JPH05158075A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide a liquid crystal display device where electrification is not caused with respect to static electricity and the defect of display is not caused. CONSTITUTION:Since voltage is comparatively low, such as 30V, in the case of performing the display, thermosetting paste 11 having varistor characteristic keeps insulation between an upper substrate 1 and a lower substrate 3. The voltage is comparatively high in the case of eliminating a potential difference caused by the electrification by the static electricity, the paste 11 exceeds the critical voltage value of the varistor characteristic. The substrates 1 and 3 are made conductive in the case of electrification, and a current flows between the substrates 1 and 3 to eliminate the potential difference. Fine powder of about several mum is formed by using ceramic showing the varistor characteristic. The conduction between the conductive electrode 2 of the upper substrate and the conductive electrode 4 of the lower substrate and the conduction between electrodes 2 and 4 on the substrates 1 and 3 are attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device capable of preventing display defects caused by static electricity.

[0002]

2. Description of the Related Art As a conventional liquid crystal display device, for example, a structure shown in FIG. 4 is known.

In the liquid crystal display device shown in FIG. 4, an upper substrate electrode 2 is provided on one main surface side of an upper substrate 1, and a lower substrate electrode 4 is provided on one main surface side of a lower substrate 3. The upper substrate electrode 2 and the lower substrate electrode 4 are opposed to each other, and the upper substrate 1 and the lower substrate 3 are positioned in parallel.

Then, the liquid crystal composition 5 is sandwiched between the alignment films 6, and the liquid crystal composition 5 and the alignment film 6 are sandwiched between the upper substrate 1 and the lower substrate 3.

A sealing material 7 is provided around the liquid crystal composition 5 and the alignment film 6 between the upper substrate 1 and the lower substrate 3.

Further, polarizing plates 8 and 9 are attached to the outer surfaces of the upper substrate 1 and the lower substrate 3, respectively.

[0007]

However, the liquid crystal display device generally has a large capacitance and is easily charged by static electricity generated during the manufacturing process. Then, due to the static electricity being charged, for example, when a display voltage is applied between the electrodes of the upper substrate 1 and the lower substrate 3, the display density becomes uneven, or the charging voltage is high and the upper substrate electrode 2 and When a discharge is generated between the lower substrate electrodes 4, the alignment of the liquid crystal composition 5 interposed between the upper substrate electrode 2 and the lower substrate electrode 4 is disturbed, which causes a fatal display defect. Have

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device that is not charged by static electricity and does not cause display defects.

[0009]

According to the present invention, conductive electrodes are formed on one surface side, respectively, and first and second substrates facing each other and sandwiched between the first and second substrates. Liquid crystal composition, and the first and second
In a liquid crystal display device including a polarizing plate provided on the other surface side of the substrate, ceramics exhibiting varistor characteristics are sandwiched between the first and second substrates.

[0010]

According to the present invention, it is necessary to maintain insulation between the first and second substrates when displaying, and a relatively high voltage is required to eliminate the potential difference due to electrostatic charging. The varistor characteristic that conducts when charged by static electricity is effective, maintains insulation when the voltage is below the critical voltage, and conducts current when the voltage exceeds the critical voltage. In addition, by using ceramics that show varistor characteristics,
It is possible to form a fine powder of about m.
Between the conductive electrodes of the substrate of the first, and the first and second
Conduction between the conductive electrodes in the substrate is possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the liquid crystal display device of the present invention will be described below with reference to the drawings. The parts corresponding to those of the conventional example shown in FIG.

The liquid crystal display device shown in FIGS. 1 to 3 has an upper substrate electrode which is a conductive electrode made of, for example, ITO (Indium Tin Oxide) on one main surface side of an upper substrate 1 made of glass, which is a first substrate. 2 is provided, a lower substrate electrode 4 which is a conductive electrode made of, for example, ITO is provided on one main surface side of a lower substrate 3 made of glass, which is a second substrate, and the upper substrate electrode 2 and the lower substrate electrode 2 are provided. The substrate electrodes 4 are opposed to each other in the orthogonal direction, and the upper substrate 1 and the lower substrate 3 are positioned in parallel.

