JPH0481887A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To maintain the color tones of a display screen always constant by providing transparent electrodes (dummy electrodes) which face also regions exclusive of an image display region and providing a circuit for impressing voltages for non-selection of X electrodes at the transparent electrodes exclusive of the image display region. CONSTITUTION:The dummy electrodes 10 are provided between display electrodes 3 and sealing parts 8. The dummy electrodes 10 are provided at points exclusive of the display electrode side and a display surface 11 on the scanning electrode side. The voltage V 7 alternately switched from the liquid crystal driving voltages V 6 and V 5 on the scanning side is impressed thereto by the driving circuit. The polarities of the AC signal M are so matched as to have the same phase as the phase of the scanning electrodes. The dummy electrodes 10 are disposed to face the scanning electrodes 4 and display electrodes 3. The voltages are selectively impressed to the electrodes 10 in such a manner that the liquid crystal is not put into a lighting state regardless of whether the impressed voltage of the electrodes facing the electrodes 10 is selection or non-selection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a liquid crystal display device, and particularly to a liquid crystal display device that can always provide a display screen with a uniform color tone.

[Prior art] A conventional liquid crystal display element is, for example, disclosed in Utility Model No. 59-1562.
As described in No. 251, it had a configuration as roughly shown in FIG. That is, upper substrate 1, lower substrate 2
, a display electrode 3, a scanning electrode 4, an alignment film 5, a liquid crystal layer 6, a liquid crystal layer spacer 7, a seal g (I8, a seal part spacer 9, etc.). The electrode 4) was present, but the other electrode (for example, the display electrode 3) was not present, and the structure was such that there were regions where the electrodes faced each other (overlapping) and were not present.

[Problems to be Solved by the Invention] In the conventional technology, as described above, one side of the electrode remains in the area other than the image display area,
For this reason, as shown in FIG. 4, at the boundary between the area where the display electrode 3 is present and the area where it is not, glass is dispersed in the liquid crystal in order to keep the distance between the upper and lower substrate electrodes constant. The liquid crystal layer spacer 7, such as beads or plastic beads, does not work effectively, and the distance between the upper and lower substrate electrodes becomes narrower, and the threshold voltage in this area decreases. At a low driving voltage, it will exhibit the same contrast characteristics as the central portion. This means that the center and periphery of the display screen are normally driven with the same drive voltage, which results in lower contrast at the periphery of the screen than in the center, and the difference between the center and periphery. There was a problem that the display color tone changed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device that can always maintain a constant color tone on a display screen by solving the problems of the prior art described above.

[Means for Solving the Problems] The above object is to provide a liquid crystal display device in which a liquid crystal is sealed between two transparent electrode substrates in which x and Y stripe electrical contacts are arranged facing each other. This can be achieved by providing a liquid crystal display device in which transparent electrodes (dummy electrodes) are also provided facing the regions, and a circuit is provided for applying an X electrode non-selection voltage to the transparent electrodes in regions other than the image display region.

[Function] With the liquid crystal display device having the above configuration, the transparent stacks are arranged vertically facing each other in all the parts where the liquid crystal is sealed, so that the space between the upper and lower electrode substrates is made constant. The spacer effectively acts to maintain the constant spacing, and since a non-selective voltage is always applied to the electrodes outside the display area, the color tone is modulated regardless of the display screen. You can get a uniform screen with no color tone.

[Example] Hereinafter, the liquid crystal display device of the present invention will be specifically explained using Examples.

FIG. 1 is a schematic partial cross-sectional view showing the structure of the end portion of the liquid crystal display device of the present invention, and shows that a dummy electrode 10 is provided between the display electrode 3 and the seal portion 8. FIG. As shown in FIG. 2, this dummy electrode 10 is provided at a location other than the display surface 11 on the display electrode side and the scanning electrode side, and the driving circuit alternately switches the liquid crystal driving voltages v6 and 5 on the scanning side. Apply voltage (7). Furthermore, the polarity of the alternating current signal M is adjusted so that it is in phase with the scanning electrode.

With the above configuration, nonuniformity in the thickness of the liquid crystal layer 6 can be eliminated, and the contrast over the entire display surface can be made uniform. Further, the dummy electrode 10 is arranged to face the scanning electrode and the display electrode, and a voltage is applied to the electrode 10 so that the liquid crystal does not turn on, regardless of whether the voltage applied to the opposing electrode is selected or not. Since it is selectively applied, a uniform display can always be obtained.

[Effects of the Invention] As described above, by using a liquid crystal display device having the structure of the present invention, the problems of the prior art can be solved and the color tone of the display screen can always be kept constant. We were able to provide a liquid crystal display device that can.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of an end portion of an embodiment of a display element of a liquid crystal display device of the present invention, FIG. 2 is a diagram showing a configuration of a liquid crystal display device of the present invention including a drive circuit, and FIG. FIG. 4 is a sectional view showing a schematic configuration of a display element of a liquid crystal display device of the prior art. FIG. 4 is a sectional view showing a schematic configuration of an end portion of a display element of the prior art. l...upper board, 2...lower board, 3...
・Display electrode, 4...Scanning electrode, 5...Alignment film, 6...Liquid crystal layer, 7...Liquid crystal layer spacer, 8...Seal part, 9...Seal part spacer, IO・...Dummy electrode, 11...Display surface.

Claims (1)

[Claims] 1. In a liquid crystal display device in which a liquid crystal is sealed between two transparent electrode substrates in which X, Y stripe electrodes are arranged facing each other, facing transparent electrodes are also provided in areas other than the image display area, and A liquid crystal display device comprising a circuit for applying an X electrode non-selection voltage to the transparent electrodes in areas other than the image display area.