CN101169531A

Movatterモバイル変換

Info

Publication number: CN101169531A
Application number: CNA2006101425305A
Authority: CN
Inventors: 戴孟杰; 柳智忠; 张月泙
Original assignee: Chunghwa Picture Tubes Ltd
Current assignee: Chunghwa Picture Tubes Ltd
Priority date: 2006-10-23
Filing date: 2006-10-23
Publication date: 2008-04-30
Anticipated expiration: 2026-10-23
Also published as: CN101169531B

Abstract

The invention discloses a pixel structure which is suitable for being controlled by a scanning line and a data line of a thin film transistor array substrate of a multi-domain vertical alignment type liquid crystal display panel. The pixel structure comprises a first thin film transistor, a second thin film transistor, a first pixel electrode, a second pixel electrode and a plurality of alignment components, wherein the first thin film transistor and the second thin film transistor are electrically connected to the scanning line and the data line. The first thin film transistor is provided with a first drain electrode, and the first pixel electrode is electrically connected to the first drain electrode. The second thin film transistor is provided with a second drain electrode, the second pixel electrode is arranged above the second drain electrode in a floating mode to form a coupling capacitor, and a voltage difference exists between the second pixel electrode and the first pixel electrode. The alignment component is configured on the first pixel electrode and the second pixel electrode.

Description

Translated fromChinese

像素结构pixel structure

技术领域technical field

本发明有关于一种液晶显示面板(liquid crystal display panel)的像素(pixel)结构，且特别有关于一种多域垂直配向式(multi-domain verticalalignment，MVA)液晶显示面板的像素结构。The present invention relates to a pixel structure of a liquid crystal display panel, and in particular to a pixel structure of a multi-domain vertical alignment (MVA) liquid crystal display panel.

背景技术Background technique

现有的液晶显示器多朝向高亮度、高对比、大面积显示与广视角的趋势发展，其中为了改善液晶显示器的视角，已有多种广视角技术被提出。目前较常见的广视角液晶显示器例如有多域垂直配向式液晶显示器、共平面转换式(in-planeswitching，IPS)液晶显示器以及边缘电场转换式(fringe field switching，FFS)液晶显示器等等。Existing liquid crystal displays tend to develop towards high brightness, high contrast, large area display and wide viewing angle. In order to improve the viewing angle of the liquid crystal display, various wide viewing angle technologies have been proposed. Wide-viewing-angle liquid crystal displays are currently common such as multi-domain vertical alignment liquid crystal displays, in-plane switching (IPS) liquid crystal displays, fringe field switching (FFS) liquid crystal displays, and the like.

图1为现有的现有的一种应用于多域垂直配向式液晶显示器的像素结构的上视示意图。请参照图1，像素结构100配置于一薄膜晶体管阵列基板上，此像素结构100包括一扫描线110、一数据线120、一薄膜晶体管130、一像素电极140与一凸起物150。其中薄膜晶体管130包括栅极132、半导体层134、源极136a、漏极136b以及接触窗138。栅极132与扫描线110电性连接，而半导体层134配置于栅极132上方。源极136a与漏极136b配置于半导体层134上，其中源极136a与数据线120电性连接。FIG. 1 is a schematic top view of a conventional pixel structure applied to a multi-domain vertical alignment liquid crystal display. Referring to FIG. 1 , thepixel structure 100 is disposed on a thin film transistor array substrate. Thepixel structure 100 includes ascanning line 110 , adata line 120 , athin film transistor 130 , apixel electrode 140 and aprotrusion 150 . Thethin film transistor 130 includes agate 132 , asemiconductor layer 134 , asource 136 a , adrain 136 b and acontact window 138 . Thegate 132 is electrically connected to thescan line 110 , and thesemiconductor layer 134 is disposed above thegate 132 . Thesource electrode 136 a and thedrain electrode 136 b are disposed on thesemiconductor layer 134 , wherein thesource electrode 136 a is electrically connected to thedata line 120 .

