US4127874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for removing ghost signals from received video signals
Assignee: Toshiba Corp
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Filing: 1977-05-26
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Granted: 1978-11-28
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Expires: 1997-05-26
Abstract
Abstract A feedback type ghost killer removes a ghost signal component from a detected composite video signal including a wanted video signal and the unwanted ghost signal. The delay time and relative amplitude of the ghost signal to the wanted video signal are detected by a detector with a plurality of tapped outputs. When an output signal appears on one of tapped outputs, the tap position represents the delay time and the amplitude of the output signal indicates the relative amplitude. The composite video signal and the output signals of the detector are supplied to a transversal filter to form a pseudo-ghost signal. The tapped outputs of the detector are used to weight the video signal in the transversal filter. The pseudo-ghost signal and the video signal are subtractively combined to remove the ghost signal from the video signal.
Inventors
- 👤 Mineo Iwasawa
- 👤 Tatsuo Sakaue
- 👤 Hikaru Date
- 👤 Takehiro Takamatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:46
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/211
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
174 words
An apparatus for removing an unwanted signal from an incoming signal including a wanted signal and the wanted signal which is the time-delayed wanted signal with a modified amplitude, comprising: an amplifier for the incoming signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the unwanted signal to the wanted signal, said detector means being so arranged that, when a signal appears on one of said tapped outputs, the tap position represents the time delay of the unwanted signal to the wanted signal and the amplitude thereof represents the relative amplitude of the unwanted signal to the wanted signal; transversal filter means connected with the output of said amplifier and the tapped outputs of said detector means for producing a pseudo-unwanted signal substantially equivalent to the unwanted signal; and subtractor means connected at the output thereof to the input of said amplifier for combining subtractively the pseudo-unwanted signal from said transversal filter means and said incoming signal.
Claim 2
Independent Claim
174 words
An apparatus for removing an unwanted signal from an incoming signal including a wanted signal and the wanted signal which is the time-delayed wanted signal with a modified amplitude, comprising: an amplifier for the incoming signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the unwanted signal to the wanted signal, said detector means being so arranged that, when a signal appears on one of said tapped outputs, the tap position represents the time delay of the unwanted signal to the wanted signal and the amplitude thereof represents the relative amplitude of the unwanted signal to the wanted signal; transversal filter means connected with the output of said amplifier and the tapped outputs of said detector means for producing a pseudo-unwanted signal substantially equivalent to the unwanted signal; and subtractor means connected at the output thereof to the input of said amplifier for combining subtractively the pseudo-unwanted signal from said transversal filter means and said incoming signal.
Claim 3
Dependent Claim
17 words
An apparatus according to claim 1, in which said transversal filter means includes an input-weighted transversal filter.
Claim 4
Dependent Claim
17 words
An apparatus according to claim 1, in which said transversal filter means includes an output-weighted transversal filter.
Claim 5
Dependent Claim
14 words
An apparatus according to claim 1, in which said amplifier has a unity gain.
Claim 6
Independent Claim
181 words
An apparatus for removing an unwanted ghost video signal from detected composite video signal including a wanted video signal and the unwanted ghost video signal, comprising: an amplifier for the detected composite video signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the ghost video signal to the wanted video signal, said detector means being so arranged that, when a signal appears on one of said tapped outputs, the tap position represents the time delay of the ghost signal to the wanted video signal and the amplitude thereof represents the relative amplitude of the ghost signal to the wanted video signal; transversal filter means connected with the output of said amplifier and the tapped outputs of said detector means for producing a pseudo-unwanted ghost video signal substantially equivalent to the unwanted ghost video signal; and subtractor means connected at the output thereof to the input of said amplifier for combining subtractively the pseudo-ghost signal from said transversal filter means and said composited video signal.
Claim 7
Independent Claim
181 words
An apparatus for removing an unwanted ghost video signal from detected composite video signal including a wanted video signal and the unwanted ghost video signal, comprising: an amplifier for the detected composite video signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the ghost video signal to the wanted video signal, said detector means being so arranged that, when a signal appears on one of said tapped outputs, the tap position represents the time delay of the ghost signal to the wanted video signal and the amplitude thereof represents the relative amplitude of the ghost signal to the wanted video signal; transversal filter means connected with the output of said amplifier and the tapped outputs of said detector means for producing a pseudo-unwanted ghost video signal substantially equivalent to the unwanted ghost video signal; and subtractor means connected at the output thereof to the input of said amplifier for combining subtractively the pseudo-ghost signal from said transversal filter means and said composited video signal.
