

In FIGS. 18 to 21, it is possible to obtain better lateral visibility characteristics than the existing conditions by combining the tendency of the viewing angle characteristic change according to the adjustment of the domain ratio of the domain and the azimuthal adjustment of the liquid crystal.

In FIG. 22, the row pixel, that is, the second pixel electrode, has the same condition as the conventional one, that is, the same area and the extension direction of the second slit portion form 45 degrees with respect to the first direction D01, In the electrode, the liquid crystal angle and the area ratio of the upper and lower domains are controlled, and the visibility index for each azimuth angle is shown at a viewing angle of 60 degrees. The lower the visibility index, the better the display quality.

22, a graph G312 shows that in the S-PVA structure, the area ratio of the high pixel and the low pixel is 2.5: 1, the low pixel has the same area of the four domains, The orientation angle of the liquid crystal is an azimuth-visibility index graph in the case of 45 degrees in the horizontal plane.

Graph G313 is an azimuth-visibility index graph in the case where the area of the upper two domains of the first pixel electrode is small and the area of the lower two domains is made large as shown in FIG.

 As shown in FIG. 17, a graph G311 is an azimuth-visibility index graph in the case where the azimuth angle of the liquid crystal along the first slit portions 2165 in the first pixel electrode is 40 degrees with the first direction D01.

 First, by comparing the graphs G313 and G311, the visibility indexes on the right and left sides of the graph G311 are remarkably reduced to improve the visibility, while the visibility indexes on the upper and lower sides are significantly increased. In this state, when the area ratio of the upper and lower domains of the first pixel electrode was changed to 3: 7, the visibility index was reduced in all directions except the lower side as shown in the graph G313, and excellent visibility was obtained. As described above, according to the present embodiment, the side visibility in all other directions can be greatly improved, instead of damaging the lower side visibility. In the table below, experimental values of the domain ratio and the azimuth angle of the slit portion are shown.

23 is a plan view of one pixel of the display device according to the ninth embodiment.

Referring to Fig. 23, the array substrate and the display device of this embodiment are the same as the Sebron display device 400 shown in Fig. 4 except that the azimuth and position of the second slit portion formed on the common electrode are changed.

The display device 2400 includes an arrange substrate, an opposing substrate, and a liquid crystal layer.

The array substrate includes a pixel electrode. The pixel electrode has first slit portions. The first slit part is formed symmetrically with respect to a center line parallel to the first direction (D01) and has a first acute angle equal to or greater than 45 degrees to the center line.

The counter substrate includes a common electrode on which second slits are formed. The second slit portion has a second acute angle that is greater than 45 degrees with the center line and is equal to or greater than the first acute angle and is formed to be located between the first slit portions. And the liquid crystal layer is positioned between the array substrate and the counter substrate.

And the center of the pair of second slits disposed on both sides of the center line is spaced apart from the center line. Therefore, the area between the first slit part and the second slit part is formed to be different on both sides with respect to the center line. The second acute angle may be greater than 45 degrees and less than or equal to 60 degrees. The pixel electrode includes a first pixel electrode and a second pixel electrode separated by the first slit portion, and the first pixel electrode may have a V shape.

According to the array substrate and the display device 2400 of this embodiment, it is very useful to adjust the angle of the slit portion and adjust the area ratio of the domains. The angle of the second slit may be an acute angle greater than 45 degrees with respect to the first direction D01. Accordingly, the second slit portion may be formed at an angle greater than about 30 degrees and less than 45 degrees with respect to the second direction D02 orthogonal to the first direction D01. This causes the orientation of the liquid crystal to change. Domain can be achieved by shifting the area of the domain to the upper side or the lower side of the boundary of the pair of second slit portions.

The orientation of the liquid crystal and the change of the domain area ratio can be achieved through the angle and center shift of the first slit portion as described above. According to the present embodiment, the visibility in the left-right direction or the right-left direction and the upward direction can be improved.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

101: array substrate 110: lower substrate
160: first pixel electrode 165: first slit part
170: second pixel electrode 175: second slit part
103: liquid crystal layer 201: array substrate
TFT01: first switching element TFT02: second switching element

Claims (7)

A lower substrate having a gate line extending in a first direction and a first data line and a second data line extending in a second direction intersecting the first direction and adjacent to each other;
And a plurality of first branch portions extending from the first support electrode portion and spaced apart from each other by a predetermined distance to define a first micro slit portion, ;
A first switching element electrically connected to the gate line, the first data line, and the first pixel electrode;
And a plurality of second branch portions extending from the second support electrode portion and spaced apart from each other by a predetermined distance to define a second micro-slit portion, wherein the first pixel electrode, the second support electrode portion, A second pixel electrode disposed adjacent to the first pixel electrode and having a larger area than the first pixel electrode;
A second switching element disposed adjacent to the first switching element and electrically connected to the gate line, the second data line, and the second pixel electrode; And
A storage support portion disposed between the first pixel electrode and the second pixel electrode and extending in a direction parallel to the gate line, and a second pixel electrode extending in a direction parallel to the first and second data lines from the storage support portion, A storage line including a first pixel electrode and a storage branch disposed between the first and second data lines,
Wherein the second pixel electrode further includes a connection electrode electrically connecting the second branch portion and the second switching element,
Wherein the connection electrode extends in a direction parallel to the first and second data lines and overlaps with the second data line. delete delete The array substrate according to claim 1, wherein the first supporting electrode part has a cross-shape. The apparatus as claimed in claim 4,
A first zigzag portion disposed at a central portion of the first pixel electrode and extending in a zigzag shape; And
And a first linear portion extending linearly from the first zigzag portion to an outer edge of the first pixel electrode. The array substrate according to claim 1, wherein the second supporting electrode portion has a cross shape. 7. The apparatus according to claim 6,
A second zigzag portion disposed in a central portion of the second pixel electrode and extending in a zigzag shape; And
And a second linear portion extending linearly from the second zigzag portion to the outer edge of the second pixel electrode.

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