Pixel driving circuit and its driving method, array substrate, transflective display apparatus

• US 10,120,504 B2
• Filed: 12/17/2014
• Issued: 11/06/2018
• Est. Priority Date: 07/24/2014
• Status: Active Grant

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Inventors: Yang, Shengji
• Primary Examiner(s): Patel, Sanjiv D
• Application Number:
  US14/770,005
• Publication Number:
  US 20160252992A1
• Time in Patent Office: 1,420 Days
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/13324 Circuits comprising solar cells
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2092 Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

There is disclosed a pixel driving circuit and its driving method, an array substrate, a transflective display apparatus. At least one of the pixels of the pixel driving circuit includes a light touch module (10) which comprises: a photosensitive unit (101) which senses the light intensity and produces an electrical signal carrying the light intensity information; a signal reading unit (102) connected with the photosensitive unit and reading the electrical signal from there; an amplifier (103) connected with the signal reading unit (102) and amplifying the electrical signal acquired therefrom; and a processor (104) connected with the amplifier (103), having a threshold of the change of the electrical signal and the electrical signal amplified at a previous time stored therein, and taking the acquired position information of the pixel where the light touch module (10) is located as the touch position when the change amount of the electrical signal amplified at a current time relative to the electrical signal amplified at the previous time acquired from the amplifier (103) is greater than the threshold. The driving circuit and the driving method provided in the present disclosure cause the array substrate and the transflective display apparatus applying the both to realize the light touch function on the basis of realizing the display function.

Claims

1. A pixel driving circuit, comprising:

a plurality of pixels arranged in a matrix, each pixel of the pixel driving circuit comprising a transmissive region and a reflective region in which a reflection structure for reflecting the light is provided;

gate lines located between two adjacent rows of the pixels, at least one of the pixels comprising a light touch module which comprises;

a photosensitive unit which senses the light intensity and produces an electrical signal carrying the light intensity information;

a signal reading unit connected with the photosensitive unit, the signal reading unit being controlled by the gate lines, being turned on under the driving of the gate lines, and reading the electrical signal from the photosensitive unit;

an amplifier connected with the signal reading unit, the amplifier acquiring the electrical signal from the signal reading unit and amplifying the electrical signal;

a processor connected with the amplifier, the processor being configured to acquire the electrical signal amplified at the current frame from the amplifier, subtract the electrical signal amplified at the current frame from the electrical signal amplified at a previous frame to obtain the change amount of the electrical signal at the current frame relative to the electrical signal at the previous frame, compare the change amount with a threshold of the change of the electrical signal, determine that a touch action occurs and acquire the position information of the pixel where the light touch module is located when the change amount is greater than the threshold of the electrical signal change, and take the position information as the touch position, the threshold of the change of the electrical signal and the electrical signal amplified at the previous frame being stored in the processor,

wherein, the pixel driving circuit further comprises a common electrode line with which the reflection structure is connected;

the pixel comprising the light touch module of the pixel driving circuit comprises a first thin film transistor and a first storage capacitor with the reflection structure being a first plate of the first storage capacitor;

the pixel comprising the light touch module of the pixel driving circuit further comprises a storage electrode which has an overlapping part with the reflection structure, is connected with the drain of the first thin film transistor and is a second plate of the first storage capacitor,

the storage electrode is located above the reflection structure, and the storage electrode is a transparent electrode so that the incident light can pass through the storage electrode, reach the reflection structure.

2. The pixel driving circuit according to claim 1, further comprising:

a common electrode line by which the photosensitive unit is controlled.

3. The pixel driving circuit according to claim 2, wherein the photosensitive unit comprises:

the first thin film transistor, the gate of which is connected with the common electrode line, the source of which is connected with the common electrode line, and the drain of which is connected with the signal reading unit;

the first storage capacitor, the first end of which is connected with the source of the first thin film transistor and the second end of which is connected with the drain of the thin film transistor.

4. The pixel driving circuit according to claim 1, further comprising:

a signal reading line through which the signal reading unit is connected with the amplifier.