Claim 8
Dependent Claim
17 words
An apparatus according to claim 5, in which said transversal filter means includes an input-weighted transversal filter.
Claim 9
Dependent Claim
17 words
An apparatus according to claim 5, in which said transversal filter means includes an output-weighted transversal filter.
Claim 10
Dependent Claim
14 words
An amplifier according to claim 5, in which said amplifier has a unity gain.
Claim 11
Independent Claim
236 words
An apparatus for removing an unwanted ghost video signal from a detected composite video signal including a wanted video signal and the unwanted ghost video signal, comprising: an amplifier for the detected composite video signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the ghost signal to the wanted video signal, said detecting means being so arranged to sample the first synchronizing pulse in the vertical synchronizing pulse interval succeeding to the equalizing pulse interval during a vertical blanking period of the composite video signal by a given sampling frequency and compare the amplitudes of adjacent two samples, whereby, when a signal appears on one of the tapped outputs, the information of the time delay and relative amplitude of the ghost signal are given by the position of the tapped output on which the signal appears and the amplitude of the signal on the tapped output; a plurality of integrator means coupled with said tapped outputs of said detector means; transversal filter means coupled with the output of said amplifier and the outputs of said integrator means to produce a pseudo-ghost signal substantially equivalent to said ghost signal; and subtractor means connected at the output thereof to the input of said amplifier for subtractively combining said pseudo-ghost signal from said transversal filter means and the detected composite video signal.
Claim 12
Independent Claim
236 words
An apparatus for removing an unwanted ghost video signal from a detected composite video signal including a wanted video signal and the unwanted ghost video signal, comprising: an amplifier for the detected composite video signal; detector means coupled to the output of said amplifier and having a plurality of tapped outputs for detecting the time delay and relative amplitude of the ghost signal to the wanted video signal, said detecting means being so arranged to sample the first synchronizing pulse in the vertical synchronizing pulse interval succeeding to the equalizing pulse interval during a vertical blanking period of the composite video signal by a given sampling frequency and compare the amplitudes of adjacent two samples, whereby, when a signal appears on one of the tapped outputs, the information of the time delay and relative amplitude of the ghost signal are given by the position of the tapped output on which the signal appears and the amplitude of the signal on the tapped output; a plurality of integrator means coupled with said tapped outputs of said detector means; transversal filter means coupled with the output of said amplifier and the outputs of said integrator means to produce a pseudo-ghost signal substantially equivalent to said ghost signal; and subtractor means connected at the output thereof to the input of said amplifier for subtractively combining said pseudo-ghost signal from said transversal filter means and the detected composite video signal.
Claim 13
Dependent Claim
16 words
An apparatus according to claim 9, in which said transversal filter includes an input-weighted transversal filter.
Claim 14
Dependent Claim
17 words
An apparatus according to claim 9, in which said transversal filter means includes an output-weighted transversal filter.
Claim 15
Dependent Claim
28 words
An apparatus according to claim 9, in which each of said integrator means has the integrating time constant corresponding to about 60-field time of the composite video signal.
Claim 16
Dependent Claim
18 words
An apparatus according to claim 9, in which said sampling frequency is three times the color sub-carrier frequency.
Claim 17
Dependent Claim
81 words
An apparatus according to claim 9, in which said detector means includes delay means for delaying the detected composite video signal by the time equal to said sampling period, subtracting means for subtractively combining the output of said delay means and the detected composite video signal, analogue shift register means connected to the output of said subtractor means and having a plurality of tapped outputs, an a plurality of analogue switches connected to said tapped outputs of said analogue shift register.
Claim 18
Dependent Claim
68 words
An apparatus according to claim 9, in which said detector means includes analogue shift register means coupled with the output of said amplifier and having a plurality of tapped outputs, analogue switch means having a plurality of stages and coupled with said tapped outputs of said analogue shift register means, and a plurality of subtractor means for subtractively combining the outputs of adjacent stages of said analogue switches.
Claim 19
Dependent Claim
14 words
An apparatus according to claim 9, in which said amplifier has a unit gain.
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) | 1981-11-27 | 1982-05-29 | 1982-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-27 | 1986-05-29 | 1986-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-27 | 1990-05-29 | 1990-11-28 | $7700.00 | Window Closed / Lapsed |