SEMICONDUCTOR DEVICE AND ERROR CANCELING METHOD

• US 20150169108A1
• Filed: 12/10/2014
• Published: 06/18/2015
• Est. Priority Date: 12/12/2013
• Status: Active Grant

• Current Assignee: Synaptics Japan GK (Synaptics Incorporated)
• Original Assignee: Synaptics Display Devices KK
• Inventors: ISHII, Tatsuya, TANAKA, Nobukazu, TAKEYAMA, Hiroshi, AKAI, Akihito
• Granted Patent: US 9,760,222 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• 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

Embodiments herein include a device, system, and method for periodically capturing sensing signals using one or more detection electrodes to generate data for detecting an object proximate to the detection electrodes. The sensing signals are captured during detection periods within periodic detection cycles where each of the detection cycles define a period of time between consecutive detection periods. In addition, the device, system and method set a duration of the detection cycle to 1/m (where m is appositive integer) of a duration of a display-scan cycle. The value of m is selected based on a periodic noise signal. Thus, the device, system, and method may prevent a periodic noise signal which has a cycle that is longer than the detection period from worsening the accuracy of touch detection.

Claims

1. A semiconductor device comprising:

a capacitive sensing controller operable to;

periodically capture sensing signals using one or more detection electrodes to generate data for detecting an object proximate to the detection electrodes, wherein the sensing signals are captured during detection periods in periodic detection cycles, each detection cycle defining a period of time between consecutive detection periods; and

a processor operable to set a duration of the detection cycles, wherein the duration of the detection cycles is 1/m (where m is a positive integer) of a duration of a display-scan cycle, wherein m is selected based on an periodic noise signal.

2. The semiconductor device according to claim 1, wherein the processor is operable to determine a value of the m based on identifying a value of the duration of the detection cycles that is substantially the same as an odd multiple of half of a cycle period of the periodic noise signal.

3. The semiconductor device according to claim 1, wherein in the capacitive sensing controller a duration of each of the detection periods is specified by detection-period-set data, and the duration of the detection periods defined by the detection-period-set data is an integer multiple of 1/n of the display-scan cycle (where n in a positive integer), wherein n is selected based on the periodic noise signal.

4. The semiconductor device according to claim 3, wherein the processor is operable to determine a value of n based on identifying a value of the duration of the detection periods that is substantially the same as an integer multiple of a cycle period of the periodic noise signal.

5. The semiconductor device according to claim 3, wherein the processor has a non-volatile memory comprising:

detection-cycle-set data for specifying 1/m of a display-scan cycle, and detection-period-set data for specifying the integer multiple of 1/n of the display-scan cycle are rewritably stored in the non-volatile memory.

6. The semiconductor device according to claim 1, wherein by using the duration of the detection cycles, the capacitive sensing controller is configured to:

align a first one of the consecutive detection periods with a positive portion of the periodic noise signal; and

align a second one of the consecutive detection periods with a negative portion of the periodic noise signal, wherein the positive portion and the negative portion have similar magnitudes.

7. The semiconductor device according to claim 1, wherein the processor has a non-volatile memory, and

detection-cycle-set data for specifying 1/m of the display-scan cycle is rewritably stored in the non-volatile memory.

8. The semiconductor device according to claim 1, further comprising:

a display controller operable to supply gradation signals to signal electrodes of a display panel in synchronization with capturing the sensing signals using the one or more detection electrodes in each display-scan cycle of the display panel.

9. The semiconductor device according to claim 1, wherein the capacitive sensing controller performs touch detection and noise detection using the detection cycles, wherein:

during touch detection, the capacitive sensing controller drives a drive electrode to capture the sensing signals,

during noise detection, the capacitive sensing controller stops driving the drive electrode to capture the sensing signals,

the processor is operable to determine the duration of the detection cycles based on data measured during noise detection.

10. The semiconductor device according to claim 9, wherein the capacitive sensing controller is operable to set a duration of the detection periods to perform the touch detection and noise detection,

wherein the duration of the detection periods is an integer multiple of 1/n of the display-scan cycle (where n is a positive integer).

11. A semiconductor device comprising:

a display controller operable to update a display panel in synchronization with a display-scan cycle; and

a capacitive sensing controller operable to detect detection data according to capacitance between drive and detection electrodes by periodically capturing sensing signals on the detection electrodes, wherein detecting the detection data is synchronized with the display-scan cycle,

wherein the capacitive sensing controller performs the periodic capture during detection periods in periodic detection cycles, each detection cycle defining a period of time between consecutive detection periods, and

a duration of the detection cycles is 1/m (where m is a positive integer) of a duration of the display-scan cycle, wherein m is selected based on an periodic noise signal.

12. The semiconductor device according to claim 11, wherein a duration of the detection periods is an integer multiple of 1/n of the display-scan cycle (where n is a positive integer).

13. A noise reduction method, comprising:

capturing sensing signals using one or more detection electrodes to generate detection data associated with an object proximate to the detection electrodes, wherein the sensing signals are captured during detection periods in periodic detection cycles, each detection cycle defining a period of time between consecutive detection periods;

setting a duration of the detection cycles, based on a periodic noise signal, such that a duration of the detection cycles is 1/m (where m is a positive integer) of a duration of a display-scan cycle.

14. The noise reduction method according to claim 13, further comprising:

determining a value of m by identifying a value of the duration of the detection cycles that is substantially the same as an odd multiple of half of a cycle period of the periodic noise signal.

15. The noise reduction method according to claim 13, wherein a duration of the detection periods is an integer multiple of 1/n of the display-scan cycle (where n is appositive integer), wherein n is selected based on the periodic noise signal.

16. The noise reduction method according to claim 15, further comprising:

determining a value of n based on identifying a value of the duration of the detection periods that is substantially the same as an integer multiple of a cycle period of the periodic noise signal.

17. The noise reduction method according to claim 13, further comprising:

aligning a first one of the consecutive detection periods with a positive portion of the periodic noise signal; and

aligning a second one of the consecutive detection periods with a negative portion of the periodic noise signal, wherein the positive portion and the negative portion have similar magnitudes.

18. The noise reduction method according to claim 13, wherein the display-scan cycle defines a time used to update one line of a display using a single gate electrode, wherein the detection cycle is within the display-scan cycle.

19. The noise reduction method according to claim 13, further comprising:

supply gradation signals to signal electrodes of a display panel in synchronization with capturing the sensing signals using the one or more detection electrodes in each display-scan cycle of the display panel.

20. The noise reduction method according to claim 13, further comprising:

performing noise detection using the one or more detection electrodes to generate noise data; and

identifying the periodic noise signal using the noise data.