EP0180432A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for reproducing digital signals
Assignee: Sony Corp
•
Filing: 1985-10-25
•
Granted: —
•
Expires: 2005-10-25
Abstract
Abstract Apparatus for reproducing digital signals recorded on a recording tape (14) comprises a rotary drum about which the tape (14) can be trained, a rotary head (11 A, 11 B) mounted in the drum, a transport mechanism (34) for transporting the tape (14) over the drum and rotating the head (11 A, 11 B) so that a relative speed is established between the head (11 A, 11 B) and the tape (14) and the head (11A, 11 B) scans the tape (14) and generates reproduced digital signals in response to digital signals recorded on the tape (14), and a mode-control mechanism for controlling the transport mechanism (34) so that the tape (14) is transported over the drum at an absolute tape speed that can be varied. A servomechanism (32,40) responsive to variations in the absolute tape speed adjusts the transport mechanism (34) so that the head (11 A, 11 B) acquires a rotary speed such that the relative speed is restored to and maintained at a substantially constant value, not withstanding changes in the absolute tape speed effected under the control of the mode-control mechanism .
Inventors
- 👤 Toshiyuki Patents Division Tani
- 👤 Yoshizumi Patents Division Inazawa
- 👤 Toshihiko Patents Division Takahashi
- 👤 Shigeyuki Patents Division Satomura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:44
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/467; G11B15/473; G11B15/1808; G11B15/1875; G11B15/4731
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
182 words
Apparatus for reproducing digital signals recorded on a recording tape (14), the apparatus comprising: a rotary drum about which the recording tape (14) can be trained; rotary head means (11A, 11B) mounted in said drum; transport means (34) for transporting said tape (14) over said drum and rotating said head means (11A, 11B) so that a relative speed is established between said head means (11A, 11B) and said tape (14), and said head means (11A, 11B) scans said tape (14) and generates reproduced digital signals in response to digital signals recorded on said tape (14); mode-control means for controlling said transport means (34) so that said tape (14) is transported over said drum at an absolute tape speed that can be varied; and servo means (32, 40) responsive to variations in said absolute tape speed for adjusting said transport means (34) so that said head means (11A, 11B) acquires a rotary speed such that said relative speed is restored to and maintained at a substantially constant value, notwithstanding changes in said absolute tape speed effected under the control of said mode-control means.
Claim 2
Dependent Claim
182 words
Apparatus for reproducing digital signals recorded on a recording tape (14), the apparatus comprising: a rotary drum about which the recording tape (14) can be trained; rotary head means (11A, 11B) mounted in said drum; transport means (34) for transporting said tape (14) over said drum and rotating said head means (11A, 11B) so that a relative speed is established between said head means (11A, 11B) and said tape (14), and said head means (11A, 11B) scans said tape (14) and generates reproduced digital signals in response to digital signals recorded on said tape (14); mode-control means for controlling said transport means (34) so that said tape (14) is transported over said drum at an absolute tape speed that can be varied; and servo means (32, 40) responsive to variations in said absolute tape speed for adjusting said transport means (34) so that said head means (11A, 11B) acquires a rotary speed such that said relative speed is restored to and maintained at a substantially constant value, notwithstanding changes in said absolute tape speed effected under the control of said mode-control means.
Claim 3
Dependent Claim
76 words
Apparatus according to claim 1 wherein said mode-control means controls said transport means (34) so that said absolute tape speed is selectively established at a value appropriate to a playback mode, a fast-forward mode, or a rewind mode, the absolute tape speed in said fast-forward and rewind modes being a substantial multiple of the absolute tape speed in said playback mode and said substantially constant value of said relative speed being appropriate to said playback mode.
Claim 4
Dependent Claim
128 words
Apparatus according to claim 1 wherein said servo means (32, 40) comprises two servo systems (32, 40), one being operative when said mode-control means controls said transport means (34) so that said absolute tape speed is increased and a momentary excursion of said relative speed from said substantially constant value results, and when operative causing said transport means (34) to adjust the rotary speed of said head means (11A, 11B) so that said relative speed is restored to said substantially constant value; and the other being operative when said relative speed is at said substantially constant value and when operative causing said transport means (34) to adjust the rotary speed of said head means (11A, 11B) so that said relative speed is maintained at said substantially constant value.
Claim 5
Dependent Claim
46 words
Apparatus according to claim 1 wherein said transport means (34) comprises first motive means for transporting said tape (14) over said drum and second motive means (34) for rotating said head means (11A, 11B), said first motive means being independent of said servo means (32, 40).
Claim 6
Dependent Claim
158 words
Apparatus according to claim 1 wherein said digital signals include recorded clock signals; and wherein the apparatus further comprises: clock reproducing means (19) responsive to said recorded clock signals for generating reproduced clock signals having a frequency proportional to said relative speed; error detecting means (20) responsive to said reproduced clock signals for detecting the presence or absence of error therein; first switching means (36) responsive to said error detecting means; frequency-to-voltage converting means (37) connected by said first switching means (36) to said clock reproducing means (19) when said error detecting means (20) detects the absence of error in said reproduced clock signals, said frequency-to-voltage converting means (37) then being responsive to said reproduced clock signals for producing a signal having a voltage proportional to said frequency; and comparing means (38) for comparing said voltage with a reference voltage and producing a compared output signal; said servo means (32, 40) being responsive to said compared output signal.
Claim 7
Dependent Claim
96 words
Apparatus according to claim 5 further comprising: second switching means (33) responsive to detection of error by said error detecting means (20); and equalizer and comparator means (17, 18) responsive to said reproduced digital signals for generating a pattern signal having a period which is a function of said relative speed; said second switching means (33) controlling said servo means (32, 40) when said error detecting means (20) detects error in said reproduced clock signals in such a manner that said servo means (32, 40) adjusts said transport means (34) in dependence on said pattern signal.
Claim 8
Dependent Claim
94 words
Apparatus according to claim 5 further comprising: second switching means (33) responsive to detection of error by said error detecting means (20); and period detecting and acceleration/deceleration means (52, 53) for generating an acceleration or deceleration signal in response to said changes in said absolute tape speed; said second switching means (33) controlling said servo means (32, 40) when said error detecting means (20) detects error in said reproduced clock signals in such a manner that said servo means (32, 40) adjusts said transport means (34) in dependence on said acceleration or deceleration signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.