JPS6321697A - Driving circuit for liquid crystal element using non-linear resistance film - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a drive circuit for a liquid crystal element using a nonlinear resistive film used in display devices, optical shutters, etc.
The present invention relates to a liquid crystal element drive circuit using a nonlinear resistive film with a simple configuration using an N-type liquid crystal element drive circuit.

[Summary of the invention]

In driving a liquid crystal element using a nonlinear resistive film, the normal T
It is driven by using the drive circuit of an N type liquid crystal element as it is, and the drive circuit of a TN type liquid crystal element includes a display data inverting circuit and a non-selection signal to make half of one scanning time non-selected. Constructed by adding a generation circuit.

[Conventional technology]

There are two ways to drive a liquid crystal element using a nonlinear resistive film: a voltage averaging method that uses the driving method of a TN liquid crystal element as is, and a phase modulation method that suppresses fluctuations in the liquid crystal interlayer voltage depending on display conditions, etc. There is a law. Previously T
Either use the drive circuit of the N liquid crystal element and drive it as it is by the voltage averaging method, or store the lighting data and the inverted data of the lighting data in the display memory on the controller side, and then set the display for the selected period! The liquid crystal element using a nonlinear resistive film was driven by a phase modulation method in which the lighting data was output during /dtl1, and the inverted data of the lighting data was output from the drive circuit on the signal electrode side and displayed, with the remaining two periods being non-selection periods. . In the driving method using the phase modulation method, the display memory is increased and the circuit configuration on the controller side is also enlarged, which causes an increase in cost.

FIG. 3 shows a drive circuit for a liquid crystal display element using a nonlinear resistive film according to the prior art. Reference numeral 10 designates a signal electrode drive circuit.

20 is a scanning electrode drive circuit, 30 is a liquid crystal display element using a nonlinear resistive film, 40 is a drive power supply circuit, 50 is display data,
60 is a control line, and 70 is a power supply.

[Problem that the invention seeks to solve]

The present invention attempts to solve the problems of an increase in display memory on the controller side and an increase in cost amplifiers when driving a liquid crystal element using a nonlinear resistive film.

[Means for solving problems]

A display data inversion circuit for inverting display data and a non-selection signal generation circuit for generating a signal for inverting the display data are provided between the controller side and a liquid crystal drive circuit using a nonlinear resistive film.

〔Example〕

By nonlinear resistive film. 'When driving and displaying a porcelain element,
Contrast fluctuates due to fluctuations in effective voltage, resulting in deterioration in display quality.

The present invention provides a driving circuit for a liquid crystal element that suppresses fluctuations in effective voltage.

FIG. 1 shows the configuration of a driving circuit for a liquid crystal element using a nonlinear resistive film according to the present invention. The signal electrode drive circuit is, for example, a 5E
A DI 600FOA (manufactured by Suwa Seiko Kin) is used, and a 5RDI 610FOA (manufactured by Suwa Seiko Kin) is used for the scanning electrode drive circuit. Figure 2 shows the time chart of Figure 1. The signal electrode side latch signal (LOAD) sends display data CD3 to Dφ to the signal electrode drive circuit for each -horizontal line.
) is latched, and at the same time J/ of the non-selection signal generation circuit is latched.
Trigger flip-flop 2. Flip-flop 2 at J/ operates as a toggle flip-flop because the terminal at J is connected to the Vcc level, and every time the latch signal (LOAD) on the signal electrode side falls, the time chart in Fig. 2 A non-selection signal (1) is generated. Non-select signal (
1) is at the "L" level, the non-selection signal terminal (INH) of the scan electrode drive circuit is driven, and the output (7) of the scan electrode drive circuit is made into a non-selection waveform. Also, the non-selection signal +11 goes to the display data inversion circuit, inverts the display data (D3 to Dφ) when the non-selection signal (1) is at "H" level, and goes to the signal electrode drive circuit. The inverted output terminal (Q) of the flip-flop and the signal electrode side latch signal (LOAD) are input to the AND gate (3) to generate the scan electrode side launch signal (5), and the scan electrode drive circuit The shift clock terminal (YSCL) of Frame signal (FRM)
When the scan electrode side latch signal (5) and the scan electrode side latch signal (5) overlap, the common electrodes of the liquid crystal display element (MSI panel) using a nonlinear resistive film are driven sequentially from Y1 to Y from the falling point of the scan electrode side latch signal (5). Go. The signal electrode side launch signal (LOAD) is connected to the latch terminal (L) of the signal electrode drive circuit.
P), and at the falling edge of the signal electrode side latch signal (LOAD), the display data (D3 to Dφ) shifted by the clock signal (CP) is latched, and the segment electrodes X, - of the MSr panel are driven. Drive X.