5. The pixel driving circuit according to claim 4, wherein the pixel driving circuit comprises data lines located between two adjacent columns of the pixels, the data lines and the signal reading line being arranged in parallel, or at least one of the data lines functioning as the signal reading line.

6. The pixel driving circuit according to claim 5, wherein the pixel driving circuit is configured to further, when at least one of the data lines functions as the signal reading line, comprise:

a switch located between the signal reading unit and the amplifier, the switch being configured to be turned on only when the light touch module is working.

7. The pixel driving circuit according to claim 4, wherein the signal reading unit comprises:

a second thin film transistor, the gate of which is connected with the gate lines, the source of which is connected with the photosensitive unit, and the drain of which is connected with the signal reading line.

8. The pixel driving circuit according to claim 1, wherein the numbers of the gate lines are a first gate line, a second gate line, . . . , a M-th gate line in order, the pixel driving circuit comprises data lines located between two adjacent columns of the pixels, the numbers of the data lines are a first data line, a second data line, . . . , a N-th data line in order, and the position information of the pixel where the light touch module is located includes the numbers of the gate line and the data line which are connected with the pixel where the light touch module is located.

9. The system according to claim 1, wherein pixels including the light touch module are distributed evenly or unevenly in the pixel driving circuit.

10. A driving method for a pixel driving circuit, for driving the pixel driving circuit according to claim 1, the driving method comprising a display driving procedure and a light touch driving procedure, wherein the light touch driving procedure comprises:

sensing the light intensity and producing an electrical signal carrying the light intensity information;

reading the electrical signal;

acquiring the electrical signal and amplifying the electrical signal;

acquiring the electrical signal amplified at a current frame, subtracting the electrical signal amplified at the current frame from the electrical signal amplified at a previous frame to obtain the change amount of the electrical signal at the current frame relative to the electrical signal at the previous frame, comparing the change amount with a threshold of the change of the electrical signal, determining that a touch action occurs and acquiring the position information of the pixel where the light touch module obtaining the change amount is located when the change amount is greater than the threshold of the electrical signal change, and taking the position information as the touch position.

11. The driving method for the pixel driving circuit according to claim 10, wherein, when the data lines and the signal reading line are arranged in parallel, the display driving procedure and the light touch driving procedure are performed simultaneously within the time of one frame.

12. The driving method for the pixel driving circuit according to claim 10, wherein, when at least one of the data lines functions as the signal reading line, within the time of one frame, the light touch driving procedure is performed after the display driving procedure is completed, or the display driving procedure is performed after the light touch driving procedure is completed.

13. An array substrate comprising the pixel driving circuit according to claim 1, each pixel of the pixel driving circuit comprising a transmissive region and a reflective region in which a reflection structure for reflecting the light is provided,

wherein, the pixel driving circuit further comprises a common electrode line with which the reflection structure is connected;

the pixel comprising the light touch module of the pixel driving circuit comprises a first thin film transistor and a first storage capacitor with the reflection structure being a first plate of the first storage capacitor;

the pixel comprising the light touch module of the pixel driving circuit further comprises a storage electrode which has an overlapping part with the reflection structure, is connected with the drain of the first thin film transistor and is a second plate of the first storage capacitor.

14. The array substrate according to claim 13, wherein, the storage electrode is located above the reflection structure.

15. The array substrate according to claim 13, wherein, the pixel is a red pixel, a green pixel or a blue pixel, and the pixel comprising the light touch module of the pixel driving circuit is a blue pixel.

16. A transflective display apparatus comprising the array substrate according to claim 13.

17. The transflective display apparatus according to claim 16, wherein, the pixel driving circuit further comprises a common electrode line with which the reflection structure is connected;

the pixel comprising the light touch module of the pixel driving circuit comprises a first thin film transistor and a first storage capacitor with the reflection structure being a first plate of the first storage capacitor;

the pixel comprising the light touch module of the pixel driving circuit further comprises a storage electrode which has an overlapping part with the reflection structure, is connected with the drain of the first thin film transistor and is a second plate of the first storage capacitor.

18. The transflective display apparatus according to claim 16, wherein, the pixel is a red pixel, a green pixel or a blue pixel, and the pixel comprising the light touch module of the pixel driving circuit is a blue pixel.