Display device

Patent metadata

Field	Value
Publication number	US-2025199348-A1
Application number	US-202318851976-A
Country	US
Kind code	A1
Filing date	Apr 17, 2023
Priority date	Apr 25, 2022
Publication date	Jun 19, 2025
Grant date	—

Abstract

A display device capable of achieving miniaturization, lower power consumption, and higher image quality is provided. A display device includes a plurality of pixels. The pixels each include a display element and a pixel circuit that controls a voltage supplied to the display element. The pixel circuit includes a capacitor that holds a charge according to the voltage supplied to the display element, a charge/discharge circuit that charges and discharges the capacitor, and a control circuit that controls the charge/discharge circuit. The charge/discharge circuit includes a first switching element that controls charging of the capacitor and a second switching element that controls discharging of the capacitor. The control circuit includes a third switching element that controls on or off of at least one of the first switching element and the second switching element on a basis of at least one of pixel data or a display timing signal.

First claim

What is claimed is:

1 . A display device, comprising:
a plurality of pixels, wherein the pixels each include a display element and a pixel circuit that controls a voltage supplied to the display element, the pixel circuit includes a capacitor that holds a charge according to the voltage supplied to the display element, a charge/discharge circuit that charges and discharges the capacitor, and a control circuit that controls the charge/discharge circuit, the charge/discharge circuit includes a first switching element that controls charging of the capacitor and a second switching element that controls discharging of the capacitor, and the control circuit includes a third switching element that controls on or off of at least one of the first switching element and the second switching element on a basis of at least one of pixel data or a display timing signal.

2 . The display device according to claim 1 , wherein
the first switching element and the second switching element have a same withstand voltage and a same conductivity type.

3 . The display device according to claim 1 , wherein
the first switching element and the second switching element in the charge/discharge circuit have a first withstand voltage, and the third switching element in the control circuit has a second withstand voltage, which is lower than the first withstand voltage.

4 . The display device according to claim 1 , wherein
the first switching element, the second switching element, and the third switching element are cascode-connected between a first reference voltage node and a second reference voltage node, and the capacitor is connected between a connection node between the first switching element and the second switching element and the second reference voltage node.

5 . The display device according to claim 4 , wherein
the third switching element has a same withstand voltage and a same conductivity type as the first switching element and the second switching element.

6 . The display device according to claim 4 , wherein
the third switching element has a different withstand voltage from and a same conductivity type as those of the first switching element and the second switching element.

7 . The display device according to claim 1 , wherein
the first switching element and the second switching element are cascode-connected between a first reference voltage node and a second reference voltage node, and the capacitor is connected between a connection node between the first switching element and the second switching element and the second reference voltage node.

8 . The display device according to claim 1 , wherein
the control circuit generates a control signal to be input to a gate of at least one of the first switching element and the second switching element on a basis of the pixel data and the display timing signal.

9 . The display device according to claim 8 , wherein
a precharge signal is input to one of gates of the first switching element and the second switching element, and the control signal is input to another gate.

10 . The display device according to claim 9 , wherein
a voltage amplitude of the precharge signal is larger than a voltage amplitude of the control signal.

11 . The display device according to claim 9 , wherein
a voltage amplitude of the precharge signal is larger than voltage amplitudes of the pixel data and the display timing signal.

12 . The display device according to claim 9 , further comprising:
a first drive circuit that sets a voltage level of the precharge signal in consideration of a threshold voltage of the first switching element or the second switching element.

13 . The display device according to claim 12 , wherein
the first switching element and the second switching element are N-type metal oxide semiconductor (MOS) transistors, a drain of the first switching element is connected to a first reference voltage node, one end of the capacitor is connected to a source of the first switching element, and the first drive circuit sets the voltage level of the precharge signal to a voltage higher than a voltage of the first reference voltage node by the threshold voltage so that the source of the first switching element has a same voltage level as the first reference voltage node when the capacitor is charged.

14 . The display device according to claim 12 , wherein
the first switching element and the second switching element are P-type metal oxide semiconductor (MOS) transistors, a source of the first switching element is connected to a first reference voltage node, a drain of the second switching element is connected to a second reference voltage node, one end of the capacitor is connected to a drain of the first switching element, and the first drive circuit sets the voltage level of the precharge signal to a voltage lower than a voltage of the second reference voltage node by the threshold voltage so that the drain of the first switching element has a same voltage level as the second reference voltage node when the capacitor is discharged.

15 . The display device according to claim 12 , wherein
the first drive circuit inputs the precharge signal having a voltage amplitude larger than a voltage amplitude of the control circuit and the display timing signal having a voltage amplitude close to the voltage amplitude of the control circuit to the control circuit.

16 . The display device according to claim 9 , wherein
the charge/discharge circuit includes a diode or a diode-connected transistor connected to the gate of the first switching element, and a compensation circuit that compensates for a decrease in a charging voltage of the capacitor caused in a case where the precharge signal is input to the gate of the first switching element via the diode or the diode-connected transistor.

17 . The display device according to claim 1 , wherein
a first reference voltage of a first reference voltage node and a second reference voltage of a second reference voltage node have opposite voltage polarities, and a precharge signal supplied to a gate of the first switching element and the display timing signal have opposite voltage polarities.

18 . The display device according to claim 17 , wherein
the precharge signal supplied to the gate of the first switching element and the pixel data have opposite voltage polarities, and the control circuit is supplied with the first reference voltage or the second reference voltage and an intermediate voltage between the first reference voltage and the second reference voltage.

19 . The display device according to claim 16 , wherein
the first switching element and the second switching element have a same withstand voltage and different conductivity types.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Shirai Kiyotoshi
• Orii Toshihiko
• Nakao Hiroshi
• Watanabe Yasuhiro
• MIYATAKE Takaaki

Classifications

• G02F1/13306 Primary

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

• G02F1/136213

  Storage capacitors associated with the pixel electrode · CPC title

• G03B21/006

  using LCD's · CPC title

• G02F1/1368 Primary

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

• G09F9/30

  in which the desired character or characters are formed by combining individual elements (panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00) · CPC title