Position-sensing and force detection panel

• US 10,146,351 B2
• Filed: 12/28/2015
• Issued: 12/04/2018
• 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 Stanley
• Primary Examiner(s): Lin, Chun-Nan
• Application Number:
  US14/981,510
• Publication Number:
  US 20160117036A1
• Time in Patent Office: 1,072 Days
• 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

In one embodiment, a sensor includes a voltage driver operable to provide an alternating voltage and an integrator circuit. The sensor further includes a first variable resistance element coupled to a first output of the voltage driver and an input of the integrator circuit. The integrator circuit is operable to measure a parameter of the first variable resistance element over a period of time. The sensor further includes circuitry operable to determine, based on the measured parameter, an amount of force applied to a touch sensing panel.

Claims

1. An apparatus, comprising:

a control unit comprising a voltage driver and an integrator circuit, the voltage driver operable to provide an alternating voltage;

a touch sensing panel operable to communicate with the control unit;

a first variable resistance element coupled to an output of the voltage driver and an input of the integrator circuit, wherein the integrator circuit is operable to measure a parameter of the first variable resistance element over a period of time, and wherein the first variable resistance element is operable to be driven by the alternating voltage provided by the voltage driver; and

circuitry operable to determine, based on the measured parameter, an amount of force applied to a sensing area of the touch sensing panel.

2. The apparatus of claim 1, wherein the parameter is current flowing through the first variable resistance element.

3. The apparatus of claim 1, further comprising a bias resistance element connected in parallel with the first variable resistance element.

4. The apparatus of claim 1, further comprising a limiting resistance element connected in series with the first variable resistance element.

5. The apparatus of claim 1, wherein the output of the voltage driver comprises a first output and further comprising a second variable resistance element coupled with a second output of the voltage driver and the input of the integrator circuit.

6. The apparatus of claim 5, further comprising a bias resistance element connected in parallel with the second variable resistance element.

7. The apparatus of claim 5, further comprising a limiting resistance element connected in series with the second variable resistance element.

8. The apparatus of claim 1, wherein the input of the integrator circuit is at a voltage between a first voltage and a second voltage of the alternating voltage provided by the voltage driver.

9. The apparatus of claim 1, wherein the circuitry is operable to determine an amount of force applied to the sensing area using a differential measurement.

10. The apparatus of claim 1, wherein the circuitry is further operable to determine a location in a sensing area of the touch sensing panel associated with the determined amount of force.