像素电极140透过接触窗138而与漏极136b电性连接。此外，为了达到液晶分子能够产生多域垂直配向，凸起物150配置于像素电极140上，而在相对的彩色滤光基板(未绘示)上配置多个凸起物(未绘示)。因此，通过凸起物150与凸起物的搭配，可以使得配置于薄膜晶体管阵列基板与彩色滤光基板之间的液晶分子呈现多方向的倾倒，进而达到广视角显示的效果。Thepixel electrode 140 is electrically connected to thedrain electrode 136 b through thecontact window 138 . In addition, in order to achieve multi-domain vertical alignment of the liquid crystal molecules, theprotrusion 150 is disposed on thepixel electrode 140, and a plurality of protrusions (not shown) are disposed on the opposite color filter substrate (not shown). Therefore, through the combination of theprotrusions 150 and the protrusions, the liquid crystal molecules disposed between the thin film transistor array substrate and the color filter substrate can be tilted in multiple directions, thereby achieving the effect of wide viewing angle display.

虽然上述的多域垂直配向式液晶显示器可以增加视角范围，但是，当视角由0度往90度变化时，此多域垂直配向式液晶显示器的光穿透率(transmission)相对于灰阶(gray level)的迦玛曲线(gamma curve)将有所不同。简单而言，随着视角的改变，此多域垂直配向式液晶显示器所提供的画面的色调及亮度分布失真的程度将越明显。Although the above-mentioned multi-domain vertical alignment liquid crystal display can increase the viewing angle range, when the viewing angle changes from 0 degrees to 90 degrees, the light transmittance (transmission) of the multi-domain vertical alignment liquid crystal display is relative to the gray scale (gray level) will have a different gamma curve. To put it simply, as the viewing angle changes, the degree of distortion of the color tone and brightness distribution of the picture provided by the multi-domain vertical alignment liquid crystal display will become more obvious.

发明内容Contents of the invention

有鉴于此，本发明的目的就是提供一种像素结构，以降低显示品质随着视角改变的程度。In view of this, the purpose of the present invention is to provide a pixel structure to reduce the degree of display quality variation with viewing angle.

为达上述或其他目的，本发明提出一种像素结构，其适于通过一多域垂直配向式液晶显示面板的一薄膜晶体管阵列基板的一扫描线与一数据线所控制。此像素结构包括一第一薄膜晶体管、一第二薄膜晶体管、一第一像素电极、一第二像素电极与多个配向构件，其中第一薄膜晶体管与第二薄膜晶体管均电性连接至扫描线与数据线。第一薄膜晶体管具有一第一漏极，且第一像素电极电性连接至第一漏极。第二薄膜晶体管具有一第二漏极，且第二像素电极浮置(floating)于第二漏极的上方，以形成一耦合电容，且第二像素电极与第一像素电极之间具有一电压差。配向构件配置于第一像素电极与第二像素电极上。To achieve the above and other objectives, the present invention provides a pixel structure suitable for being controlled by a scanning line and a data line of a thin film transistor array substrate of a multi-domain vertical alignment liquid crystal display panel. The pixel structure includes a first thin film transistor, a second thin film transistor, a first pixel electrode, a second pixel electrode and a plurality of alignment members, wherein the first thin film transistor and the second thin film transistor are both electrically connected to the scanning line with data lines. The first thin film transistor has a first drain, and the first pixel electrode is electrically connected to the first drain. The second thin film transistor has a second drain, and the second pixel electrode is floating above the second drain to form a coupling capacitor, and there is a voltage between the second pixel electrode and the first pixel electrode Difference. The alignment member is disposed on the first pixel electrode and the second pixel electrode.

在本发明的一实施例中，第一像素电极与第二像素电极的面积比可以是1∶1。In an embodiment of the present invention, the area ratio of the first pixel electrode and the second pixel electrode may be 1:1.

在本发明的一实施例中，第一像素电极与第二像素电极的面积比可以是1∶2。In an embodiment of the present invention, the area ratio of the first pixel electrode and the second pixel electrode may be 1:2.

在本发明的一实施例中，第一薄膜晶体管与第二薄膜晶体管可以是具有一共用源极。In an embodiment of the present invention, the first thin film transistor and the second thin film transistor may have a common source.

在本发明的一实施例中，第一像素电极与第二像素电极可以是分别位于扫描线的两侧。In an embodiment of the present invention, the first pixel electrode and the second pixel electrode may be respectively located on two sides of the scan line.

在本发明的一实施例中，像素结构还包括一共通线，其配置于第一像素电极与第二像素电极下方。In an embodiment of the present invention, the pixel structure further includes a common line disposed under the first pixel electrode and the second pixel electrode.

