INPUT APPARATUS HAVING CAPACITIVE TOUCH ELEMENT AND PRESSURE-BASED SENSING ELEMENT INTEGRATED THEREIN, AND TOUCH EVENT PROCESSING METHOD THEREOF

• US 20120299866A1
• Filed: 08/22/2011
• Published: 11/29/2012
• Est. Priority Date: 05/27/2011
• Status: Abandoned Application

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Pao, Tien-Wen, Wu, Chien-Hui, Jung, Bor-Lin
• Application Number:
  US13/214,255
• Publication Number:
  US 20120299866A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• 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

An input apparatus includes a capacitive touch element, at least a pressure-based sensing element, and a control circuit. The control circuit includes a switch unit and a shared processing unit. The switch unit is coupled to the capacitive touch element and the pressure-based sensing element, for selectively generating an output signal according to a touch signal generated by the capacitive touch element or a sensor signal generated by the pressure-based sensing element. The shared processing unit is coupled to the switch unit, for processing the output signal to detect a touch event. A touch event processing method includes scanning traces for detecting if a touch event occurs, checking whether the touch event occurs in a capacitive touch element or a pressure-based sensing element, and processing the touch event with a corresponding algorithm.

Claims

1. An input apparatus, comprising:

a capacitive touch element;

at least a pressure-based sensing element; and

a control circuit, comprising;

a switch unit, coupled to the capacitive touch element and the pressure-based sensing element, for selectively generating an output signal according to a touch signal generated by the capacitive touch element or a sensor signal generated by the pressure-based sensing element; and

a shared processing unit, coupled to the switch unit, for processing the output signal to detect a touch event.

2. The input apparatus of claim 1, wherein the control circuit continues processing the touch event until the touch event is no longer valid.

3. The input apparatus of claim 1, wherein a sensing mode corresponding to the capacitive touch element is a self-capacitance mode or a mutual capacitance mode.

4. The input apparatus of claim 1, wherein the switch unit comprises:

a trace switch, having an input port and an output port, wherein each of the capacitive touch element and the pressure-based sensing element is connected to the input port via traces, the switch unit is connected to the shared processing unit via a trace, and the trace switch selectively couples the capacitive touch element or the pressure-based sensing element to the output port.

5. The input apparatus of claim 4, wherein the shared processing unit further controls switching of the trace switch according to a touch sequence of the capacitive touch element and the pressure-based sensing element.

6. The input apparatus of claim 4, wherein the shared processing unit comprises:

a processor;

a charge detector, coupled to the output port of the trace switch, for performing charge detection on the output signal outputted by the output port to generate a detection result; and

an analog-to-digital converter, coupled between the charge detector and the processor, for converting the detection result into a digital signal, and outputting the digital signal to the processor, wherein the processor detects the touch event according to the digital signal.

7. The input apparatus of claim 1, wherein the switch unit comprises:

a first trace switch, having a first input port and a first output port, for selectively couple the first output port to the first input port, wherein the press-based sensing element is connected to the first input port via traces;

a converter, coupled between the first output port and the shared processing unit, for converting a voltage variation of the sensor signal into a charge variation to generate the output signal to the shared processing unit when the first output port is coupled to the first input port; and

a second trace switch, having a second input port and a second output port, for selectively couple the second output port to the second input port, wherein the capacitive touch element is connected to the second input port via traces, and the second output port outputs the touch signal as the output signal when the second output port is coupled to the second input port.

8. The input apparatus of claim 7, wherein a sensing mode corresponding to the capacitive touch element is a self-capacitance mode or a mutual capacitance mode.

9. The input apparatus of claim 7, wherein the shared processing unit further controls switching of the first trace switch and the second trace switch according to a touch sequence of the capacitive touch element and the pressure-based sensing element.

