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US5173784A Expired / Lapsed US ⏱️ 0.0 years remaining

Video disc player

Assignee: Sony Corp
•
Filing: 1990-04-23
•
Granted: 1992-12-22
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Expires: 2010-04-23
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Abstract

Abstract A video disc player comprises a gray level picture display device for displaying a gray level picture during a track jump and a phase difference detecting circuit for detecting a phase difference between a phase of a horizontal synchronizing signal involved in a reproduced video signal and a horizontal phase for a gray level display during a so-called scan reproduction mode. The horizontal synchronizing signal of the gray picture is corrected so that the above-described phase difference will fall within a tolerance range. Therefore, a satisfactory reproduced video signal without horizontal synchronization disturbance can be obtained.

Inventors

  • 👤 Tooru Ootsuka
  • 👤 Noriyuki Yamashita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 20:54
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/9305; Y; Y10; Y10S; Y10S358/00; Y10S358/907

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 276 words
A video disc player for reproducing a video signal recorded on a video disc with the constant linear velocity comprising: a pickup head scanned in the radial direction of said video disc for obtaining a reproduced video signal therefrom; time base correction means connected to said pickup head for correcting the time base error of said reproduced signal; signal output means connected to said time base correction means; a first horizontal oscillator to be used for controlling said time base correction means; a gray level source for applying a gray level signal to said signal output means; a second horizontal oscillator separately provided with said first horizontal oscillator for adding a reference horizontal synchronizing signal to said gray level signal; a sync. separator connected to the input side of said time base correction means for separating a horizontal signal from said reproduced video signal; and scan reproducing means for scanning said pickup head in the radial direction of the video disc at a higher speed intermittently by means of a series of track jumps, said scan reproducing means selectively and intermittently applying said gray level signal and said reproduced signal to said signal output means in synchronism with said series of track jumps, characterized by synchronizing means for synchronizing said first horizontal oscillator with the horizontal signal from said sync. separator during said track jumps; phase detection means for detecting the phase difference between the output signals of said first and second horizontal oscillators during said track jumps; and control means connected between said phase detection means and said second horizontal oscillator for controlling the frequency of the latter until said phase difference becomes substantially zero.
Claim 2
Dependent Claim 276 words
A video disc player for reproducing a video signal recorded on a video disc with the constant linear velocity comprising: a pickup head scanned in the radial direction of said video disc for obtaining a reproduced video signal therefrom; time base correction means connected to said pickup head for correcting the time base error of said reproduced signal; signal output means connected to said time base correction means; a first horizontal oscillator to be used for controlling said time base correction means; a gray level source for applying a gray level signal to said signal output means; a second horizontal oscillator separately provided with said first horizontal oscillator for adding a reference horizontal synchronizing signal to said gray level signal; a sync. separator connected to the input side of said time base correction means for separating a horizontal signal from said reproduced video signal; and scan reproducing means for scanning said pickup head in the radial direction of the video disc at a higher speed intermittently by means of a series of track jumps, said scan reproducing means selectively and intermittently applying said gray level signal and said reproduced signal to said signal output means in synchronism with said series of track jumps, characterized by synchronizing means for synchronizing said first horizontal oscillator with the horizontal signal from said sync. separator during said track jumps; phase detection means for detecting the phase difference between the output signals of said first and second horizontal oscillators during said track jumps; and control means connected between said phase detection means and said second horizontal oscillator for controlling the frequency of the latter until said phase difference becomes substantially zero.
Claim 3
Dependent Claim 34 words
A video disc player according to claim 1, wherein said control means is formed as frequency changing means for slightly changing the frequency of said second horizontal oscillator when said phase difference is detected.
Claim 4
Dependent Claim 26 words
A video disc player according to claim 2, wherein the horizontal period of said second horizontal oscillator is changed by the order of hundreds of nano-seconds.

References Cited (Backward Citations)

US4970602A Cited
US5111305A Cited
US5089900A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-12-22 1996-06-22 1996-12-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-12-22 2000-06-22 2000-12-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-12-22 2004-06-22 2004-12-22 $7700.00 Window Closed / Lapsed

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