在本发明的一实施例中，配向构件可以是凸起物或狭缝。In an embodiment of the present invention, the alignment members may be protrusions or slits.

基于上述，由于本发明的像素结构采用两个像素电极，并让其中一个像素电极浮置于两个薄膜晶体管其中之一的漏极上方，以形成耦合电容，故两像素电极之间可产生一电压差。此电压差能使位于两像素电极上方的液晶分子的倾倒角度不同，而降低多域垂直配向式液晶显示面板的光穿透率相对于灰阶的迦玛曲线随着视角改变的程度。Based on the above, since the pixel structure of the present invention adopts two pixel electrodes, and one of the pixel electrodes is floated above the drain of one of the two thin film transistors to form a coupling capacitance, a gap can be generated between the two pixel electrodes. Voltage difference. The voltage difference can cause the liquid crystal molecules on the two pixel electrodes to have different inclination angles, thereby reducing the extent to which the gamma curve of the light transmittance of the multi-domain vertical alignment liquid crystal display panel changes with the viewing angle relative to the gray scale.

为让本发明的上述和其他目的、特征和优点能更明显易懂，下文特举较佳实施例，并配合附图作详细说明如下。In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are exemplified below and described in detail with accompanying drawings.

附图说明Description of drawings

图1为现有的一种应用于多域垂直配向式液晶显示器的像素结构的上视示意图。FIG. 1 is a schematic top view of a conventional pixel structure applied to a multi-domain vertical alignment liquid crystal display.

图2为本发明一实施例的一种像素结构的上视示意图。FIG. 2 is a schematic top view of a pixel structure according to an embodiment of the present invention.

图3为图2所示的像素结构的等效电路图。FIG. 3 is an equivalent circuit diagram of the pixel structure shown in FIG. 2 .

具体实施方式Detailed ways

图2为本发明一实施例的一种像素结构的上视示意图。请参照图2，本实施例的像素结构200适于配置于一多域垂直配向式液晶显示面板的一薄膜晶体管阵列基板的一扫描线310与一数据线320所控制。像素结构200包括一第一薄膜晶体管210、一第二薄膜晶体管220、一第一像素电极230、一第二像素电极240以及多个配向构件250。其中，第一薄膜晶体管210电性连接至扫描线310及数据线320，且第二薄膜晶体管220也电性连接至扫描线310及数据线320。此外，第一薄膜晶体管210具有一第一漏极212，且第一像素电极230电性连接至第一漏极212。第二薄膜晶体管220具有一第二漏极222，且第二像素电极240浮置于第二漏极222的上方，以形成一耦合电容C_cp，且第二像素电极240与第一像素电极230之间具有一电压差。另外，该些配向构件250配置于第一像素电极230与第二像素电极240上。FIG. 2 is a schematic top view of a pixel structure according to an embodiment of the present invention. Referring to FIG. 2 , the pixel structure 200 of this embodiment is suitable for being controlled by ascan line 310 and adata line 320 disposed on a thin film transistor array substrate of a multi-domain vertical alignment liquid crystal display panel. The pixel structure 200 includes a firstthin film transistor 210 , a secondthin film transistor 220 , afirst pixel electrode 230 , asecond pixel electrode 240 and a plurality ofalignment members 250 . Wherein, the firstthin film transistor 210 is electrically connected to thescan line 310 and thedata line 320 , and the secondthin film transistor 220 is also electrically connected to thescan line 310 and thedata line 320 . In addition, the firstthin film transistor 210 has afirst drain 212 , and thefirst pixel electrode 230 is electrically connected to thefirst drain 212 . The secondthin film transistor 220 has a second drain 222, and thesecond pixel electrode 240 is floating above the second drain 222 to form a coupling capacitor C_cp , and thesecond pixel electrode 240 is connected to thefirst pixel electrode 230 There is a voltage difference between them. In addition, thealignment members 250 are disposed on thefirst pixel electrode 230 and thesecond pixel electrode 240 .