10. The input apparatus of claim 7, wherein the shared processing unit comprises:

a processor;

a charge detector, coupled to the second output port of the second trace switch and the converter, for performing charge detection on the output signal to generate a detection result; and

an analog-to-digital converter, coupled between the charge detector and the processor, for converting the detection result into a digital signal, and outputting the digital signal to the processor, wherein the processor detects the touch event according to the digital signal.

11. The input apparatus of claim 7, wherein the converter is a capacitor.

12. The input apparatus of claim 1, wherein the pressure-based sensing element is a force sensor.

13. The input apparatus of claim 12, wherein a sensing mode corresponding to the force sensor is a self-capacitance mode or a mutual capacitance mode.

14. The input apparatus of claim 1, wherein the pressure-based sensing element is a pointing stick.

15. An input apparatus, comprising:

a capacitive touch element;

a capacitive pressure sensor;

a trace switch, coupled to the capacitive touch element and the capacitive pressure sensor, for performing switching between the capacitive touch element and the capacitive pressure sensor to generate an output signal; and

a shared processing unit, coupled to the trace switch, for referring to switching of the trace switch to selectively execute first firmware corresponding to the capacitive touch element or second firmware corresponding to the capacitive pressure sensor to process the output signal for detecting a touch event.

16. The input apparatus of claim 15, wherein the shared processing unit comprises:

a processor;

a charge detector, coupled to the trace switch, for performing charge detection on the output signal to generate a detection result; and

an analog-to-digital converter, coupled between the charge detector and the processor, for converting the detection result into a digital signal, and outputting the digital signal to the processor, wherein the processor detects the touch event according to the digital signal.

17. An input apparatus, comprising:

a capacitive touch element;

a resistive pointing stick;

a first trace switch, for selectively outputting an output of the resistive pointing stick;

a converter, for converting the output of the resistive pointing stick;

a second trace switch, for selectively outputting an output of the capacitive touch element; and

a shared processing unit, coupled to the converter and the second trace switch, for referring to switching of the first trace switch and the second trace switch to selectively execute first firmware to process the output of the capacitive touch element or second firmware to process an output of the converter for detecting a touch event.

18. The input apparatus of claim 17, wherein the shared processing unit comprises:

a processor;

a charge detector, coupled to the second trace switch and the converter, for performing charge detection on the output of the capacitive touch element or the output of the converter to generate a detection result; and

an analog-to-digital converter, coupled between the charge detector and the processor, for converting the detection result into a digital signal, and outputting the digital signal to the processor, wherein the processor detects the touch event according to the digital signal.

19. The input apparatus of claim 17, wherein the converter is a capacitor.

20. A touch event processing method, comprising:

scanning traces for detecting if a touch event occurs;

checking if the touch event occurs in a capacitive touch element or a pressure-based sensing element;

when the touch event occurs in the capacitive touch element, performing algorithm corresponding to the capacitive touch element upon the touch event; and

when the touch event occurs in the pressure-based sensing element, performing algorithm corresponding to the pressure-based sensing element upon the touch event.

21. The touch event processing method of claim 20, further comprising:

when the touch event occurs in the capacitive touch element, scanning traces corresponding to the capacitive touch element to check if the touch event is no longer valid; and

when the touch event occurs in the pressure-based sensing element, scanning traces corresponding to the pressure-based sensing element to check if the touch event is no longer valid;

wherein when the touch event is no longer valid, the traces are scanned again to detect if another touch event occurs;

otherwise, a corresponding algorithm is still performed upon the touch event.

22. The touch event processing method of claim 20, wherein the step of scanning the traces for detecting if the touch event occurs comprises:

scanning traces corresponding to the capacitive touch element by utilizing a self-capacitance mode or a mutual capacitance mode.

23. The touch event processing method of claim 20, wherein the step of scanning the traces for detecting if the touch event occurs comprises:

when the pressure-based sensing element is a force sensor, scanning traces corresponding to the force sensor by utilizing a self-capacitance mode or a mutual capacitance mode.