Simplified capacitive touchpad and method thereof

• US 20050179672A1
• Filed: 02/08/2005
• Published: 08/18/2005
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Chiu, Yen-Chang, Chien, Yung-Lieh, Tang, Cheng-Hao
• Granted Patent: US 7,436,395 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/0213 Arrangements providing an integrated pointing device in a keyboard, e.g. trackball, mini-joystick for pointing devices integrated in a laptop computer G06F1/169; joysticks G05G9/047; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• 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
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/96066 Thumbwheel, potentiometer, scrollbar or slider simulation by touch switch

Abstract

In a capacitive touchpad, a plurality of sensing zones are defined, and a controller is connected with a plurality of scan lines for sensing a movement of an object slipping on the plurality of sensing zones, wherein at least one of the plurality of scan lines is connected to at least two of the plurality of sensing zones. The distance, speed and direction of the movement are determined by detecting the object on the touchpad at two positions upon two scans, and thereby the control of a scroll bar is accomplished. The capacitive touchpad is applied for a Z-axis arrangement on a mouse and a scroll arrangement on a keyboard.

Claims

1. A simplified capacitive touchpad comprising:

a plurality of sensing zones;

a plurality of scan lines for scanning the plurality of sensing zones; and

a controller connected with the plurality of scan lines for sensing a movement of an object slipping on the plurality of sensing zones;

wherein at least one of the plurality of scan lines is connected to at least two of the plurality of sensing zones.

2. The touchpad of claim 1, wherein the plurality of sensing zones have a substantially same area.

3. The touchpad of claim 1, wherein the plurality of sensing zones have a same number of traces.

4. The touchpad of claim 1, wherein at least two of the sensing zones have different numbers of traces.

5. A method for sensing a movement of an object slipping on a capacitive touchpad, the method comprising the steps of:

defining a plurality of sensing zones on the touchpad;

connecting a plurality of scan lines to the touchpad with at least one of the plurality of scan lines connected to at least two of the plurality of sensing zones;

scanning the plurality of sensing zones by the plurality of scan lines for detecting the object on the touchpad at a first position upon a first scan and at a second position upon a second scan; and

determining a distance and a direction of the movement from the first and second positions.

6. The method of claim 5, further comprising initializing an automatic scroll function upon the first or second position at a top end or a bottom end of the touchpad.

7. The method of claim 5, further comprising determining a speed of the movement from a time interval and the distance between the first and second positions.

8. The method of claim 5, further comprising performing a scroll bar control upon the distance and direction of the movement.

9. A capacitive touchpad for a Z-axis arrangement on a mouse, the touchpad comprising:

a plurality of sensing zones;

a plurality of scan lines for scanning the plurality of sensing zones; and

a controller connected with the plurality of scan lines for sensing a movement of an object slipping on the plurality of sensing zones, and performing a scroll function including scrolling on a window upon a distance and direction of the movement or determining a scroll acceleration on the window upon a speed of the movement;

wherein at least one of the plurality of scan lines is connected to at least two of the plurality of sensing zones.

10. The touchpad of claim 9, wherein the plurality of sensing zones have a substantially same area.

11. The touchpad of claim 9, wherein the plurality of sensing zones have a same number of traces.

12. The touchpad of claim 9, wherein at least two of the sensing zones have different numbers of traces.

13. A capacitive touchpad for a scroll arrangement on a keyboard, the touchpad comprising:

a plurality of sensing zones;

a plurality of scan lines for scanning the plurality of sensing zones; and

a controller connected with the plurality of scan lines for sensing a movement of an object slipping on the plurality of sensing zones, and performing a scroll function including scrolling on a window upon a distance and direction of the movement or determining a scroll acceleration on the window upon a speed of the movement;

wherein at least one of the plurality of scan lines is connected to at least two of the plurality of sensing zones.

14. The touchpad of claim 13, wherein the plurality of sensing zones have a substantially same area.

15. The touchpad of claim 13, wherein the plurality of sensing zones have a same number of traces.

16. The touchpad of claim 13, wherein at least two of the sensing zones have different numbers of traces.

17. A simplified capacitive touchpad comprising:

a plurality of sensing zones in a first and second directions;

a first group of scan lines for scanning the plurality of sensing zones in the first direction;

a second group of scan lines for scanning the plurality of sensing zones in the second direction; and

a controller connected with the first and second groups of scan lines for sensing a movement of an object slipping on the plurality of sensing zones in the first or second directions;

wherein at least one of the plurality of scan lines is connected to at least two of the plurality of sensing zones.

18. The touchpad of claim 17, wherein the plurality of sensing zones have a substantially same area.

19. The touchpad of claim 17, wherein the plurality of sensing zones have a same number of traces.

20. The touchpad of claim 17, wherein at least two of the sensing zones in the first or second directions have different numbers of traces.