Then, the liquid crystal composition 5 is sandwiched between the alignment films 6 made of polyimide, and the liquid crystal composition 5 and the alignment film 6 are sandwiched between the upper substrate 1 and the lower substrate 3.

A sealing material 7 made of, for example, epoxy resin is provided around the liquid crystal composition 5 and the alignment film 6 between the upper substrate 1 and the lower substrate 3, and the upper substrate 1 and the lower substrate 3 are attached to each other. I'm wearing it. Then, as shown in FIG. 1 and FIG. 2, a fine ceramic powder that is sandwiched between the upper substrate 1 and the lower substrate 3 and has zinc oxide (ZnO) -based varistor characteristics around the sealing material 7. The formed thermosetting paste 11 is provided. Further, since the thermosetting paste 11 is sandwiched so as to surround the sealing material 7 as shown in FIG. 3, it is also in contact with the lower substrate electrode 4 of the lower substrate 3. Although zinc oxide was used as the ceramic exhibiting the varistor characteristics, silicon carbide (S
Similar effects can be obtained by using ceramics such as iC) type and titanium oxide (TiO ₂ ) type.

Further, polarizing plates 8 and 9 are attached to the outer surfaces of the upper substrate 1 and the lower substrate 3, respectively.

When displaying, the voltage is 30
The thermosetting paste 11 having a varistor characteristic maintains the insulation between the upper substrate 1 and the lower substrate 3 because it is relatively low at about V.

Further, when eliminating the potential difference due to electrostatic charging, the voltage becomes relatively high, so that the critical voltage value of the varistor characteristic is exceeded, and the upper substrate 1 and the lower substrate 3 are electrically connected during charging, A current flows and the potential difference disappears.

Further, by using a ceramic exhibiting varistor characteristics, it is possible to form a fine powder having a size of about several μm, and between the upper substrate electrode 2 and the lower substrate electrode 4 of the upper substrate 1 and the lower substrate 3. Conduction and conduction between the upper substrate electrode 2 and the lower substrate electrode 4 in the upper substrate 1 and the lower substrate 3 are also possible.

[0019]

According to the liquid crystal display device of the present invention, it is necessary to maintain insulation between the first and second substrates when displaying, and to eliminate the potential difference due to electrostatic charging. Has an effective varistor characteristic in that it conducts when charged by static electricity having a relatively high voltage, maintains insulation at a voltage lower than the critical voltage, and conducts a current at a voltage higher than the critical voltage. Further, by using a ceramic exhibiting varistor characteristics, it is possible to form a fine powder having a size of several μm, and to provide conduction between the conductive electrodes of the first and second substrates,
In addition, conduction can be established between the conductive electrodes in the first and second substrates. Therefore, it is possible to prevent a display defect from being generated due to no electrostatic charge.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line I-I shown in FIG. 3 of an embodiment of the liquid crystal display device of the present invention.

FIG. 2 is a sectional view taken along line II-II shown in FIG.

FIG. 3 is a plan view of the same.

FIG. 4 is a cross-sectional view showing a conventional liquid crystal display device.

[Explanation of symbols]

 1 upper substrate which is a first substrate 2 upper substrate electrode which is a conductive electrode 3 lower substrate which is a second substrate 4 lower substrate electrode which is a conductive electrode 5 liquid crystal composition 8 9 polarizing plate 11 formed of ceramics Thermosetting paste

Claims (1)

[Claims] 1. A conductive electrode is formed on one surface side,
First and second substrates with these conductive electrodes facing each other;
A liquid crystal display device comprising a liquid crystal composition sandwiched between these first and second substrates and a polarizing plate provided on the other surface side of the first and second substrates, wherein A liquid crystal display device, wherein ceramics exhibiting varistor characteristics are sandwiched between second substrates.