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. 07, 1982
Filed:
Mar. 13, 1980
Andreas Ilmer, Ludwigshafen, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Equalizer circuitry for a wideband signal recording/playback system, in particular a home video system, comprises a pre-emphasis and a de-emphasis circuit in the recording channel and the playback channel respectively. In an advantageous embodiment, the pre-emphasis and de-emphasis circuits are of the second-order type. In the preferred embodiment of the circuitry, in each of said channels there is provided a circuit for group-delay equalization, preferably an all-pass filter which comprises at least one substantially symmetrical transistor stage provided with a bridge circuit consisting of at least one reactive impedance and ohmic resistance and located between emitter and collector. Practical embodiments of the bridge circuit comprise several series-connected parallel LC sections and one ohmic resistance. Advantageously, conventional filter stages in the channels may be at least partially included in said circuit for group-delay equalization. Conventional delay means provided in color video systems for equalization of the delay between color and video signals can therefore be integrated in said circuit for group-delay equlization.