JPH0646275B2 - Matrix type liquid crystal display device - Google Patents

Description

The present invention relates to a matrix type liquid crystal display device using liquid crystal.

2. Description of the Related Art In recent years, liquid crystal display devices are required to display more information, such as image displays, and for this reason, the segment type has been changed to a dot matrix type configuration. It is moving in the direction of change.

Conventionally, in a matrix type liquid crystal color display device, as shown in FIG. 5, a pair of transparent electrodes is divided into strips,
Combining one scan electrode 5 and the other signal electrode 2 so as to be orthogonal to each other, each intersection of the divided electrode groups forms a pixel, and a voltage is selectively applied to these electrode groups. By this, arbitrary information can be displayed.

To perform color display in such a matrix display device, as shown in FIG. 4, for example, as shown in FIG. 4, a plurality of colors are applied to a portion where a pixel on one of the scanning electrode 5 and the signal electrode 2 is formed. Color filter, for example, 6th
They were formed in the arrangement as shown in the figure (for example, author Uchida et al., "Multi-color liquid crystal display with colored layer on electrodes" 8th Liquid Crystal Conference, 3W20, 1982 10
Month).

Usually, such a display device employs a so-called time-division driving method in which a scanning electrode is selected at a constant cycle and a color signal voltage corresponding to information is applied to the signal electrode in synchronization with this.

Problems to be Solved by the Invention However, in the case of the matrix display having the conventional configuration, there are two major problems that the color balance and the contrast of the display are significantly lowered.

That is, when a twisted nematic (hereinafter referred to as TN type) liquid crystal display panel is used for negative display, the amount of spectrally transmitted light of the liquid crystal display panel when an off signal is applied (when a low voltage is applied) is red due to optical dispersion The component (long wavelength region) is large, and the blue component (short wavelength region) is small.

Therefore, one of the drawbacks of the conventional color display device is that the blue component is weakened and the color display is not well balanced.

Another drawback is that as a means of improving the contrast, the electrode structures are usually multiplexed in order to improve the drive duty, for example as shown in FIGS. in this case,
A lead electrode 2 ′ of another picture element electrode is provided between adjacent picture element electrodes 2. A voltage is naturally applied between the lead electrode 2'and the scanning electrode 5, and this portion is displayed in white. The display of this portion is completely unnecessary display, and the contrast is significantly lowered.

Means for Solving the Problems In order to solve the above problems, the present invention provides a plurality of mosaic transparent signal electrodes on one transparent substrate, and the signal electrodes are transparent lead electrodes in the row direction. The display picture elements are arranged in a matrix by connecting them and the other strip-shaped transparent scanning electrodes so as to face each other, and a filter layer of a plurality of colors is provided on each of the signal electrodes, and a portion other than the display portion is provided. Is a blue filter layer provided so as to cover the lead electrodes.

Operation According to the present invention, the lead electrode connected to the signal electrode is displayed in blue regardless of the voltage applied to any signal electrode. For this reason, the blue display area on the entire display surface is larger than the other monochrome display areas. As a result,
It is possible to improve the deterioration of the color balance caused by the light dispersion. Further, the white display of the lead electrode is eliminated, and the contrast is improved.

Embodiment One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view schematically showing the constitution of a matrix type liquid crystal color display device of the present invention, and FIG. 2 is a plan view showing the electrode constitution thereof. FIG. 3 is a plan view schematically showing the display surface.

Reference numeral 1 is a transparent glass substrate. A transparent conductive film of indium oxide containing tin is formed on this substrate 1, and this is etched to provide a signal electrode 2 and its lead electrode 2 '.

Next, a plurality of colors (for example, R, G, B) are formed on the signal electrode 2.
The color filter layer 3 is provided. After that, the signal electrode 2
A blue filter layer 3'is formed over the entire surface of the other portion so as to cover the lead electrode 2 '.

Here, as a means for forming these color filter layers, a dyeing method or a printing method by a photolithography method may be used. In the case of the photolithography method, the alignment accuracy of the signal electrode and the filter layer is good, and a fine electrode is used. Suitable for forming a filter layer on a pattern.

In general, the thicker the color filter layer, the better the color purity, but the poorer the light transmittance.

On the other hand, from the viewpoint of the characteristics of the liquid crystal, it is preferable that the thickness of the filter layer is thin because the characteristics of the filter layer deteriorate as the thickness increases.

Therefore, the film thickness of the color filter layer is 1.0-1.7μ
About m is preferable.

Next, a transparent conductive film of indium oxide containing tin is formed on the other transparent glass substrate 4 and is etched to form a band-shaped scanning electrode group 5.

These substrates 1 and 4 are combined so that the signal electrode group 2 and the scanning electrode group 5 are orthogonal to each other, and a constant gap is maintained to seal the periphery with a sealant, and the liquid crystal material 6 is placed inside. After encapsulation, the matrix display device is completed.

In the liquid crystal matrix display device of the embodiment configured as described above, the scanning electrodes are selected at a constant cycle, and a color signal voltage according to information is applied to the signal electrodes in synchronization with this.

Here, for example, when a certain scan electrode is selected and a white signal voltage is applied to the signal electrode in synchronization with this, all the R, G, B picture elements and the lead electrode portion on the selected scan electrode are It will be displayed as shown in FIG. Here, since all the lead electrode portions display blue, the blue display area is increased as a whole, and the deterioration of the color balance caused by the liquid crystal light dispersion is improved. That is, the conventional brownish white is improved to the standard white.

Further, since the display of the lead electrode portion is not white, the blue contrast, which has been a problem in the past, is dramatically improved.

EFFECTS OF THE INVENTION As described above, according to the present invention, the color balance and the contrast characteristics in color display are greatly improved by the improvement of the extremely simple structure, so that excellent color display with good visibility is possible. Is.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the structure of a matrix type liquid crystal display device according to an embodiment of the present invention, FIG. 2 is a plan view schematically showing the electrode structure of FIG. 1, and FIG. Plan views schematically showing a color display surface when driving the matrix type liquid crystal display device of the present invention, FIG. 4 and FIG.
FIG. 6 is a plan view showing a cross section showing the configuration of a conventional matrix type liquid crystal display device and its electrode configuration, and FIG. 6 is a plan view showing a color display surface when the conventional matrix type liquid crystal display device is driven. . 1, 4 ... Transparent substrate, 2 ... Signal electrode, 2 '... Lead electrode, 3 ... Color filter layer, 3' ... Blue filter layer, 5 ... Scan electrode, 6 ... Liquid crystal material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shingo Fujita 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-60-75819 (JP, A) JP-A-60-218626 (JP, A)

Claims (1)

[Claims] 1. A pair of transparent substrates sandwiching a liquid crystal is provided, and a plurality of transparent signal electrodes having a mosaic shape or a predetermined shape are provided on a surface of one substrate facing the other substrate, and the signal electrodes are The display pixels are connected in the row direction by transparent lead electrodes, and a plurality of transparent strip-shaped scanning electrodes are provided on the surface of the other substrate facing the one substrate to form the display pixels in a matrix. A matrix type liquid crystal display device characterized in that filter layers of a plurality of colors are provided on the constituent signal electrodes, and a blue filter layer is provided in a portion other than the display picture elements so as to cover the lead electrodes.