JPS59141070A - Liquid crystal bar graph display unit - Google Patents

Abstract

PURPOSE:To enable a bar graph display according to the level of an input signal by running a pulse current to a pair of electrodes as transparent resistance electrode according to the level of an analog input signal to cause a voltage drop in the direction of display. CONSTITUTION:There are an oscillation circuit 1 for generating a pulse P with a duty ratio of 50%, an inverter 2 thereof and first and a second circuits 3 and 4 receiving an analog input signal A to be displayed as input. When the pulse signal P is generated, the gate circuit 3 turns ON and the gate circuit 4 turns ON by a pulse signal from the inverter. A belt-shaped liquid crystal display element 5 has transparent substrates 7 and 8 facing each other through a spacer 6 and transparent resistance electrodes 9 and 10 are provided on the opposed surfaces thereof with a liquid crystal material 11 sealed therebetween. Outputs of the gate circuits 3 and 4 are supplied to the resistance electrodes 9 and 10 with the other end thereof grounded respectively. This enables an graph display of the level of an analog input signal without requiring a number of segment electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a liquid crystal pergraph display device that can display a pergraph in an analog manner without arranging a large number of segment electrodes in parallel.

BACKGROUND ART A liquid crystal display device displays a liquid crystal material by interposing a liquid crystal material between a pair of opposing electrodes and changing the light transmission characteristics of the liquid crystal material by applying a voltage between the two electrodes.

In this case, in various devices, a pergraph display is used to display the liquid level and the like. A pergraph display device using this liquid crystal display element is constructed by forming one of the opposing electrodes by arranging narrow segment electrodes in parallel, and successively selecting the segment electrodes in a number corresponding to the level of the analog input signal. A pergraph display is performed by applying a driving voltage between the selected segment and the other electrode.

However, in the above configuration, one of the liquid crystals 'Ml must be constructed by arranging segment electrodes in parallel.
When displaying minute changes or over a wide range, the number of segment electrodes increases significantly, making manufacturing them extremely difficult. In addition, each segment electrode must be electrically drawn out to the outside in a state that it is independent from each other, and for devices with a large number of segment electrodes, it is extremely difficult to draw out the electrical power.
Even if one electrical lead is disconnected, it will become defective.

DISCLOSURE OF THE INVENTION Accordingly, it is an object of the present invention to provide a liquid crystal display device capable of graphically displaying the level of an analog input signal without requiring a large number of segment electrodes.

In order to achieve such an object, the present invention provides a pair of electrodes provided inside a liquid crystal display element, each of which is a transparent resistance electrode, and a noggle current corresponding to the level of an analog input signal is applied to both resistance electrodes. By generating a voltage drop across the resistive electrode along the display direction, a pergraph display having a length corresponding to the analog input signal level is performed.

In the liquid crystal graph display device constructed in this manner, it is no longer necessary to provide a large number of segments as in the prior art, so that the manufacturing thereof can be greatly simplified compared to the prior art. Furthermore, since the present invention uses continuous electrodes without using a large number of segments, the display becomes continuous and clear. Furthermore, since the electrodes are continuous, flickering at the leading edge of the display can be prevented when the analog input signal fluctuates.

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a circuit diagram showing an embodiment of a liquid crystal pergraph display device according to the present invention. In the figure, l is an oscillator circuit that generates a pulse P with a duty ratio of 50%, 2 is an inverter that inverts the pulse signal P, and 3 is an input signal A that is the analog value to be displayed. The first gate circuit opens when the pulse signal P generated from the oscillation circuit 1 is generated, and outputs the input signal A. Reference numeral 4 denotes a second gate circuit which receives the input signal A, and is opened during the "H" period of the pulse signal P supplied from the inverter 2, and outputs the input signal A. Reference numeral 5 has a band shape. This is a liquid crystal display element having a rimming substrate 7°8 with a spacer 6 interposed therebetween.
are placed facing each other. Transparent resistance electrodes 9 and 10 are provided on opposing surfaces of the transparent substrates 7 and 8, respectively, and drawn out to the outside, and a liquid crystal substance 11 is sealed between these electrodes. The output signal B of the first gate circuit 3 and the output signal 0 of the third gate circuit 4 are applied to the resistance electrodes 9 and 10 located on the one end X (display start end side) side of the liquid crystal display element 5 configured in this way. are supplied to each terminal, and the other end is grounded.

