Energy-efficient Touch Panel Device and Related Method

• US 20100214255A1
• Filed: 07/08/2009
• Published: 08/26/2010
• Est. Priority Date: 02/23/2009
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Chang, Hui-Hung, Huang, He-Wei, Chang, Chih-Yuan, Yu, Tsung-Yin
• Granted Patent: US 8,115,747 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet

Abstract

An energy-efficient touch panel control device includes a touch panel, a buffer memory, an interrupt initiation unit, for outputting an interrupt signal, an analog to digital conversion unit, for converting analog output voltage to digital trace data and storing the digital trace data in the buffer memory, and according to a control signal, switching an operating mode, an operation unit, generating a detecting result according to the digital trace data, switching the operating mode according to the control signal, a mode control unit, for generating the control signal according to the interrupt signal, and a host interface unit.

Claims

1. An energy-efficient touch panel control device comprising:

a touch panel comprising a plurality of horizontal traces and a plurality of vertical traces, corresponding to a plurality of capacitive load parameters, for generating a plurality of analog output voltages;

a buffer memory for storing data;

an interrupt initiation unit, for counting a data number of the data stored in the buffer memory, and outputting an interrupt signal while the data number is greater than or equal to a predefined value;

an analog to digital conversion unit, coupled to the touch panel and the buffer memory, for converting the plurality of analog output voltages to a plurality of digital trace data and storing the plurality of digital trace data in the buffer memory, and switching an operating mode according to a control signal;

an operation unit, coupled to the buffer memory, for generating a detecting result according to the plurality of digital trace data, and switching the operating mode according to the control signal;

a mode control unit, coupled to the interrupt initiation unit, the operation unit and the analog to digital conversion unit, for generating the first control signal to the analog to digital conversion unit, and the second control signal to the operation unit according to the interrupt signal; and

a host interface unit, coupled to the operation unit, for transmitting a touch event message to a computer host according to the detecting result.

2. The touch panel control device of claim 1, wherein the mode control unit is utilized for generating the first control signal according to the interrupt signal such that the analog to digital conversion unit is operated in a sleep mode, and the operation unit is operated in an active mode.

3. The touch panel control device of claim 1, wherein the mode control unit is utilized for generating the first control signal according to the interrupt signal such that the analog to digital conversion unit is operated in an active mode, and the operation unit is operated in a sleep mode.

4. The touch panel control device of claim 1 further comprising a load parameter storing unit, coupled to the analog to digital conversion unit, for temporarily storing the plurality of capacitive load parameters.

5. The touch panel control device of claim 4, wherein the operation unit is further utilized for moving the plurality of capacitive load parameters to the load parameter storing unit while the touch panel control device is being bootstrapped or reset.

6. The touch panel control device of claim 4, wherein the load parameter storing unit and the buffer memory share the same memory module, or use as two memory modules.

7. The touch panel control device of claim 5 further comprising a program memory, coupled to the operation unit, for storing the plurality of capacitive load parameters.

8. The touch panel control device of claim 1, wherein the program memory is a non-volatile memory.

9. The touch panel control device of claim 1, wherein the predefined value is less than or equal to the memory size of the buffer memory.

10. The touch panel control device of claim 1, wherein the first control signal and the second control signal are of the same control signal, or two different control signals.

11. An energy-efficient touch panel control method comprising:

transforming a plurality of analog output voltages into a plurality of digital trace data according to a plurality of capacitive load parameters by an analog to digital conversion unit;

storing the plurality of the digital trace data into a buffer memory; and

controlling operating modes of the analog to digital conversion unit and an operation unit according to a data number of the data stored in the buffer memory.

12. The touch panel control method of claim 11, wherein controlling the operating modes of the analog to digital conversion unit and the operation unit according to the data number of the data stored in the buffer memory is to have the analog to digital conversion unit operated in a sleep mode, and the operation unit operated in an active mode when the data number is greater than or equal to a predefined value, such that the operation unit processes the data stored in the buffer memory.

13. The touch panel control method of claim 12 further comprising having the analog to digital conversion unit operated in an active mode, and the operation unit operated in a sleep mode, after the operation unit completing processing the data stored in the memory buffer.

14. The touch panel control method of claim 11 further comprising storing the plurality of the capacitive load parameters.

15. The touch panel control method of claim 11, wherein the predefined value is less than or equal to the memory size of the buffer memory.