Systems and methods for sensor devices having a non-commensurate number of transmitter electrodes

• US 9,063,608 B2
• Filed: 06/14/2012
• Issued: 06/23/2015
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Roberson, Jeremy, Schwartz, Adam
• Primary Examiner(s): HOLLOWAY III, EDWIN C
• Application Number:
  US13/523,183
• Publication Number:
  US 20130335252A1
• Time in Patent Office: 1,104 Days
• Field of Search: 341/173, 341/33, 345/173, 345/174
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

A processing system for an input device includes a transmitter modules coupled to a plurality of transmitter electrodes including a first set and a second set of transmitter electrodes, the first set and second set being disjoint and having different sizes. The transmitter module is configured to simultaneously transmit a first plurality of transmitter signals with the first set of transmitter electrodes during a first period, and to simultaneously transmit a second plurality of transmitter signals with the second set of transmitter electrodes during a second period, wherein the first period and the second period are non-overlapping. Each of the first plurality of transmitter signals is based on a different sequence of a code, which includes a set of mathematically independent sequences and has a size equal to the size of the first set of transmitter electrodes.

Claims

1. A processing system for an input device, the processing system comprising:

A transmitter module comprising transmitter circuitry, the transmitter module coupled to a plurality of transmitter electrodes comprising a first set of transmitter electrodes and a second set of transmitter electrodes, wherein the first set of transmitter electrodes and the second set of transmitter electrodes are disjoint and have different sizes;

wherein the transmitter module is configured to simultaneously transmit a first plurality of transmitter signals with the first set of transmitter electrodes during a first period, and to simultaneously transmit a second plurality of transmitter signals with the second set of transmitter electrodes during a second period, wherein the first period and the second period are non-overlapping;

wherein, during the first period, each of the first plurality of transmitter signals is based on a different sequence of a code, and, during the second period, each of the second plurality of transmitter signals is based on a different sequence of the code, wherein the code comprises a set of mathematically independent sequences and has a size equal to the size of the first set of transmitter electrodes;

a receiver module coupled to a plurality of receiver electrodes and configured to receive first resulting signals during the first period and second resulting signals during the second period; and

a determination module configured to produce a plurality of demodulated signals based on the code, the first resulting signals, and the second resulting signals, and to determine positional information for an input object in a sensing region of the input device based on the demodulated signals.

2. The processing system of claim 1, wherein the transmitter module is configured to simultaneously transmit the second plurality of transmitter signals with the second set of transmitter electrodes and at least one transmitter electrode selected from the first set of transmitter electrodes during the second period.

3. The processing system of claim 2, wherein the at least one transmitter electrode comprises a number of transmitter electrodes equal to the difference between the size of the first set of transmitter electrodes and the size of the second set of transmitter electrodes.

4. The processing system of claim 2, wherein a demodulated signal of the plurality of demodulated signals is based on both the first resulting signals and the second resulting signals.

5. The processing system of claim 1, wherein the sum of the sizes of the first set of transmitter electrodes and the second set of transmitter electrodes is a non-integer multiple of the size of the set of mathematically independent sequences.

6. The processing system of claim 1, wherein the determination module is configured to produce the plurality of demodulated signals by applying a first deconvolving process to the first resulting signals and applying a second deconvolving process to the second resulting signals, wherein the first deconvolving process is different from the second deconvolving process.

7. The processing system of claim 1, wherein during a first sub-period of the first period, at least one of the first plurality of transmitter signals has a polarity different than a polarity of each of other transmitter signals in the first plurality of transmitter signals.

8. The processing system of claim 1, wherein the code is a ternary code.

9. An input device comprising:

a plurality of transmitter electrodes comprising a first set of transmitter electrodes and a second set of transmitter electrodes, wherein the first set of transmitter electrodes and the second set of transmitter electrodes are disjoint and have different sizes;

a plurality of receiver electrodes; and

a processing system communicatively coupled to the plurality of transmitter electrodes and the plurality of receiver electrodes, the processing system configured to;

simultaneously transmit a first plurality of transmitter signals with the first set of transmitter electrodes during a first period, and to simultaneously transmit a second plurality of transmitter signals with the second set of transmitter electrodes during a second period, wherein the first period and the second period are non-overlapping, wherein, during the first period, each of the first plurality of transmitter signals is based on a different sequence of a code, and, during the second period, each of the second plurality of transmitter signals is based on a different sequence of the code, wherein the code comprises a set of mathematically independent sequences and has a size equal to the size of the first set of transmitter electrodes;

receive first resulting signals during the first period and second resulting signals during the second period; and

produce a plurality of demodulated signals based on the code, the first resulting signals, and the second resulting signals, and to determine positional information for an input object in a sensing region of the input device based on the demodulated signals.

10. The input device of claim 9, wherein the processing system is configured to simultaneously transmit the second plurality of transmitter signals with the second set of transmitter electrodes and at least one transmitter electrode selected from the first set of transmitter electrodes during the second period.

11. The input device of claim 10, wherein the at least one transmitter electrode comprises a number of transmitter electrodes equal to the difference between the size of the first set of transmitter electrodes and the size of the second set of transmitter electrodes.

12. The input device of claim 10, wherein a demodulated signal of the plurality of demodulated signals is based on both the first resulting signals and the second resulting signals.

13. The input device of claim 9, wherein the sum of the sizes of the first set of transmitter electrodes and the second set of transmitter electrodes is a non-integer multiple of the size of the set of mathematically independent sequences.

14. The input device of of claim 9, wherein during a first sub-period of the first period, at least one of the first plurality of transmitter signals has a polarity different than a polarity of each of the other transmitter signals.

15. A method of capacitive sensing, the method comprising:

simultaneously transmitting a first plurality of transmitter signals with a first set of transmitter electrodes during a first period, and simultaneously transmitting a second plurality of transmitter signals with a second set of transmitter electrodes during a second period, wherein the first set of transmitter electrodes and second set of transmitter electrodes are disjoint and have different sizes, and the first period and the second period are non-overlapping;

wherein, during the first period, each of the first plurality of transmitter signals is based on a different sequence of a code, and, during the second period, each of the second plurality of transmitter signals is based on a different sequence of the code, the code comprising a set of mathematically independent sequences having a size equal to the size of the first set of transmitter electrodes;

receiving first resulting signals during the first period and second resulting signals during the second period; and

producing a plurality of demodulated signals based on the code, the first resulting signals, and the second resulting signals, and to determine positional information for an input object in a sensing region of the input device based on the demodulated signals.

16. The method of claim 15, further including simultaneously transmitting the second plurality of transmitter signals with the second set of transmitter electrodes and at least one transmitter electrode selected from the first set of transmitter electrodes during the second period.

17. The method of claim 16, wherein the at least one transmitter electrode comprises a number of transmitter electrodes equal to the difference between the size of the first set of transmitter electrodes and the size of the second set of transmitter electrodes.

18. The method of claim 16, wherein a demodulated signal of the plurality of demodulated signals is based on both the first resulting signals and the second resulting signals.

19. The method of claim 15, wherein the sum of the sizes of the first set of transmitter electrodes and the second set of transmitter electrodes is a non-integer multiple of the size of the set of mathematically independent sequences.

20. The method of claim 15, further including producing the plurality of demodulated signals by applying a first deconvolving process to the first resulting signals and applying a second deconvolving process to the second resulting signals, wherein the first deconvolving process is different from the second deconvolving process.