Circuit for interfacing mouse input device to computer system
Patent 4886941 Issued on December 12, 1989. Estimated Expiration Date: 
May 19, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 19, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMan-machine link for converting coordinates to phase differences representative of increments in the coordinates Patent #: 4739303 InventorsApplicationNo. 051451 filed on 05/19/1987US Classes:178/19.01, Writing digitizer stylus345/163MouseExaminersPrimary: Schreyer, Stafford D.Attorney, Agent or FirmInternational ClassG08C 021/00AbstractA computer system mouse-type input device. Movements of a track-ball motion sensor are converted to quadrature signals and are accumulated in a counting circuit. The contents of the counter are pulse-position modulated with waveforms characteristic of a resistive-capacitive charging circuit and are read periodically by a computer input channel normally used for input of potentiometer-generated commands. The pulse-position modulated signals are converted to digital values used by the computer to position the cursor on a display screen. | |
