Display panel for detecting biometric information and driving method thereof

• US 9,946,386 B2
• Filed: 07/01/2016
• Issued: 04/17/2018
• Est. Priority Date: 07/21/2015
• 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: Liu, Yingming, Dong, Xue, Wang, Haisheng, Chen, Xiaochuan, Zhao, Weijie, Li, Changfeng, Ding, Xiaoliang, Yang, Shengji, Liu, Hongjuan, Liu, Wei, Wang, Lei
• Primary Examiner(s): Pham, Long D
• Application Number:
  US15/325,437
• Publication Number:
  US 20170199606A1
• Time in Patent Office: 655 Days
• Field of Search: 345173
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement

Abstract

The present application discloses a display panel having an array of a plurality of pixel units, each pixel unit including at least three subpixels for image display, at least some of the plurality of pixel units including a semiconductor photodetector for detecting biometric information; a plurality of first scan lines and a plurality of data lines, each first scan line being connected to a row of subpixels, each data line being connected to a column of subpixels; each subpixel including a first transistor for image display; a plurality of common voltage terminals, each common voltage terminal being connected to a semiconductor photodetector; a plurality of second scan lines, each second scan line being connected to a plurality of semiconductor photodetectors for providing a control voltage signal; each semiconductor photodetector having a second transistor; the second transistor being a phototransistor having a gate node connected to a corresponding second scan line for receiving the control voltage signal to turn on the second transistor, and a first node connected to a corresponding common voltage terminal; and a plurality of read lines, each read line being connected to each semiconductor photodetector in a column of pixel units.

Claims

1. A display panel, comprising:

an array of a plurality of pixel units, each pixel unit comprising at least three subpixels for image display, each of the at least three subpixels comprising a first transistor, at least some of the plurality of pixel units comprising a semiconductor photodetector for detecting biometric information;

a plurality of first scan lines and a plurality of data lines, each of the plurality of first scan lines being connected to a row of subpixels, each of the plurality of data lines being connected to a column of subpixels;

a plurality of common voltage terminals, each of the plurality of common voltage terminals being connected to a semiconductor photodetector;

a plurality of second scan lines, each of the plurality of second scan lines being connected to a plurality of semiconductor photodetectors for providing a control voltage signal; and

a plurality of read lines, each of the plurality of read lines being connected to each semiconductor photodetector in a column of pixel units; and

wherein each semiconductor photodetector comprises a second transistor;

the second transistor being a phototransistor comprising a gate node connected to one of the plurality of second scan lines for receiving the control voltage signal to turn on the second transistor, and a first node connected to one of the plurality of common voltage terminals;

the control voltage signal is configured to be in a range such that a difference between a first photocurrent change corresponding to a touching ridge line and a second photocurrent change corresponding to a touching valley line is substantially maximized.

2. The display panel of claim 1, further comprising a plurality of touch electrodes and a plurality of touch signal lines, each touch electrode being connected to a touch signal line.

3. The display panel of claim 1, further comprising a plurality of signal lines, each of which is connected to a plurality of common voltage terminals.

4. The display panel of claim 3, wherein a second node of the phototransistor is connected to one of the plurality of read lines.

5. The display panel of claim 4, wherein the plurality of first scan lines, the plurality of second scan lines, and the plurality of signal lines are configured to drive the plurality of pixel units;

each of the plurality of first scan lines in a first time period of each frame of image is configured to apply a first scan signal to each subpixel in the row of subpixels to allow a data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the data signal; and

each of the plurality of second scan lines in a second time period of each frame of image is configured to apply a control voltage signal to each phototransistor in the row of subpixels and each of the plurality of signal lines in a second time period is configured to apply a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels, for detecting a biometric signal in each pixel unit;

the second time period being later in time than the first time period.

6. The display panel of claim 3, wherein each semiconductor photodetector further comprises a third transistor comprising a gate node, a first node connected to a second node of the second transistor, and a second node connected to one of the plurality of read lines.

7. The display panel of claim 6, wherein the gate node of the third transistor is connected to one of the plurality of first scan lines.

