US5235574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk drive relative position sensor
Assignee: International Business Machines Corp
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Filing: 1991-11-04
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Granted: 1993-08-10
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Expires: 2011-11-04
Abstract
Abstract An optical disk drive is disclosed in which sensing the position of a tilting prism driven by a fine tracking actuator uses the optical beam prior to its interaction with an optical disk. The optical beam emitted by a laser is redirected by the tilting prism. Most of the optical beam is reflected by the tilting prism in a direction through an objective lens for focused interaction with an optical disk. assuming a disk is mounted in the optical disk drive. The remainder of the optical beam is transmitted through the tilting prism, including any offset of the beam resulting from the refraction characteristics of the tilting prism, and received by a split far field detector. The split far field detector measures the offset of the optical beam which is a direct measure of the rotational position of the tilting prism. A relative position error signal is then generated and input to the coarse tracking actuator to coordinate its operation with that of the fine tracking actuator.
Inventors
- 👤 Henry E. Aviles
- 👤 Edwin R. Childers
- 👤 James L. Overacker
- 👤 Ronald P. Stahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:04
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1356; G11B7/08; G11B7/09; G11B7/0901; G11B7/094
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
131 words
A system for measuring the relative displacement of a first component with respect to a second component upon which the first component is movably mounted, the system comprising: means for emitting a beam a first portion of which reflects off of the first component and a second portion of which refracts through the first component; and means for detecting the offset of the second portion of the beam caused solely by the relative movement of the first component with respect to the second component, the means for detecting including means for removing variations in a detected offset caused by the means for emitting, there being no reflection of the beam off of the first component in the path of the beam from the means for emitting to the means for detecting.
Claim 2
Independent Claim
131 words
A system for measuring the relative displacement of a first component with respect to a second component upon which the first component is movably mounted, the system comprising: means for emitting a beam a first portion of which reflects off of the first component and a second portion of which refracts through the first component; and means for detecting the offset of the second portion of the beam caused solely by the relative movement of the first component with respect to the second component, the means for detecting including means for removing variations in a detected offset caused by the means for emitting, there being no reflection of the beam off of the first component in the path of the beam from the means for emitting to the means for detecting.
Claim 3
Dependent Claim
17 words
The system of claim 1 wherein the means for emitting is not mounted on the second component.
Claim 4
Dependent Claim
16 words
The system of claim 1 wherein the means for emitting is a coherent, collimated light source.
Claim 5
Dependent Claim
13 words
The system of claim 3 wherein the first component is a tilting prism.
Claim 6
Dependent Claim
13 words
The system of claim 3 wherein the first component is a tilting mirror.
Claim 7
Dependent Claim
16 words
The system of claim 1 wherein the means for detecting is mounted on the second component.
Claim 8
Dependent Claim
16 words
The system of claim 1 wherein the means for detecting is a split far field detector.
Claim 9
Independent Claim
151 words
A system for measuring the relative displacement of a first component with respect to a second component upon which the first component is tiltably mounted, the system comprising: a light source for emitting an optical beam a first portion of which reflects off of the first component and a second portion of which refracts through the first component; and a split far field detector for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the first component with respect to the second component, the split far field detector including means for removing variations in a detected offset caused by the light source, there being no reflection of the optical beam off of the first component in the path of the optical beam from the collimated light source to the split far field detector, the far field detector mounted on the second component.
Claim 10
Independent Claim
151 words
A system for measuring the relative displacement of a first component with respect to a second component upon which the first component is tiltably mounted, the system comprising: a light source for emitting an optical beam a first portion of which reflects off of the first component and a second portion of which refracts through the first component; and a split far field detector for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the first component with respect to the second component, the split far field detector including means for removing variations in a detected offset caused by the light source, there being no reflection of the optical beam off of the first component in the path of the optical beam from the collimated light source to the split far field detector, the far field detector mounted on the second component.
Claim 11
Independent Claim
156 words
A system for positioning a coarse actuator in an optical storage device, the system comprising: an optical component movably coupled to a fine actuator and mounted upon a carriage movably coupled to the coarse actuator; a light source for emitting an optical beam a first portion of which reflects off of the optical component and a second portion of which reflects through the optical component; means for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the optical component with respect to the carriage, the means for detecting including means for removing variations in a detected offset caused by the light source, there being no reflection of the optical beam off of the optical component in the path of the optical beam from the light source to the means for detecting; and means for adjusting the coarse actuator coupled to the output of the means for detecting.
Claim 12
Independent Claim
156 words
A system for positioning a coarse actuator in an optical storage device, the system comprising: an optical component movably coupled to a fine actuator and mounted upon a carriage movably coupled to the coarse actuator; a light source for emitting an optical beam a first portion of which reflects off of the optical component and a second portion of which reflects through the optical component; means for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the optical component with respect to the carriage, the means for detecting including means for removing variations in a detected offset caused by the light source, there being no reflection of the optical beam off of the optical component in the path of the optical beam from the light source to the means for detecting; and means for adjusting the coarse actuator coupled to the output of the means for detecting.
Claim 13
Dependent Claim
17 words
The system of claim 9 wherein the light source is not movably coupled to the coarse actuator.
Claim 14
Dependent Claim
13 words
The system of claim 9 wherein the optical component is a tilting prism.
Claim 15
Dependent Claim
13 words
The system of claim 9 wherein the optical component is a tilting mirror.
Claim 16
Dependent Claim
17 words
The system of claim 9 wherein the means for detecting is movably coupled to the coarse actuator.
Claim 17
Dependent Claim
16 words
The system of claim 9 wherein the means for detecting is a split far field detector.
Claim 18
Dependent Claim
150 words
An optical drive comprising: an objective lens movably mounted on a focus actuator; a coarse tracking actuator; a fine tracking actuator; an optical component movably coupled to the fine tracking actuator and mounted upon a carriage movably coupled to the coarse tracking actuator; a light source for emitting an optical beam a first portion of which reflects off of the optical component and through the objective lens and a second portion of which refracts through the optical component; means for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the optical component with respect to the means for detecting including means for removing variations in a detected offset caused by the light source, the means for detecting movably coupled to the coarse tracking actuator; and means for adjusting the coarse tracking actuator coupled to the output of the means for detecting.
Claim 19
Dependent Claim
150 words
An optical drive comprising: an objective lens movably mounted on a focus actuator; a coarse tracking actuator; a fine tracking actuator; an optical component movably coupled to the fine tracking actuator and mounted upon a carriage movably coupled to the coarse tracking actuator; a light source for emitting an optical beam a first portion of which reflects off of the optical component and through the objective lens and a second portion of which refracts through the optical component; means for detecting the offset of the second portion of the optical beam caused solely by the relative movement of the optical component with respect to the means for detecting including means for removing variations in a detected offset caused by the light source, the means for detecting movably coupled to the coarse tracking actuator; and means for adjusting the coarse tracking actuator coupled to the output of the means for detecting.
Claim 20
Dependent Claim
18 words
The optical disk drive of claim 15 further comprising a split far field detector for measuring track misregistration.
Claim 21
Dependent Claim
27 words
The optical disk drive of claim 15 further comprising means for controlling the light source to read data from a disk mounted in the optical disk drive.
Claim 22
Dependent Claim
18 words
The optical disk drive of claim 15 wherein the means for detecting is a split far field detector.
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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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |