JPH0568710B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a matrix-type full-color display device using liquid crystals and a method for manufacturing the same.

Conventional configuration and problems Generally, in a matrix display, a pair of electrodes is divided into strips, one is used as a scanning electrode and the other is a signal electrode, and they are combined so as to be orthogonal to each other, and liquid crystal is filled between the pair of electrodes. It is known that the structure is as follows. Each intersection of each divided electrode group forms a picture element, and arbitrary information can be displayed by selectively applying a voltage to these electrode groups. Normally, such a display device is driven using a so-called time-division drive method in which scanning electrodes are line-sequentially scanned at a constant period, and in synchronization with this, a signal voltage waveform corresponding to information is applied to a signal electrode.

A configuration for displaying color in such a matrix type liquid crystal display device will be described with reference to the drawings. FIGS. 1 and 2 are sectional views of main parts schematically showing the structure of a conventional color matrix display device. That is, FIG. 1 shows a structure in which filter layers 7 of a plurality of colors, such as red, green, and blue, are provided in rows or grids on the signal electrode 6 or the scanning electrode 2. Color display is performed by supplying corresponding color signal voltages to the signal electrodes 6, respectively. In this configuration, the color filter layer provided on the electrode is generally formed by a photolithography method or a printing method, and the former is usually a method of dyeing an organic insulator such as gelatin.
In the latter case, a method is used in which the pigment is dispersed in an organic resin. The color purity of the filter layer formed by these methods is poor if the film thickness is thin;
Generally speaking, the thicker the better. However, when such an insulating layer is formed on the electrodes, the optical characteristics of a liquid crystal display device are significantly impaired in the rise characteristic (hereinafter referred to as steepness) of the amount of transmitted light relative to the applied voltage or the threshold voltage characteristic. For this reason, particularly when driving a matrix type display device with a large display capacity in a time-division manner, this deterioration of the steepness lowers the display contrast, and an increase in the threshold voltage increases the driving voltage.

Therefore, as a method of eliminating the defects caused by such a filter layer, a configuration as shown in FIG. 2 can be considered. This structure is such that a color filter layer 7 is first formed on one substrate 1, and then a transparent scanning electrode 3 or signal electrode 6 is provided on this filter layer 7 by sputtering indium oxide containing tin at a low temperature. .

However, in this structure and manufacturing method, the transparent electrode formed on the filter layer has shortcomings in terms of its electrical properties and mechanical strength, and this causes problems that are fatal to the display properties and reliability of the display device. There are some drawbacks. These points will be explained in detail.

In other words, the heat resistance of color filter layers is generally low, whether dyed or pigmented.
At temperatures above about 210°C, color fading occurs and color purity becomes extremely poor. Therefore, the transparent electrode provided on this filter layer must be formed at a low temperature of 200° C. or lower. Low-temperature sputtering is generally used to form transparent conductive films at temperatures below 200°C, but transparent conductive films formed by low-temperature sputtering usually have a high electrical resistance, and are formed on organic resin films. Generally, the resulting film has extremely low mechanical strength and adhesive strength against friction.

Therefore, in a matrix display device consisting of a group of strip-shaped electrodes subdivided into a plurality of electrodes, the first
The disadvantage of this is that the electric resistance in the length direction of each transparent electrode is extremely high, so when voltage is supplied from one end of this electrode, a voltage drop occurs in the length direction due to the electric resistance. Display unevenness occurs. Furthermore, the second drawback is that liquid crystal display devices usually have
In the manufacturing process, a so-called alignment treatment is performed to align liquid crystal molecules in a certain direction, and this treatment method generally involves providing an alignment film on a transparent electrode.
Thereafter, the surface is rubbed in a certain direction using cotton cloth or the like. In this case, the transparent electrode formed by the low-temperature sputtering method has low mechanical strength and adhesive strength, so it may break due to friction caused by rubbing, or may be damaged by thermal history that occurs during the subsequent manufacturing process of the display device. There were problems with the reliability of the display device, such as wire breakage or poor conduction often occurring due to repeated voltage application after completion.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and provides a highly reliable matrix-type liquid crystal display device that can provide a homogeneous full-color display with excellent contrast and does not cause disconnection, and such a matrix-type liquid crystal display device. An object of the present invention is to provide a manufacturing method that can easily manufacture a display device.

