JP2007094024A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which is made free from crosstalk and flicker without increasing the scale of the device nor increasing a cost. <P>SOLUTION: The liquid crystal display device includes; a plurality of scan electrodes 8 and a plurality of signal electrodes 9 arranged like a matrix on a first insulating substrate and a plurality of pixel electrodes 10 disposed near intersections between the scan electrodes 8 and the signal electrodes 9; switching elements 11 connected to respective scan electrodes 8, respective signal electrodes 9, and respective pixel electrodes 10; a plurality of first common electrodes C1 to C220 disposed on the first insulating substrate; auxiliary capacitors 12 connected between respective pixel electrodes 10 and respective first common electrodes C1 to C220; and a second common electrode 13 which is connected to respective first common electrodes C1 to C220 and has a common voltage applied thereto and is made into a closed circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device.

Conventionally, this type of apparatus is disclosed in, for example, Patent Document 1 (see FIG. 4). In FIG. 4, a plurality of scanning electrodes 1 and a plurality of signal electrodes 2 and a plurality of pixel electrodes 10 located in the vicinity of their intersections are arranged. A TFT 5 connected to each scanning electrode 1, each signal electrode 2, and each pixel electrode 10 is provided. Each auxiliary capacitor 13 connected between the plurality of common electrodes 6 and each pixel electrode 6 is provided.
JP 2003-162265 A

  The above apparatus has a drawback that crosstalk and flicker are likely to occur. As a result of investigation by the inventor of the present invention, it was found that the voltage applied to each auxiliary capacitor 13 connected to each common electrode 6 is not constant and varies. As a result, it was found that the characteristics of the voltage applied to each pixel electrode after the gate pulse applied to each scan electrode 1 rises, so that crosstalk and flicker are likely to occur.

  In the first place, in order to achieve high definition, the gap between the pixels 30 cannot be increased, so the width of the common electrode 6 must be narrowed to 10 to 20 μm. Therefore, the voltage drop in the vicinity of the tip of the common electrode 6 is large.

  Therefore, the present invention provides a liquid crystal display device in which crosstalk and flicker are eliminated without increasing the size of the device and without significantly increasing the cost in consideration of the conventional drawbacks.

  In order to solve the above-mentioned problem, the present invention of claim 1 includes a first insulating substrate, a second insulating substrate, and a liquid crystal provided between the two substrates, and the matrix is formed on the first insulating substrate. A plurality of scanning electrodes and a plurality of signal electrodes disposed in the plurality of pixel electrodes, a plurality of pixel electrodes disposed near intersections of the scanning electrodes and the signal electrodes, and each scanning electrode, each signal electrode, and each pixel electrode. Each switching element, a plurality of first common electrodes disposed on the first insulating substrate, each auxiliary capacitor connected between each pixel electrode and each first common electrode, and each first common electrode And a second common electrode which is supplied with a common voltage and is a closed circuit.

  According to a second aspect of the present invention, a third common circuit is disposed on the first insulating substrate so as to be separated from the second common electrode, connected to each first common electrode and supplied with the common voltage, thereby forming a closed circuit. An electrode was provided.

  In the present invention of claim 3, the second common electrode and the third common electrode are electrically connected.

  In a fourth aspect of the present invention, a common electrode is disposed on the back surface of the second insulating substrate, and the first common electrode and / or the second common electrode and / or the third common electrode are electrically connected to the common electrode. Connected.

  In this invention of Claim 5, each width | variety of a said 2nd common electrode and a said 3rd common electrode is 100 micrometers-500 micrometers.

  As in claim 1, by providing a second common electrode connected to each first common electrode, supplied with a common voltage, and having a closed circuit, a voltage drop at each portion of each first common electrode is reduced. . As a result, the applied voltage of each auxiliary capacitor connected to each first common electrode becomes substantially constant, and the occurrence of crosstalk and flicker can be prevented.

  As in claim 2, in addition to the structure of claim 1, the third common electrode is located apart from the second common electrode, connected to each first common electrode, supplied with a common voltage, and closed circuit By providing the voltage drop, the voltage drop at each portion of each first common electrode is further reduced. As a result, the applied voltage of each auxiliary capacitor connected to each first common electrode becomes substantially constant, and the occurrence of crosstalk and flicker can be prevented.

