Frequency compensation apparatus for disc-shaped record reproduction
CA 1054256 A · Owner: N.V. Philips Gloeilampenfabrieken · Inventors: Hoogendijk, Adrianus H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus for reading a disc-shaped record carrier on which a video signal is recorded in optically coded form. To compensate for the varying frequency response of the record carrier as a function of the radial scanning position a correction device is provided. Said correction device employs the-amplitude of a first carrier which is modulated with the luminance information of the video signal as a measuring signal, which is compared with a reference signal, the resultant signal controlling a correction filter. As reference signal the amplitude of a signal component of a relatively low frequency may be used, for example a pilot signal or a second carrier which is frequency-modulated with …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted May 8, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 8, 1996.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.