US5140433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Noise reduction circuit for reducing video signal noise by mixing current and previous video signal
Assignee: Pioneer Corp
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Filing: 1990-06-11
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Granted: 1992-08-18
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Expires: 2010-06-11
Abstract
Abstract A noise reduction circuit in a recording medium player is disclosed in which the time-axis of a video signal read out from a memory to be used for noise reduction is changed by a shift command signal for changing the time-axis of a video signal in order to keep the continuity of the phase of a color burst in special playback operation. Owing to the arrangement, even in a special playback operation, the phases of a chrominance signal and a luminance signal contained in a read out video signal, and those of a chrominance signal and a luminance signal contained in a video signal as a signal to be mixing-processed coincide with each other, which makes it possible to prevent the blur in a played back picture.
Inventors
- 👤 Kazuo Kuroda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:59
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/7908; H04N9/87; Y; Y10; Y10S; Y10S358/00; Y10S358/907
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
257 words
A recording medium player comprising: read means for reading a video signal recorded in a recording medium; play control means for controlling a special playback operation including a track jumping operation for moving an information reading point of said read means across at least one track of said recording medium; command issuing means for issuing a current shift command signal when said track jumping operation is performed; first time-axis shift means for changing a time-axis of said video signal by an amount equaling N quarters of a period of a color subcarrier based upon said current shift command signal; and a noise reduction circuit including: mixing means for mixing said video signal read from said recording medium by said read means and a signal to be mixing-processed, at a mixing ratio corresponding to an instantaneous level difference between said video signal and said signal to be mixing-processed; memory; memory control means for writing an output of said mixing means and a corresponding current shift command signal into said memory, and for reading data from said memory, said data representing a previous output of said mixing means and a corresponding previous shift command signal, said data being delayed in said memory by an amount of time almost equal to M times of one field period, said previous mixing means output representing said signal to be mixing-processed; and second time-axis shift means for changing the time-axis of the signal to be mixing-processed by N quarters of the color subcarrier period based on said current and previous shift command signals.
Claim 2
Dependent Claim
257 words
A recording medium player comprising: read means for reading a video signal recorded in a recording medium; play control means for controlling a special playback operation including a track jumping operation for moving an information reading point of said read means across at least one track of said recording medium; command issuing means for issuing a current shift command signal when said track jumping operation is performed; first time-axis shift means for changing a time-axis of said video signal by an amount equaling N quarters of a period of a color subcarrier based upon said current shift command signal; and a noise reduction circuit including: mixing means for mixing said video signal read from said recording medium by said read means and a signal to be mixing-processed, at a mixing ratio corresponding to an instantaneous level difference between said video signal and said signal to be mixing-processed; memory; memory control means for writing an output of said mixing means and a corresponding current shift command signal into said memory, and for reading data from said memory, said data representing a previous output of said mixing means and a corresponding previous shift command signal, said data being delayed in said memory by an amount of time almost equal to M times of one field period, said previous mixing means output representing said signal to be mixing-processed; and second time-axis shift means for changing the time-axis of the signal to be mixing-processed by N quarters of the color subcarrier period based on said current and previous shift command signals.
Claim 3
Dependent Claim
234 words
A recording medium player comprising: read means for reading a video signal recorded in a recording medium; play control means for performing a still picture playback operation by making an information reading point in said read means perform a one track jump; first time-axis shift means for changing a time-axis of said video signal by an amount equaling N quarters of a period of a color subcarrier; command generation means for issuing a shift command signal when said still picture playback operation is performed, and a noise reduction circuit including: mixing means for mixing said video signal and a signal to be mixing-processed at a mixing ratio corresponding to an instantaneous level difference between said video signal and said signal to be mixing-processed; memory; memory control means for writing an output of said mixing means in said memory, and for reading out data, representing a previous output of said mixing means and a corresponding previous shift command signal, said data being delayed in said memory by M times of one field period, said read out data representing said signal to be mixing-processed; and second time-axis shift means for changing a time-axis of said mixing means output before writing said mixing means output to said memory and a time-axis of said previous mixing means output read from said memory based on said shift command signal by N quarters of a period of said color subcarrier.
Claim 4
Dependent Claim
234 words
A recording medium player comprising: read means for reading a video signal recorded in a recording medium; play control means for performing a still picture playback operation by making an information reading point in said read means perform a one track jump; first time-axis shift means for changing a time-axis of said video signal by an amount equaling N quarters of a period of a color subcarrier; command generation means for issuing a shift command signal when said still picture playback operation is performed, and a noise reduction circuit including: mixing means for mixing said video signal and a signal to be mixing-processed at a mixing ratio corresponding to an instantaneous level difference between said video signal and said signal to be mixing-processed; memory; memory control means for writing an output of said mixing means in said memory, and for reading out data, representing a previous output of said mixing means and a corresponding previous shift command signal, said data being delayed in said memory by M times of one field period, said read out data representing said signal to be mixing-processed; and second time-axis shift means for changing a time-axis of said mixing means output before writing said mixing means output to said memory and a time-axis of said previous mixing means output read from said memory based on said shift command signal by N quarters of a period of said color subcarrier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |