Pixel compensation circuit and display device

• US 10,210,799 B2
• Filed: 07/21/2017
• Issued: 02/19/2019
• Est. Priority Date: 06/28/2017
• Status: Active Grant

• Current Assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Ltd.
• Original Assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Ltd.
• Inventors: Mao, Peng
• Primary Examiner(s): Rabindranath, Roy P
• Application Number:
  US15/554,219
• Publication Number:
  US 20190005873A1
• Time in Patent Office: 578 Days
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 3/20 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 Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

The invention provides a pixel compensation circuit and a display device. Control terminals of first and second switches connects first and second light-emitting control terminals, first terminals of the first and second switches are connected; a control terminal of a third switch receives a first signal, a first terminal connects a second terminal of the first switch, a second terminal connects a first terminal of a driving switch; an anode of a diode connects a second terminal of the driving switch, a cathode connects a second voltage terminal; a control terminal and a first terminal of a fourth switch receive second and third signals, a second terminal connects a control terminal of the driving switch; a first capacitor connects the control terminal of the driving switch and a second terminal of the second switch, a second capacitor connects the second terminals of the first and second switches.

Claims

1. A pixel compensation circuit, wherein the pixel compensation circuit comprises:

a first controllable switch, the first controllable switch comprising a control terminal, a first terminal and a second terminal, the control terminal of the first controllable switch being connected to a first light-emitting control terminal, the first terminal of the first controllable switch being connected to a first voltage terminal;

a second controllable switch, the second controllable switch comprising a control terminal, a first terminal and a second terminal, the control terminal of the second controllable switch being connected to a second light-emitting control terminal, the first terminal of the second controllable switch being connected to the first terminal of the first controllable switch;

a third controllable switch, the third controllable switch comprising a control terminal, a first terminal and a second terminal, the control terminal of the third controllable switch being connected to receive a first control signal, the first terminal of the third controllable switch being connected to the second terminal of the first controllable switch;

a driving switch, the driving switch comprising a control terminal, a first terminal and a second terminal, the first terminal of the driving switch being connected to the second terminal of the third controllable switch;

an organic light-emitting diode, the organic light-emitting diode comprising an anode and a cathode, the anode of the organic light-emitting diode being connected to the second terminal of the driving switch, the cathode of the organic light-emitting diode being connected to a second voltage terminal;

a fourth controllable switch, the fourth controllable switch comprising a control terminal, a first terminal and a second terminal, the control terminal of the fourth controllable switch being connected to receive a second control signal, the first terminal of the fourth controllable switch being connected to receive a third control signal, the second terminal of the fourth controllable switch being connected to the control terminal of the driving switch;

a first capacitor, the first capacitor comprising a first terminal and a second terminal, the first terminal of the first capacitor being connected to the control terminal of the driving switch, the second terminal of the first capacitor being connected to the second terminal of the second controllable switch;

a second capacitor, the second capacitor comprising a first terminal and a second terminal, the first terminal of the second capacitor being connected to the second terminal of the second controllable switch and the second terminal of the first capacitor, the second terminal of the second capacitor being connected to the second terminal of the first controllable switch and the first terminal of the third controllable switch;

wherein the second control signal is a current stage scan signal, the third control signal is a data signal;

wherein the pixel compensation circuit further comprises a fifth controllable switch, when the second control signal received by the control terminal of the fourth controllable switch is the current stage scan signal and the third control signal received by the first terminal of the fourth controllable switch is the data signal, a control terminal of the fifth controllable switch is connected to receive a preceding stage scan signal, a first terminal of the fifth controllable switch is connected to receive a reference voltage signal, a second terminal of the fifth controllable switch is connected to the control terminal of the driving switch;

a phase of an output signal of the first light-emitting control terminal and a phase of an output signal of the second light-emitting control terminal are inverted, a phase of the first control signal and a phase of the current stage scan signal are inverted, a voltage on the second voltage terminal is lower than a voltage on the first voltage terminal;

the driving switch and the first through fifth controllable switches all are PMOS transistors, the control terminals, the first terminals and the second terminals of the driving switch and the first through fifth controllable switches respectively are corresponding to gates, sources and drains of the PMOS transistors.

2. A pixel compensation circuit, wherein the pixel compensation circuit comprises:

a first controllable switch, wherein the first controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the first controllable switch is connected to a first light-emitting control terminal, the first terminal of the first controllable switch is connected to a first voltage terminal;

a second controllable switch, wherein the second controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the second controllable switch is connected to a second light-emitting control terminal, the first terminal of the second controllable switch is connected to the first terminal of the first controllable switch;

a third controllable switch, wherein the third controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the third controllable switch is connected to receive a first control signal, the first terminal of the third controllable switch is connected to the second terminal of the first controllable switch;

a driving switch, wherein the driving switch comprises a control terminal, a first terminal and a second terminal, the first terminal of the driving switch is connected to the second terminal of the third controllable switch;

