1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) panel, and more particularly, to an LCD panel comprising tri-gate pixels having a high aperture ratio.
2. Description of the Prior Art
A thin flat display is widely used in current consumer electronic products. Liquid crystal displays (LCDs) which are colorful monitors with high resolution are widely used in various electronic products such as monitors for mobile phones, personal digital assistants (PDAs), digital cameras, laptop computers, and notebook computers.
The pixel structure of the TFT-LCD device may generally be categorized into two types; single-gate pixel structure and tri-gate pixel structure. When displaying images with the resolution of n×m pixels, the TFT-LCD device having the tri-gate pixel structure includes 3×m gate lines and n data lines, whereas the TFT-LCD device having a single-gate pixel structure comprises m gate lines and 3×n data lines. In other words, under identical resolution, the number of gate lines of the TFT-LCD device having the tri-gate pixel structure is triple to that of the TFT-LCD device having the single-gate pixel structure; however the number of scan lines of the TFT-LCD device having the tri-gate pixel structure is only one-third of that of the TFT-LCD device having the single-gate pixel structure. Therefore the conventional TFT-LCD device having the tri-gate pixel structure, compare to the single-gate pixel structure, employs more gate drivers but less source drivers. Since the cost and power consumption of the gate driver is less than that of the source driver, utilizing the TFT-LCD device having the tri-gate pixel structure is more advantageous due to the relatively low cost and low power consumption.
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In the conventional technology, the gate of the TFT 102, the shielding metallic areas 110, and the scan line 104 all are formed by a first metallic layer, while the source and drain of the TFT 102, the data line 106, and the common electrode line 108 all are formed by a second metallic layer. The TFT 102, the shielding metallic areas 110, the scan line 104, the data line 106, and the common electrode line 108 are defined as the opaque area of the subpixel 100. The aperture ratio of the subpixel 100 is defined as the ratio of a light-permeable area to the total subpixel 100 (including the opaque area). The subpixel 100 aperture ratio directly affects the utilization of backlight sources and the brightness of the LCD panel. The large subpixel 100 aperture ratio provides the LCD panel with a high brightness and a high contrast ratio, and vice versa. In other words, in order to increase the subpixel 100 aperture ratio, the opaque area has to be decreased as more as possible and the total pixel area has to be minimalized. The smaller the TFT 102 (or the thinner the scan line 104 and the data line 106) is, the higher the subpixel 100 aperture ratio is.
However, the width W1 of the scan line 104 is generally larger than the width W2 of the data line 106 due to the restriction of manufacturing processes. Also, a specific distance d1 needs to be spared between each of the shielding metallic areas 110 and the scan line 104 since the shielding metallic area 110 and the scan line 104 are formed by the same metallic layer. The two reasons cause the aperture ratio to be lowered.
Although the LCD panel having the tri-gate pixels has advantages of low cost and low power consumption, the low pixel aperture ratio has room to be improved.
Therefore, an object of the present invention is to provide an LCD panel having a high pixel aperture ratio for solving problems occurring in the conventional technology.
The present invention proposes a liquid crystal display (LCD) panel, comprising a plurality of pixels, a plurality of rows of scan lines parallel to one another and arranged along a first direction, and a plurality of columns of data lines parallel to one another and arranged along a second direction. The second direction is perpendicular to the first direction. The plurality of rows of scan lines are formed by a first metallic layer for transmitting scan signals. The plurality of columns of data lines are formed by a second metallic layer for transmitting data signals. Each of the plurality of pixels comprises a plurality of subpixels. Each of the plurality of subpixels comprises: a pixel electrode, formed by a transparent conducting layer; a thin-film transistor (TFT), connected to the pixel electrode, the scan line, and the data line; and a common electrode line, comprising a main branch, a first shielding metallic area, and a second shielding metallic area, the first and second shielding metallic areas being parallel to the plurality of scan lines and being connected to the main branch, and the common electrode line formed by the second metallic layer. An insulating layer is disposed between the first and second metallic layers. Two vias are defined on the insulating layer, and the transparent conducting layer is positioned on the two vias and on the first metallic layer, so that two main branches of common electrode lines corresponding to two subpixels which are on two sides of one of the data lines and are connected to one of the scan lines are electrically connected to each other through the transparent conducting layer and the first metallic layer.
The present invention also proposes a liquid crystal display (LCD) panel, comprising a plurality of pixels, a plurality of rows of scan lines parallel to one another and arranged along a first direction, and a plurality of columns of data lines parallel to one another and arranged along a second direction. The second direction is perpendicular to the first direction. The plurality of rows of scan lines are formed by a first metallic layer for transmitting scan signals. The plurality of columns of data lines are formed by a second metallic layer for transmitting data signals. Each of the plurality of pixels comprises a plurality of subpixels. Each of the plurality of subpixels comprises: a pixel electrode, formed by a transparent conducting layer; a thin-film transistor (TFT), connected to the pixel electrode, the scan line, and the data line; and a common electrode line, comprising a main branch, a first shielding metallic area, and a second shielding metallic area, the first and second shielding metallic areas being parallel to the plurality of scan lines and being connected to the main branch, and the common electrode line formed by the second metallic layer.
According to present invention, the main branch of the common electrode line appears cruciform.
According to present invention, the LCD panel further comprises an insulating layer disposed between the first and second metallic layers.
According to present invention, two common electrode lines which correspond to two of the plurality of subpixels, are disposed at two sides of one of the data lines, and are connected to one of the scan lines are electrically connected to each other.
According to present invention, the LCD panel further comprises two vias penetrating the insulating layer, and the transparent conducting layer is positioned on the two vias and on the first metallic layer, causing the two common electrode lines to be electrically connected to each other through the transparent conducting layer and the first metallic layer.
According to present invention, the first shielding metallic area of one of the two common electrode lines is electrically connected to the first shielding metallic area of the other, or the second shielding metallic area of one of the two common electrode lines is electrically connected to the second shielding metallic area of the other through the transparent conducting layer and the first metallic layer.
According to present invention, each pixel comprises a red subpixel, a green subpixel, and a blue subpixel.
According to present invention, the transparent conducting layer is made of indium tin oxide.
The present invention also proposes a method of manufacturing an LCD panel. The method comprises:
providing a glass substrate;
forming a first metallic layer on the glass substrate;
etching the first metallic layer for forming a gate of a TFT and a scan line;
forming an insulating layer on a gate of the TFT and on the scan line;
forming a passage of the TFT on the insulating layer; and
forming and etching a second metallic layer for forming a source and a drain of the TFT, a common electrode line, and a data line wherein the common electrode line comprises a main branch, a first shielding metallic area, and a second shielding metallic area, and the first and second shielding metallic areas are parallel to the scan line and are connected to the main branch.
According to present invention, the method further comprises:
forming a passivation layer on the data line, the common electrode line, and on the source and drain of the TFT;
etching a via on the passivation layer under the common electrode line; and forming a transparent conducting layer on the via and on the first metallic layer, causing the common electrode line to be electrically connected to the first metallic layer through the transparent conducting layer.
According to present invention, the method further comprises:
etching the passivation layer on the drain for forming a hole while etching the passivation layer under the common electrode line for forming the via; and
forming the transparent conducting layer on the hole for producing a pixel electrode while forming the transparent conducting layer on the via and on the first metallic layer.
In contrast to the conventional technology, the present invention provides an LCD panel and a method of manufacturing the same. The LCD panel has a scan line formed by a first metallic layer and a data line and a common electrode line formed by a second metallic layer. The scan line and the common electrode line are formed after the first and second metallic layers undergo different etching processes, causing the distance between the scan line and the common electrode line to be shortened and the width of the common electrode line serving as a shielding metallic area partially to be properly decreased. Accordingly, the pixel aperture ratio is increased.
These and other features, aspects and advantages of the present disclosure will become understood with reference to the following description, appended claims and accompanying figures.
Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, electronic equipment manufacturers may refer to a component by different names. This documents does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . . ” Also, the term “electrically connect” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.
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A common electrode line 48 positioned on the glass substrate 32 crosses and partially overlaps the scan line 40. A storage capacitor is formed by the overlapping area of the common electrode line 48 and the pixel electrode 58. The common electrode line 48 and the scan line 40 are formed on two different metallic layers. An insulating layer (not shown) is disposed between the two metallic layers for preventing the metallic layers from being electrically connected directly. So the common electrode line 48 and the scan line 40 can be placed in different directions. The common electrode line 48 can also cross the scan line 40. For example, the scan line 40 extends along the longer side (the first direction) of the subpixels 20S, and the common electrode line 48 extends along the shorter side (the second direction) and penetrates the subpixels 20S. Thus, the area that the common electrode line 48 occupies in the display zone is reduced, causing the shielding area to be reduced, increasing the pixel aperture ratio. The common electrode line 48 and the data line 42 can be formed by the same conducting pattern such as the second metallic layer, or the common electrode line 48 can be formed by another conducting layer in this embodiment.
The common electrode line 48 comprises a main branch 480, a first shielding metallic area 481, and a second shielding metallic area 482. The first and second shielding metallic areas 481 and 482 are parallel to a plurality of rows of scan lines 40 and are connected to the main branch 480. A plurality of columns of data lines 42 and the common electrode line 48 are formed by the second metallic layer. The main branch 480 appears cruciform and is subdivided into first and second extensions 4801 and 4802. The first extension 4801 is perpendicular to the second extension 4802. The second extension 4802 crosses the first and second shielding metallic areas 481 and 482 vertically. The second extension 4802 disposed along the second direction passes through the subpixels 20S in the same column so that the common electrode lines 48 in the same column are electrically connected.
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In sum, the scan line 40 on the LCD panel is formed by the first metallic layer, and the data line 42 and the common electrode line 48 are formed by the second metallic layer. For the LCD panel having the tri-gate pixels, since the scan line 40 and the common electrode line 48 are formed when different metallic layers undergo different etching processes, the distance d2 between the scan line 40 and the common electrode line 48 can be shortened. Moreover, the width W3 of the common electrode line 48 which partially serves as the first and second shielding metallic areas 481 and 482 can be properly decreased. So the pixel aperture ratio can be increased.
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While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.
Number | Date | Country | Kind |
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201110318252.5 | Oct 2011 | CN | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN2011/081093 | 10/21/2011 | WO | 00 | 12/6/2011 |