Method and apparatus for avoiding pressing inaccuracies on a touch panel

• US 7,105,752 B2
• Filed: 06/17/2003
• Issued: 09/12/2006
• Est. Priority Date: 01/20/2003
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: HTC Corporation
• Inventors: Tsai, Jung-Yuan, Lan, Wei-Tun, Tsai, Wan-Ting
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US10/462,650
• Publication Number:
  US 20040140958A1
• Time in Patent Office: 1,183 Days
• Field of Search: 345/178, 345/180, 178/18.01
• US Class Current: 178/18.01
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method and apparatus for avoiding pressing inaccuracies on a touch panel. The touch panel includes a panel, a control module having an analog-to-digital converter (ADC) and a delay buffer, and a processor, the delay buffer able to buffer a trigger signal for interrupting the processor. The method includes sequentially receiving a plurality of analog signals generated by the panel when the panel is touched with the control module, transforming the plurality of analog signals into a plurality of corresponding digital signals and transmitting the plurality of digital signals to the processor with the analog-to-digital converter, neglecting a first m digital signals of the plurality of digital signals, and neglecting a last n digital signals of the plurality of digital signals, where m and n are integers with values equal to or larger than 1.

Claims

1. A method for avoiding pressing inaccuracies in a touch pad,

the touch pad comprising:

a panel for generating a plurality of analog voltage signals;

a control module, comprising an analog-to-digital converter for transforming the plurality of analog signals to a plurality of corresponding digital signals, electrically connected to the panel for monitoring the panel and receiving a plurality of analog voltage signals, (he control module further comprising a touch apparatus for generating a trigger signal and a delay buffer electrically connected between the touch apparatus and the processor for buffering the trigger signal; and

a processor electrically connected to the control module for receiving and processing the plurality of digital signals to control operations of the touch pad;

the method comprising;

(a) sequentially receiving the plurality of analog signals generated by the panel when the panel is touched with the control module;

(b) transforming the plurality of analog voltage signals to a plurality of corresponding digital signals and transmitting the plurality of digital signals to the processor with the analog-to-digital converter;

(c) neglecting a first m digital signals of the plurality of digital signals wherein m is an integer with value equal to or larger than 1 with the processor to avoid pressing inaccuracies when touch of the panel is initiated;

(d) neglecting a last n digital signals of the plurality of digital signals wherein n is an integer with value equal to or larger than 1 with the processor to avoid pressing inaccuracies when touch is removed from the panel;

(j) in step (a), when the panel is touched, outputting the trigger signal with the touch apparatus to the processor for initiating the processor to sequentially read the plurality of digital signals; and

(k) in step (j), before the trigger signal is transmitted to the processor, buffering the trigger signal with the delay buffer to avoid pressing inaccuracies of the touch pad.

2. The method of claim 1, wherein the panel comprises a margin domain and a central domain, the method further comprising:

(e) after step (c), determining where the plurality of digital signals are generated in the margin domain or the central domain of the panel with the processor;

(f) after step (e), when the processor determines that the plurality of digital signals are generated in the margin domain of the panel, determining whether the plurality of digital signals fits a predetermined margin error tolerating standard with the processor, and if so, performing step (d); and

(g) after step (e), when the processor determines that the plurality of digital signals are generated in the central domain of the panel, determining whether the plurality of digital signals fits a predetermined central error tolerating standard with the processor, and if so, performing step (d).

3. The method of claim 2 further comprising:

(h) in step (f), when the plurality of digital signals are generated in the margin domain, calculating a difference of any two signals of the plurality of digital signals and determining whether a value of the difference is less than a margin tolerating error value for determining whether the plurality of digital signals fits the margin error tolerating standard with the processor; and

(i) in step (g), when the plurality of digital signals are generated in the central domain, calculating a difference of any two signals of the plurality of digital signals and determining whether a value of the difference is less than a central error tolerating value for determining whether the plurality of digital signals fits the central error tolerating standard with the processor.

4. The method of claim 3 wherein the central error tolerating value is larger than the margin error tolerating value.

5. The method of claim 1 wherein the delay buffer is an analog resistance-capacitance (R-C) or a digital delay circuit.

6. The method of claim 1 wherein the processor comprises an operating system for processing the plurality of digital signals, the method further comprising:

(l) after step (c), outputting the plurality of digital signals with the processor to the operating system wherein the first m and the last n digital signals of the plurality of digital signals are neglected.

7. The method of claim 6 wherein the touch pad further comprises a memory for sequentially temporarily storing the plurality of digital signals, the method further comprising:

(m) before step (l), sequentially storing the plurality of digital signals into the memory except for the first m digital signals; and

(n) in step (m), outputting a first n digital signals of the digital signals being processed and stored in the memory with the processor to transmit the plurality of digital signals to the operating system, except for the last n digital signals.

