Touch detector and method of driving the same, display with touch detection function, and electronic unit having plural different drive electrodes

• US 9,442,595 B2
• Filed: 04/03/2015
• Issued: 09/13/2016
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Azumi, Kohei, Kida, Yoshitoshi, Noguchi, Koji, Ishizaki, Koji
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): SCHNIREL, ANDREW B
• Application Number:
  US14/678,422
• Publication Number:
  US 20150212646A1
• Time in Patent Office: 529 Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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 3/044 by capacitive means
• 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 touch detector capable of achieving high position resolution while improving detection sensitivity to a touch is provided. The touch detector includes: a plurality of drive electrodes arranged side by side to extend in one direction; a detection electrode extending in a direction orthogonal to a direction where the drive electrodes extend, and arranged to form a capacitance at each of intersections with the drive electrodes; and a scanning drive section sequentially selecting a predetermined plural number of target electrodes from the plurality of drive electrodes in a time-divisional manner, and applying a touch detection drive signal with a plurality of pulse waveforms for detecting an external adjacent object to the selected target electrodes to perform a scanning drive. A scanning pitch in the scanning drive is smaller than the total width of the plural number of selected target electrodes.

Claims

1. A touch detector comprising:

a plurality of drive electrodes arranged side by side to extend in one direction;

a detection electrode extending in a direction orthogonal to a direction where the drive electrodes extend, and arranged to form a capacitance at each of intersections with the drive electrodes; and

a scanning drive section sequentially selecting a predetermined plural number of target electrodes from the plurality of drive electrodes in a time-divisional manner, and applying a touch detection drive signal with a plurality of pulse waveforms for detecting an external adjacent object to the selected target electrodes to perform a scanning drive,

wherein a scanning pitch in the scanning drive is smaller than the total width of the plural number of selected target electrodes in a drive area;

the scanning drive section sequentially selects the target electrodes by shifting the drive area by the scanning pitch so that the shifted drive area includes a part of the most recently selected target electrodes;

the plurality of drive electrodes includes two kinds of drive electrodes, and

the two kinds of drive electrodes are alternately arranged side by side; and

in the scanning drive, while the touch detection drive signal is simultaneously applied to three adjacent target electrodes selected from the two kinds of drive electrodes which are alternately arranged side by side, scanning is performed to shift the target electrodes by two electrodes at a time.

2. The touch detector according to claim 1, further comprising:

a touch detection section sampling a detection signal of the detection electrode at timings according to transitions of the plurality of pulse waveforms of the touch detection drive signal to detect an external adjacent object.

3. The touch detector according to claim 2, wherein

when the scanning drive section drives the target electrodes, the touch detection section completes detection of an external adjacent object in a region corresponding to the driven target electrodes.

4. The touch detector according to claim 3, wherein the plurality of drive electrodes have equal widths.

5. The touch detector according to claim 3, wherein

the plurality of drive electrodes includes two kinds of drive electrodes with different widths.

6. The touch detector according to claim 1, wherein

the touch detection section determines a touched position based on all detection results obtained from the target electrodes sequentially selected.

7. The touch detector according to claim 1, further comprising a control section providing control signals, wherein

the total width of the selected target electrodes and the scanning pitch are allowed to be independently controlled according to the control signals provided by the control section.