an organic light-emitting diode, wherein the organic light-emitting diode comprises an anode and a cathode, the anode of the organic light-emitting diode is connected to the second terminal of the driving switch, the cathode of the organic light-emitting diode is connected to a second voltage terminal;

a fourth controllable switch, wherein the fourth controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the fourth controllable switch is connected to receive a second control signal, the first terminal of the fourth controllable switch is connected to receive a third control signal, the second terminal of the fourth controllable switch is connected to the control terminal of the driving switch;

a first capacitor, wherein the first capacitor comprises a first terminal and a second terminal, the first terminal of the first capacitor is connected to the control terminal of the driving switch, the second terminal of the first capacitor is connected to the second terminal of the second controllable switch;

a second capacitor, wherein the second capacitor comprises a first terminal and a second terminal, the first terminal of the second capacitor is connected to the second terminal of the second controllable switch and the second terminal of the first capacitor, the second terminal of the second capacitor is connected to the second terminal of the first controllable switch and the first terminal of the third controllable switch;

wherein the second control signal is a current stage scan signal, and the third control signal is a data signal;

wherein the pixel compensation circuit further comprises a fifth controllable switch;

when the second control signal received by the control terminal of the fourth controllable switch is the current stage scan signal and the third control signal received by the first terminal of the fourth controllable switch is the data signal, a control terminal of the fifth controllable switch is connected to receive a preceding stage scan signal, a first terminal of the fifth controllable switch is connected to receive a reference voltage signal, a second terminal of the fifth controllable switch is connected to the control terminal of the driving switch.

3. The pixel compensation circuit as claimed in claim 2, wherein a phase of an output signal of the first light-emitting control terminal and a phase of an output signal of the second light-emitting control terminal are inverted, a phase of the first control signal and a phase of the current stage scan signal are inverted, a voltage on the second voltage terminal is lower than a voltage on the first voltage terminal.

4. The pixel compensation circuit as claimed in claim 2, wherein the driving switch and the first through fifth controllable switches all are PMOS transistors, the control terminals, the first terminals and the second terminals of the driving switch and the first through fifth controllable switches respectively are corresponding to gates, sources and drains of the PMOS transistors.

5. A display device, wherein the display device comprises pixel compensation circuit, the pixel compensation circuit comprising:

a first controllable switch, wherein the first controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the first controllable switch is connected to a first light-emitting control terminal, the first terminal of the first controllable switch is connected to a first voltage terminal;

a second controllable switch, wherein the second controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the second controllable switch is connected to a second light-emitting control terminal, the first terminal of the second controllable switch is connected to the first terminal of the first controllable switch;

a third controllable switch, wherein the third controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the third controllable switch is connected to receive a first control signal, the first terminal of the third controllable switch is connected to the second terminal of the first controllable switch;

a driving switch, wherein the driving switch comprises a control terminal, a first terminal and a second terminal, the first terminal of the driving switch is connected to the second terminal of the third controllable switch;

an organic light-emitting diode, wherein the organic light-emitting diode comprises an anode and a cathode, the anode of the organic light-emitting diode is connected to the second terminal of the driving switch, the cathode of the organic light-emitting diode is connected to a second voltage terminal;

a fourth controllable switch, wherein the fourth controllable switch comprises a control terminal, a first terminal and a second terminal, the control terminal of the fourth controllable switch is connected to receive a second control signal, the first terminal of the fourth controllable switch is connected to receive a third control signal, the second terminal of the fourth controllable switch is connected to the control terminal of the driving switch;

a first capacitor, wherein the first capacitor comprises a first terminal and a second terminal, the first terminal of the first capacitor is connected to the control terminal of the driving switch, the second terminal of the first capacitor is connected to the second terminal of the second controllable switch;

a second capacitor, wherein the second capacitor comprises a first terminal and a second terminal, the first terminal of the second capacitor is connected to the second terminal of the second controllable switch and the second terminal of the first capacitor, the second terminal of the second capacitor is connected to the second terminal of the first controllable switch and the first terminal of the third controllable switch;

wherein the second control signal is a current stage scan signal, the third control signal is a data signal;

wherein the pixel compensation circuit further comprises a fifth controllable switch;

when the second control signal received by the control terminal of the fourth controllable switch is the current stage scan signal and the third control signal received by the first terminal of the fourth controllable switch is the data signal, a control terminal of the fifth controllable switch is connected to receive a preceding stage scan signal, a first terminal of the fifth controllable switch is connected to receive a reference voltage signal, a second terminal of the fifth controllable switch is connected to the control terminal of the driving switch.

6. The display device as claimed in claim 5, wherein a phase of an output signal of the first light-emitting control terminal and a phase of an output signal of the second light-emitting control terminal are inverted, a phase of the first control signal and a phase of the current stage scan signal are inverted, a voltage on the second voltage terminal is lower than a voltage on the first voltage terminal.

7. The display device as claimed in claim 5, wherein the driving switch and the first through fifth controllable switches all are PMOS transistors, the control terminals, the first terminals and the second terminals of the driving switch and the first through fifth controllable switches respectively are corresponding to gates, sources and drains of the PMOS transistors.