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. 15, 1986
Filed:
Jul. 09, 1982
Joannes L van de Venne, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
In order to provide a passive electro-optical display medium in a matrix display device with a sufficiently steep threshold with respect to the applied voltage and having a memory, a switching element (9) is placed in series having each picture element. The switching element (9) is provided between a picture electrode (6) of each picture element and a driving electrode (8). The switching element (9) is formed by a polysilicon island (20) in which n.sup.+ -doped regions (22,23) are provided which are separated by a p-doped region (21). As a result of this, two series-arranged, oppositely directed p-n junctions are formed of which one is always reverse biased. The width of the p-doped regions is so small that punch-through occurs between the two p-n junctions before one of the p-n junctions breaks down. Due to the occurrence of punch-through, the series resistance of the switching element is negligibly small so that a favorable R.sub.ON /R.sub.OFF ratio is obtained and the picture elements can be driven with comparatively low voltages.