  As in the third aspect, by electrically connecting the second common electrode and the third common electrode, the voltage drop at each portion of each first common electrode is further reduced.

  The voltage is supplied to the common electrode by electrically connecting the first common electrode and / or the second common electrode and / or the third common electrode to the common electrode of the second insulating substrate. There is no need to provide a new means for doing this.

  As in the fifth aspect, by setting the widths of the second common electrode and the third common electrode to 100 μm to 500 μm, the voltage drop at each portion of each first common electrode can be further reduced. Further, it is not necessary to increase the cost without enlarging the apparatus.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples and drawings. The following embodiments exemplify an example of a liquid crystal display device for embodying the technical idea of the present invention. The present invention can be equally applied to various modifications without departing from the technical idea shown in the claims.

  Hereinafter, the liquid crystal display device 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is an electric circuit diagram of the liquid crystal display device 1. FIG. 2 is a detailed view of part A of FIG. 1 and is a plan view of a wiring pattern. 3 is a cross-sectional view taken along the line BB in FIG. 2, and is a partial cross-sectional view of the liquid crystal display device 1.

  In FIG. 3, the liquid crystal display device 1 includes a first insulating substrate 2, a second insulating substrate 3, and a liquid crystal 4 provided between the substrates 2 and 3. The first insulating substrate 2 and the second insulating substrate 3 are made of, for example, a glass plate.

  A color filter layer 5, a protective layer 6, a common electrode 7, and the like are sequentially formed on the back surface of the second insulating substrate 3. The color filter layer 5 is, for example, one in which R, G, B filters are repeatedly arranged in order in a stripe shape.

  In FIG. 1, a plurality of scanning electrodes 8 and a plurality of signal electrodes 9 are formed in a matrix on the first insulating substrate 2.

  The signal electrodes 9 are indicated by s1, s2,... S527, s528 in order from the top of FIG. The scanning electrodes 8 are indicated by g1,... G110, g220,.

  The plurality of pixel electrodes 10 are arranged in the vicinity of the intersections of the scanning electrodes 8 and the signal electrodes 9. Each switching element 11 is connected to each scanning electrode 8, each signal electrode 9, and each pixel electrode 10.

  Each switching element 11 includes, for example, a TFT (Thin Film Transistor). The source of each switching element 11 is connected to each signal electrode 9. The gate of each switching element 11 is connected to each scanning electrode 8. The drain of each switching element 11 is connected to each pixel electrode 10.

The plurality of first common electrodes C1, ... C110, C220, ... C111 are arranged on the first insulating substrate 2. Each of the first common electrodes C1,... C110, C220,... C111 is disposed adjacent to the scanning electrodes g1,.

  Each auxiliary capacitor 12 is connected between each pixel electrode 10 and each first common electrode C1 to C220.

  That is, as shown in FIG. 2, the first common electrode C <b> 220 is formed on the first insulating substrate 2. An insulating film (not shown) is partially formed on the first common electrode C220.

  The pixel electrode 10 is formed on this insulating film and on the first insulating substrate 2. The first common electrode C220, the insulating film, and the pixel electrode 10 form an auxiliary capacitor 12.

  The second common electrode 13 is formed on the first insulating substrate 2, connected to the first common electrodes C1 to C220, and configured as a closed circuit.

  The second common electrode 13 is supplied with a common voltage (for example, DC 5 volts) via the input terminals 14, 15, and 16.

  The second common electrode 13 is made of, for example, aluminum. The second common electrode 13 is formed on the first insulating substrate 2 with a thickness of 2000 angstroms and a width of 100 μm to 500 μm, for example.

  When the width of the second common electrode 13 is 100 μm or more, the voltage drop in the first common electrodes C1 to C220 is reduced, so that the occurrence of crosstalk and flicker can be prevented to the extent that there is no practical problem.

  Further, even if the width of the second common electrode 13 exceeds 500 μm, the voltage drop value does not change from that when the width is 500 μm. Accordingly, the second common electrode 13 preferably has a width of 100 μm to 500 μm.

