JPS61250617A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To suppress a decrease in visibility even when pitch is made fine by generating a voltage higher than the threshold voltage of liquid crystal at a no-electrode part adjacent to a selected point so that the optical property at the no-electrode part is nearly the same as the optical property at the selected point. CONSTITUTION:A crosstalk voltage Vc has a value corresponding to a voltage applied to an adjacent selected point A, so the voltage applied to the selected point A is so set that the crosstalk voltage Vc developed at the adjacent no- electrode part C is higher than the threshold voltage Vt. Then, the optical property at the no-electrode part C adjacent to the selected point A is nearly the same as that at the selected point A and different from that at an unselected point B and when a zone display is made on negative basis, a quantity and a number are displayed in a beltlike shape continuously and brightly without any gap. When a segment display is made, a single segment having no break is displayed. Consequently, even when the pitch is made fine, a decrease in visibility is suppressed without decreasing the rate of the area of a segment electrode part to the unit area of a liquid crystal display element.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a display element using liquid crystal, in particular, by generating brightness and darkness due to the difference in optical properties between selected points and non-selected points. The present invention relates to a liquid crystal display element that displays a predetermined amount or number in a zone display or a segment display.

[Conventional technology]

For example, a liquid crystal display element that performs zone display or segment display by sealing liquid crystal between opposing transparent electrodes and changing the optical properties of a desired selected point by controlling the voltage applied to the electrodes is disclosed in Japanese Patent Publication No. It is disclosed in the publications No. 58-86518 and Japanese Utility Model Application Laid-open No. 57-78078.

That is, as shown in FIG. 1, a plurality of segment electrodes 2 made of a transparent conductive material such as ITO are formed on the inner surface of a transparent insulating substrate 1, and another transparent conductive material is formed so as to face the entire segment electrode 2. A common electrode 4 made of a transparent conductive material such as ITO is formed on the inner surface of the insulating substrate 3, and the substrate 1.3
A sealing material 5 is formed in a frame shape on the opposing circumferential surfaces of the electrodes 2 and 4, and a liquid crystal, for example, a field-effect nematic liquid crystal 6, is sealed between the electrodes 2 and 4 in a twisted arrangement in which the axial direction is twisted by 90 degrees to form a liquid crystal self. Configure. A liquid crystal display element 10 is constructed by disposing polarizing plates 8.9 on the outer surface of this liquid crystal cell so that their polarizing axes are parallel to each other.

Such a liquid crystal display element 10 constitutes a liquid crystal display device together with a drive circuit (not shown) that receives an external input signal and applies a predetermined voltage to the electrodes 2 and 4 of the liquid crystal display element 10. The transmitted light intensity (reflected light intensity in the case of a reflective type) depends on the effective value of the applied voltage, and as shown in Figure 2, as the voltage is increased, the transmitted light decreases at a certain threshold voltage Vt. The general characteristic is that the light intensity begins to change, that is, the optical properties of the liquid crystal self begin to change, and are almost saturated at the saturation voltage V.

Therefore, the segment electrodes 2 are formed by the driving circuit applying a predetermined voltage to the electrodes 2 and 4 of the liquid crystal display element 10 in response to an external input signal corresponding to the amount or number of detection points. The location where a voltage equal to or higher than the threshold voltage ■ (approximately the saturation voltage V) is generated between the common electrode 4 becomes the selection point A, and the transmitted light intensity (reflected light intensity) is large. (The location where the electrode 2 is formed and where a voltage lower than the threshold voltage vt is generated between the electrode 2 and the common electrode 4 becomes a non-selected point B, and the transmitted light intensity (reflected light intensity) becomes small. Furthermore, the area where the segment electrode 2 is not formed becomes a non-electrode area C, and the transmitted light intensity (reflected light intensity) is extremely small.Therefore, in the liquid crystal display element 10, only the selected point A appears bright, and the non-selected point B The amount and number are displayed in zones using a so-called negative display in which the non-electrode portion C becomes dark (see FIG. 3).

In addition, although it is a similar negative display, the segment electrode 2
The transmitted light intensity (
The amount or number may be displayed in segments by increasing the reflected light intensity (see Figure 4).

Note that if the liquid crystal display element 10 is constructed by arranging the polarizing plates 8 and 9 so that their polarization axes are orthogonal, only the selected point A appears dark, and the non-selected point B and the non-electrode portion C become bright. It goes without saying that each of the above displays can be performed in so-called positive display.

[Problem that the invention seeks to solve]

In recent years, there has been an increasing demand for finer pitch in liquid crystal display devices that perform such zone display or segment display.

Here, fine pitching means reducing the pitch of the segment electrodes 2 (see FIG. 5).

By the way, conventionally, the gap width between the segment electrodes 2 is
The segment electrode 2 is set to a certain value within the range of about 0.1 tm to about 0.05 m, and has a fine pitch.
The gap width between them is also not much different from the above value.

