POSITION-SENSING AND FORCE DETECTION PANEL

• US 20120139864A1
• Filed: 12/02/2010
• Published: 06/07/2012
• Est. Priority Date: 12/02/2010
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Sleeman, Peter, Dubery, John
• Granted Patent: US 9,223,445 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G01L 1/14 by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G01L 5/228 using tactile array force sensors
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/044 by capacitive means
• 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 position sensor. Force detection circuitry can be included with the position sensor, for example, to determine an amount of force applied to a touch panel of the sensor.

Claims

1. A touch sensor comprising:

a controller comprising a voltage driver and an integrator circuit with an input;

a plurality of first electrodes formed of a first conductive material and arranged in a first direction in a sensing area, each of the plurality of electrodes in communication with the controller;

a plurality of second electrodes formed of a second conductive material and arranged in a second direction different from the first direction such that the first and second electrodes are coupled with each other to form touch sensing nodes in the sensing area, each of the second plurality of electrodes in communication with the controller;

a variable resistance element in communication with the voltage driver and the input of the integrator circuit, and configured to change a parameter of the element in response to a force applied thereto wherein the integrator circuit is configured to measure the parameter over a period of time; and

circuitry configured to determine an amount of force applied to the sensor in response to the measured parameter.

2. The touch sensor of claim 1 wherein the parameter is current flowing through the variable resistance element.

3. The touch sensor of claim 1 wherein the variable resistance element comprises a Quantum Tunnel Composite (QTC) material.

4. The touch sensor of claim 1 wherein the controller provides an alternating voltage via the voltage driver to the variable resistance element.

5. The touch sensor of claim 1 wherein the variable resistance element comprises a force sensitive resistor.

6. The touch sensor of claim 1 further comprising another variable resistance element in communication with another voltage driver of the controller and the input of the integrator circuit of the controller.

7. A touch sensitive device comprising:

a housing;

a controller, within the housing, comprising a voltage driver and an integrator circuit with an input;

a touch sensitive position-sensing panel housed partially within the housing, the touch sensitive position-sensing panel comprising;

a plurality of first electrodes formed of a first conductive material and arranged in a first direction in a sensing area of the panel, each of the plurality of electrodes in communication with the controller; and

a plurality of second electrodes formed of a second conductive material and arranged in a second direction different from the first direction such that the first and second electrodes are coupled with each other to form touch sensing nodes in the sensing area, each of the second plurality of electrodes in communication with the controller; and

a variable resistance element in communication with the voltage driver and the input of the integrator circuit, and configured to change a parameter of the element in response to a force applied thereto wherein the integrator circuit is configured to measure the parameter over a period of time; and

circuitry configured to determine an amount of force applied to the sensing area of the touch sensitive panel in response to the measured parameter.

8. The touch sensitive device of claim 7 wherein the parameter is current flowing through the variable resistance element.

9. The touch sensitive device of claim 7 wherein the variable resistance element comprises a Quantum Tunnel Composite (QTC) material.

10. The touch sensitive device of claim 7 wherein the controller provides an alternating voltage via the voltage driver to the variable resistance element.

11. The touch sensitive device of claim 7 wherein the variable resistance element comprises a force sensitive resistor.

12. The touch sensitive device of claim 7 further comprising another variable resistance element disposed within the housing in communication with another voltage driver of the controller and the input of the integrator circuit of the controller.

13. A force sensor, for a touch sensor, the force sensor comprising:

a variable resistance element having a first node in communication with a voltage driver of a controller of the touch sensor and a second node;

a bias resistance element connected in parallel with the variable resistance element; and

a limiting resistance element in communication with the second node of the variable resistance element and an input of an integrator of the controller.

14. The force sensor of claim 13 wherein the variable resistance element comprises a Quantum Tunnel Composite (QTC) material.

15. The force sensor of claim 13 wherein the variable resistance element receives an alternating voltage from the controller via the voltage driver.

16. The force sensor of claim 13 wherein variable resistance element comprises a force sensitive resistor.

17. The force sensor of claim 13 wherein the controller is in communication with a plurality of drive electrodes and sense electrodes of a touch sensitive panel of the touch sensor.