CONCURRENT DRIVING CAPACITIVE TOUCH SENSING DEVICE CAPABLE OF RESENDING DRIVE SIGNALS

• US 20150268758A1
• Filed: 03/19/2014
• Published: 09/24/2015
• Est. Priority Date: 03/19/2014
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: LO, CHUNG-WEN, CHEN, HSIN-CHIA, SAHGAL, RAMAN, CRANDALL, KEN
• Granted Patent: US 9,256,332 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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

There is provided a concurrent driving capacitive touch sensing device including a drive end, a capacitive sensing matrix and a detection end. The capacitive sensing matrix includes a plurality of drive electrodes and sense electrodes crossing to each other. The drive end is configured to concurrently input cycle data of encoded and modulated drive signals into the drive electrodes. The detection end is coupled to one of the sense electrodes and configured to acquire a predetermined number of sampled values corresponding to the cycle data associated with the coupled sense electrode and generate a response signal to the drive end according to the sampled values, wherein the drive end resends the cycle data according to the response signal.

Claims

1. A concurrent driving capacitive touch sensing device comprising:

a capacitive sensing matrix comprising a plurality of drive electrodes and a plurality of sense electrodes configured to form coupling capacitance;

a drive end configured to concurrently input cycle data of encoded and modulated drive signals into the drive electrodes; and

a detection end coupled to one of the sense electrodes and configured to acquire a predetermined number of sampled values corresponding to the cycle data associated with the coupled sense electrode and generate a response signal to the drive end according to the sampled values,

wherein the drive end resends the cycle data according to the response signal.

2. The sensing device as claimed in claim 1, wherein when a magnitude variation of the sampled values is not within a predetermined detection range, the detection end generates the response signal to the drive end, and the drive end resends the cycle data when receiving the response signal.

3. The sensing device as claimed in claim 1, wherein when a magnitude variation of the sampled values is within a predetermined detection range, the detection end generates the response signal to the drive end, and the drive end resends the cycle data when not receiving the response signal for a predetermined time interval.

4. The sensing device as claimed in claim 1, wherein

the drive end is further configured to concurrently input a plurality of cycle data into the drive electrodes in each of a plurality of drive time slots of a frame of the capacitive sensing matrix, and the cycle data within a same drive time slot and corresponding to a same drive electrode are identical;

and

the detection end is further configured to be coupled to the sense electrodes of the capacitive sensing matrix so as to acquire the predetermined number of sampled values corresponding to each of the cycle data of each of the drive time slots, and generate a detection signal according to notch filtering or standard deviation of the sampled values of each of the drive time slots.

5. The sensing device as claimed in claim 4, wherein the sampled values not within a predetermined detection range is not used to generate the detection signal.

6. The sensing device as claimed in claim 4, wherein the detection end is further configured to

generate a detection matrix according to the detection signal of each of the drive time slots;

and

decode the detection matrix so as to generate a two-dimensional detection vector corresponding to each channel.

7. The sensing device as claimed in claim 6, wherein the encoded and modulated drive signals are encoded by a Hadamard matrix and the detection end decodes the detection matrix using an inverse matrix of the Hadamard matrix.

8. The sensing device as claimed in claim 1, wherein the encoded and modulated drive signals are modulated by phase modulation or quadrature amplitude modulation.

9. A concurrent driving capacitive touch sensing device comprising:

a capacitive sensing matrix comprising a plurality of drive electrodes and a plurality of sense electrodes configured to form coupling capacitance;

a drive end configured to concurrently input a plurality of cycle data of encoded and modulated drive signals into the drive electrodes in each of a plurality of drive time slots of a frame of the capacitive sensing matrix; and

a detection end coupled to one of the sense electrodes and configured to acquire a predetermined number of sampled values corresponding to each of the cycle data of the drive time slots associated with the coupled sense electrode and generate a response signal to the drive end according to the sampled values,

wherein the drive end extends the associated drive time slot according to the response signal.

10. The sensing device as claimed in claim 9, wherein when a magnitude variation of sampled values corresponding to a cycle data is not within a predetermined detection range, the detection end generates the response signal to the drive end, and the drive end extends the drive time slot associated with the cycle data when receiving the response signal.

11. The sensing device as claimed in claim 9, wherein when a magnitude variation of sampled values corresponding to a cycle data is within a predetermined detection range, the detection end generates the response signal to the drive end, and the drive end extends the drive time slot associated with the cycle data when not receiving the response signal for a predetermined time interval.

12. The sensing device as claimed in claim 9, wherein the detection end is further configured to

sequentially couple to the sense electrodes of the capacitive sensing matrix so as to acquire the predetermined number of sampled values corresponding to each of the cycle data of each of the drive time slots;

and

generate a detection signal according to notch filtering or standard deviation of the sampled values of each of the drive time slots.

13. The sensing device as claimed in claim 12, wherein the sampled values not within a predetermined detection range is not used to generate the detection signal.

14. The sensing device as claimed in claim 12, wherein the detection end is further configured to

generate a detection matrix according to the detection signal of each of the drive time slots;

and

decode the detection matrix so as to generate a two-dimensional detection vector corresponding to each channel.

15. The sensing device as claimed in claim 14, wherein the encoded and modulated drive signals are encoded by a Hadamard matrix and the detection end decodes the detection matrix using an inverse matrix of the Hadamard matrix.

16. The sensing device as claimed in claim 9, wherein the encoded and modulated drive signals are modulated by phase modulation or quadrature amplitude modulation.

17. A concurrent driving capacitive touch sensing device comprising:

a capacitive sensing matrix comprising a plurality of drive electrodes and a plurality of sense electrodes configured to form coupling capacitance;

a drive end configured to concurrently input a plurality of cycle data of encoded and modulated drive signals into the drive electrodes in each of a plurality of drive time slots of a frame of the capacitive sensing matrix, wherein an cycle number of the cycle data of at least a part of the drive time slots is larger than a predetermined cycle number; and

a detection end configured to be sequentially coupled to the sense electrodes of the capacitive sensing matrix and decode a detection matrix obtained by detecting channels of the drive electrodes and the sense electrodes so as to generate a two-dimensional detection vector corresponding to each of the channels.

18. The sensing device as claimed in claim 17, wherein the encoded and modulated drive signals are encoded by a Hadamard matrix and the detection end decodes the detection matrix using an inverse matrix of the Hadamard matrix.

19. The sensing device as claimed in claim 17, wherein the encoded and modulated drive signals are modulated by phase modulation or quadrature amplitude modulation.

20. The sensing device as claimed in claim 17, wherein a slot number of the drive time slots is equal to an electrode number of the drive electrodes concurrently driven by the drive end.