RU2269807C2 - Liquid-crystalline display - Google Patents

Abstract

FIELD: engineering of displays.

SUBSTANCE: to decrease number of external outputs of screen in liquid-crystalline display, containing two dielectric plates with transparent current-guiding electrodes applied on them, each electrode of one plate is connected to selected electrode of another plate by electric-conductive contact, while each pair of electrodes is let out onto controlling contact zone, and electrodes, forming image elements of information field of screen, on each plate are positioned at angle φ similar relatively to external sides of plates, while angle φ satisfies following condition: 10°≤φ≤85°.

EFFECT: decreased constructive requirements for display.

4 cl, 4 dwg, 1 tbl

Description

The invention relates to indicator technology, namely to liquid crystal screens, and can be used to create devices for displaying information for individual and collective use.

Structurally, the liquid crystal screen is a flat capillary consisting of two dielectric (for example, glass) plates parallel to the circumference of which the transparent conductive electrodes of a certain configuration are applied on the inner surfaces of each other to form image elements of the screen, covered with dielectric orienting films, filled with liquid crystal through a hole in the capillary. Polaroids are located on the outer surfaces of the capillary (Indicator devices on liquid crystals. / Under the editorship of Z.Yu. Gotry. - M .: Sov. Radio, 1980, p. 80-135).

Various liquid crystal display devices are known in which the formation of controlled screen electrodes is different.

First, the formation of controlled screen electrodes consists in the fact that image elements are located on one of the plates and each element for its control has an individual external contact pad (see ibid., P. 85, 86, fig. 3.8 and 3.11). On the other plate, a common electrode is formed for all image elements of the first plate having one external contact pad.

The disadvantage of this design is that if there are N screen image elements, N + 1 external contact pads are necessary, a large number of control outputs of the microcircuits practically eliminates the creation of screens of large information capacity.

Secondly, the formation of the information field of the screen consists in the fact that the image elements on one plate are combined into groups (lines) consisting of many image elements and each group (line) has one external control pad. On another plate, groups (columns) of image elements are also formed. When connecting the plates to the capillary, the electrodes on both plates form a projection matrix of image elements, consisting of U rows and X columns. The number of image elements is Y · X, and the number of control external contacts is Y + X (see ibid., P.106, Fig.3.29 - prototype).

The disadvantage of this design of a liquid crystal device is that:

- as in the first case, to control the screen requires a large number of external control contacts (Y + X) and, accordingly, the outputs of the chips;

- pads of rows and columns are located on mutually perpendicular sides of the screen, which limits the number of electrically independent matrices formed in one screen, for example, for passive-matrix liquid crystal screens, only two independent matrices are used in one screen. This significantly limits the information content of the screen and imposes severe restrictions on the design of the screen in terms of requirements for the parameters of the liquid crystal and the orientation of the liquid crystal molecules.

The invention consists in the following. The problem to which the invention is directed is to reduce the number of external screen pins inherent in the standard matrix execution of electrodes while maintaining the number of image elements and reducing the design requirements for the screen due to the possibility of its formation from N independent controlled matrices.

The specified technical result during the implementation of the invention is achieved by the fact that in a liquid crystal screen containing two dielectric plates, at least one of the plates is transparent, with transparent conductive electrodes deposited on the inner surfaces of the plates, forming image elements of the information field of the screen of a given configuration, coated with a dielectric orienting film connected around the perimeter by a sealant into a flat capillary filled with a liquid crystal, polaroids on external surfaces surfaces of plates and external control contact pads, each electrode of one plate is connected to a selected electrode of another plate by an electrical contact, each pair of electrodes is connected to one common control contact pad, and the electrodes forming the image elements of the information field of the screen are located on each plate under the angle φ equal to the outer sides of the plates, while the angle φ satisfies the following condition: 10 ° ≤φ≤85 °.

In addition, the liquid crystal screen contains j, where j = 1, 2, 3, ..., N electrically independent controlled matrixes of the screen with a constant pitch of image elements of the information field throughout the screen, or with a different pitch of image elements of the information field in each matrix screen; external control pads are located on parallel sides of the screen; electrical contacts in a pair of electrodes of one and the other plates are made along the periphery of the screen in the area of the external control contact pads with an anisotropic conductive paste.

The invention is illustrated by graphic materials, description and examples of specific performance.

Figure 1 shows the design of a liquid crystal screen.

Figure 2 schematically shows the location of the electrodes on each of the plates at an angle φ to the outer sides of the plates,

Figure 3 schematically shows the design of the electrodes and their connection with external control pads.

