Patent US5098125A successfully refreshed from Google Patents.
US4780772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for reproducing digital signals from a digital audio recording medium
Assignee: Hitachi Ltd
•
Filing: 1986-09-02
•
Granted: 1988-10-25
•
Expires: 2006-09-02
Abstract
Abstract A digital signal reproducing apparatus in which the frequency of a basic clock signal generated from a clock generator having a fixed oscillation frequency is divided to produce a clock signal used for processing a digital signal, and, when the transmission speed of the digital signal is changed, the frequency division ratio is also changed to produce a clock signal synchronous with the digital signal transmitted at the changed transmission speed.
Inventors
- 👤 Toshifumi Shibuya
- 👤 Takao Arai
- 👤 Hiroshi Endoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:52
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/1808; G11B15/1875; G11B19/00; G11B19/20; G11B19/24; G11B19/247; G11B20/00; G11B20/10; G11B20/10527; G11B27/00; G11B27/005; G11B5/00; G11B5/008; G11B5/00813; G11B5/00847; G11B5/0086; G11B7/00; G11B7/004; G11B7/005; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2537; G11B2220/2545; G11B2220/90; G11B2220/91; G11B2220/913
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
196 words
A digital audio signal reproducing apparatus for reproducing the digital audio signals recorded on a disk with a predetermined line speed and a predetermined sampling frequency, comprising: switching means for switching between a first reproduction transmission rate which is equal to the recorded transmission rate and a second reproduction transmission rate which is N times (N is an integer>1) the recorded transmission rate; equalizing means, responsive to said switching means, for switching the frequency characteristic of the digital audio signals reproduced from said disk; clock reproducing means for reproducing clock signals synchronized with said first and second reproduction transmission rates after shaping the output from said equalizing means; signal processing means for detecting and correcting errors generated in the reproduced signals and for outputting said reproduced signals to a D/A converter; control means for controlling rotation speed of said disk by the freuqency of synchronized signal detected in said reproduced signal; oscillating means for oscillating at a fixed frequency; and dividing means for dividing an output from said oscillating means by N such that an output from said dividing means can be used as a reference signal for said controlling means and said signal processing means.
Claim 2
Dependent Claim
196 words
A digital audio signal reproducing apparatus for reproducing the digital audio signals recorded on a disk with a predetermined line speed and a predetermined sampling frequency, comprising: switching means for switching between a first reproduction transmission rate which is equal to the recorded transmission rate and a second reproduction transmission rate which is N times (N is an integer>1) the recorded transmission rate; equalizing means, responsive to said switching means, for switching the frequency characteristic of the digital audio signals reproduced from said disk; clock reproducing means for reproducing clock signals synchronized with said first and second reproduction transmission rates after shaping the output from said equalizing means; signal processing means for detecting and correcting errors generated in the reproduced signals and for outputting said reproduced signals to a D/A converter; control means for controlling rotation speed of said disk by the freuqency of synchronized signal detected in said reproduced signal; oscillating means for oscillating at a fixed frequency; and dividing means for dividing an output from said oscillating means by N such that an output from said dividing means can be used as a reference signal for said controlling means and said signal processing means.
Claim 3
Dependent Claim
37 words
A digital audio signal reproduction apparatus according to claim 1, wherein said clock reproducing means includes a small phase error at said first reproduction transmission rate and a large phase error at said second reproduction transmission rate.
Claim 4
Dependent Claim
20 words
A digital audio signal reproduction apparatus according to claim 2, wherein said clock reproducing means is digital data strobe circuit.
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) | 1991-10-25 | 1992-04-25 | 1992-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-25 | 1996-04-25 | 1996-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-25 | 2000-04-25 | 2000-10-25 | $7700.00 | Window Closed / Lapsed |