JPH11352520A - Active drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active drive device in which opening ratios of pixels are high and a high-density mounting is possible and satisfactory yield is to be obtained. SOLUTION: This device is provided with plural pairs of two line pairs of gate lines, and pixel electrodes 13 forming a train are arranged between gate lines 12n A, 12n B forming pairs. Gate electrodes 12G and storage capacitance electrode parts 12C are formed, so as to be alternately projected toward pixel electrodes forming the train from the gate lines 12n A, and the storage capacitance electrode parts 12C and the gate electrodes 12G are alternately formed so as to become alternate with those of the gate lines 12n A from the gate lines 12n B on the other sides. Drain lines 15 are formed at rate of one line with respect to pixel electrodes 13 of adjacent two rows. A signal voltage is impressed on the pixel electrodes 13 of both sides of the drain lines 15 with different timings. Since an area occupied by signal lines is reduced by half in this manner, numerical apertures of pixels can be enhanced by an amount equivalent to the reduced area, and moreover, manufacturing yield is enhanced by reducing the number of lines of the signal lines and the mounting of driver ICs is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active driver, and more particularly, to an active driver using a thin film transistor (hereinafter, referred to as a TFT) as an active element.

[0002]

2. Description of the Related Art A conventional active drive device is used for a display device such as a liquid crystal display panel, and has a structure as shown in FIG. FIG. 4 is a plan view of a main part of a so-called TFT substrate on which TFTs, pixel electrodes, and the like are formed. The liquid crystal display panel is configured by sealing liquid crystal between a TFT substrate and a common substrate facing each other. In the TFT substrate, a gate line 1G as a scanning line and an auxiliary capacitance electrode 1C are formed on a transparent substrate made of, for example, glass so as to form a predetermined pattern by etching the same metal film. An insulating film is formed on the entire surface of the display region in which the gate line 1G and the auxiliary capacitance electrode 1C are formed, and the pixel electrode 2 is formed on the insulating film so as to form a matrix by ITO (indium tin oxide) or In ₂ O _3. (Z
nO) _m (where m> 0). The pixel electrode 2 is disposed so as to overlap the auxiliary capacitance electrode 1C on three sides. At a predetermined position of the gate line 1G, a semiconductor layer 3 is formed via a gate insulating film, and a source electrode 4 connected to the pixel electrode 2 on the semiconductor layer 3 and a drain electrode connected to a drain line 5 as a signal line. 5D are formed, and the TFT 6 is formed. FIG. 5 shows an equivalent circuit of such a conventional liquid crystal display device. As shown in FIG. 1, in the conventional active driving device, the gate line 1 is used as a component per pixel.
G, drain line 5, TFT6, liquid crystal pixel capacitance CL,
There is an auxiliary capacitance Cs, a common electrode 7, and an auxiliary capacitance electrode 1C.

[0003]

However, in such a conventional active drive device, as described above, one of
Since the pixel has a gate line 1G, a drain line 5, a TFT 6, a liquid crystal pixel capacitance CL, an auxiliary capacitance Cs, a common electrode 7, and an auxiliary capacitance electrode 1C overlapping three sides of the pixel electrode 2, higher definition is achieved. When an attempt is made to achieve a high aperture ratio with a (narrow pitch), there are restrictions such as the minimum size and the minimum interval of each pattern. In addition, since there are a large number of various wirings in a TFT substrate, there is a problem that it is difficult to secure a yield and to perform high-density mounting when a higher definition is promoted.

An object of the present invention is to provide an active drive device having a high aperture ratio of pixels, enabling high-density mounting, and having a good yield.

[0005]

According to the first aspect of the present invention,
An active drive device, wherein a plurality of pixel electrodes are arranged on a substrate, and switching elements connected to the corresponding pixel electrodes are arranged at intersections of each scanning line and each signal line, wherein the scanning line A plurality of pairs are formed in parallel with one pair of two parallel lines, and a plurality of pairs are formed between the two paired scanning lines in a row along the extending direction of the scanning lines. Are arranged, and each of the signal lines is adjacent to each other in an extending direction of the scanning line.
It is characterized by being connected to two pixel electrodes.

According to the first aspect of the present invention, the signal line is formed at a ratio of one to two adjacent pixel electrodes in a column, that is, for two rows of the arranged pixel electrodes. Since only one signal line is required, the area occupied by the signal line can be reduced by half. Therefore, the aperture ratio of the pixel can be improved by the reduced area. Further, by reducing the number of signal lines, the manufacturing yield can be improved, and the mounting of the driver IC can be facilitated.

According to a second aspect of the present invention, in the active driving device according to the first aspect, the scanning line is a gate line, the signal line is a source line or a drain line, and the switching element is a thin film transistor. It is characterized by having.

