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:
Dec. 14, 1993
Filed:
Apr. 15, 1993
Kenichiro Hayashi, Toyonaka, JP;
Shuji Inoue, Burlington, NJ (US);
Sadashi Kageyama, Hirakata, JP;
Hideyo Uwabata, Hirakata, JP;
Todd S Bowser, Itami, JP;
Yoshio Yasumoto, Nara, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In the television broadcasting system called letter box method, it is proposed to transmit an image having a larger aspect ratio than that of the existing broadcasting system by using some of the scanning lines of the existing broadcasting system, and transmit some additional information signal in the remaining portion. An offset value applied to the additional information signal at the transmission side must be removed completely at the reception side. Accordingly, at the reception side, in the scanning line in which an offset reference signal indicative of the offset value is transmitted, the offset reference value and a DC level reference value of the scanning line are detected, and these values are retained until a next offset reference signal is detected. By detecting a DC level of a scanning line containing the additional information signal, a difference from the DC level reference value previously detected and retained is obtained, and the offset reference value detected and retained previously is corrected by this difference. Thus obtained offset value is subtracted from the transmitted additional information signal.