Structure of the Invention In order to achieve the above-mentioned object, a matrix type liquid crystal display device according to the first invention of the present application is provided with a pair of transparent substrates facing each other, and the surface of one substrate facing the other substrate is arranged in a grid, rows or A plurality of color filter layers having a predetermined shape are provided, a metal layer having a predetermined shape is provided in a portion other than the picture element at a position corresponding to the scanning electrode, and then a plurality of transparent filter layers covering the filter layer and the metal layer are provided. A scan electrode is provided, a plurality of transparent signal electrodes are provided on the surface of the other substrate facing the one substrate, and a liquid crystal material is filled between the pair of substrates. Further, the method for manufacturing a matrix liquid crystal display device according to the second invention of the present application includes a step of forming a metal layer having a predetermined shape on a portion other than the picture elements at a position corresponding to a scanning electrode on a transparent first substrate. Then, a step of forming a plurality of color filter layers at positions corresponding to the picture elements other than this metal layer, and a step of forming a plurality of transparent scanning electrodes so as to cover the metal layer and the filter layer. The method includes the steps of: forming a plurality of transparent signal electrodes on a transparent second substrate; and filling a gap between the first and second substrates with a liquid crystal material. Further, the method for manufacturing a matrix type liquid crystal display device according to the third invention of the present application includes a step of forming a plurality of color filter layers having a grid, rows, or a predetermined shape on a transparent first substrate, and then forming filter layers on scanning electrodes. forming a metal layer having a predetermined shape on the filter layer in a portion other than the picture element at a corresponding position; and then forming a plurality of transparent scanning electrodes so as to cover the filter layer and the metal layer. , the structure includes a step of forming a plurality of transparent signal electrodes on a transparent second substrate, and a step of filling a gap between the first substrate and the second substrate with a liquid crystal material.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 3 is a cross-sectional view schematically showing the main part of the structure of a matrix type liquid crystal display device according to an embodiment of the present invention, and FIGS. 4, 5, and 6 are plan views of the main part. be. 1 is a transparent glass substrate, on which
First, a metal coating is formed over the entire surface of the substrate. As this metal coating, a single coating of Cr, Au, Ni, Al, Pa, etc. or a laminated coating of several of these materials can be applied, but from the viewpoint of conductivity, adhesive strength, and electrical connection with the transparent conductive coating, Cr-Ni is preferable. - A three-layer structure of Au is preferred. The metal coating was formed by a conventional vacuum deposition method. Thereafter, this metal coating is etched by a photoetching method to obtain a metal layer 10 having a shape in which the portion where the filter layer is buried is removed. Next, as shown in Figure 4, this metal layer 1
A plurality of color filter layers 7 are formed on the cut portion of 0.

The filter layer 7 can be formed by forming a gelatin layer by photolithography and then coloring it with a desired dye. In this embodiment, filters of three colors red, blue, and green are arranged in this arrangement in the column direction, and for the n+1st row (even row),
Green, red,
They were each formed into a pattern of blue arrays. These filter layers were formed at predetermined positions in the order of red, green, and blue. The film thickness of the filter layer 7 formed here is preferably 1 to 3 μm. If it is less than 1μm, the color purity will be poor.
Further, if the thickness is 3 μm or more, the light transmittance of the coating decreases, which is not preferable. 200% of indium oxide containing tin (hereinafter referred to as ITO) is placed on the metal layer 10 and the multi-color filter layer 7 formed as described above.
It is formed by a low temperature sputtering method below ℃, and then this
The ITO film is etched using a photoetching method as shown in Figure 5 to form a band-shaped transparent scanning electrode 3.
And so. Thereafter, a liquid crystal alignment film 4 was formed over the entire surface of the substrate 1 on the scanning electrode 3 side, and then the surface was rubbed in a certain direction using polyester fibers to perform an alignment treatment. On the other hand, a transparent glass substrate 5
An ITO film was formed on the surface facing the substrate 1, and this was photoetched to provide a transparent signal electrode 6 as shown in FIG. In this case, as a method for forming the ITO film, the usual sputtering method or vacuum evaporation method can be applied since there is no need to lower the substrate heating temperature to 200° C. or lower during the formation process. Thereafter, an alignment film 8 was formed on the surface of the substrate 5 on the signal electrode 6 side in the same manner as the substrate 1, and was subjected to an alignment treatment by rubbing.

Thereafter, the substrates 1 and 5 are made to face each other so that the scanning electrodes 4 and the signal electrodes 6 are perpendicular to each other, and the filter layer 7 is located in the pixel area formed by the scanning electrodes 4 and the signal electrodes 6. After sealing the periphery of the substrates 1 and 5 with a constant gap between them and the signal electrode 6, an optically active agent was added to the nematic liquid crystal having positive dielectric anisotropy in the gap between the substrates 1 and 5. The liquid crystal cell was completed by filling the mixed liquid crystal.

A matrix-type liquid crystal display device was completed by sandwiching the thus manufactured liquid crystal cell between two linear polarizing plates to provide a negative type display.

In the matrix type liquid crystal display device of this example, a filter layer that deteriorates the characteristics of the liquid crystal is not provided between the scanning electrode and the signal electrode, and furthermore, the scanning electrode on the filter layer is located in a portion other than the picture element. Since it has a structure in which it is connected to a metal layer integrated in the column direction, the electrical resistance of the scanning electrode is low, and furthermore, disconnection or poor conduction does not occur. Furthermore, as an electrode configuration, two signal electrodes are provided in one display line.
Since it has a double matrix structure divided into individual parts, the drive duty can be practically doubled. This has made it possible to provide highly reliable color display with excellent display contrast.

Example 2 Next, an example of the third invention of the present application will be described.

FIG. 7 is a cross-sectional view schematically showing the main part of the structure of a matrix type liquid crystal display device according to an embodiment of the present invention, and FIGS. 8 and 9 are plan views of the main part showing the manufacturing process. It is.