  The third common electrode 17 is disposed on the first insulating substrate 2 away from the second common electrode 13. For example, the second common electrode 13 is disposed near one side of the first insulating substrate 2. The third common electrode 17 is disposed in the vicinity of the other side of the first insulating substrate 2 at a position facing the one side.

  The third common electrode 17 is connected to each of the first common electrodes C1 to C220 and is configured as a closed circuit.

  The third common electrode 17 is supplied with a common voltage (for example, DC 5 volts) via the input terminal 18.

  The third common electrode 17 is made of, for example, aluminum. The third common electrode 17 is formed on the first insulating substrate 2 with, for example, a thickness of 2000 angstroms and a width of 100 μm to 500 μm.

  The reason why the width of the third common electrode 17 is preferably 100 μm to 500 μm is the same as that of the second common electrode 13.

  The connection portion 19 is for electrically connecting the second common electrode 13 and the third common electrode 17. The connecting portion 19 is formed of aluminum having a thickness of 2000 angstroms and a width of 100 μm to 500 μm on an insulating substrate (not shown) in the IC 20.

  The first common electrodes C <b> 1 to C <b> 220 and / or the second common electrode 13 and / or the third common electrode 17 are electrically connected to the common electrode 7 provided on the back surface of the second insulating substrate 3.

  The output terminals GD1 to G110 of the scanning line driving unit 43 constituting the IC 20 are connected to the scanning electrodes 23 and g1 to g110, and drive the scanning electrodes 23 and g1 to g110, respectively.

  The output terminals GD3 to G220 of the scanning line driving unit 44 constituting the IC 20 are connected to the scanning electrodes 22, g111 to g220, and drive the scanning electrodes 22, g111 to g220, respectively.

  The output terminals S1 to S528 of the signal line driving unit 45 constituting the IC 20 are connected to the signal electrodes s1 to s528, and drive the signal electrodes s1 to s528, respectively.

  The features of the present invention are summarized below. The first feature includes a first insulating substrate 2, a second insulating substrate 3, and a liquid crystal 4 provided between the two substrates, and a plurality of scans arranged in a matrix on the first insulating substrate 2. An electrode 8 and a plurality of signal electrodes 9 and a plurality of pixel electrodes 10 disposed in the vicinity of the intersections of the scanning electrodes 8 and the signal electrodes 9 are provided. Each scanning electrode 8, each signal electrode 9, each switching element 11 connected to each pixel electrode 10, a plurality of first common electrodes C1 to C220 disposed on the first insulating substrate 2, and each pixel electrode 10 and the auxiliary capacitors 12 connected between the first common electrodes C1 to C220. And the 2nd common electrode 13 connected to each 1st common electrode C1-C220, a common voltage is supplied, and was used as the closed circuit is provided.

  The second feature is that a third circuit is arranged on the first insulating substrate 2 apart from the second common electrode 13 and connected to each of the first common electrodes C1 to C220, supplied with a common voltage, and a closed circuit. A common electrode 17 is provided.

  The third feature is a configuration in which the second common electrode 13 and the third common electrode 17 are electrically connected.

  A fourth feature is that the common electrode 7 is disposed on the back surface of the second insulating substrate 3, and the first common electrodes C <b> 1 to C <b> 220 and / or the second common electrode 13 and / or the third common electrode 17 are formed on the common electrode 7. It is an electrically connected configuration.

  A fifth feature is that each width of the second common electrode 13 and the third common electrode 17 is 100 μm to 500 μm. This completes the description of the features of the present invention.

  The common line 21 is formed on the left side of the scanning electrode g111. The column electrode 22 is formed on the left side of the common line 21.

  A column electrode 23 and common lines 24, 25, 26, 27, and 28 are sequentially formed on the right side of the first common electrode C1. The common lines 24 to 28 are connected between the second common electrode 13 and the third common electrode 17.

  Row electrodes 28, 29, and 30 are formed in order on the upper side of the signal electrode s1. Row electrodes 31, 32, and 33 are sequentially formed below the signal electrode s528.

