Touch-pad digital computer pointing-device

• US 5,856,822 A
• Filed: 10/27/1995
• Issued: 01/05/1999
• Est. Priority Date: 10/27/1995
• Status: Expired due to Term

• Current Assignee: Maishi Electronic (Shanghai) Limited
• Original Assignee: O2 Micro Incorporated
• Inventors: Du, Sterling S., Lee, Yung-Yu Joe
• Primary Examiner(s): Saras, Steven J.
• Assistant Examiner(s): LEWIS, DAVID LEE
• Application Number:
  US08/549,422
• Time in Patent Office: 1,166 Days
• Field of Search: 345/157, 345/158, 345/159, 345/173, 345/174, 345/175, 345/179, 345/180, 345/145
• US Class Current: 345/73
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus

Abstract

A touch-pad digital computer pointing-device, for controlling a position of a cursor appearing on a display screen of a digital computer, senses and resolves respective locations within an active area at which concurrent multi-finger contacts occur. Multi-finger contacts with the active area activate or deactivate a drag-lock operating mode, computer power conservation, and other touch-pad operating characteristics such as the touch-pad'"'"'s sensitivity to finger contact. The touch-pad also senses a velocity and direction for finger contact with the active area for use in transmitting data to the computer which effects continuous cursor movement across the computer'"'"'s display screen in a direction fixed by the initial direction of contact movement across the active area. While there is no finger contact with the active area, the touch-pad monitors the active area and adjusts its operation to compensate for changes in the surrounding environment such as changes in temperature, humidity and atmospheric pressure.

Claims

1. A touch-pad for controlling a position of a cursor appearing on a display screen of a digital computer, the touch-pad comprising:

an active area that responds to finger contact thereto;

finger contact sensing device that is coupled to said active area for sensing a response of said active area to a finger contact, wherein said finger contact sensing device;

senses a velocity at which a finger contacting the touch-pad moves across said active area, the touch-pad responding to a finger contact velocity which exceeds a pre-established threshold by altering a characteristic of data subsequently transmitted from the touch-pad to the digital computer in response to finger contact with said active area; and

also senses a direction at which a finger contact to the touch-pad moves across said active area, the touch-pad after sensing a finger contact velocity which exceeds the pre-established threshold altering the characteristic of transmitted data so the cursor continues moving across the display screen of the digital computer in a direction fixed by an initial direction of finger contact movement across the active area even if such contact subsequently becomes stationary; and

computer port interface means that is coupled to said finger contact sensing device and that is responsive to finger contact with said active area for transmitting data to a digital computer that indicates finger contact in said active area.