VOLTAGE SUPPLY UNIT AND METHOD, DISPLAY DRIVING CIRCUIT AND DISPLAY DEVICE

• US 20200135135A1
• Filed: 06/26/2019
• Published: 04/30/2020
• Est. Priority Date: 10/24/2018
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd., Hefei Xinsheng Optoelectric Technology Co. Ltd. (BOE Technology Group Co., Ltd.)
• Original Assignee: Hefei Xinsheng Optoelectric Technology Co. Ltd. (BOE Technology Group Co., Ltd.)
• Inventors: Yang, Kun, Nie, Chunyang, Dai, Ke, Guo, Lei, Hu, Shenghua, Li, Ruilian
• Granted Patent: US 10,692,464 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2330/027 Arrangements or methods related to powering off a display
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A voltage supply unit includes a control circuit, a capacitor circuit and a unidirectionally-conductive circuit. The control circuit controls an output end of the control circuit to be electrically connected to a first input end or a second input end of the control circuit under the control of a voltage signal from a first voltage output end. The capacitor circuit controls a potential at a first input end. When a difference between a first level and a potential at the first input end is greater than or equal to a predetermined on-state voltage, the unidirectionally-conductive circuit allows a unidirectional current flowing from a first level end to a first end thereof, and when the difference between the first level and the potential at the first input end is smaller than the predetermined on-state voltage, controls the first level end to be electrically disconnected from the first input end.

Claims

1. A voltage supply unit, comprising a control circuit, a capacitor circuit and a unidirectionally-conductive circuit, wherein

a control end of the control circuit is connected to a first voltage output end, a first input end of the control circuit is connected to a first end of the capacitor circuit, a second input end of the control circuit is connected to a second level end, and an output end of the control circuit is configured to provide a voltage;

the control circuit is configured to control the output end to be electrically connected to the first input end or the second input end under the control of a voltage signal from the first voltage output end;

the first end of the capacitor circuit is connected to a first end of the unidirectionally-conductive circuit, and a second end of the capacitor circuit is connected to the control end;

the capacitor circuit is configured to control a potential at the first input end;

a second end of the unidirectionally-conductive circuit is connected to a first level end; and

the unidirectionally-conductive circuit is configured to, when a difference between a first level inputted by the first level end and a potential at the first end of the unidirectionally-conductive circuit is greater than or equal to a predetermined on-state voltage, allow a unidirectional current flowing from the first level end to the first end of the unidirectionally-conductive circuit to flow therethrough, and when the difference between the first level and the potential at the first end of the unidirectionally-conductive circuit is smaller than the predetermined on-state voltage, control the first level end to be electrically disconnected from the first end of the unidirectionally-conductive circuit.

2. The voltage supply unit according to claim 1, wherein the control circuit comprises a first control transistor and a second control transistor, wherein

a control electrode of the first control transistor is connected to the control end, a first electrode of the first control transistor is connected to the first input end, and a second electrode of the first control transistor is connected to the output end;

and

a control electrode of the second control transistor is connected to the control end, a first electrode of the second control transistor is connected to the second input end, and a second electrode of the second control transistor is connected to the output end.

3. The voltage supply unit according to claim 2, wherein the first control transistor is an NPN-type transistor, an n-type Thin Film Transistor (TFT) or a Negative Metal-Oxide-Semiconductor (NMOS) transistor, and the second control transistor is a PNP-type transistor, a p-type TFT or a Positive Metal-Oxide-Semiconductor (PMOS) transistor.

4. The voltage supply unit according to claim 1, wherein the capacitor circuit comprises a storage capacitor, wherein a first end of the storage capacitor is connected to the first end of the unidirectionally-conductive circuit, and a second end of the storage capacitor is connected to the control end.

5. The voltage supply unit according to claim 1, wherein the capacitor circuit comprises at least two storage capacitors connected in parallel to each other, wherein a first end of each storage capacitor is connected to the first end of the unidirectionally-conductive circuit, and a second end of each storage capacitor is connected to the control end.

6. The voltage supply unit according to claim 4, wherein a capacitance of the storage capacitor is greater than or equal to 100 μ

F.

7. The voltage supply unit according to claim 4, wherein the storage capacitor is an electrolytic capacitor.

8. The voltage supply unit according to claim 1, wherein the unidirectionally-conductive circuit comprises a control diode, the first end of the unidirectionally-conductive circuit is a cathode of the control diode, and the second end of the unidirectionally-conductive circuit is an anode of the control diode, wherein the anode of the control diode is connected to the first level end, and the cathode of the control diode is connected to the first end of the capacitor circuit.

9. The voltage supply unit according to claim 8, wherein the predetermined on-state voltage is a threshold voltage of the control diode.

10. The voltage supply unit according to claim 1, wherein the first voltage output end is a first voltage output end of a level shifter, the first level is a high level provided by a power source management integrated circuit, and the second level is a low level provided by the power source management integrated circuit.

11. A voltage supply method for applying a voltage to a display panel through the voltage supply unit according to claim 1, wherein the voltage supply method comprises:

within a display time period, outputting, by the first voltage output end, a first voltage signal, and controlling, by the control circuit, the output end of the control circuit to be electrically connected to the second input end of the control circuit, so as to enable a unidirectional current flowing from the first level end to the first end of the unidirectionally-conductive circuit to flow through the unidirectionally-conductive circuit to charge the capacitor circuit, thereby to pull up the potential at the first input end of the control circuit, until the unidirectionally-conductive circuit controls the first level end to be electrically disconnected from the first end of the unidirectionally-conductive circuit; and

within a shutdown time period, outputting, by the first voltage output end, a second voltage signal, and controlling, by the control circuit, the output end of the control circuit to be electrically connected to the first input end of the control circuit.

12. A display driving circuit, comprising the voltage supply unit according to claim 1.

13. A display device, comprising the display driving circuit according to claim 12.