Touch panel

• US 10,613,690 B2
• Filed: 05/18/2016
• Issued: 04/07/2020
• Est. Priority Date: 05/28/2015
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takahashi, Kei
• Primary Examiner(s): Rosario, Nelson M
• Application Number:
  US15/575,487
• Publication Number:
  US 20180088705A1
• Time in Patent Office: 1,420 Days
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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 panel or the like having a novel structure in which an influence of noise of an electrode included in an organic EL element on an electrode for touch sensing can be suppressed is provided.

A voltage of the electrode for touch sensing and a voltage for reference are input to input terminals of an operational amplifier, and in an integrator circuit in which a change in capacitance due to touch sensing is sensed, the input terminal to which the voltage for reference is supplied is connected to a common electrode included in the organic EL element. Such a structure does not amplify but can cancel noise of the electrode for touch sensing, on which noise of the common electrode is superimposed.

Claims

1. A touch panel comprising:

a pixel comprising a transistor, and a light-emitting element;

a touch sensor comprising a first electrode configured to supply a pulse signal, and a second electrode configured to sense a signal in accordance with the pulse signal; and

an integrator circuit comprising an operational amplifier,

wherein;

the light-emitting element comprises a pixel electrode, a common electrode, and a light-emitting layer therebetween,

the operational amplifier comprises a first input terminal electrically connected to the second electrode, and a second input terminal electrically connected to the common electrode,

the second input terminal is configured to receive a first signal including a noise waveform generated in the common electrode,

the first input terminal is configured to receive a second signal including the noise waveform, and a signal waveform based on the pulse signal, and

the operational amplifier is configured to cancel the noise waveform by a difference between the first and second signals.

3. The touch panel according to claim 1, wherein the first and second electrodes are on a substrate side provided with the transistor.

5. The touch panel according to claim 1, wherein one of the first and second electrodes is on a same layer as a conductive layer included in the transistor.

7. The touch panel according to claim 5, wherein the other of the first and second electrodes is on a counter substrate side.

9. The touch panel according to claim 5, wherein the one of the first and second electrodes is on a layer below the pixel electrode.

11. The touch panel according to claim 1, wherein the touch sensor is a mutual capacitive touch sensor.

2. A touch panel comprising:

a pixel comprising a transistor, and a light-emitting element electrically connected to a current supply line through the transistor;

a touch sensor comprising a first electrode configured to supply a pulse signal, and a second electrode configured to sense a signal in accordance with the pulse signal; and

an integrator circuit comprising an operational amplifier,

wherein;

the light-emitting element comprises a pixel electrode, a common electrode, and a light-emitting layer therebetween,

the operational amplifier comprises a first input terminal electrically connected to the second electrode, and a second input terminal electrically connected to the current supply line,

the second input terminal is configured to receive a first signal including a noise waveform generated in the current supply line,

the first input terminal is configured to receive a second signal including the noise waveform, and a signal waveform based on the pulse signal, and

the operational amplifier is configured to cancel the noise waveform by a difference between the first and second signals.

4. The touch panel according to claim 2, wherein the first and second electrodes are on a substrate side provided with the transistor.

6. The touch panel according to claim 2, wherein one of the first and second electrodes is on a same layer as a conductive layer included in the transistor.

8. The touch panel according to claim 6, wherein the other of the first and second electrodes is on a counter substrate side.

10. The touch panel according to claim 6, wherein the one of the first and second electrodes is on a layer below the pixel electrode.

12. The touch panel according to claim 2, wherein the touch sensor is a mutual capacitive touch sensor.