8. The method of claim 1 wherein the touch pad is a resistive panel.

9. A method for avoiding pressing inaccuracies of a touch pad, wherein the touch pad comprises:

a panel, comprising at least a margin domain and a central domain, the panel for generating a plurality of analog voltage signals; and

a control module electrically connected to the panel for monitoring the panel and receiving the plurality of the analog voltage signals, the control module comprising;

an analog-to-digital converter (ADC) for transforming the plurality of the analog voltage signals to a plurality of corresponding digital signals;

a touch apparatus for generating a trigger signal; and

a delay buffer electrically connected to the touch apparatus for buffering the trigger signal;

a processor electrically connected to the control module for controlling operations of the touch pad; and

an operating system for processing the plurality of the digital signals;

the method comprising;

(a) determining whether the panel is being touched with the control module;

(b) outputting the trigger signal with the touch apparatus to the processor to initiate the processor when the control module determines the panel has been touched;

(c) in step (b), buffering the trigger signal with the delay buffer;

(d) after step (a), sequentially generating the plurality of analog voltage signals with the panel;

(e) after step (d), sequentially receiving the plurality of analog voltage signals with the control module, the analog-to-digital converter for transforming the plurality of analog voltage signals to the plurality of corresponding digital signals, and the control module for transmitting the plurality of digital signals to the processor;

(f) neglecting a first re digital signals of the plurality of digital signals with the processor, wherein m is an integer with a value equal to or larger than 1 to avoid pressing inaccuracies when touch of the panel is initiated;

(g) after step (f), determining whether the plurality of digital signals are generated in the margin domain or the central domain of the panel with the processor;

(h) after step (g), when the plurality of digital signals are generated in the central domain of the panel, calculating a difference of values of any two signals of the plurality digital signals and determining whether the difference is less than a central error tolerating value with the processor;

(i) after step (g), when the plurality of digital signals are generated in the margin domain of the panel, calculating a difference of values of any two signals of the plurality digital signals and determining whether the difference is less than a margin error tolerating value with the processor;

(j) sequentially generating the plurality of digital signals to the operating system with the processor when a difference is less than the central or margin tolerating value; and

(k) in step (j), neglecting a last n digital signals of the plurality of digital signals with the processor, wherein n is a integer with value equal to or larger than 1 to avoid pressing inaccuracies when touch is removed from the panel.

10. The method of claim 9 wherein the plurality of digital signals are output to the operating system except for the first m and the last n digital signals.

11. The method of claim 9 wherein the central error tolerating value is larger than the margin error tolerating value.

12. The method of claim 9 wherein the touch pad further comprises a memory for storing the plurality of digital signals, the method further comprising:

(l) after step (f), sequentially storing the plurality of digital signals into the memory;

(m) in step (j), outputting a first n digital signals of the digital signals being processed and stored in the memory to neglect the last n digital signals of the plurality of digital signals in step (k) with the processor.

13. A touch pad comprising:

a panel for generating a plurality of analog voltage signals;

a control module electrically connected to the panel for receiving the plurality of analog voltage signals, the control module comprising;

an analog-to-digital converter for transforming the plurality of analog voltage signals to a plurality of corresponding digital signals;

a touch apparatus for generating a trigger signal; and

a delay buffer electrically connected to the touch apparatus for buffering the trigger signal;

a processor electrically connected to the control module for controlling operations of the touch pad; and

an operating system for processing the plurality of digital signals;

wherein when the control module determines that the panel is being touched, the panel will sequentially generate the plurality of analog voltage signals, the touch panel will output the trigger signal to the processor for initiating the processor, and before the processor receives the trigger signal, the delay buffer is capable of buffering the trigger signal for avoiding pressing inaccuracies of the touch pad;

at the same time, the control module will sequentially receive the plurality of analog voltage signals, utilize the analog-to-digital converter to transform the plurality of analog voltage signals to the plurality of corresponding digital signals, and output the plurality of digital signals to the processor for sequentially outputting the plurality of digital signals to the operating system, the processor neglecting to output to the operating system a first m digital signals of the plurality of digital signals, wherein m is an integer with value equal to or larger than 1 to avoid pressing inaccuracies when touch of the panel is initiated;

wherein the panel comprises a margin domain and a central domain, and before the operating system receives the plurality of digital signals, the processor will determine whether the plurality of digital signals are generated from the margin domain or the central domain of the panel;

wherein before the processor determines whether the plurality of digital signals are generated from the margin domain or the central domain of the panel, the processor will neglect the first m digital signals of the plurality of digital signals for outputting the plurality of digital signals to the operating system without the first m digital signals of the plurality of digital signals, wherein m is an integer with value equal to or larger than 1.

14. The touch pad of claim 13 wherein when the processor determines that the plurality of digital signals are generated from the margin domain of the panel, the processor will calculate a difference of values of any two digital signals of the plurality of digital signals for determining whether the difference is less than a margin error tolerating value;

and when the processor determines that the plurality of digital signals are generated from the central domain of the panel, the processor will calculate a difference of values of any two digital signals of the plurality of digital signals for determining whether the difference is less than a central error tolerating value.

15. The touch pad of claim 14 wherein the central error tolerating value is larger than the margin error tolerating value.

16. The touch pad of claim 14 wherein when the plurality of digital signals are generated from the margin domain of the panel and the difference of values of any two digital signals of the plurality of digital signals is less than the margin error tolerating value, or when the plurality of digital signals are generated from the central domain of the panel and difference of values of any two digital signals of the plurality of digital signals is less than the central error tolerating value, the processor will neglect a last n digital signals of the plurality of digital signals for outputting the plurality of digital signals to the operating system without the last n digital signals of the plurality of digital signals, wherein n is an integer with value equal to or larger than 1.

17. The touch pad of claim 16 further comprising a memory for temporarily storing the plurality of digital signals, wherein the processor will output a first n digital signals of the plurality of digital signals being processed and stored in the memory to the operating system for making the control module neglect the last n digital signals of the plurality of digital signals.