8. The display panel of claim 6, wherein the plurality of first scan lines, the plurality of second scan lines, and the plurality of signal lines are configured to drive the plurality of pixel units;

the gate node of the third transistor is connected to one of the plurality of first scan lines;

each of the plurality of first scan lines in a first time period of a frame of image is configured to apply a first scan signal to each subpixel in the row of subpixels, allowing a data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the data signal;

each of the plurality of second scan lines in a second time period of each frame of image is configured to apply a control voltage signal to each phototransistor in the row of subpixels and each of the plurality of signal lines in a second time period is configured to apply a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels, for detecting a biometric signal in each pixel unit; and

each of the plurality of first scan lines in the second time period of each frame of image is configured to apply a third scan signal to switch on the third transistor in the row of subpixels to transmit the biometric signal detected in each pixel unit to one of the plurality of read lines;

the second time period being later in time than the first time period.

9. The display panel of claim 6, wherein the plurality of first scan lines, the plurality of second scan lines, and the plurality of signal lines are configured to drive the plurality of pixel units;

the gate node of the third transistor is connected to one of the plurality of first scan lines;

each of the plurality of first scan lines in a first time period of each frame of image is configured to apply a first scan signal to each subpixel in the row of subpixels, allowing a first data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the first data signal;

each of the plurality of first scan lines in a second time period of each frame of image is configured to apply a second scan signal to each subpixel in the row of subpixels to allow a second data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the second data signal so that a substantially same illuminance level for each pixel is produced; and

each of the plurality of second scan lines in a second time period of each frame of image is configured to apply a control voltage signal to each phototransistor in the row of subpixels and each of the plurality of signal lines in a second time period of each frame of image is configured to apply a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels, for detecting a biometric signal in each pixel unit;

the second time period being later in time than the first time period.

10. The display panel of claim 1, wherein each subpixel further comprises a pixel electrode;

a second node of the first transistor being connected to the pixel electrode.

11. The display panel of claim 1, wherein each pixel unit comprises a red subpixel, a green subpixel, and a blue subpixel, wherein the semiconductor photodetector is in the blue subpixel.

12. A display panel, comprising:

an array of a plurality of pixel units, each pixel unit comprising at least three subpixels for image display, each of the at least three subpixels comprising a first transistor, at least some of the plurality of pixel units comprising a semiconductor photodetector for detecting biometric information;

a plurality of first scan lines and a plurality of data lines, each of the plurality of first scan lines being connected to a row of subpixels, each of the plurality of data lines being connected to a column of subpixels;

a plurality of common voltage terminals, each of the plurality of common voltage terminals being connected to a semiconductor photodetector;

a plurality of second scan lines, each of the plurality of second scan lines being connected to a plurality of semiconductor photodetectors for providing a control voltage signal;

a plurality of read lines, each of the plurality of read lines being connected to each semiconductor photodetector in a column of pixel units;

a plurality of signal lines, each of which is connected to a plurality of common voltage terminals; and

a plurality of touch electrodes and a plurality of touch signal lines, each touch electrode being connected to a touch signal line;

wherein each semiconductor photodetector comprises a second transistor and a third transistor;

the second transistor being a phototransistor comprising a gate node connected to one of the plurality of second scan lines for receiving the control voltage signal to turn on the second transistor, and a first node connected to one of the plurality of common voltage terminals, the third transistor comprising a gate node, a first node connected to a second node of the second transistor, and a second node connected to one of the plurality of read lines;

the gate node of the third transistor is connected to one of the plurality of first scan lines;

the plurality of first scan lines, the plurality of second scan lines, and the plurality of signal lines are configured to drive the plurality of pixel units;

each of the plurality of first scan lines in a first time period of each frame of image is configured to apply a first scan signal to each subpixel in the row of subpixels to allow a first data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the first data signal;

each of the plurality of touch signal lines in a second time period of each frame of image is configured to apply a touch signal to each touch electrode for detecting a touch event at each touch electrode thereby determining a touch area comprising a plurality of subpixels where the touch event is detected;

if a touch event is detected, the display panel is configured to display an inserted image with equal illuminance level for each pixel;

each of the plurality of first scan lines in each frame of inserted image is configured to apply a second scan signal to each subpixel in the row of subpixels to allow a second data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the second data signal so that a substantially same illuminance level for each pixel is produced; and

each of the plurality of second scan lines in each frame of inserted image is configured to apply a control voltage signal to each phototransistor in the row of subpixels in the touch area and each signal line in each frame of inserted image is configured to apply a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels in the touch area, for detecting a biometric signal in each pixel unit in the touch area.

13. The display panel of claim 12, wherein each of the plurality of first scan lines in each frame of inserted image is configured to apply the second scan signal to each third transistor in the row of subpixels for transmitting the biometric signal at the each pixel unit in the touch area to one of the plurality of read lines.

