Display device with touch detection, drive circuit, driving method, and electronic unit

• US 9,280,954 B2
• Filed: 11/13/2014
• Issued: 03/08/2016
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Noguchi, Koji, Kida, Yoshitoshi, Nakanishi, Takayuki
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): DICKE, CHAD M
• Application Number:
  US14/540,804
• Publication Number:
  US 20150070314A1
• Time in Patent Office: 481 Days
• Field of Search: 345173-178, 178 1801- 2001
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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
• CPC Class Codes: G09G 3/3674 Details of drivers for scan electrodes
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

A display device includes: a plurality of drive electrodes; a plurality of detection electrodes intersecting the plurality of drive electrodes; and a scan driving unit performing a first scan drive and a second scan drive. The first scan drive allows a display drive signal for driving the display elements to be applied to each of the plurality of common drive electrodes, and the second scan drive allows a touch detection drive signal for detecting an external proximity object to be applied to each of the plurality of common drive electrodes.

Claims

1. A display device with touch detection, comprising:

display elements;

a plurality of common drive electrodes arranged in parallel to extend in one direction;

a plurality of detection electrodes arranged in parallel to extend in a direction which intersects the common drive electrodes and allowing electrostatic capacitance to be formed at each intersection;

a scan driving unit performing a first scan drive and a second scan drive, the first scan drive allowing a display drive signal for driving the display elements to be time-divisionally applied to each of the plurality of common drive electrodes in succession, the second scan drive allowing a touch detection drive signal for selecting a block of the plurality of detection electrodes and driving said block to be time-divisionally applied to each of the plurality of common drive electrodes in succession; and

a detection circuit detecting the external proximity object based on a touch detection signal which is outputted from the detection electrode in response to application of the touch detection drive signal,

wherein

the scan driving unit is configured to drive the respective common drive electrodes with the display drive signal and the touch detection drive signal, the display drive signal being not synchronized with the touch detection drive signal, the detection circuit is configured to detect the external proximity object based on a change of the touch detection signal during a time period from a change of the touch detection drive signal to a change of the display drive signal, and the change of the touch detection signal is based on the change of the touch detection drive signal,

the detection circuit is configured to sample a first voltage of the touch detection signal at a first timing period between starting of transition of the display drive signal and starting of transition of the touch detection drive signal, and sample a second voltage of the touch detection signal, the second voltage being different from the first voltage, at a second timing period between ending of transition of the touch detection drive signal and starting of next transition of the display drive signal, and

the detection circuit is configured to detect the external proximity object on the basis of the difference between the first voltage of the touch detection signal sampled at the first timing period and the second voltage of the touch detection signal sampled at the second timing period.

2. The display device according to claim 1, wherein a signal cycle of the display drive signal is identical to a signal cycle of the touch detection drive signal, and transition edges of the display drive signal and the touch detection drive signal are shifted by a predetermined time period.