The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 01, 1989
Filed:
May. 13, 1988
Abstract
A data input device having key switches which are temporarily in an operated position, and position-hold switches each having selectable stable positions. The device includes a first matrix, a second matrix, and a matrix scanning arrangement. The first matrix comprises first and second signal lines which cross each other, and the second matrix comprises third and fourth signal lines which cross each other. Each key switch is connected between the first and second lines at a corresponding one of the intersections. Similarly, each position-hold switch is connected between the third and fourth lines at a corresponding one of the intersections. Some of the first or second lines are used as the third or fourth lines. The matrix scanning arrangement scans the first matrix to determine whether each key switch as been operated, and scans the second matrix to determine the selected stable positions of each position-hold switch, only when a scanning of the first matrix indicates that the number of the key switches which have been operated is not greater than a reference value.