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. 27, 1977
Filed:
Oct. 20, 1975
Hideo Kuroda, Kodaira, JA;
Fumio Kanaya, Seki, JA;
Abstract
An input video signal is fed to a substracter wherein a difference is taken between the input and the output from a frame memory to provide a difference signal, the magnitude of which is controlled by a magnitude adjuster. The controlled output is then fed to a threshold circuit, from which a significant difference signal is derived which has a magnitude above a given level. The significant difference signal is quantized by an encoder into a code having a reduced number of bits as compared with the inputted significant difference signal. The quantized code is written into a buffer memory, and is read out therefrom at a uniform bit rate to a transmission line. A sum of a signal indicative of the representative level of the quantized code from the encoder and the output of the frame memory is formed in an adder, and the sum signal is written into the frame memory and read out subsequently or after one frame. The occupancy of the buffer memory is detected to provide a control over the magnitude adjuster in accordance with the detected value so as to prevent an overflow from the buffer memory. A signal to refresh the frame memory located on the receiving side is transmitted by writing the output of the adder into the buffer memory after switching from the output of the encoder to the output of the adder.