Liquid crystal display device, method for driving liquid crystal display device, and electronic device

Patent metadata

Field	Value
Publication number	US-2021173249-A1
Application number	US-201816771360-A
Country	US
Kind code	A1
Filing date	Dec 10, 2018
Priority date	Dec 21, 2017
Publication date	Jun 10, 2021
Grant date	—

Abstract

A liquid crystal display device including a pixel containing a first memory circuit, a second memory circuit, and a liquid crystal element is provided. The first memory circuit includes a first capacitor. One electrode of the first capacitor is electrically connected to one electrode of the liquid crystal element. The second memory circuit includes a second capacitor. One electrode of the second capacitor is electrically connected to the one electrode of the liquid crystal element. The first memory circuit has a function of storing a charge corresponding to a first signal. The second memory circuit has a function of storing a charge corresponding to a second signal. A voltage is applied to the liquid crystal element by supplying a third signal to the other electrode of the first capacitor and supplying a fourth signal to the other electrode of the second capacitor, whereby an image is displayed.

First claim

1 . A liquid crystal display device comprising:
a pixel comprising a first memory circuit, a second memory circuit, and a liquid crystal element, wherein the first memory circuit comprises a first capacitor, wherein one electrode of the first capacitor is electrically connected to one electrode of the liquid crystal element, wherein the second memory circuit comprises a second capacitor, wherein one electrode of the second capacitor is electrically connected to the one electrode of the liquid crystal element, wherein the first memory circuit has a function of storing a charge corresponding to a first signal, wherein the second memory circuit has a function of storing a charge corresponding to a second signal, and wherein a voltage is applied to the liquid crystal element by supplying a third signal to the other electrode of the first capacitor and supplying a fourth signal to the other electrode of the second capacitor.

2 . The liquid crystal display device according to claim 1 ,
wherein the first memory circuit comprises a first transistor, a second transistor, and the first capacitor, wherein the second memory circuit comprises the second transistor, a third transistor, and the second capacitor, and wherein the first transistor to the third transistor comprise a metal oxide in channel formation regions, and the metal oxide comprises In, Zn, and M (M being Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf).

3 . The liquid crystal display device according to claim 2 ,
wherein the pixel is electrically connected to a first wiring that supplies the first signal or the second signal, wherein the pixel is electrically connected to a second wiring that supplies a reference voltage or the third signal, wherein the pixel is electrically connected to a third wiring that supplies the reference voltage or the fourth signal, wherein the first transistor has a function of controlling the conduction state between the second wiring and the other electrode of the first capacitor, wherein the second transistor has a function of controlling the conduction state between the first wiring, the one electrode of the first capacitor and the one electrode of the second capacitor, and wherein the third transistor has a function of controlling the conduction state between the third wiring and the other electrode of the second capacitor.

4 . The liquid crystal display device according to claim 1 ,
wherein the pixel comprises a third capacitor, wherein one electrode of the third capacitor is electrically connected to the one electrode of the liquid crystal element, and wherein the other electrode of the third capacitor is electrically connected to a fourth wiring that has a function of supplying a common potential.

5 . The liquid crystal display device according to claim 2 ,
wherein a gate of the first transistor is electrically connected to a fifth wiring to which a signal that controls the conduction state of the first transistor is supplied, wherein a gate of the second transistor is electrically connected to a sixth wiring to which a signal that controls the conduction state of the second transistor is supplied, and wherein a gate of the third transistor is electrically connected to a seventh wiring to which a signal that controls the conduction state of the third transistor is supplied.

6 . An electronic device comprising the liquid crystal display device according to claim 1 , and a camera.

7 . A driving method of a liquid crystal display device comprising:
a pixel comprising a first memory circuit, a second memory circuit, and a liquid crystal element, wherein the first memory circuit comprises a first capacitor, wherein the second memory circuit comprises a second capacitor, wherein by supplying one electrode of the first capacitor with a reference voltage and the other electrode of the first capacitor with a first signal, a charge corresponding to the first signal is stored in the first memory circuit, wherein by supplying one electrode of the second capacitor with the reference voltage and the other electrode of the second capacitor with a second signal, a charge corresponding to the second signal is stored in the second memory circuit, and wherein by supplying the one electrode of the first capacitor with a third signal and the one electrode of the second capacitor with a fourth signal, a voltage is applied to one electrode of the liquid crystal element.

8 . The driving method of the liquid crystal display device according to claim 7 , wherein the first signal and the second signal are signals for performing inversion driving.

Assignees

• Semiconductor Energy Lab

Inventors

• Kawashima Susumu
• Kusunoki Koji
• Watanabe Kazunori
• Takahashi Kei
• Yamazaki Shunpei

Classifications

• G02F1/136213 Primary

  Storage capacitors associated with the pixel electrode · CPC title

• G02F1/13454 Primary

  Drivers integrated on the active matrix substrate (G02F1/136277 takes precedence) · CPC title

• G09G3/20

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/13306

  Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence) · CPC title