Energy-efficient Touch Panel Device and Related Method

• US 20120105372A1
• Filed: 01/15/2012
• Published: 05/03/2012
• 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, Yu, Tsung-Yin, Chang, Chih-Yuan
• Granted Patent: US 9,001,071 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 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 an interrupt signal, and including 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 digital trace data;

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 detection result according to the plurality of digital trace data read from the buffer memory, and switching the operating mode according to an interrupt signal outputted when the number of digital trace data stored in the buffer memory is greater than or equal to a predefined value, the operation unit comprising;

a mode control unit, coupled to the analog to digital conversion unit, for generating the control signal for the analog to digital conversion unit; and

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

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; and

wherein the mode control unit is utilized for generating the first control signal after the operating unit completes generating the detection result such that the analog to digital conversion unit is operated in an active mode and the operation unit is operated in a sleep mode.

2. The touch panel control device of claim 1 further comprising an interrupt initiation unit, for counting a number of digital trace data stored in the buffer memory, and outputting the interrupt signal when the number of digital trace data stored in the buffer memory is greater than or equal to the predefined value.

3. The touch panel control device of claim 1, wherein the buffer memory outputs the interrupt signal when the number of digital trace data stored in the buffer memory is greater than or equal to the predefined value.

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 to update the plurality of capacitive load parameters to the analog to digital conversion unit while the touch panel control device is power on 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 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 7, 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 operation unit enters the sleep mode when the touch panel is not touched for more than a specific time.

15. The touch panel control device of claim 1, wherein the operation unit enters the sleep mode when a touch panel is not touched for more than a specific time.

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;

wherein the analog to digital conversion unit is operated in a sleep mode, and the operation unit is 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; and

wherein the analog to digital conversion unit is operated in an active mode, and the operation unit is operated in a sleep mode, after the operation unit completing processing the data stored in the memory buffer.

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

13. The touch panel control method of claim 11 further comprising:

update the plurality of capacitive load parameters to the analog to digital conversion unit while the touch panel control device is power on or reset.

14. 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.