更详细而言，由于第二像素电极240以浮置方式配置于第二漏极222的上方，因此第二像素电极240与第一像素电极230之间便产生了一电压差。故能使位于第一像素电极230与第二像素电极240上方的液晶分子的倾倒角度不同，以减少光穿透率相对于灰阶的迦玛曲线随着视角改变的现象。因此，采用本实施例之像素结构200的多域垂直配向式液晶显示器将能提供较佳的显示品质。In more detail, since thesecond pixel electrode 240 is disposed above the second drain electrode 222 in a floating manner, a voltage difference is generated between thesecond pixel electrode 240 and thefirst pixel electrode 230 . Therefore, the inclination angles of the liquid crystal molecules above thefirst pixel electrode 230 and thesecond pixel electrode 240 can be made different, so as to reduce the phenomenon that the gamma curve of the light transmittance relative to the gray scale changes with the viewing angle. Therefore, the multi-domain vertical alignment liquid crystal display adopting the pixel structure 200 of this embodiment can provide better display quality.

在本实施例中，第一像素电极230与第二像素电极240分别位于扫描线310的两侧，然而第一像素电极230与第二像素电极240也可以是位在扫描线310的同一侧。此外，在本实施例中，第一像素电极230与第二像素电极240的面积比为1∶1，然而在另一实施例中，第一像素电极230与第二像素电极240的面积比也可以是1∶2或其他比例。In this embodiment, thefirst pixel electrode 230 and thesecond pixel electrode 240 are respectively located on two sides of thescan line 310 , however, thefirst pixel electrode 230 and thesecond pixel electrode 240 may also be located on the same side of thescan line 310 . In addition, in this embodiment, the area ratio of thefirst pixel electrode 230 and thesecond pixel electrode 240 is 1:1, but in another embodiment, the area ratio of thefirst pixel electrode 230 and thesecond pixel electrode 240 is also It can be 1:2 or other ratios.

在本实施例中，第一薄膜晶体管210与第二薄膜晶体管220具有一共用源极215。然而，在另一实施例中，第一薄膜晶体管210与第二薄膜晶体管220亦可个别具有独立的源极。此外，在本实施例中，第一薄膜晶体管210与第二薄膜晶体管220均采用部分的扫描线310作为栅极，然而在另一实施例中，第一薄膜晶体管210与第二薄膜晶体管220也可以具有独立的栅极。另外，在本实施例中，配向构件250为狭缝，然而在另一实施例中，配向构件250也可以是凸起物。再者，为了避免第二漏极222的电场对于液晶分子产生干扰，在第二漏极222对于配向构件250的区域同样配置有狭缝A。In this embodiment, the first TFT 210 and the second TFT 220 have a common source 215 . However, in another embodiment, the firstthin film transistor 210 and the secondthin film transistor 220 may also have independent sources. In addition, in this embodiment, both the firstthin film transistor 210 and the secondthin film transistor 220 use part of thescan line 310 as a gate, but in another embodiment, the firstthin film transistor 210 and the secondthin film transistor 220 also use Can have separate gates. In addition, in this embodiment, thealignment member 250 is a slit, but in another embodiment, thealignment member 250 may also be a protrusion. Furthermore, in order to prevent the electric field of the second drain 222 from interfering with the liquid crystal molecules, a slit A is also arranged in the area of the second drain 222 facing thealignment member 250 .

在本实施例中，像素结构200还包括一共通线260，其配置于第一像素电极230与第二像素电极240下方，以形成一存储电容。换言之，本实施例所揭示的存储电容的架构为存储电容形成于共通线上(Cst on common)。然而，本发明并非限定存储电容的架构为存储电容形成于共通线(Cst on common)。在其他实施例中，存储电容的架构也可为存储电容形成于扫描线上(Cst on gate)。举例而言，由第一像素电极230及第二像素电极240分别与扫描线310有部分重叠而形成。以下将就本实施例的等效电路图进行说明。In this embodiment, the pixel structure 200 further includes acommon line 260 disposed under thefirst pixel electrode 230 and thesecond pixel electrode 240 to form a storage capacitor. In other words, the structure of the storage capacitor disclosed in this embodiment is that the storage capacitor is formed on a common line (Cs on common). However, the present invention does not limit the structure of the storage capacitor to the fact that the storage capacitor is formed on a common line (Cs on common). In other embodiments, the structure of the storage capacitor can also be that the storage capacitor is formed on the scan line (Cs on gate). For example, thefirst pixel electrode 230 and thesecond pixel electrode 240 are formed by partially overlapping thescanning line 310 respectively. The equivalent circuit diagram of this embodiment will be described below.

