Source driver and display apparatus including the same

• US 10,643,567 B2
• Filed: 12/27/2018
• Issued: 05/05/2020
• Est. Priority Date: 07/24/2018
• Status: Active Grant

• Current Assignee: DB HiTek Co., Ltd.
• Original Assignee: DB HiTek Co., Ltd.
• Inventors: Kim, Yoo Sung
• Primary Examiner(s): Liang, Dong Hui
• Application Number:
  US16/233,693
• Publication Number:
  US 20200035187A1
• Time in Patent Office: 495 Days
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• 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 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2330/026 Arrangements or methods related to booting a display
• CPC Class Codes: G09G 2330/027 Arrangements or methods related to powering off a display
• CPC Class Codes: G09G 2330/04 Display protection
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A source driver includes an amplification unit including a plurality of groups of amplifiers, each of the plurality of groups of amplifiers including a first amplifier and a second amplifier, multiplexers configured to select and provide an output of one of the first and second amplifiers in each of the plurality of groups to one of a plurality of data lines, charge share switch units corresponding to the multiplexers and between the plurality of data lines and a common line, and a control switch between the common line and a power supply configured to provide a reference voltage. Based on or in response to a power off reset (PFR) signal, the control switch provides the reference voltage to the common line, and the charge share switches connect the common line to the data lines, based on or in response to a power off rest (PFR) signal.

Claims

1. A source driver comprising:

an amplification unit including a plurality of groups of amplifiers, each of the plurality of groups of amplifiers including a first amplifier and a second amplifier;

multiplexers configured to select and provide an output of one of the first and second amplifiers in each of the plurality of groups of amplifiers to one of a plurality of data lines;

charge share switch units corresponding to the multiplexers and between the plurality of data lines and a common line; and

a control switch between the common line and a power supply configured to provide a reference voltage,

wherein based on or in response to a power off reset (PFR) signal, the control switch provides the reference voltage to the common line, and the charge share switches connect the common line to the data lines.

2. The source driver according to claim 1, wherein:

when a voltage of the power supply to the amplification unit becomes less than a predetermined voltage, the PFR signal has a first level,

the control switch is turned on by the PFR signal having the first level,

the charge share switch units are turned on by the PFR signal having the first level, and

each of the multiplexers is turned off by the PFR signal having the first level.

3. The source driver according to claim 2, wherein:

the multiplexers are sequentially turned off with a predetermined time difference, and

the charge share switch units are sequentially turned on in synchronization with turning off a corresponding one of the multiplexers.

4. The source driver according to claim 3, wherein:

each of the charge share switch units includes first and second charge share switches respectively corresponding to the multiplexers, and

each of the first and second charge share switches is between a corresponding one of two data lines and the common line, and the two data lines are connected to the corresponding multiplexer.

5. The source driver according to claim 4, wherein the control switch is connected to a part or region of the common line between (i) a first node where the first charge share switch and the common line are connected and (ii) a second node where the second charge share switch and the common line are connected.

6. The source driver according to claim 4, wherein the control switch includes control switches corresponding to the multiplexers.

7. The source driver according to claim 3, wherein:

each of the multiplexers includes a plurality of switches, and

the switches in each of the multiplexers selectively output a data signal from the first and second amplifiers of a corresponding one of the plurality of groups of amplifiers to two neighboring or adjacent data lines of the plurality of data lines.

8. The source driver according to claim 7, wherein the switches in each of the multiplexers are turned off by the PFR signal having the first level.

9. The source driver according to claim 2, wherein:

the first amplifier has a first driving voltage selected from an HVDD voltage and a VDD voltage,

the VDD voltage is greater than the HVDD voltage,

the second amplifier has a second driving voltage selected from a VSS voltage and the HVDD voltage, and

the HVDD voltage is greater than the VSS voltage.

10. The source driver according to claim 9, wherein the predetermined voltage is greater than the VSS voltage and less than the HVDD voltage.

11. The source driver according to claim 9, wherein the reference voltage is the HVDD voltage.

12. The source driver according to claim 2, wherein:

the multiplexers are sequentially turned off with a predetermined time difference, and

each of the charge share switch units is turned on when a corresponding one of the multiplexers is turned off.

13. The source driver according to claim 2, further comprising a signal generator configured to sense a voltage level of the power supply and to generate the PFR signal having the first level when the sensed voltage level is less than the predetermined voltage.

14. A display apparatus comprising:

a display panel including gate lines, data lines and pixels connected to the gate lines and the data lines, the pixels being in a matrix including rows and columns;

a data driver configured to drive the data lines; and

a gate driver configured to drive the gate lines,

wherein the data driver is the source driver of claim 1.

15. A source driver comprising:

a plurality of amplifiers;

multiplexers configured to select and provide an output of one of the plurality of amplifiers to one of a plurality of data lines;

charge share switch units corresponding to the multiplexers and between the plurality of data lines and a common line; and

a control switch between the common line and a power supply configured to provide a reference voltage,

wherein;

the amplifiers are divided into a plurality of groups of amplifiers, and each of the plurality of groups of amplifiers includes a first amplifier and a second amplifier,

each of the multiplexers selectively outputs a data signal from the first and second amplifiers of a corresponding one of the plurality of groups of amplifiers to two neighboring or adjacent data lines of the plurality of data lines, and

when a voltage from the power supply to the amplifiers becomes less than a predetermined voltage, the control switch is turned on, the multiplexers are turned off, and the charge share switch units are turned on.

16. The source driver according to claim 15, wherein:

the multiplexers are sequentially turned off with a predetermined time difference, and

the charge share switch units are sequentially turned on in synchronization with turning off a corresponding one of the multiplexers.

17. The source driver according to claim 16, wherein:

each of the charge share switch units includes first and second charge share switches respectively corresponding to the multiplexers, and

each of the first and second charge share switches is between a corresponding one of two data lines connected to the corresponding multiplexer and the common line.

18. The source driver according to claim 17, wherein:

the first amplifier having a driving voltage selected from an HVDD voltage and a VDD voltage,

the VDD voltage is greater than the HVDD voltage,

the second amplifier has a driving voltage selected from a VSS voltage and the HVDD voltage, and

the HVDD voltage is greater than the VSS voltage.

19. The source driver according to claim 18, wherein:

the reference voltage is the HVDD voltage, and

the control switch is connected to a part or region of the common line between (i) a first node where the first charge share switch and the common line are connected and (ii) a second node where the second charge share switch and the common line are connected.

20. The source driver according to claim 19, wherein the predetermined voltage is greater than the VSS voltage and less than the HVDD voltage.