First, a plurality of color filter layers 7 having desired shapes are formed on a transparent glass substrate 1 by photolithography. Here, as shown in Figure 8, filter layers of three colors red, blue, and green are arranged in this arrangement in the column direction, and for the n+1st row (even row), in the column direction for the n row (odd row). Green, shifted half a pitch.
The red and blue arrays were each formed into a pattern.
Here, the film thickness of the filter layer 7 is preferably 1 to 3 μm for the same reason as in Example 1. next,
A metal film is provided on this filter layer 7 in the same manner as in Example 1, and this is etched to form a metal layer 10 as shown in FIGS. 7 and 8 at positions that do not correspond to picture elements. Then, transparent scanning electrodes 3 are formed in the same manner as in Example 1 so as to cover these filter layer 7 and metal layer 10. Thereafter, an alignment film is further formed on this, and the surface thereof is rubbed for alignment treatment. Thereafter, in the same manner as in Example 1, a transparent signal electrode 6 is formed on the other substrate 5, an alignment film 8 is formed thereon, and after alignment treatment, these are combined to form a matrix display device. Finalize.

According to this embodiment, it is possible to obtain the same effect as in the case of embodiment 1, and by performing the step of forming the metal layer 10 after the step of forming the filter layer 7, the size at the time of forming the filter layer is Less precision is required, which improves production fractionation and
Due to this, manufacturing costs can be reduced.

Effects of the Invention As explained above, according to the matrix type liquid crystal display device of the first invention, the scanning electrode is formed on the filter layer, and the scanning electrode is embedded in the filter layer or formed on the filter layer. Since the structure is such that the filter layer is electrically connected to the metal layer, there is no deterioration of liquid crystal characteristics due to the filter layer, the electrical resistance of the scanning electrode is low, and there is no disconnection or conduction failure. Furthermore, since the metal layer is formed at a position other than the picture elements, unnecessary transmitted light leaking from between adjacent picture elements can be cut off.

Therefore, an excellent color display with no display unevenness and good contrast can be obtained, and reliability can be improved. Moreover, according to the method for manufacturing a matrix type liquid crystal display device of the second invention, the matrix type liquid crystal display device according to the first invention can be manufactured easily and efficiently. Further, according to the method of manufacturing a matrix type liquid crystal display device of the third invention, the method of manufacturing the matrix type liquid crystal display device of the first invention is performed more easily and quickly than the method of manufacturing a matrix type liquid crystal display device of the second invention, and at a lower cost. A matrix type liquid crystal display device can be manufactured.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the structure of a conventional matrix type liquid crystal display device, Figure 2 is a sectional view showing another structure of the conventional matrix type liquid crystal display device, and Figure 3 is a sectional view showing the structure of a conventional matrix type liquid crystal display device.
4, 5 and 6 are cross-sectional views schematically showing the structure of a matrix type liquid crystal display device according to an embodiment of the second invention, and FIGS. 4, 5 and 6 are embodiments of the first and second inventions Figure 7 is a plan view of the main parts showing the manufacturing process of a matrix type liquid crystal display device.
FIGS. 8 and 9 are sectional views schematically showing the structure of a matrix type liquid crystal display device according to an embodiment of the third invention, and FIGS. FIG. 2 is a plan view of main parts showing the manufacturing process of a liquid crystal display device. 1, 5... Transparent substrate, 2, 3, 6... Scanning electrode, 4, 8... Alignment film, 7... Filter layer, 9
...Liquid crystal material, 10...Metal layer.

Claims (1)

[Claims] 1. A pair of transparent substrates facing each other is provided, and a filter layer of multiple colors in a grid, rows, or a predetermined shape is provided on the surface of one substrate facing the other substrate, and a scanning method is performed. A metal layer having a predetermined shape is provided in a portion other than the picture element at a position corresponding to the electrode, and then a plurality of transparent scanning electrodes are provided covering the filter layer and the metal layer, and the surface of the other substrate facing the one substrate is provided. A matrix type liquid crystal display device, characterized in that a plurality of transparent signal electrodes are provided, and a liquid crystal material is filled between the pair of substrates. 2. Forming a metal layer having a predetermined shape in a portion other than the picture element at a position corresponding to the scanning electrode on the transparent first substrate, and then forming a metal layer corresponding to the picture element in the part other than the metal layer. forming a plurality of transparent scanning electrodes on a transparent second substrate; forming a plurality of transparent scanning electrodes on a transparent second substrate; A method for manufacturing a matrix liquid crystal display device, comprising the steps of: forming a signal electrode; and filling a gap between the first substrate and the second substrate with a liquid crystal material. 3. A step of forming a plurality of color filter layers having a grid, rows, or predetermined shape on a transparent first substrate, and then forming a filter layer on a portion other than the picture elements at a position corresponding to a scanning electrode. , a step of forming a metal layer having a predetermined shape, and then a step of forming a plurality of transparent scanning electrodes so as to cover the filter layer and the metal layer;
A matrix type liquid crystal display device comprising the steps of forming a plurality of transparent signal electrodes on a transparent second substrate, and filling a gap between the first substrate and a second substrate with a liquid crystal material. Production method.