图3为图2所绘示的像素结构的等效电路图。请参照图3，C_lc1代表由第一像素电极230与对向基板上的共通电极(未绘示)所形成的第一液晶电容、C_st1代表由第一像素电极230与共通线260所形成的第一存储电容、C_cp代表由第二像素电极240与第二漏极222所形成的耦合电容、C_lc2代表由第二像素电极240与共通电极所形成的第二液晶电容以及C_st2代表由第二像素电极240与共通线260所形成的第二存储电容。FIG. 3 is an equivalent circuit diagram of the pixel structure shown in FIG. 2 . Please refer to FIG. 3 , C_lc1 represents the first liquid crystal capacitance formed by thefirst pixel electrode 230 and the common electrode (not shown) on the opposite substrate, and C_st1 represents the first liquid crystal capacitance formed by thefirst pixel electrode 230 and thecommon line 260. C_cp represents the coupling capacitance formed by thesecond pixel electrode 240 and the second drain electrode 222, C_lc2 represents the second liquid crystal capacitance formed by thesecond pixel electrode 240 and the common electrode, and C_st2 represents A second storage capacitor formed by thesecond pixel electrode 240 and thecommon line 260 .

请同时参考图2与图3，当开启信号输入扫描线310时，第一薄膜晶体管210与第二薄膜晶体管220将开启，而数据电压便经由第一漏极212而输入第一像素电极230。此外，数据电压也输入第二漏极222，然而由于第二像素电极240浮置于第二漏极222上方，因此第二像素电极240所感应到的电压将小于第一像素电极230的电压。换言之，位于第一像素电极230与第二像素电极240上方的液晶分子的倾倒角度将不同，以改善因视角改变所产生的色偏(color shift)的现象。因此，采用本实施例的像素结构200的多域垂直配向式液晶显示器将能提供较佳的显示品质。Please refer to FIG. 2 and FIG. 3 at the same time. When a turn-on signal is input to thescan line 310 , thefirst TFT 210 and thesecond TFT 220 are turned on, and the data voltage is input to thefirst pixel electrode 230 through thefirst drain 212 . In addition, the data voltage is also input into the second drain 222 , but since thesecond pixel electrode 240 floats above the second drain 222 , the voltage induced by thesecond pixel electrode 240 will be smaller than the voltage of thefirst pixel electrode 230 . In other words, the inclination angles of the liquid crystal molecules above thefirst pixel electrode 230 and thesecond pixel electrode 240 are different, so as to improve the phenomenon of color shift caused by the change of viewing angle. Therefore, the multi-domain vertical alignment liquid crystal display adopting the pixel structure 200 of this embodiment can provide better display quality.

虽然本发明已以较佳实施例揭示如上，然其并非用以限定本发明，任何本领域普通技术人员在不脱离本发明的精神和范围内，当可作些许更动与润饰，因此本发明的保护范围当以权利要求所界定的为准。Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be defined by the claims.

Claims

1. dot structure, the one scan line and the data line that are suitable for the thin-film transistor array base-plate by a multi-field vertical assigned LCD panel are controlled, and this dot structure comprises:

One the first film transistor is electrically connected to this sweep trace and this data line, and this first film transistor has one first drain electrode;

One second thin film transistor (TFT) is electrically connected to this sweep trace and this data line, and this second thin film transistor (TFT) has one second drain electrode;

One first pixel electrode is electrically connected to this first drain electrode;

One second pixel electrode is floated on this second drain electrode top, forming a coupling capacitance, and has a voltage difference between this second pixel electrode and this first pixel electrode; And

A plurality of orientation members are disposed on this first pixel electrode and this second pixel electrode.

2. dot structure as claimed in claim 1 is characterized in that, this first pixel electrode is 1: 1 with the area ratio of this second pixel electrode.

3. dot structure as claimed in claim 1 is characterized in that, this first pixel electrode is 1: 2 with the area ratio of this second pixel electrode.

4. dot structure as claimed in claim 1 is characterized in that, this second thin film transistor (TFT) of this first film transistor AND gate has a shared source electrode.

5. dot structure as claimed in claim 1 is characterized in that, this first pixel electrode and this second pixel electrode lay respectively at the both sides of this sweep trace.

6. dot structure as claimed in claim 1 is characterized in that, also comprises a common line, is disposed at this first pixel electrode and this second pixel electrode below.

7. dot structure as claimed in claim 1 is characterized in that, those orientation members comprise protrusion or slit.