Patent US4583120A successfully refreshed from Google Patents.
US4583120A
Expired / Lapsed
US
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Ghost canceller
Assignee: Toshiba Corp
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Filing: 1984-05-10
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Granted: 1986-04-15
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Expires: 2004-05-10
Abstract
Abstract A ghost canceller includes a ghost canceling circuit having a transversal filter for receiving a television input signal and a tap gain holding circuit for holding tap gains of the filter, a ghost detector, and a means for writing tap gain data into the tap gain data holding circuit in response to the ghost detector to permit a ghost component in an output signal of the ghost canceling circuit to be canceled out. In order to prevent the disturbance of a TV screen due to a transient response which occurs upon writing tap gain data into the tap gain data holding circuit, an output means is provided for permitting a signal other than the output signal of the ghost canceling circuit to be selectively taken out during a first time period including an interval in which tap gain data is written into the tap gain holding circuit and for permitting an output signal of the ghost canceling circuit to be selectively taken out during a second time period other than the first time period.
Inventors
- 👤 Junzo Murakami
- 👤 Hisao Fujiwara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:34
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/211
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
244 words
A ghost canceller comprising: a ghost canceling circuit including a tranversal filter connected to receive a television input signal including a ghost component and having variable tap gains, and a tap gain holding circuit for holding tap gains of said transversal filter; a ghost detector for detecting the ghost component in an output signal of said ghost canceling circuit; means for successively and periodically writing tap gain data into said tap gain holding circuit in response to said ghost detector to cause said tap gain holding circuit to successively correct the tap gains of said transversal filter so that the ghost component in the output signal of said ghost canceling circuit are canceled out; and output means for permitting a signal other than the output signal of said ghost canceling circuit to be selectively taken out during a first time period including an interval in which tap gain data is written into said tap gain holding circuit and for permitting an output signal of said ghost canceling circuit to be selectively taken out during a second time period other than the first time period; wherein the first time period is a portion of a vertical blanking period of the television input signal, a synchronizing signal generating means is provided for generating synchronizing signals in the vertical blanking period in response to the television input signal, and the signal selected during the first time period is an output signal of said synchronizing signal generating means.
Claim 2
Dependent Claim
244 words
A ghost canceller comprising: a ghost canceling circuit including a tranversal filter connected to receive a television input signal including a ghost component and having variable tap gains, and a tap gain holding circuit for holding tap gains of said transversal filter; a ghost detector for detecting the ghost component in an output signal of said ghost canceling circuit; means for successively and periodically writing tap gain data into said tap gain holding circuit in response to said ghost detector to cause said tap gain holding circuit to successively correct the tap gains of said transversal filter so that the ghost component in the output signal of said ghost canceling circuit are canceled out; and output means for permitting a signal other than the output signal of said ghost canceling circuit to be selectively taken out during a first time period including an interval in which tap gain data is written into said tap gain holding circuit and for permitting an output signal of said ghost canceling circuit to be selectively taken out during a second time period other than the first time period; wherein the first time period is a portion of a vertical blanking period of the television input signal, a synchronizing signal generating means is provided for generating synchronizing signals in the vertical blanking period in response to the television input signal, and the signal selected during the first time period is an output signal of said synchronizing signal generating means.
Claim 3
Dependent Claim
31 words
A ghost canceller according to claim 1, in which the signal which is selectively taken out during the first time period is the television input signal of said ghost canceling circuit.
Claim 4
Dependent Claim
214 words
A ghost canceller comprising: a ghost canceling circuit including a transversal filter connected to receive a television input signal containing vertical blanking periods, video signal periods, and a ghost component and having variable tap gains, and a tap gain holding circuit for holding tap gains of said transversal filter; a ghost detector coupled to said ghost canceling circuit for detecting the ghost component contained in an output signal of said ghost canceling circuit; means responsive to said ghost detector for successively writing tap gain data into said tap gain holding circuit during vertical blanking periods of the television input signal to cause said tap gain holding circuit to successively correct the tap gains of said transversal filter so that the ghost component in the output signal of said ghost canceling circuit is canceled out; and output means for permitting a signal other than the output signal of said ghost canceling circuit to be selectively taken out during a first time period in the vertical blanking period including a time period during which tap gain data is written into said tap gain holding circuit and permitting the output signal of said ghost canceling circuit to be selectively taken out during a second time period following the first time period and including the video signal period.
Claim 5
Dependent Claim
214 words
A ghost canceller comprising: a ghost canceling circuit including a transversal filter connected to receive a television input signal containing vertical blanking periods, video signal periods, and a ghost component and having variable tap gains, and a tap gain holding circuit for holding tap gains of said transversal filter; a ghost detector coupled to said ghost canceling circuit for detecting the ghost component contained in an output signal of said ghost canceling circuit; means responsive to said ghost detector for successively writing tap gain data into said tap gain holding circuit during vertical blanking periods of the television input signal to cause said tap gain holding circuit to successively correct the tap gains of said transversal filter so that the ghost component in the output signal of said ghost canceling circuit is canceled out; and output means for permitting a signal other than the output signal of said ghost canceling circuit to be selectively taken out during a first time period in the vertical blanking period including a time period during which tap gain data is written into said tap gain holding circuit and permitting the output signal of said ghost canceling circuit to be selectively taken out during a second time period following the first time period and including the video signal period.
Claim 6
Dependent Claim
29 words
A ghost canceling circuit according to claim 3, in which the signal taken out during the first time period is the television input signal of said ghost canceling circuit.
Claim 7
Dependent Claim
68 words
A ghost canceling circuit according to claim 3, further comprising a synchronizing signal generating means responsive to the television input signal for generating synchronizing signals in the televisionsignal, and in which the first time period is a portion of the vertical blanking period of the television input signal, and the signal taken out during the first time period is an output signal of said synchronizing signal generating means.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |