Display device

• US 10,664,094 B2
• Filed: 04/18/2018
• Issued: 05/26/2020
• Est. Priority Date: 04/20/2017
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Koide, Gen
• Primary Examiner(s): Castiaux, Brent D
• Application Number:
  US15/956,329
• Publication Number:
  US 20180307368A1
• Time in Patent Office: 769 Days
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• 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: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/1315 comprising structures specially adapted for lowering the resistance
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

According to one embodiment, a display device includes a display unit including electrodes, a touch sensor configured to supply drive signals to the electrodes and receive signals from the electrodes, and a switch circuit group including transistors connected between the touch sensor and the electrodes. The transistors include a first transistor connected to a first electrode via a line of a first length and a second transistor connected to a second electrode via a line of a second length longer than the first length. The channel width of the first transistor is smaller than a channel width of the second transistor.

Claims

1. A display device comprising:

a display unit comprising plural electrodes two-dimensionally arrayed on a substrate, the plural electrodes including first electrodes arranged in a first row and second electrodes arranged in a second row;

a touch sensor configured to supply drive signals for touch detection to the plural electrodes and receive signals from the plural electrodes; and

a switch circuit group comprising transistors connected between the touch sensor and the plural electrodes to select at least one of the plural electrodes, wherein

the transistors comprises first transistors respectively connected to the first electrodes via lines of a first length and second transistors respectively connected to the second electrodes via a line of second length longer than the first length,

the first transistors are not connected to the second electrodes,

the second transistors are not connected to the first electrodes, and

a channel width of the first transistors along gate lines of the first transistors is smaller than a channel width of the second transistors along gates lines of the second transistors.

2. The display device of claim 1, wherein

the substrate includes a display area and a frame area on a periphery of the display area,

the display unit is formed in the display area, and

the switch circuit group is formed in the frame area.

3. The display device of claim 2, wherein

the touch sensor is formed on a flexible printed circuit connecting the substrate and a host device.

4. The display device of claim 3, wherein

the flexible printed circuit comprises pads connected to the plural electrodes at a portion of connection to the substrate,

the touch sensor comprises detectors which are connected to the pads via signal lines, the detectors configured to supply the drive signals to the pads and detect the signals from the plural electrodes,

the pads are provided at two or more positions.

5. The display device of claim 4, wherein

video signal lines configured to supply video signals to the plural electrodes are formed on the substrate,

the video signal lines are formed in two areas, and

the pads are provided between the two areas and an outer side of the two areas.

6. The display device of claim 5, wherein

the substrate comprises wiring layers,

the video signal lines are formed in a first wiring layer,

the signal lines are formed in a second wiring layer, and

the signal lines are formed to overlap the video signal line.

7. The display device of claim 5, wherein

the substrate comprises wiring layers,

the video signal lines comprise a portion formed in a first wiring layer and a portion formed in the first wiring layer and the second wiring layer,

the signal lines are formed in the first wiring layer or the second wiring layer, and

the signal lines do not overlap the video signal lines and are formed while bypassing the video signal lines.

8. The display device of claim 2, further comprising:

a control signal generator formed in the frame area and configured to control conduction of the transistors.

9. The display device of claim 8, wherein

the control signal generator is configured to simultaneously select a second number of electrodes, of a first number of electrodes arranged in a row, and change the selected electrodes to drive the second number of electrodes, based on a coding pattern, and

the touch sensor is configured to operate signals from the first number of electrodes, based on an inverse matrix of the coding pattern.

10. The display device of claim 1, wherein

the touch sensor is configured to detect variation in electric capacitance of the plural electrodes in accordance with presence of an external object.

11. The display device of claim 1, wherein

the touch sensor comprises detectors,

each of the detectors is connected to electrodes arranged in each row, electrodes arranged in each column, or electrodes arranged in plural rows and plural columns.