Current compensation circuit, virtual reality device and control method

Patent metadata

Field	Value
Publication number	US-11189237-B2
Application number	US-201916609342-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 8, 2018
Publication date	Nov 30, 2021
Grant date	Nov 30, 2021

Abstract

A current compensation circuit, a virtual reality device and a control method are disclosed. The current compensation circuit includes: a first constant current sub-circuit, configured to generate a driving current of a backlight module; a second constant current sub-circuit, configured to generate a compensation current of the backlight module; a compensation gating sub-circuit, configured to determine whether to select the second constant current sub-circuit to supply power to the backlight module; and a black insertion control signal generation sub-circuit, configured to generate a black insertion control signal, connected with the first constant current sub-circuit and the compensation gating sub-circuit, and configured to control, by the black insertion control signal, the first constant current sub-circuit and the second constant current sub-circuit to simultaneously supply power to or power off the backlight module, so that the black light module realizes a backlight black insertion.

First claim

What is claimed is:

1. A current compensation circuit, comprising:
a first constant current sub-circuit, configured to generate a driving current of a backlight module;
a second constant current sub-circuit, configured to generate a compensation current of the backlight module;
a compensation gating sub-circuit, connected with the second constant current sub-circuit, and configured to determine, according to a level of a black insertion control signal, whether to select the second constant current sub-circuit to supply power to the backlight module; and
a black insertion control signal generation sub-circuit, configured to generate the black insertion control signal, connected with the first constant current sub-circuit and the compensation gating sub-circuit, and configured to control, by the black insertion control signal, the first constant current sub-circuit and the second constant current sub-circuit to simultaneously supply power to or power off the backlight module, so that the backlight module realizes a backlight black insertion.

2. The current compensation circuit according to claim 1 , wherein the first constant current sub-circuit comprises a first constant current boosting chip, a first energy storage inductor, and a voltage regulating resistor,
the first energy storage inductor is connected between a power input terminal of the first constant current boosting chip and a switch output terminal of the first constant current boosting chip, a regulating terminal of the first constant current boosting chip is grounded through the voltage regulating resistor, an output control terminal of the first constant current boosting chip is configured to receive the black insertion control signal, the switch output terminal of the first constant current boosting chip is connected with a first electrode of the backlight module, and a negative electrode output terminal of the first constant current boosting chip is connected with a second electrode of the backlight module.

3. The current compensation circuit according to claim 2 , wherein the first constant current sub-circuit further comprises a first energy storage capacitor, and wherein an electrical connection point, between the switch output terminal of the first constant current boosting chip and the first electrode of the backlight module, is grounded through the first energy storage capacitor.

4. The current compensation circuit according to claim 3 , wherein the first constant current sub-circuit further comprises a first diode which is configured to prevent flowing back of electric current,
a positive electrode of the first diode is connected with the switch output terminal of the first constant current boosting chip, and an electrical connection point between a negative electrode of the first diode and the first electrode of the backlight module is grounded through the first energy storage capacitor.

5. The current compensation circuit according to claim 2 , wherein the second constant current sub-circuit comprises a second constant current boosting chip, and a second energy storage inductor,
the second energy storage inductor is connected between a power input terminal of the second constant current boosting chip and a switch output terminal of the second constant current boosting chip, a boosting switch terminal of the second constant current boosting chip is configured to receive the black insertion control signal through an inverter, a switch output terminal of the second constant current boosting chip is connected with the first electrode of the backlight module, and a negative electrode output terminal of the second constant current boosting chip and the second electrode of the backlight module are connected with the compensation gating sub-circuit.

6. The current compensation circuit according to claim 5 , wherein the second constant current sub-circuit further comprises a second energy storage capacitor, and wherein an electrical connection point, between the switch output terminal of the second constant current boosting chip and the first electrode of the backlight module, is grounded through the second energy storage capacitor.

7. The current compensation circuit according to claim 6 , wherein the second constant current sub-circuit further comprises a second diode which is configured to prevent flowing back of electric current,
a positive electrode of the second diode is connected with the switch output terminal of the second constant current boosting chip, and a negative electrode of the second diode is grounded through the second energy storage capacitor.

8. The current compensation circuit according to claim 6 , further comprising a third diode which is configured to prevent flowing back of electric current,
a negative electrode of the third diode is connected with the first electrode of the backlight module, and a positive electrode of the third diode is grounded through the second energy storage capacitor.

9. The current compensation circuit according to claim 5 , wherein the compensation gating sub-circuit comprises a first switching transistor, a second switching transistor, a third switching transistor and a fourth switching transistor, a first operational amplifier, a second operational amplifier, a first resistor and a second resistor,
a drain electrode of the first switching transistor is connected with a drain electrode of the second switching transistor, a gate electrode of the second switching transistor is connected with the drain electrode of the second switching transistor, a source electrode of the second switching transistor is configured to receive a reference voltage, an electrical connection point between a source electrode of the first switching transistor and an inverting input terminal of the first operational amplifier is grounded through the first resistor, a non-inverting input terminal of the first operational amplifier is configured to receive the black insertion control signal, an output terminal of the first operational amplifier is connected with a gate electrode of the first switching transistor, the gate electrode of the second switching transistor is connected with a gate electrode of the fourth switching transistor, a source electrode of the fourth switching transistor is configured to receive the reference voltage, a drain electrode of the fourth switching transistor is connected with an enable terminal of the second operational amplifier, a non-inverting input terminal of the second operational amplifier is configured to receive the black insertion control signal, an electrical connection point between an inverting input terminal of the second operational amplifier and a source electrode of the third switching transistor is grounded through the second resistor, an output terminal of the second operational amplifier is connected with a gate electrode of the third switching transistor, and a drain electrode of the third switching transistor is connected with the negative electrode output terminal of the second constant current boosting chip.

10. The current compensation circuit according to claim 9 , wherein the first switching transistor and the third switching transistor are N-typed transistors, and the second switching transistor and the fourth switching transistor are P-typed transistors.

11. A virtual reality device, comprising:
a liquid crystal display panel, and
the current compensation circuit according to claim 1 , wherein the liquid crystal display panel comprises the backlight module.

12. A control method of a current compensation circuit, wherein the current compensation circuit comprises:
a first constant current sub-circuit, configured to generate a driving

Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Pan Feng
• Zhang Hao
• Chen Lili
• Sun Jian
• Wang Yakun
• Du Yuanyuan
• Miao Jinghua
• Lei Yu
• Liu Xinjian
• Guo Ziqiang
• Zhao Bin
• Qin Ruifeng
• Zi Feng

Classifications

• G09G2330/02

  Details of power systems and of start or stop of display operation · CPC title

• H05B45/37

  Converter circuits · CPC title

• G09G3/36

  using liquid crystals · CPC title

• G09G2320/02

  Improving the quality of display appearance · CPC title

• G09G3/3406 Primary

  Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336) · CPC title