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US4984093A Expired / Lapsed US ⏱️ 0.0 years remaining

Video recorder with increased bandwidth recording

Assignee: Deutsche Thomson Brandt GmbH
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Filing: 1988-09-12
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Granted: 1991-01-08
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Expires: 2008-09-12
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Abstract

Abstract A luminance signal is frequency modulated with an FM carrier to generate a frequency modulated YFM signal having a frequency spectrum within a frequency band of e.g. 1.6 to 8 megahertz. A quadrature modulated PAL color signal is down-converted in a mixer to the empty frequency band below the YFM band and filtered by a Nyquist filter having a Nyquist slope centered on the mixing carrier frequency of e.g. 1 megahertz. The YFM and down-converted color signals are added and then recorded on magnetic tape. The frequency spectrum of the down-converted color signal has a vestigial sideband characteristic that permits the recording of a relatively wideband color signal in the luminance-free free frequency band of e.g. 0-1.2 megahertz.

Inventors

  • 👤 Burchard Schmidtmann
  • 👤 Silvestre Cerda-Davo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 13:45
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H04N9/00; H04N9/79; H04N9/80; H04N9/82; H04N9/83; H04N9/835; H04N9/8355; H04N9/7921; H04N9/7925; H04N9/832

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 170 words
Video recording apparatus, comprising: a source of a luminance containing signal; means for frequency modulating said luminance containing signal with an FM carrier to generate a frequency modulated signal having a first frequency spectrum in a first frequency band; a source of a chrominance containing signal; means including a modulator for modulating said chrominance containing signal with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band below said first frequency band in a region that is generally empty of frequencies belonging to said frequency modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combination and recording said frequency and second modulated signals on a magnetic tape.
Claim 2
Dependent Claim 170 words
Video recording apparatus, comprising: a source of a luminance containing signal; means for frequency modulating said luminance containing signal with an FM carrier to generate a frequency modulated signal having a first frequency spectrum in a first frequency band; a source of a chrominance containing signal; means including a modulator for modulating said chrominance containing signal with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band below said first frequency band in a region that is generally empty of frequencies belonging to said frequency modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combination and recording said frequency and second modulated signals on a magnetic tape.
Claim 3
Dependent Claim 38 words
Apparatus according to claim 1 wherein said second modulated signal generating means includes a filter coupled to an output of said modulator, said filter having associated therewith a Nyquist slope centered near the frequency of said second carrier.
Claim 4
Dependent Claim 15 words
Apparatus according to claim 1 wherein said second carrier has a frequency near 1 megahertz.
Claim 5
Dependent Claim 25 words
Apparatus according to claim 1 wherein said chrominance containing signal comprises a PAL formatted chrominance signal that is frequency translated to said second frequency band.
Claim 6
Dependent Claim 19 words
Apparatus according to claim 4 wherein said modulator comprises a mixer having a mixing carrier frequency near 3.4 megahertz.
Claim 7
Dependent Claim 21 words
Apparatus according to claim 4 wherein said PAL chrominance signal includes two color-difference signals quadrature modulated with a PAL color carrier.
Claim 8
Dependent Claim 41 words
Apparatus according to claim 1 including time-shifting means responsive to at least one of said luminance and chrominance containing signals for generating said frequency modulated signal time shifted by at least one scanning line relative to said second carrier modulated signal.
Claim 9
Dependent Claim 46 words
Apparatus according to claim 1 wherein said source of chrominance containing signal comprises a source of a SECAM formatted chrominance signal coupled to a transcoder that transcodes said SECAM formatted signal to a PAL formatted chrominance signal, said PAL formatted signal comprising said chrominance containing signal.
Claim 10
Dependent Claim 178 words
Video recording apparatus, comprising: a source of a first video information containing signal; means for frequency modulating said first video information containing signal with an FM carrier to generate a frequency modulated signal having a first frequency spectrum in a first frequency band; a source of a second video information containing signal; means including a modulator for modulating said second video information containing signal with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band outside said first frequency band in a region that is generally empty of frequencies belonging to said frequency modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combination and recording said frequency and second modulated signals on a magnetic tape.
Claim 11
Dependent Claim 178 words
Video recording apparatus, comprising: a source of a first video information containing signal; means for frequency modulating said first video information containing signal with an FM carrier to generate a frequency modulated signal having a first frequency spectrum in a first frequency band; a source of a second video information containing signal; means including a modulator for modulating said second video information containing signal with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band outside said first frequency band in a region that is generally empty of frequencies belonging to said frequency modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combination and recording said frequency and second modulated signals on a magnetic tape.
Claim 12
Dependent Claim 183 words
Apparatus, comprising: a source of a first video information containing signal; means for modulation said first video information containing signal with a carrier to generate a first modulated signal having a first frequency spectrum in a first frequency band; a source of second and third signals; means including a modulator for quadrature modulating said second and third signals with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band outside said first frequency band in a region that is generally empty of frequencies belonging to said first modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combining the two modulated signals to obtain a third signal having a combined generally nonoverlapping frequency spectrum that represents the aforementioned two frequency spectrums.
Claim 13
Dependent Claim 183 words
Apparatus, comprising: a source of a first video information containing signal; means for modulation said first video information containing signal with a carrier to generate a first modulated signal having a first frequency spectrum in a first frequency band; a source of second and third signals; means including a modulator for quadrature modulating said second and third signals with a second carrier to generate a second modulated signal having a second frequency spectrum that is located in a second frequency band outside said first frequency band in a region that is generally empty of frequencies belonging to said first modulated signal, said second frequency spectrum including a band of upper sidebands and a band of lower sidebands with respect to said second carrier frequency having a corresponding pair of upper and lower cut-off frequencies such that one of said upper and lower cut-off frequencies is substantially closer to said second carrier frequency than the other one; and means for combining the two modulated signals to obtain a third signal having a combined generally nonoverlapping frequency spectrum that represents the aforementioned two frequency spectrums.
Claim 14
Dependent Claim 82 words
Apparatus according to claim 10 wherein said quadrature modulating means includes means for generating said second carrier such that the phase of said second carrier alternately reverses from period to period in a manner that produces upper and lower sidebands for said second modulated signal that correspondingly and alternately reverse their positions relative to the frequency position of said second carrier, and means for processing said second modulated signal to provide said second frequency spectrum in the form of said vestigial sideband.

References Cited (Backward Citations)

GB1058604A Cited
US4335393A Cited
EP0111150A2 Cited
US4665427A Cited
US4730222A Cited
US4831463A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-01-07 1994-07-09 1995-01-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-01-07 1998-07-09 1999-01-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-01-07 2002-07-09 2003-01-08 $7700.00 Window Closed / Lapsed

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