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:
Apr. 05, 1988
Filed:
Jul. 24, 1987
Hitachi, ltd, Tokyo, JP;
Abstract
In a matrix display device, a signal drive circuit comprises selection means for sequentially selecting at least one of display information signals corresponding to a plurality of signal electrodes when at least one of a plurality of scan electrodes is selected, hold means for holding the display information signal selected by the selection means until selection of at least corresponding scan electrode is completed, and voltage conversion means for selecting one of a plurality of voltage levels in accordance with the display information signal held by the hold means and supplying the selected voltage level to the signal electrodes. Since the display information signal is held by the hold means until the selection of at least corresponding scan electrode is completed, one of the plurality of voltage levels is always applied to the signal electrodes and the switching elements do not assume the high impedance state. Accordingly, ununiformity in display image is prevented and a large size matrix display device is provided.