According to a third aspect of the present invention, in the active driving device according to the second aspect, the paired gate lines are connected to one of the gate lines for each of the pixel electrodes sandwiched between the two gate lines. A gate electrode is formed, and a storage capacitor electrode portion that partially overlaps with the pixel electrode via an insulating film is formed on the other gate line, and the gate electrode and the gate electrode are arranged along a column of the pixel electrode at each gate line. The storage capacitor electrode portion is formed alternately.

According to the third aspect of the invention, when attention is paid to one pixel electrode, one of the paired gate lines functions as a storage capacitor electrode portion, and the other functions as a gate electrode.

According to a fourth aspect of the present invention, there is provided the active driving device according to any one of the first to third aspects, wherein the signal line is connected to the switching elements located on both sides of the signal line. And the signal voltage is applied in a time division manner.

According to the fourth aspect of the present invention, in addition to the above-described operation, all the pixel electrodes required for display are displayed by dividing the signal voltage applied to the signal lines even though the signal lines are halved. It is possible to do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of an active drive device according to the present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a plan view of a main part showing an active driving device according to an embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of a liquid crystal display panel using the active driving device of the present embodiment as a TFT substrate. FIG. 3A is a comparison between a driving timing chart of the conventional liquid crystal display panel and FIG. 3B is a comparison between a driving timing chart of the liquid crystal display panel of the present embodiment. The structure of the liquid crystal display panel on the side of the common substrate facing the TFT substrate has the same configuration as that of the related art, and a description thereof will be omitted.

The configuration on the TFT substrate side will be described with reference to FIG. On a TFT substrate 11 made of glass, a plurality of pairs of gate lines 12 _nA and 12 _nB (n is a natural number) which are parallel to each other are formed in parallel with each other. As shown in the figure, an adjacent gate line 12 _{(n-1) B} and a gate line 12 _nA of a pair of adjacent gate lines are formed close to each other. These gate lines are TFT
The conductive film formed on the substrate 11 is formed at the same time by using photolithography technology. These gate lines are covered with a gate insulating film (not shown).

A substantially rectangular pixel electrode 13 made of transparent ITO is arranged between each pair of gate lines so as to form a line along the direction in which the gate lines extend. I have. From each pair of gate lines, a gate electrode 12G and a storage capacitor electrode portion 12C are formed so as to alternately project toward a pixel electrode 13 forming a column sandwiched between these lines. When focusing on the electrode 13, as shown in FIG. 1, when the gate electrode 12G protrudes from one of the gate lines 12 _nA forming the pair, the storage capacitor electrode section 12C is formed from the other gate line 12 _nB. If the storage capacitor electrode portion 12C protrudes from the one gate line 12 _nA and conversely, if the storage capacitor electrode portion 12C protrudes from the other gate line 12 _{nA, the} gate electrode 12G will protrude from the other gate line 12 _nB.
Are projected. Note that the storage capacitor electrode unit 1
2C is formed so as to overlap with an edge of one side of the pixel electrode 13 close to the gate line to which it belongs via an insulating film.

Further, a plurality of drain lines 15 as signal lines are formed in a direction intersecting with the gate lines. In particular, in the present embodiment, the drain line 15
Drain electrodes 15D, 15D protruding to be connected to the drain regions of the semiconductor layer 14 corresponding to the two pixel electrodes 13 on the same column located on both sides of the pixel column are formed for each pixel column. For this reason, the drain line 15 is arranged and formed at a ratio of one to two pixel electrodes 13 arranged in the column direction. The source region of each semiconductor layer 14 has a pixel electrode 13 corresponding to each semiconductor layer 14.
Is connected to the source electrode 16. As a result, the gate electrode 12G, a gate insulating film (not shown),
Semiconductor layer 14, source electrode 16, and drain electrode 15
D constitutes a TFT 17 as a switching element of each pixel electrode 13.

Although the structure on the TFT substrate 11 side has been described above, the structure on the common substrate side is the same as that of the related art. An alignment film is formed on the opposing surfaces of both substrates, and the two substrates are interposed with a sealant therebetween. The liquid crystal display panel of the present embodiment is configured by sealing the liquid crystal by bonding together. Further, in the liquid crystal display panel of the present embodiment, a color filter, a polarizing plate, and the like are appropriately arranged.

FIG. 2 is an equivalent circuit diagram of the liquid crystal display panel of the present embodiment. In the figure, reference numeral 18 denotes a common electrode (V _COM ) on the common substrate side, 19 denotes a liquid crystal pixel capacitance (C _LC ), 20
Indicates a storage capacity (C _S ). As shown in the figure,
This embodiment has a structure in which one drain line 15 is shared by pixels on both sides. In addition, the storage capacity 20 corresponds to FIG.
As shown in FIG. 3, the storage capacitor electrode portion 12C formed on the adjacent gate line, the gate insulating film, and the storage capacitor electrode portion 12C
And a gate electrode 13 overlapping the gate electrode 13.

Next, a driving method of the liquid crystal display panel of the present embodiment will be described in comparison with a conventional driving method of the liquid crystal display panel, using a timing chart shown in FIG. First, in the conventional liquid crystal display panel having the configuration shown in FIG. 5, when a certain gate line and a certain drain line are selected, there is only one combination. Therefore, as shown in FIG. Scanning is performed in a time-division manner as in the case of the matrix. The data signal voltage is applied to the drain line group corresponding to the gate line selected in synchronization with the scanning timing. In the present embodiment, since the same source line 15 is used to write data to the pixels on both sides, as shown in FIG. 3B, the drain line is driven by time division. That is, during the period from the rise to the fall of the data signal of the drain line 5 corresponding to the conventional gate line 1G _(n-1) , the signal of the gate line 12 _{(n-1) A} and the gate line 12 _{(n -1)} Two signals of _B are sequentially raised, and a signal voltage corresponding to the driving state of the pixel is input to the drain line 15 at each of these timings. The same driving operation is performed on the next pair of gate lines 12 _nA and 12 _nB .
In this way, by sequentially scanning a pair of gate lines and applying a voltage according to the driving state of each pixel to all drain lines at the timing at this time, all necessary pixels are displayed. It is possible to do. In this manner, one frame is displayed, and a moving image can be displayed by repeating the display.

In the present embodiment, by adopting such a driving method, only one drain line 15 is required for two pixels in the same column, and the number of drain lines can be reduced to half of the conventional one. Further, since it is not necessary to provide an auxiliary capacitance electrode line as in the related art, the reduced area can be allocated to the pixel opening, and the wiring density when the pixel area is reduced can be reduced. For this reason, in the present embodiment, there is an advantage that the aperture ratio of the liquid crystal display panel can be increased, and a decrease in the aperture ratio particularly when the definition is increased can be suppressed. Also, by reducing the number of the drain lines 15 by half, the number of connections between the drain driver and the pixel can be reduced by half, and there are advantages such as improvement in manufacturing yield and high-density mounting.

Although the embodiments have been described above, the present invention is not limited to these embodiments, and various changes accompanying the gist of the configuration are possible.

[0021]

As is apparent from the above description, according to the present invention, there is an effect that an aperture ratio of a pixel can be improved and an active driving device capable of performing high-definition display can be realized. Further, since the number of electrode wirings can be significantly reduced, the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a main part plan view showing an embodiment of an active drive device according to the present invention.

FIG. 2 is an equivalent circuit diagram of a liquid crystal display panel using the active driving device of the embodiment.

3A is a timing chart showing a driving waveform of a conventional liquid crystal display panel, and FIG. 3B is a timing chart showing a driving waveform of a liquid crystal display panel of the present embodiment.

FIG. 4 is a plan view of a main part of a conventional active drive device.

FIG. 5 is an equivalent circuit diagram of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 TFT substrate 12 Gate line 12G Gate electrode 12C Storage capacitor electrode part 13 Pixel electrode 15 Drain line 17 TFT

Claims (4)

[Claims] 1. An active driving device comprising: a plurality of pixel electrodes arranged on a substrate; and switching elements connected to the corresponding pixel electrodes arranged at intersections of each scanning line and each signal line. A plurality of pairs of the scanning lines are formed in parallel with one pair of the two parallel lines, and between the two pairs of the scanning lines, along the extending direction of the scanning lines. A plurality of the pixel electrodes forming one column are arranged, and each of the signal lines is
An active driving device, wherein the active driving device is connected to two pixel electrodes adjacent to each other in the direction in which the scanning lines extend. 2. The active driving device according to claim 1, wherein the scanning line is a gate line, the signal line is a source line or a drain line, and the switching element is a thin film transistor. 3. A pair of the gate lines, wherein, for each of the pixel electrodes sandwiched between the two gate lines, a gate electrode is formed on one of the gate lines and the pixel electrode and an insulating film are formed on the other of the gate lines. A storage capacitor electrode portion that partially overlaps with the gate electrode, and the gate electrode and the storage capacitor electrode portion are alternately formed along the columns of the pixel electrodes in each gate line. The active drive device according to claim 2. 4. The signal line according to claim 1, wherein a signal voltage is applied to the switching elements located on both sides of the signal line in a time division manner. An active drive as described.