14. The display panel of claim 12, wherein the plurality of touch electrodes are used for conducting touch signals in the second time period, and for applying common voltage in the first time period.

15. The display panel of claim 12, wherein at least one of the plurality of touch signal lines is used as a read line in each frame of inserted image, and used as a touch signal line in second time period of each frame of image.

16. A method for driving an operation of a display panel, wherein the display panel comprises:

an array of a plurality of pixel units, each pixel unit comprising at least three subpixels for image display, each of the at least three subpixels comprising a first transistor, at least some of the plurality of pixel units comprising a semiconductor photodetector for detecting biometric information;

a plurality of first scan lines and a plurality of data lines, each of the plurality of first scan lines being connected to a row of subpixels, each of the plurality of data lines being connected to a column of subpixels;

a plurality of common voltage terminals, each of the plurality of common voltage terminals being connected to a semiconductor photodetector;

a plurality of second scan lines, each of the plurality of second scan lines being connected to a plurality of semiconductor photodetectors for providing a control voltage signal; and

a plurality of read lines, each of the plurality of read lines being connected to each semiconductor photodetector in a column of pixel units;

wherein each semiconductor photodetector comprises a second transistor;

the second transistor being a phototransistor comprising a gate node connected to one of the plurality of second scan lines for receiving the control voltage signal to turn on the second transistor, and a first node connected to one of the plurality of common voltage terminals;

the method comprises;

providing a plurality of control voltage signals respectively to the plurality of second scan lines in a time period of each frame of image; and

turning on the phototransistor by one of the plurality of control voltage signals provided by one of the plurality of second scan lines;

wherein the one of the plurality of control voltage signals provided by one of the plurality of second scan lines is configured to be in a range such that a difference between a first photocurrent change corresponding to a touching ridge line and a second photocurrent change corresponding to a touching valley line is substantially maximized.

17. The method of claim 16, further comprising:

providing a plurality of first scan signals to the plurality of first scan lines in a first time period of each frame of image;

each of the plurality of first scan lines in the first time period applies a first scan signal to each subpixel in the row of subpixels to allow a data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the data signal; and

transmitting a plurality of biometric signals through the plurality of read lines;

each of the plurality of read lines in a second time period is configured to transmit a biometric signal from each semiconductor photodetector, the second time period being later in time than the first time period;

wherein providing the plurality of control voltage signals to the plurality of second scan lines comprises providing the plurality of control voltage signals to the plurality of second scan lines in a second time period of each frame of image, each of the plurality of second scan lines in the second time period of each frame of image applies a control voltage signal to turn on each phototransistor in the row of subpixels.

18. The method of claim 17, further comprising providing a plurality of common voltage signals to a plurality of signal lines in the second time period of each frame of image;

each of the plurality of signal lines in the second time period applies a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels for detecting a biometric signal in each pixel unit.

19. The method of claim 17,

wherein each semiconductor photodetector further comprises a third transistor;

the third transistor comprising a gate node, a first node connected to a second node of the second transistor, and a second node connected to one of the plurality of read lines;

the method further comprising;

providing a plurality of common voltage signals to a plurality of signal lines in the second time period of each frame of image;

each of the plurality of signal lines in the second time period applies a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels for detecting a biometric signal in each pixel unit; and

providing a plurality of third scan signals to the plurality of first scan lines in the second time period of each frame of image;

each of the plurality of first scan lines in the second time period applies a third scan signal to switch on the third transistor in the row of subpixels for transmitting the biometric signal at each pixel unit to one of the plurality of read lines;

the second time period being later in time than the first time period.

20. The method of claim 17, further comprising:

providing a plurality of second scan signals to the plurality of first scan lines in the second time period of each frame of image;

each of the plurality of first scan lines in each frame of inserted image applies a second scan signal to each subpixel in the row of subpixels to allow a second data signal be passed from one of the plurality of data lines to the each subpixel in the row of subpixels to produce a subpixel of image based on the second data signal so that a substantially same illuminance level for each pixel is produced; and

providing a plurality of common voltage signals to a plurality of signal lines in the second time period;

each of the plurality of signal lines in each frame of inserted image applies a common voltage signal via one of the plurality of common voltage terminals to each phototransistor in the row of subpixels, for detecting a biometric signal in each pixel unit.