US4499571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk system with laser safety arrangement
Assignee: Toshiba Corp
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Filing: 1982-04-30
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Granted: 1985-02-12
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Expires: 2002-04-30
Abstract
Abstract An optical disk apparatus has a detector for detecting absence of an optical disk in a prescribed position, a detection circuit for detecting non-rotation of the disk and an AND circuit for producing a logical product of the outputs from the detector and detection circuit. The detector comprises a light-emitting diode and a light-receiving element. An output signal from the AND circuit is supplied to a beam source driver/control circuit, thereby turning off a beam source.
Inventors
- 👤 Tsuneshi Yokota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:34
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B19/10; G11B19/04; G11B7/00; G11B7/002; G11B7/0037; G11B7/12; G11B7/125
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
An optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and read out data from the disk, the improvement comprising: (a) first detection means for detecting non-rotation of the disk; (b) second detection means for detecting absence of the disk in a prescribed position; and (c) control means electrically connected to the first and second detection means for turning off a laser beam source in response to output signals from the first and second detection means.
Claim 2
Dependent Claim
104 words
An optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and read out data from the disk, the improvement comprising: (a) first detection means for detecting non-rotation of the disk; (b) second detection means for detecting absence of the disk in a prescribed position; and (c) control means electrically connected to the first and second detection means for turning off a laser beam source in response to output signals from the first and second detection means.
Claim 3
Dependent Claim
40 words
An optical disk apparatus according to claim 1, wherein said first detection means has a pulse generator connected to said motor and detects upon receipt of a pulse signal from the pulse generator whether or not said motor is rotating.
Claim 4
Dependent Claim
34 words
An optical disk apparatus according to claim 1, wherein said second detection means comprises a light-emitting diode for emitting light to said disk and a light-receiving element for receiving light reflected from said disk.
Claim 5
Dependent Claim
83 words
An optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and retrieve data from the disk, the improvement comprising: (a) detection means for detecting non-rotation of said disk; and (b) control means electrically connected to said detecting means for turning off a laser beam source in response to an output signal from the detecting means.
Claim 6
Dependent Claim
83 words
An optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and retrieve data from the disk, the improvement comprising: (a) detection means for detecting non-rotation of said disk; and (b) control means electrically connected to said detecting means for turning off a laser beam source in response to an output signal from the detecting means.
Claim 7
Dependent Claim
39 words
An optical disk apparatus according to claim 4, wherein said detection means has a pulse generator connected to said motor and detects upon receipt of a pulse signal from the pulse generator whether or not said motor is rotating.
Claim 8
Dependent Claim
113 words
In an optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and read out data from the disk, the improvement comprising: (a) detection means for detecting absence of the disk in a prescribed position, the detection means including a light-emitting diode for emitting light to said disk and a light-receiving element for receiving light reflected from said disk; and (b) control means electrically connected to said detecting means for turning off a laser beam source in response to an output signal from the detection means.
Claim 9
Dependent Claim
113 words
In an optical disk apparatus having an optical disk, a motor for rotating the disk and an optical head for emitting a laser beam, in which a laser beam illuminates the disk thereby to record data on the disk and read out data from the disk, the improvement comprising: (a) detection means for detecting absence of the disk in a prescribed position, the detection means including a light-emitting diode for emitting light to said disk and a light-receiving element for receiving light reflected from said disk; and (b) control means electrically connected to said detecting means for turning off a laser beam source in response to an output signal from the detection means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |