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:
Sep. 30, 1980
Filed:
Jul. 12, 1978
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
The present facsimile transmission system is a combination of the prior Skipping White Space (SWS) system which is a digital system capable of rapid transmission, and the prior AM-PM-VSB (Amplitude Modulation, Phase Modulation, Vestigial Side Band Modulation), which is a simple analog system. Each scanning line of a picture is divided into a plurality of blocks each of which has a plurality of picture cells, and only those blocks having a black cell are transmitted as a picture signal. On the other hand the block having no black cell is not transmitted, and instead, the flag information indicating that the block is omitted is transmitted. Also a line synchronization signal is transmitted for each scanning line. When said signals (picture signals, flag information and a line synchronization signal) are modulated into an AM-PM-VSB signal, a picture signal is modulated as an ordinary analog signal, and a flag information and a line synchronization signal has the twice level as high as the highest level of the picture information, and have the duration longer than that of each picture cell. Thus, although a simple analog AM-PM-VSB system is utilized, the important information like a line synchronization signal and a flag information which affect much to the received picture quality are transmitted with a small error rate and a high reliability.