Display device with touch detection function, control circuit, driving method of display device with touch detection function, and electronic unit

• US 9,671,905 B2
• Filed: 06/17/2011
• Issued: 06/06/2017
• Est. Priority Date: 08/24/2010
• Status: Expired due to Fees

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Noguchi, Koji, Kida, Yoshitoshi, Azumi, Kohei
• Primary Examiner(s): Edwards, Carolyn R
• Assistant Examiner(s): NEUPANE, KRISHNA P.
• Application Number:
  US13/067,658
• Publication Number:
  US 20120050217A1
• Time in Patent Office: 2,181 Days
• Field of Search: 345104, 345173-179, 345 87-100
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A display device with a touch detection function includes, a plurality of display elements performing display operation based on a pixel signal and a display drive signal, a touch detection element detecting an external proximity object based on a touch detection drive signal, a scan drive section performing display scanning by sequentially supplying the pixel signal and the display drive signal to the plurality of display elements in a time-divisional manner, and the scan drive section supplying the touch detection drive signal to the touch detection element, and a touch detection circuit performing touch detection by sampling a detection result from the touch detection element with a period shorter than a period of the display scanning. The scan drive section supplies the touch detection drive signal to the touch detection element in a touch detection operation period different from a display operation period for performing the display scanning.

Claims

1. A display device with a touch detection function comprising:

a plurality of display elements each performing display operation based on a pixel signal and a display drive signal;

a touch detection element detecting an external proximity object based on a touch detection drive signal having a high frequency;

a scan drive section performing display scanning by sequentially supplying the pixel signal and the display drive signal to the plurality of display elements in a time-divisional manner, and the scan drive section supplying the touch detection drive signal to the touch detection element; and

a touch detection circuit detecting a touch detection signal by sampling at a sampling frequency a detection result from the touch detection element with a period shorter than a period of the display scanning, wherein

the scan drive section supplies the touch detection drive signal to the touch detection element in a touch detection operation period different from a display operation period for performing the display scanning during each of a plurality of image frame periods,

the scan drive section performs display scanning of each of the display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods,

a plurality of the touch detections are respectively performed during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signal is in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.

2. The display device with a touch detection function according to claim 1, wherein the display drive signal is a rectangular wave signal.

3. The display device with a touch detection function according to claim 1, wherein

the display operation period is divided into plural periods by a period in which the display scanning is interrupted, and

the touch detection operation period is provided within the period in which the display scanning is interrupted.

4. The display device with a touch detection function according to claim 3, wherein each of the plural periods corresponds to the display operation of the display elements within a respective display area.

5. The display device with a touch detection function according to claim 1, wherein

the touch detection drive signal is a rectangular wave signal with a frequency higher than a frequency of the display drive signal, and

the touch detection circuit samples the detection result from the touch detection element at timings in synchronization with the touch detection drive signal.

6. The display device with a touch detection function according to claim 1, wherein the touch detection element uses a change of an electrostatic capacitance based on proximity or contact of the external proximity object to detect the external proximity object.

7. The display device with a touch detection function according to claim 1, further comprising:

common drive electrodes arranged in parallel to extend in one direction, wherein

the scan drive section applies the common drive electrodes with the display drive signal in the display operation period, and with the touch detection drive signal in the touch detection operation period.

8. The display device with a touch detection function according to claim 1, wherein

the touch detection element detects the external proximity object based also on the display drive signal, and

the touch detection circuit performs touch detection by sampling the detection result at timings in synchronization with the display drive signal also in the display operation period.

9. The display device according to claim 1, wherein the detection operation period corresponds to a blanking period of the display scanning.

10. A display device comprising:

a plurality of display elements;

a detection element; and

a scan drive section performing display scanning by sequentially supplying a display drive signal to the plurality of display elements, and supplying a detection drive signal to the detection element, wherein

the scan drive section supplies the detection drive signal to the detection element in a detection operation period different from a display operation period for performing the display scanning during each of a plurality of image frame periods,

the scan drive section performs display scanning of each of the display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods, and

a plurality of touch detections signals are respectively detected by sampling at a sampling frequency during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signals are each in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.

11. The display device according to claim 10, wherein the detection operation period corresponds to a blanking period of the display scanning.

12. The display device according to claim 10, wherein

the display operation period is divided into plural periods by a period in which the display scanning is interrupted, and

the detection operation period is provided within a period in which the display scanning is interrupted.

13. A control circuit comprising:

a scan drive section performing display scanning by sequentially supplying a pixel signal and a display drive signal to a plurality of display elements in a time-divisional manner, and supplying a touch detection drive signal to a touch detection element detecting an external proximity object; and

a touch detection circuit detecting a touch detection signal by sampling at a sampling frequency a detection result from the touch detection element with a period shorter than a period of the display scanning, wherein

the scan drive section supplies the detection drive signal to the detection element in a detection operation period different from a display operation period for performing the display scanning during each of a plurality of image frame periods,

the scan drive section performs display scanning of each of the display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods,

a plurality of the touch detections are respectively performed during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signal is in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.

14. A driving method of a display device with a touch detection function comprising:

performing display scanning by sequentially supplying a pixel signal and a display drive signal to a plurality of display elements in a display operation period, and supplying a touch detection drive signal to a touch detection element for detecting an external proximity object, in a touch detection operation period different from the display operation period for performing the display scanning during each of image frame periods; and

driving the display device with a touch detection function to detect a touch detection signal by sampling with a sampling frequency a detection result from the touch detection element with a first period shorter than a second period of the display scanning, wherein

the display scanning is performed for each of the plurality of display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods,

a plurality of the touch detections are respectively performed during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signal is in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.

15. An electronic unit including a display device with a touch detection function and a control section performing operation control with use of the display device with a touch detection function, the display device with a touch detection function comprising:

a plurality of display elements each performing display operation based on a pixel signal and a display drive signal;

a touch detection element detecting an external proximity object based on a touch detection drive signal having a high frequency;

a scan drive section performing display scanning by sequentially supplying the pixel signal and the display drive signal to the plurality of display elements in a time-divisional manner, and the scan drive section supplying the touch detection drive signal to the touch detection element; and

a touch detection circuit detecting a touch detection signal by sampling at a sampling frequency a detection result of the touch detection element with a period shorter than a period of the display scanning, wherein

the scan drive section supplies the detection drive signal to the detection element in a detection operation period different from a display operation period for performing the display scanning during each of a plurality of image frame periods,

the scan drive section performs display scanning of each of the display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods,

a plurality of the touch detections are respectively performed during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signal is in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.

16. A display device with a touch detection function comprising:

a plurality of display elements each performing display operations based on a pixel signal and a display drive signal;

a touch detection element detecting an external proximity object based on a touch detection drive signal having a high frequency;

a scan drive section performing display scanning by sequentially supplying the pixel signal and the display drive signal to the plurality of display elements in a time-divisional manner, and the scan drive section supplying the touch detection drive signal to the touch detection element; and

a touch detection circuit detecting a touch detection signal by sampling at a sampling frequency a detection result from the touch detection element with a period shorter than a period of the display scanning, wherein

the scan drive section supplies the touch detection drive signal to the touch detection element in a touch detection operation period different from a display operation period for performing the display scanning during each of a plurality of image frame periods,

the scan drive section performs display scanning of each of the display elements sequentially at a sampling time in synchronization with the touch detection drive signal,

each of the image frame periods includes a plurality of the display operation periods and a plurality of the touch detection operation periods,

a plurality of the touch detections are respectively performed during the plurality of the touch detection operation periods and a plurality of the display operations are respectively performed during the plurality of the display operation periods,

the touch detection signal is in synchronization with the touch detection drive signal, and

the sampling frequency is an integral multiple of a frequency of the touch detection signal.