EP0307095A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Helical scan recording
Assignee: EMI Group Ltd
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Filing: 1988-08-15
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Granted: —
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Expires: 2008-08-15
Abstract
Abstract A helical scan optical system comprises, in coaxial disposition, a drum (2) around which a tape is helically wrapped and an optical image rotator. The rotator is disposed inside the drum (2) and both the drum (2) and the rotator are coupled to respective hollow, coaxial drive shafts (5). The optical axis of the system passes coaxially along the two drive shafts.
Inventors
- 👤 Brian John Baker
- 👤 Terence Francis Dean
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 11:48
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/002; G11B7/003; G11B7/0031; G11B7/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
A helical scan optical recording and reproducing system including a rotatable drum, arranged to receive tape wrapped helically therearound, and an optical image rotator disposed to compensate for undesired motion, relative to the tape, of information to be recorded thereon or reproduced therefrom, said optical image rotator being mounted within said drum and coaxially rotatable relative thereto.
Claim 2
Dependent Claim
57 words
A helical scan optical recording and reproducing system including a rotatable drum, arranged to receive tape wrapped helically therearound, and an optical image rotator disposed to compensate for undesired motion, relative to the tape, of information to be recorded thereon or reproduced therefrom, said optical image rotator being mounted within said drum and coaxially rotatable relative thereto.
Claim 3
Dependent Claim
21 words
A system according to Claim 1 wherein the optical axes of said drum and said optical image rotator are substantially coincident.
Claim 4
Dependent Claim
20 words
A system according to either Claim 1 or Claim 2 wherein said optical image rotator comprises a Pechan prism assembly.
Claim 5
Independent Claim
39 words
A system according to any preceding Claim wherein said drum and said optical image rotator are coupled to respective hollow, coaxial drive shafts and wherein bearing means are provided to permit said shafts to rotate relative to one another.
Claim 6
Dependent Claim
14 words
A system according to Claim 4 including respective drive means coupled to said shafts.
Claim 7
Independent Claim
28 words
A system according to Claims 3 and 5 wherein said respective drive means are arranged to rotate said drum at twice the speed of said optical image rotator.
Claim 8
Independent Claim
57 words
A system according to any preceding Claim including an axially mounted deflection mirror fixed within the drum and arranged to direct light incident thereon by way of said optical image rotator through objective lens means and through said drum to said tape and to likewise direct light reflected from said tape back through said optical image rotator.
References Cited (Backward Citations)
No citation records indexed.
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