Figure 4 schematically shows the information field of the liquid crystal screen with j, where j = 1,2,3, ..., N are electrically independent controlled matrixes of the screen with a constant pitch of image elements of the information field throughout the screen.

In the drawings, the following notation:

1, 2 - two dielectric plates, at least one of the plates is transparent;

3 - sealant;

4 - liquid crystal;

5, 6 - conductive electrodes;

7, 8 - dielectric orienting films;

9, 10 - polaroids;

11 - external control pads;

12 - image elements of the information field;

13 - conductive contact.

The proposed liquid crystal screen (see figure 1) consists of two parallel arranged transparent glass plates 1 and 2, connected around the perimeter by a sealant 3, so that a flat capillary with external control contact pads is formed 11. A liquid crystal 4 is introduced into the gap of the flat capillary, then the gap is sealed with a sealant. Transparent conductive electrodes 5 and 6 are applied to the inner sides of the plates 1 and 2 in the form of a specific pattern — a given configuration, forming image elements of the information field of the liquid crystal screen. Transparent conductive electrodes 5 and 6 are coated with a dielectric orienting film 7 and 8. Polaroids 9 and 10 are deposited on the outer surfaces of the dielectric plates.

Figure 2 shows the location of the electrodes at an angle φ to the outer sides of the dielectric plates 1 and 2, while the angle φ satisfies the following condition: 10≤φ≤85 °.

The indicated parameters of the angle φ are determined experimentally, taking into account the known laws adopted in the design of liquid crystal screens, taking into account the geometry of the dielectric plates used: rectangular or diamond-shaped.

The operation of the liquid crystal screen is as follows.

When voltage is applied to the selected electrodes 5, 6, made of a transparent conductive material deposited on dielectric plates, such as glass 1 and 2, the liquid crystal 4 molecules are reoriented. As a result of the reorientation of the liquid crystal 4 molecules, the light transmission on the selected image element changes fields. The unambiguity and independence of the choice of any image element of the information field in the proposed design of the liquid crystal screen is illustrated by examples.

EXAMPLE 1

A prototype of the liquid crystal screen was made according to the claimed technical solution. Figure 1 shows that the electrode 5 of one plate 1 is connected to the selected electrode 6 of the other plate 2 by an electrical conductive contact 13. Figure 3 shows 24 external control contact pads 11, the configuration of the patterns of the electrodes 5 and 6 on one 1 and the other 2 dielectric glass plates, as well as the scheme of pairwise connection of electrodes with external control pads.

The table shows the necessary combination of external control pads, when applying voltage to which any of the image elements of the information field of the screen is turned on. The table shows that any of the selected combinations of supplying control voltage to external contact pads includes only one desired image element. The example also shows that with the number of image elements 288 pieces, the number of external terminals in the proposed design of the liquid crystal screen is 24, and with a standard matrix connection, 34 external terminals will be required for the same number of image elements.

EXAMPLE 2

A prototype liquid crystal screen according to the invention was made. Figure 4 schematically shows that the proposed design of the liquid crystal screen allows you to form j independently controlled matrices in one screen, where j = 1, 2, 3, ..., N, with the preserving regularity of image elements in the information field of the screen in each matrix. The size of the LCD screen is limited only by technological capabilities.

The effectiveness of the invention is to reduce the number of external control contact pads, which will reduce the number of microcircuit pins used for control and increase the reliability of liquid crystal screens, as well as reduce the requirement for the design of a liquid crystal screen by using N independently controlled matrices.

Claims (4)

1. A liquid crystal screen containing two dielectric plates, at least one of the plates is transparent, with transparent conductive electrodes deposited on the inner surfaces, forming image elements of the information field of the screen of a given configuration, covered with a dielectric orienting film, connected around the perimeter by a sealant in a flat capillary filled liquid crystal, polaroids on the outer surfaces of the plates and external control pads, characterized in that each elec the electrode of one plate is connected to the selected electrode of the other plate by an electrically conductive contact, with each pair of electrodes brought to one common control pad, and the electrodes forming the image elements of the screen information field on each plate are located at an angle φ equal to the outer sides of the plates, at this angle φ satisfies the following condition: 10 ° ≤φ≤85 °. 2. The liquid crystal screen according to claim 1, characterized in that it contains j, where j = 1, 2, 3, ..., N, electrically independent controlled screen matrices with a constant pitch of image elements of the information field throughout the screen or with different steps in each of the screen matrices. 3. The liquid crystal screen according to claim 1, characterized in that the external control contact pads are located on parallel sides of the screen. 4. The liquid crystal screen according to claim 1, characterized in that the electrical contacts in the pair of electrodes of one and the other plates are made on the periphery of the screen in the area of the control contact pads with an anisotropic conductive paste.

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