Method and device for position detection

• US 20110084929A1
• Filed: 10/08/2010
• Published: 04/14/2011
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Lee, Cheng-Han, Ho, Shun-Lung, Tang, Chi-Hao, Chang, Chin-Fu
• Granted Patent: US 8,570,289 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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 3/03545 Pens or stylus
• 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
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A method and device for position detection are disclosed. A self-capacitance detection can be performed by a sensing device. According to the result of the self-capacitance detection, a first mutual-capacitance detection can be performed for determining one or more first 1-D positions. According to the result of the first mutual-capacitance detection, a second mutual-capacitance detection can be performed for determining one or more second 1-D positions corresponding to each first 1-D position. One or more 2-D positions can be provided according to the one or more second 1-D positions corresponding to each first 1-D position. Besides, during the self-capacitance detection, the first mutual-capacitance detection, and the second mutual-capacitance detection, a touch related sensing information corresponding to a touch that covers a wide area can be neglected for palm rejection.

Claims

1. A method for position detection, comprising:

providing a sensing device including a plurality of sensors including a plurality of first sensors and a plurality of second sensors, these first and second sensors intersecting each other at a plurality of intersecting points;

determining at least one first 1-D position corresponding to at least one external touch based on signals of these first sensors by self-capacitance detection; and

determining at least one second 1-D position corresponding to the at least one first 1-D position based on signals of these second sensors by mutual-capacitance detection.

2. The method of claim 1, further comprising:

providing at least a 2-D position based on the at least one second 1-D position corresponding to the at least one first 1-D position.

3. The method of claim 1, further comprising:

determining at least one third 1-D position corresponding to the at least one second 1-D position based on signals of these first sensors by mutual-capacitance detection; and

providing at least a 2-D position based on the at least one third 1-D position corresponding to the at least one second 1-D position.

4. The method of claim 1, further comprising:

determining at least one touch-related first sensor based on the at least one first 1-D position; and

determining at least one touch-related second sensor based on the at least one second 1-D position.

5. The method of claim 4, further comprising:

when the number of the at least one touch-related second sensor is greater than the number of the at least one touch-related first sensor, providing at least one 2-D position based on the at least one second 1-D position corresponding to the at least one first 1-D position.

6. The method of claim 4, wherein when the number of the at least one touch-related second sensor is not greater than the number of the at least one touch-related first sensor, the method further comprising:

determining at least one third 1-D position corresponding to the at least one second 1-D position based on signals of these first sensors by mutual-capacitance detection; and

providing at least a 2-D position based on the at least one third 1-D position corresponding to the at least one second 1-D position.

7. The method of claim 1, wherein the self-capacitance detection includes providing a driving signal to these first sensors and providing signals of these first sensors.

8. The method of claim 1, wherein the mutual-capacitance detection includes:

when one of these first sensors is provided with a driving signal, providing signals of these second sensors;

or

when one of these second sensors is provided with a driving signal, providing signals of these first sensors.

9. The method of claim 8, wherein the mutual-capacitance detection further includes:

selecting at least one first sensor provided with the driving signal based on the at least one first 1-D position; and

selecting at least one second sensor provided with the driving signal based on the at least one second 1-D position.

10. The method of claim 1, wherein the self-capacitance detection includes:

determining at least one fourth 1-D position and at least one fifth 1-D position corresponding to the at least one external touch based on variations in signals of these sensors,

wherein the at least one fourth 1-D position and the at least one fifth 1-D position that is greater in number is used as the at least one first 1-D position, and

when the number of the at least one fourth 1-D position and the number of the at least one fifth 1-D position are the same, one of the at least one fourth 1-D position and the at least one fifth 1-D position is used as the at least one first 1-D position.

11. A device for position detection, comprising:

a sensing device including a plurality of sensors including a plurality of first sensors and a plurality of second sensors, these first and second sensors intersecting each other at a plurality of intersecting points; and

a controller for performing at least the following operations;

determining at least one first 1-D position corresponding to at least one external touch based on signals of these first sensors by self-capacitance detection; and

determining at least one second 1-D position corresponding to the at least one first 1-D position based on signals of these second sensors by mutual-capacitance detection.

12. The device of claim 11, wherein the controller further includes performing the following operations:

providing at least a 2-D position based on the at least one second 1-D position corresponding to the at least one first 1-D position.

13. The device of claim 11, wherein the controller further includes performing the following operations:

determining at least one third 1-D position corresponding to the at least one second 1-D position based on signals of these first sensors by mutual-capacitance detection; and

providing at least a 2-D position based on the at least one third 1-D position corresponding to the at least one second 1-D position.

14. The device of claim 11, wherein the controller further includes performing the following operations:

determining at least one touch-related first sensor based on the at least one first 1-D position; and

determining at least one touch-related second sensor based on the at least one second 1-D position.

15. The device of claim 14, wherein the controller further includes performing the following operations:

when the number of the at least one touch-related second sensor is greater than the number of the at least one touch-related first sensor, providing at least one 2-D position based on the at least one second 1-D position corresponding to the at least one first 1-D position.

16. The device of claim 14, wherein when the number of the at least one touch-related second sensor is not greater than the number of the at least one touch-related first sensor, the controller further includes performing the following operations:

determining at least one third 1-D position corresponding to the at least one second 1-D position based on signals of these first sensors by mutual-capacitance detection; and

providing at least a 2-D position based on the at least one third 1-D position corresponding to the at least one second 1-D position.

17. The device of claim 11, wherein the self-capacitance detection includes providing a driving signal to these first sensors and providing signals of these first sensors.

18. The device of claim 11, wherein the mutual-capacitance detection includes:

when one of these first sensors is provided with a driving signal, providing signals of these second sensors;

or

when one of these second sensors is provided with a driving signal, providing signals of these first sensors.

19. The device of claim 18, wherein the mutual-capacitance detection further includes:

selecting at least one first sensor provided with the driving signal based on the at least one first 1-D position; and

selecting at least one second sensor provided with the driving signal based on the at least one second 1-D position.

20. The device of claim 11, wherein the self-capacitance detection includes:

determining at least one fourth 1-D position and at least one fifth 1-D position corresponding to the at least one external touch based on variations in signals of these sensors,

wherein the at least one fourth 1-D position and the at least one fifth 1-D position that is greater in number is used as the at least one first 1-D position, and

when the number of the at least one fourth 1-D position and the number of the at least one fifth 1-D position are the same, one of the at least one fourth 1-D position and the at least one fifth 1-D position is used as the at least one first 1-D position.

21. The device of claim 11, wherein each first 1-D position is determined based on a dual-differential sensing information whose each value is based on signals of three sensors by self-capacitance detection, wherein the three sensors are adjacent or non-adjacent.