Touch Sensor

• US 20160011711A1
• Filed: 03/19/2015
• Published: 01/14/2016
• Est. Priority Date: 07/08/2014
• Status: Active Grant

• Current Assignee: DB HiTek Co., Ltd.
• Original Assignee: Dongbu HiTek Co., Ltd.
• Inventors: Hwang, Tae Ho
• Granted Patent: US 9,483,140 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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

Disclosed is a touch sensor including a touch panel including driving lines and sensing lines, a node capacitor being formed between the neighboring driving and sensing lines, and a sensing unit electrically connected to the sensing lines to sense variation in the capacitance of the node capacitor. The sensing unit includes an amplifier including a first input terminal configured to receive a signal from any one of the sensing lines, a second input terminal connected to a first power source, and an output terminal, a feedback capacitor connected between the first input terminal and the output terminal, and a current controller connected in parallel to the feedback capacitor between the first input terminal and the output terminal to control current flowing to the feedback capacitor.

Claims

1. A touch sensor comprising:

a touch panel including driving lines and sensing lines, wherein a node capacitor is formed between the neighboring driving and sensing lines; and

a sensing unit electrically connected to the sensing lines to sense variation in the capacitance of the node capacitor,

wherein the sensing unit comprises;

an amplifier including a first input terminal configured to receive a signal from any one of the sensing lines, a second input terminal connected to a first power source, and an output terminal;

a feedback capacitor connected between the first input terminal and the output terminal; and

a current controller connected in parallel to the feedback capacitor between the first input terminal and the output terminal to control current flowing to the feedback capacitor.

2. The touch sensor according to claim 1, wherein the current controller is a constant current limiter configured to supply a predetermined current.

3. The touch sensor according to claim 2, wherein the current controller is a variable resistor operable to supply a variable resistance value.

4. The touch sensor according to claim 1, wherein the current controller is a pass transistor configured to operate in response to a first control signal and a second control signal.

5. The touch sensor according to claim 4, wherein the current controller further comprises a feedback resistor connected between the first input terminal and the output terminal, wherein the feedback resistor is connected in parallel to the pass transistor and the feedback capacitor.

6. The touch sensor according to claim 1, wherein current introduced to the first input terminal is divided into a first current flowing to the feedback capacitor and a second current flowing to the current controller.