Method of Controlling Power Level of Output Driver in Source Driver and Source Driver Using the Same

• US 20180374427A1
• Filed: 07/23/2017
• Published: 12/27/2018
• Est. Priority Date: 06/26/2017
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Kuei, Cheng-Kai, Hsu, Chin-Hung
• Granted Patent: US 10,957,260 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/22 using controlled light sources
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A source driver of a display system includes a plurality of channels, and each of the plurality of channels includes a first latch, a second latch, an output driver and a comparator. The first latch receives a first data code and a second data code from a timing controller of the display system. The second latch receives the first data code from the first latch. The output driver is used for transmitting the first data code to a display panel of the display system. The comparator, coupled to the first latch, the second latch and the output driver, is used for comparing the first data code stored in the second latch with the second data code stored in the first latch, to generate a signal indicating a power level for the output driver to transmit the second data code.

Claims

1. A source driver of a display system, the source driver comprising a plurality of channels, each of the plurality of channels comprising:

a first latch, for receiving a first data code and a second data code from a timing controller of the display system;

a second latch, for receiving the first data code from the first latch;

an output driver, for transmitting the first data code to a display panel of the display system; and

a comparator, coupled to the first latch, the second latch and the output driver, for comparing the first data code stored in the second latch with the second data code stored in the first latch, to generate a signal indicating a power level for the output driver to transmit the second data code.

2. The source driver of claim 1, wherein the comparator transmits the signal to the output driver, to control the output driver to adjust a slew rate, in order to transmit the second data code with the power level.

3. The source driver of claim 1, wherein the power level of the output driver is increased when the comparator determines that a difference value between the first data code and the second data code is greater than a threshold.

4. The source driver of claim 1, wherein the power level of the output driver is decreased when the comparator determines that a difference value between the first data code and the second data code is less than a threshold.

5. The source driver of claim 1, wherein the power level of the output driver in each of the plurality of channels is independently controlled according to a comparison result for the channel.

6. The source driver of claim 1, wherein the power level of the output driver in all of the plurality of channels is controlled according to a comparison result generated by comparing the first data code with the second data code in all of the plurality of channels.

7. The source driver of claim 6, wherein the power level of the output driver in all of the plurality of channels is adjusted to a value determined by using the signal generated from the comparator detecting that the first data code and the second data code have a maximum difference value among the plurality of channels.

8. A method of controlling a power level of an output driver used for a source driver of a display system, comprising:

receiving a first data code and a second data code from a timing controller of the display system; and

comparing the first data code with the second data code, to generate a signal indicating the power level for the output driver to transmit the second data code to a display panel of the display system.

9. The method of claim 8, further comprising:

transmitting the signal to the output driver, to control the output driver to adjust a slew rate, in order to transmit the second data code with the power level.

10. The method of claim 8, wherein the power level of the output driver is increased when a difference value between the first data code and the second data code is determined to be greater than a threshold.

11. The method of claim 8, wherein the power level of the output driver is decreased when a difference value between the first data code and the second data code is determined to be less than a threshold.

12. The method of claim 8, wherein the source driver comprises a plurality of channels, each of which comprises an output driver, and the method further comprises:

independently controlling the power level of the output driver in each of the plurality of channels according to a comparison result for the channel.

13. The method of claim 8, wherein the source driver comprises a plurality of channels, each of which comprises an output driver, and the method further comprises:

controlling the power level of the output driver in all of the plurality of channels according to a comparison result generated by comparing the first data code with the second data code in all of the plurality of channels.

14. The method of claim 13, wherein the power level of the output driver in all of the plurality of channels is adjusted to a value determined by using the signal indicating that the first data code and the second data code have a maximum difference value among the plurality of channels.