JPS63262622A - Driving method for liquid crystal element - Google Patents

Abstract

PURPOSE:To execute stable driving of a liquid crystal which can execute a high speed response and can be driven by a low voltage, by setting the potential of an opposed electrode of non-selection, to a floating state. CONSTITUTION:At the time of selection, a scanning electrode control signal 1 is in an 'L' level, and turns on an NPN type transistor 3 through an inverter 2. As a result, a PNP type transistor 4 is turned on, a selected voltage is applied to the transistor 4 from a power source 6, a scanning electrode signal 5 is inputted to an opposed electrode of a liquid crystal 9, and to the opposed electrode, the potential required for changing an oriented state of the liquid crystal 9 by an electric field between said electrode and a picture element electrode of the liquid crystal 9 is given. At the time of non-selection, when the scanning electrode control signal is set to an 'H' level, both the NPN type transistor 3 and the PNP type transistor 4 are turned off, the scanning electrode signal 5 becomes a floating state, and the potential of the opposed electrode of non- selection becomes a floating state. In such a way, stable driving of a liquid crystal which can execute a high speed response, and can be driven by a low voltage can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a driving system for optical shutter arrays, image display devices, etc. using liquid crystals, and particularly to a driving system for ferroelectric liquid crystals having bistability.

[Conventional technology]

The liquid crystal element includes a first substrate provided with a plurality of pixel electrodes connected to a display signal line, and a second substrate provided with a counter electrode connected to a scanning signal line opposite to the pixel electrodes. ,
There is a structure in which a ferroelectric liquid crystal having bistability to an electric field is sandwiched between the pixel electrode and the counter electrode.

Incidentally, conventionally, this type of liquid crystal element is driven by applying a potential to non-selected counter electrodes as well.

[Problem that the invention seeks to solve]

In the conventional driving method described above, a potential is also applied to the non-selected counter electrode, so in liquid crystals that can be driven at high speed and at low voltages, the electric field between the counter electrode and the pixel electrode maintains the alignment state even when the pixel electrode is not selected. The disadvantage is that it changes.

An object of the present invention is to provide a method for driving a liquid crystal element that eliminates the above-mentioned problems.

[Means for solving problems]

The present invention has a first cutting board provided with a plurality of pixel electrodes connected to a display signal line, and a second substrate provided with a counter electrode connected to a scanning signal line opposite to the pixel electrode, In the time-division driving method of a liquid crystal element having a structure in which a ferroelectric liquid crystal having bistability with respect to an electric field is sandwiched between the pixel electrode and the counter electrode, a selected counter electrode is exposed to an electric field between the pixel electrode and the pixel electrode. This method of driving a liquid crystal element is characterized by applying a potential to change the alignment state of the liquid crystal at a point, and setting the potential of an unselected counter electrode to a floating state.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a circuit for floating the potential of the counter electrode when not selected in the present invention. In FIG. 1, 9 is an NPN transistor, 4 is a PNP transistor, and the inverter 2 is at the base of the NPN transistor 3, and the PNP transistor 4 is at the collector.
The bases of the PNP transistors 4 and 4 are connected to each other.
A liquid crystal 9 is connected to the collector. 6 is a power source that selectively changes the voltage, and 7 is a display signal generator.

In the embodiment, when selected, scan electrode control signal 1 is 1L#
level, and turns on the NPN transistor 3 through the inverter 2. As a result, the PNP transistor 4 is ONL, a selection voltage is applied to the transistor 4 from the power supply 6, the scanning electrode signal 5 is input to the counter electrode of the liquid crystal 9, and the counter electrode is connected to the pixel electrode of the liquid crystal 9. An electric potential required to change the alignment state of the liquid crystal 9 is given by an electric field.

When not selected, by setting the scan electrode control signal to H level, both the NPN transistor 3 and the PNP transistor 4 are turned off, the scan electrode signal 5 is in a floating state, and the potential of the unselected counter electrode is floating. state.

In addition to the above operations, the display signal generator 7 generates a display signal 8.
is output, and a differential voltage shown in FIG. 2 is applied to the liquid crystal 9. In FIG. 2, * indicates that the previous potential difference is maintained.

〔Effect of the invention〕

As described above, the present invention has the effect of making it possible to stably drive a liquid crystal capable of high-speed response and low-voltage driving by floating the potential of unselected counter electrodes.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a circuit for realizing the present invention, and FIG. 2 is a diagram showing each signal and voltage applied to the liquid crystal. 1...Scanning electrode control signal 2...Inverter 3.
...NPN type transistor 4...PNP type transistor 5...Scanning electrode signal 6...Selection voltage 7
... Display signal generator 8 ... Display signal 9 ... Liquid crystal

Claims (1)

[Claims] (1) A first substrate provided with a plurality of pixel electrodes connected to a display signal line, and a second substrate provided with a counter electrode connected to a scanning signal line opposite to the pixel electrode; In a time-division driving method for a liquid crystal device that has a structure in which a ferroelectric liquid crystal that is bistable with respect to an electric field is sandwiched between a pixel electrode and a counter electrode, a selected counter electrode is A method for driving a liquid crystal element, characterized by applying a potential to change the alignment state of a liquid crystal, and causing the potential of an unselected counter electrode to be in a floating state.