Touch controller, touch sensing device, and touch sensing method

• US 9,841,841 B2
• Filed: 12/22/2015
• Issued: 12/12/2017
• Est. Priority Date: 01/14/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Hee-Chang
• Primary Examiner(s): Johnson, Gerald
• Application Number:
  US14/978,588
• Publication Number:
  US 20160202839A1
• Time in Patent Office: 721 Days
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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 touch controller includes a driving signal transmitter and a sensing signal receiver. The driving signal transmitter is configured to generate a driving signal by spreading a frequency of an input signal to a first frequency and a second frequency. The first frequency is higher than a preset carrier frequency and the second frequency is less than the carrier frequency. The driving signal transmitter inputs the driving signal to a touch panel. The sensing signal receiver is configured to receive a sensing signal generated in the touch panel based on the driving signal and generate touch data based on the sensing signal.

Claims

1. A touch controller comprising:

a driving signal transmitter configured to generate a driving signal by spreading a frequency of an input signal to a first frequency and a second frequency, wherein the first frequency is higher than a preset carrier frequency, and the second frequency is less than the carrier frequency, and to input the driving signal to a touch panel; and

a sensing signal receiver configured to receive a sensing signal generated in the touch panel based on the driving signal and generate touch data based on the sensing signal.

2. The touch controller of claim 1, wherein a difference between the carrier frequency and the first frequency is equal to a difference between the carrier frequency and the second frequency.

3. The touch controller of claim 1, wherein the driving signal transmitter is further configured to encode the input signal based on a code signal having a third frequency so that a frequency of the input signal is spread in a positive direction and a negative direction due to the third frequency.

4. The touch controller of claim 3, wherein the driving signal transmitter is further configured to vary a code interval of the code signal to correspond to the third frequency.

5. The touch controller of claim 3, wherein the code signal comprises a first signal and a second signal having a negative value with respect to a value of the first signal.

6. The touch controller of claim 1, wherein the driving signal transmitter comprises:

an encoder configured to generate an encoding signal by encoding the input signal based on a code signal having a third frequency; and

a modulator configured to modulate the encoding signal based on a carrier signal having the carrier frequency.

7. The touch controller of claim 6, wherein the driving signal transmitter further comprises a pulse shaper configured to change a waveform of the encoding signal.

8. The touch controller of claim 1, wherein the sensing signal receiver comprises:

a correlator circuit configured to remove a component of the carrier frequency from the sensing signal and generate a touch signal having a logic level selected from among M logic levels, wherein M is a natural number equal to or greater than 2; and

a decoder configured to decode the touch signal based on a code signal having a third frequency to generate the touch data.

9. The touch controller of claim 8, wherein the sensing signal receiver further comprises a pulse window circuit configured to synthesize the touch signal and a preset pulse waveform.

10. The touch controller of claim 1, further comprising control logic configured to determine a frequency of noise input to the touch panel based on the touch data and determine a frequency difference between the carrier frequency and the first frequency and a frequency difference between the carrier frequency and the second frequency such that the frequency of the noise is removed.

11. The touch controller of claim 10, wherein the control logic is further configured to select one of a plurality of preset frequencies as the frequency difference based on the frequency of the noise.

12. The touch controller of claim 1, wherein the touch controller is formed on a same semiconductor chip or module as a display driving circuit configured to drive a display panel.

13. A touch sensing method comprising:

generating a driving signal by spreading a frequency of an input signal to a first frequency and a second frequency, wherein the first frequency is higher than a preset carrier frequency, and the second frequency is less than the carrier frequency;

sensing a touch on a touch panel based on the driving signal to generate a sensing signal; and

generating touch data based on the sensing signal received from the touch panel.

14. The touch sensing method of claim 13, wherein the generating of a driving signal comprises:

encoding an input signal based on a code signal having a preset frequency to generate an encoding signal; and

modulating the encoding signal based on a carrier signal.

15. The touch sensing method of claim 14, wherein the generating of a driving signal further comprises shaping the encoding signal by changing a waveform of the encoding signal.

16. The touch sensing method of claim 14, wherein the generating of touch data comprises:

decoding the sensing signal based on the code signal to generate a decoding signal; and

demodulating the decoding signal based on the carrier signal.

17. The touch sensing method of claim 13, wherein the generating of touch data comprises separating a touch signal from the sensing signal via a match filter having a transfer function corresponding to a transfer function of the driving signal.

18. A touch controller for a touch panel, the touch controller comprising:

a receiver configured to receive a sensing signal from the touch panel and derive touch data from the sensing signal;

a noise analysis circuit configured to determine an amount of noise in the touch data;

a frequency adjustment circuit configured to change a dodging frequency when the amount is equal to or greater than a reference amount and otherwise maintains the dodging frequency; and

a transmitter configured to perform a frequency spreading on an input signal using the dodging frequency to generate a driving signal for application to the touch panel.

19. The touch controller of claim 18, wherein the frequency spreading spreads a frequency of the input signal to a first frequency and a second frequency, wherein the first frequency is higher than a preset carrier frequency, and the second frequency is less than the carrier frequency.

20. The touch controller of claim 19, wherein a difference between the carrier frequency and the first frequency is equal to a difference between the carrier frequency and the second frequency.