Therefore, as the pitch becomes finer, the number of gaps increases, and the ratio of the area of the segment electrode 2 to the unit area of the liquid crystal display element 10 decreases, resulting in a problem of reduced visibility.

This is a big problem especially in the case of negative display.

[Purpose of the invention]

The present invention was conceived with attention paid to such conventional problems, and an object of the present invention is to provide a liquid crystal display element that can suppress a decrease in visibility even when the pitch is made finer.

[Summary of the invention]

In order to achieve the above object, the present invention seals a liquid crystal between opposing transparent electrodes and changes the optical properties of a selected point, which is a desired segment electrode location, by controlling the voltage applied to the electrodes, thereby displaying a zone or segment. In a liquid crystal display element that performs display, in order to make the optical properties of the non-electrode portion adjacent to the selected point substantially similar to the optical properties of the selected point, the non-electrode portion is provided with a voltage lower than the threshold voltage of the liquid crystal. The device is also driven to generate a high voltage.

〔Example〕

In the liquid crystal display element 10 shown in FIG.
becomes the selection point A and a predetermined voltage is applied between it and the common electrode 4, a crosstalk voltage vc is generated in the adjacent non-electrode portion C, so that other points, for example, The optical properties of the selected point A are closer to those of the non-selected point B.

However, since the crosstalk voltage vc is usually sufficiently lower than the threshold voltage Vt, this non-electrode portion C will display a different image than the selection point A.

By the way, since the crosstalk voltage vc has a value corresponding to the voltage applied to the adjacent selection point A, the voltage applied to the selection point A is equal to the crosstalk voltage generated at the adjacent non-electrode portion C. . By setting the voltage to be higher than the threshold voltage 1, the optical properties of the non-electrode portion C adjacent to the selected point A are approximately the same as those of the selected point A, but are different from those of the non-selected point B. Therefore, when displaying a zone in a negative display, the amount or number is displayed brightly in a continuous strip without any gaps (see FIG. 6).

In addition, even if the same screw display is displayed in segments, it is displayed as a single unbroken segment (see FIG. 7).

It goes without saying that even in the case of positive display, continuous display with no gaps can be performed in the case of zone display, and display can be performed as a single uninterrupted segment in the case of segment display.

Furthermore, even if the liquid crystal display element 10 is of a dot matrix type that displays a predetermined amount or number of dots in a zone display or segment display consisting of a large number of dots, the non-electrode portion (segment electrode) adjacent to the selection point A 2 and common electrode 4
Crosstalk voltage (■) generated at C) where the electrodes 2 and 4 are not facing each other or where both electrodes 2 and 4 are not formed. By setting the voltage to be higher than the threshold voltage Vt, continuous display without gaps (zone display) or display as a single segment without breaks (segment display) can be performed.

Such a display operation may be performed either constantly or as needed. In the latter case, for example, when the liquid crystal display element 10 is configured to perform zone display in negative display, the surrounding area may be displayed during the daytime. Since the display is bright, the display on the liquid crystal display element 10 is bright.On the other hand, since the surroundings are dark at night, if the display on the liquid crystal display element 10 is the same as daytime brightness, the display will be dazzling for the viewer, so it is necessary to reduce the brightness slightly. desirable. Therefore, if the embodiment of the present invention brightly displays the selection point A and the adjacent non-electrode portion C during the day, and the conventional example displays only the selection point A brightly during the night, it would be possible to switch between the two. Desired display can be performed.

〔Effect of the invention〕

The present invention provides a liquid crystal display element that performs zone display or segment display by sealing liquid crystal between opposing transparent electrodes and changing the optical properties of selected points, which are desired segment electrode locations, by controlling the voltage applied to the electrodes. , a voltage higher than a threshold voltage of the liquid crystal is generated in the non-electrode portion in order to make the optical properties of the non-electrode portion adjacent to the selection point substantially similar to the optical properties of the selection point. This device is designed to be driven, and has the effect of suppressing a decrease in visibility even in the case of fine-pitch technology without reducing the ratio of the area of the segment electrodes to the unit area of the liquid crystal display element. It is.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of the liquid crystal display element, Figure 2 is the applied voltage and transmitted light of the same liquid crystal display element.
FIG. 5 is a diagram illustrating the state of application to the same liquid crystal display element, and FIGS. 6 and 7 are diagrams illustrating the display state of the liquid crystal display element to which the present invention is applied. 2.--Segment electrode 4-Common electrode 101 Liquid crystal display element A-Selected point B-Non-selected point c-Non-electrode portion Fig. 1 S Fig. 2

Claims (1)

[Claims] In a liquid crystal display element that performs zone display or segment display by sealing liquid crystal between opposing transparent electrodes and changing the optical properties of a selected point, which is a desired segment electrode location, by controlling a voltage applied to the electrodes, the selected point The non-electrode portion is driven to generate a voltage higher than the threshold voltage of the liquid crystal in order to make the optical properties of the non-electrode portion adjacent to the selected point substantially similar to the optical properties of the selected point. A liquid crystal display element featuring: