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:
Feb. 03, 1981
Filed:
Mar. 26, 1979
Richard Storey, Sutton, GB;
John O Drewery, Coulsdon, GB;
British Broadcasting Corporation, London, GB;
Abstract
Reduction of noise in a television signal is achieved by comparing signals from successive scans to produce a difference signal. Low amplitude differences are assumed to represent noise and are attenuated. Differences above a predetermined level are assumed to represent movement and are not so attenuated. The attenuation is achieved by a multiplier which receives as multiplier the output of a non-linear transfer characteristic element. The non-linear element receives the differences after rectification and after passing through a variable-gain element. The non-linear element is such that above a predetermined value a constant predetermined minimum attenuation factor applies. A noise measurement circuit measures the noise present in the difference signal and controls the gain of the variable-gain element accordingly. Several noise-measurement circuits may be provided, a selected one of which is used in dependence upon the magnitude of the input signal to the apparatus.