Digitizer having flat tablet with magnetic shield plate
Patent 4956526 Issued on September 11, 1990. Estimated Expiration Date: 
July 18, 2009. 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.
July 18, 2009. 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 ReferencesDigitizing tablet Coordinates input apparatus Patent #: 4848496 InventorsAssigneeApplicationNo. 381757 filed on 07/18/1989US Classes:178/18.08Having shieldExaminersPrimary: Schreyer, Stafford D.Attorney, Agent or FirmInternational ClassG08C 021/00AbstractA digitizer for determining coordinate value of a point designated on a given two-dimensional coordinate plane. A pointing instrument is manually operable to designate a point on the given two-dimensional coordinate plane of a tablet. The tablet includes a flat sensor defining the given two-dimensional coordinate plane and operative for transmitting magnetic signal between the flat sensor and the pointing instrument disposed thereon to detect the designated point to thereby produce a detection signal, and a shielding plate disposed under the flat sensor to magnetically shield the flat sensor. The shielding plate is composed of silicon steel containing 4.0 to 7.0 weight % of silicon. A processing circuit is connected to the flat sensor for processing the detection signal to determine the coordinate value of the designated point. | |