In the liquid crystal pergraph display device configured in this way,
When a power switch (not shown) is turned on, the oscillation circuit 1 is activated and generates the Noculus signal P shown in FIG. 2(a).

Then, this o pulse signal P is inverted in the inverter 2 and is generated as the o pulse signal P shown in FIG. 2(b).

On the other hand, the first gate circuit 3 is opened only during the "H" period of the nozzle signal P generated from the oscillation circuit 1, thereby sampling and outputting the input signal A. here,
If, for example, a sawtooth wave signal shown in FIG. 3(a) is input as the input signal A, the output signal B of the first gate circuit 3 will be as shown in FIG. 3(b). Further, the output signal C of the second gate circuit 4, which is opened and closed by the pulse signal P having the opposite polarity to the pulse signal P supplied to the first gate circuit 3, is as shown in FIG. 3(C). Become.

And this first one. Output signal B of second gate circuits 3 and 4
, O are supplied to the display start end side X of the resistance electrodes 9 and 10 constituting the liquid crystal display element 5, respectively. In this case, since the X ends of the resistance electrodes 9 and 10 as the display end are grounded, a voltage drop occurs in which the voltage gradually decreases from the Y side as the start end toward the Y side. Therefore, when the input signal A gradually increases as shown in FIG.
Without moving as shown in the figure, the level of the input signal A can be displayed graphically without providing a large number of segment electrodes and their external lead lines.

In the above embodiment, a transmissive type liquid crystal display device is used, but the present invention can also be applied to a reflective type liquid crystal display device or a type using a polarizing plate. Also,
Since the liquid crystal has a certain activation voltage, a relatively sharp boundary will occur between the display area and the non-display area.

As explained above, in the liquid crystal bar graph display device according to the present invention, it is possible to indicate the level of an analog input signal without providing a large number of segment electrodes and their lead lines. Accordingly, the structure of the liquid crystal display element is greatly simplified. Further, according to the present invention, there is no need to control the number of segment electrodes to be selected depending on the level of an analog input signal as in the conventional case, so that the drive circuit itself can be simplified, and various other excellent effects can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the liquid crystal pargraph display device according to the present invention, Fig. 2 (,), (b), and Fig. 3 (
A) to (C) are operation waveform diagrams of each part of the circuit shown in FIG. 1, and FIG. 4 is a diagram showing an example of a graph. l...Oscillation circuit, 2...Inverter, 3...First
Gate circuit, 4... Second gate circuit, 5... Liquid crystal display element, 6... Spacer, 7, 8... Transparent substrate, 9
゜10...Resistive electrode, 11...Liquid crystal. Applicant: Nippon Electric Co., Ltd.

Claims (1)

[Claims] (1) An oscillation circuit that generates a noise signal with a duty ratio of approximately 50%, and an analog input signal that is sampled and output using the noise signal generated from this oscillation circuit. A first gate circuit, a second gate circuit that is opened by an inverted signal of a pulse signal generated from the oscillation circuit to sample and output an analog input signal, and a pair of opposing electrodes connected to a transparent first gate circuit; ．． a liquid crystal display element as a second resistance electrode; The output signal of the second gate circuit is transmitted to the first gate circuit. A pergraph display according to the input signal level is performed by supplying the signals to the display start ends of the second resistance electrodes and connecting the display end sides of the first and second resistance electrodes to ground. Liquid crystal pergraph display device.