  The switching element 11 is connected to each column electrode 22, g 111,... G 1, 23, each row electrode 29, 28, and each pixel electrode 10.

  Each auxiliary capacitor 12 is formed between each pixel electrode 10 and each common line 21, C111,.

  Similarly, the switching element 11 is connected to each column electrode 22, g 111,... G 1, 23, the row electrode 31, and each pixel electrode 10. Each auxiliary capacitor 12 is formed between each pixel electrode 10 and each common line 21, C111,.

  In this manner, the scanning electrodes g1 to g220, the signal electrodes s1 to s220, and the pixel 34 having each TFT connected to the pixel electrode 10 are effective display areas.

  Further, the pixel 35 having each TFT outside the pixel 34 is a non-display area. This non-display area is necessary for the display area to accurately display the input image data.

  The first protection diode 36 is connected between the column electrode 23 and the scan electrodes g <b> 1 to g <b> 110 and the row electrode 30. The first protection diode 36 allows a current generated by static electricity to flow from the scan electrodes g1 to g110 to the second common electrode 13 via the row electrode 30. Moreover, there is also a flow reverse to the above flow.

  The first protection diode 37 is connected between the column electrode 22 and the scan electrodes g111 to g220 and the row electrode 33. The first protection diode 37 allows a current generated by static electricity to flow from the scan electrodes g111 to g220 to the third common electrode 17 via the row electrode 33. Moreover, there is also a flow reverse to the above flow.

  The second protection diode 38 is connected between the row electrodes 29 and 28, the signal electrodes s 1 to s 528 and the row electrodes 31 and 32, and the common line 26. The second protection diode 38 allows a current generated by static electricity to flow from the signal electrodes s1 to s528 to the second common electrode 13 and the third common electrode 17 via the common line 26. Moreover, there is also a flow reverse to the above flow.

  An intersection 39 between the third common electrode 17 and the first common electrode C220 is shown in FIGS.

  In FIG. 2, the end of the first common electrode C220 located away from the auxiliary capacitor 12 is formed in the shape of six comb teeth.

  Further, the left end of the third common electrode 17 is formed in the shape of six comb teeth. The comb teeth of the first common electrode C220 and the comb teeth of the third common electrode 17 are electrically connected.

  An insulating layer 40 is provided on the comb teeth of the third common electrode 17. The insulating layer 40 is provided with two holes 41. An ITO layer 42 is provided so as to conduct the two holes 41.

It is an electric circuit diagram of the liquid crystal display device 1 which concerns on the Example of this invention. FIG. 2 is a detailed view of part A in FIG. 1. It is BB sectional drawing of FIG. It is an electric circuit diagram which shows the conventional liquid crystal display device.

Explanation of symbols

4 Liquid crystal 8 Scan electrode 9 Signal electrode 10 Pixel electrode 11 Switching element 12 Auxiliary capacitor 13 Second common electrode C1 to C220 First common electrode

Claims (5)

A plurality of scanning electrodes and a plurality of signal electrodes arranged in a matrix on the first insulating substrate, the first insulating substrate; a second insulating substrate; and a liquid crystal provided between the substrates. A plurality of pixel electrodes arranged in the vicinity of the intersection of the scanning electrode and the signal electrode, each scanning electrode, each signal electrode, each switching element connected to each pixel electrode, and each arranged on the first insulating substrate A plurality of first common electrodes, each auxiliary capacitor connected between each pixel electrode and each first common electrode, each connected to each first common electrode, supplied with a common voltage, and closed circuit A liquid crystal display device comprising two common electrodes. A third common electrode is provided on the first insulating substrate, spaced apart from the second common electrode, connected to each first common electrode, supplied with the common voltage, and closed circuit. The liquid crystal display device according to claim 1. 3. The liquid crystal display device according to claim 2, wherein the second common electrode and the third common electrode are electrically connected. A common electrode is disposed on a back surface of the second insulating substrate, and the first common electrode and / or the second common electrode and / or the third common electrode are electrically connected to the common electrode. The liquid crystal display device according to claim 2 or 3. 3. The liquid crystal display device according to claim 2, wherein each width of the second common electrode and the third common electrode is 100 μm to 500 μm.

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