The signal electrode side latch signal (LOAD) is generated every number of horizontal dots (n dots) on the MS+ panel.

On the other hand, the scanning electrode side launch signal (5) is generated every 2,000 dots. As is clear from the time chart of FIG. 2, during the first horizontal dot period of two horizontal dots, the non-selection signal (1) is at the "H" level, so the signal electrode display data (4
) is inverted and input to the signal electrode drive circuit, and during the latter half of the two horizontal dot count (when the non-selection signal (1) is at the "L" level, that is, the output (7) of the scanning electrode drive circuit is a non-selection waveform). period) appears in the output (6) of the signal electrode drive circuit, and applies a non-selection signal waveform to the MSI panel. During the second half of the second horizontal dot period, the display data (D3 to Dφ) is input to the signal electrode drive circuit as is without being inverted, so that the display data (D3 to Dφ) is input to the signal electrode drive circuit as is, so that the display data (D3 to Dφ) is not inverted and is input to the signal electrode drive circuit as it is. 2) is displayed correctly. Thereafter, the non-selected and 2-selected states are repeatedly displayed.

MS with a drive circuit like this! By driving the panel, fluctuations in the effective voltage of the pixel depending on the pixel state can be suppressed, and a driving circuit for the MS■ panel without contrast unevenness can be achieved. Another advantage is that a normal TN type drive circuit can be used as is, and a particularly complicated circuit is not required.

〔Effect of the invention〕

According to the present invention, it is possible to configure an MSI panel drive circuit using a phase modulation method using a normal TN drive circuit without increasing the display memory, and it is also possible to prevent an increase in cost on the controller side. It can be used in various liquid crystal elements, such as optical shutters such as shutters.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a drive circuit for a liquid crystal display element using a nonlinear resistive film, FIG. 2 is a time chart of FIG. 1, and FIG. 3 is a conventional drive circuit for a liquid crystal display element using a nonlinear resistive film. Dφ~D3...Display data CP...Clock signal DF...AC inverted signal FRM...Frame signal LOAD...Signal electrode side launch signal MSI panel...Liquid crystal display element 1 using a nonlinear resistive film・Non-selection signal 2...J/Nifuri, Pflo, P3...And gate 6...Output of the signal electrode drive circuit F...Output of the scanning electrode drive circuit or more Applicant: Seiko Electronics Industries, Ltd.゛e゛′

Claims (1)

[Claims] In driving a liquid crystal element using a non-linear resistance film, a display data inversion circuit inverts display data using a non-selection switch signal, a non-selection signal generation circuit that generates the non-selection switch signal, and a non-selection signal generation circuit that generates a signal from the display data inversion circuit. A signal electrode drive circuit that receives signal electrode display data and drives the signal electrode, a scan electrode drive circuit that has a non-selection signal input terminal, a liquid crystal element using a nonlinear resistive film, and the signal electrode drive circuit and the scan electrode drive circuit. A drive circuit for a liquid crystal element using a nonlinear resistive film consisting of a drive power supply circuit that supplies power.