Patent US3969574A successfully refreshed from Google Patents.
US3969574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tubular player arm for an optical recording and reproducing device with drive coil and tachogenerator coil on other end
Assignee: US Philips Corp
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Filing: 1974-04-29
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Granted: 1976-07-13
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Expires: 1994-04-29
Abstract
Abstract A device for writing information in a disk-shaped record carrier, and/or for reproducing the recorded information, the transducer being radially movable relative to the record carrier, which transducer is disposed on a tubular member, which at its one end is provided with a drive coil and at its other end with a tachometer coil, which coils are movable in an air gap of a stationary magnet system.
Inventors
- 👤 Peter Johannes Michiel Janssen
- 👤 Gerard Eduard VAN Rosmalen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:40
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/08; G11B7/085; G11B7/0857; G11B7/08582; G11B7/09; G11B7/0925; G11B7/0929; H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356; H02P; H02P25/00; H02P25/02; H02P25/032; H02P25/034
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 words
A device for recording information on a rotating disk-shaped record carrier and/or for reading the recording from the carrier with a radiation beam, comprising a tubular member, a transducer on the tubular member in the path of the radiation beam, said radiation beam being projected through said tubular member in a direction substantially parallel to the longitudinal axis of said tubular member, means positioned within said tubular member for deflecting the radiation beam out of said tubular member through said transducer, a drive coil surrounding one end of said tubular member, a tacho-generator coil surrounding the other end of said tubular member and providing a tacho-generator signal in response to motion of the tubular member, a separate stationary magnetic system means magnetically coupled to each of said coils for providing a stationary magnetic field and an air gap surrounding each of said coils, a signal source for providing an energizing signal for said drive coil, and means for combining the tacho-generator signal with said energizing signal and for connecting said combined signal to said drive coil.
Claim 2
Independent Claim
176 words
A device for recording information on a rotating disk-shaped record carrier and/or for reading the recording from the carrier with a radiation beam, comprising a tubular member, a transducer on the tubular member in the path of the radiation beam, said radiation beam being projected through said tubular member in a direction substantially parallel to the longitudinal axis of said tubular member, means positioned within said tubular member for deflecting the radiation beam out of said tubular member through said transducer, a drive coil surrounding one end of said tubular member, a tacho-generator coil surrounding the other end of said tubular member and providing a tacho-generator signal in response to motion of the tubular member, a separate stationary magnetic system means magnetically coupled to each of said coils for providing a stationary magnetic field and an air gap surrounding each of said coils, a signal source for providing an energizing signal for said drive coil, and means for combining the tacho-generator signal with said energizing signal and for connecting said combined signal to said drive coil.
Claim 3
Dependent Claim
27 words
A device as claimed in claim 1, wherein the tubular member extends through the magnet system means and wherein the transducer is disposed at said one end.
Claim 4
Dependent Claim
67 words
A device as claimed in claim 1, wherein each of the magnet system means consists of a hollow core and is at one end provided with a cylindrical pole shoe, which together with a pole plate disposed opposite said pole shoe defines the air gap of each of said magnetic system means, and a magnetic connection provided between said plate and the other end of the core.
Claim 5
Dependent Claim
27 words
A device as claimed in claim 3, wherein the tubular member extends through the magnet system means and wherein the transducer is disposed at said one end.
Claim 6
Dependent Claim
35 words
A device as claimed in claim 3, wherein the pole shoe and/or the pole plate is provided with ducts which terminate in the air gap, through which a pressurised gas or liquid may flow out.
Claim 7
Dependent Claim
27 words
A device as claimed in claim 5, wherein the tubular member extends through the magnet system means and wherein the transducer is disposed at said one end.
References Cited (Backward Citations)
US2581133A
Cited
US3391255A
Cited
US3544980A
Cited
US3576454A
Cited
US3521092A
Cited
US3842197A
Cited
US3833769A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-13 | 1980-01-12 | 1980-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-13 | 1984-01-12 | 1984-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-13 | 1988-01-12 | 1988-07-13 | $7700.00 | Window Closed / Lapsed |