Patent US3778634A successfully refreshed from Google Patents.
Patent US4853797A successfully refreshed from Google Patents.
US4853797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fir type digital filter for recording and reproducing apparatus
Assignee: Sony Corp
•
Filing: 1988-02-25
•
Granted: 1989-08-01
•
Expires: 2008-02-25
Abstract
Abstract In a recording/reproducing apparatus, having an analog-to-digital converter used in a recording mode and a digital-to-analog converter used in a reproducing mode; a digital filter comprises memories for storing first and second multiplication coefficient groups which provide predetermined filter characteristics and are in interpolated relation to each other; and, in the recording mode for first-and second-channel signals, the first and second multiplication coefficient groups are used for the first-and second-channel signals, respectively, and, in the reproducing mode, the second-and first-multiplication coefficient groups are used for the first-and second-channel signals, respectively. In recording and reproducing modes for a single-channel signal, the first and second multiplication coefficient groups are alternately used for successive samplings.
Inventors
- 👤 Makoto Yamada
- 👤 Kentaro Odaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:13
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/06; H03H17/0621; H03H17/0635; H03H17/065; H03H17/0657; G; G11; G11B; G11B20/00; G11B20/10; G11B20/10527; H03H17/0294
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
A digital filter for a recording/reproducing apparatus comprising: analog-to-digital and digital-to-analog converter means for 2-channel signals; means for storing first and second multiplication coefficient groups which provide predetermined filter characteristics and are in interpolated relation to each other; and signal processing means operative, in a recording mode, to employ the first multiplication coefficient group for processing one of said 2-channel signals and to employ the second multiplication coefficient group for processing the other of said 2-channel signals, said signal processing means being operative, in a reproducing mode to employ the second multiplication coefficient group for processing said one channel signal, and to employ the first multiplication coefficient group for processing said other channel signal.
Claim 2
Dependent Claim
114 words
A digital filter for a recording/reproducing apparatus comprising: analog-to-digital and digital-to-analog converter means for 2-channel signals; means for storing first and second multiplication coefficient groups which provide predetermined filter characteristics and are in interpolated relation to each other; and signal processing means operative, in a recording mode, to employ the first multiplication coefficient group for processing one of said 2-channel signals and to employ the second multiplication coefficient group for processing the other of said 2-channel signals, said signal processing means being operative, in a reproducing mode to employ the second multiplication coefficient group for processing said one channel signal, and to employ the first multiplication coefficient group for processing said other channel signal.
Claim 3
Dependent Claim
39 words
A digital filter according to claim 1, wherein, in recording and reproducing modes for a single-channel signal, the first and second multiplication coefficient groups are alternately employed by said signal processing means for successive samplings of said single-channel signal.
Claim 4
Dependent Claim
16 words
A digital filter according to claim 1, wherein said converter means oversample an input signal thereto.
Claim 5
Dependent Claim
52 words
A digital filter according to claim 3, wherein said filter has a predetermined impulse response characteristic curve, and said interpolated first and second multiplication coefficient groups are alternately offset from each other at an interval corresponding to 1/2 of an oversampling period on said impulse response characteristic curve of said digital filter.
Claim 6
Dependent Claim
75 words
A digital filter according to claim 1, further comprising first delay means receiving said one channel signal, second delay means receiving said other channel signal, selection means for alternately selecting output signals from said first and second delay means as an output signal from said selection means, and arithmetic means for multiplying said output signal from said selection means with coefficients of said first or second multiplication coefficient groups and performing predetermined arithmetic processing thereon.
Claim 7
Dependent Claim
39 words
A digital filter according to claim 5, wherein one of said said first and second delay means is used for a single-channel input signal, and an output signal from said one delay means is supplied to said arithmetic means.
Claim 8
Dependent Claim
84 words
A digital filter according to claim 5, wherein said arithmetic means includes multiplier means for effecting said multiplying of said output signal from said selection means with said coefficients of the first or second multiplication coefficient groups and providing a multiplied output, adder means having a first input receiving said multiplied output from said multiplier means and a second input, and accumulator means latching an output of said adder means and providing a latched output applied to said second input of the adder 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) | 1992-07-31 | 1993-01-30 | 1993-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-31 | 1997-01-30 | 1997-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-31 | 2001-01-30 | 2001-08-01 | $7700.00 | Window Closed / Lapsed |