EP0443822A2
Expired / Lapsed
EP
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Optical disk inclination detection device
Assignee: Victor Company of Japan Ltd
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Filing: 1991-02-20
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Granted: —
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Expires: 2011-02-20
Abstract
Abstract A system for the detection of relative inclination of an optical disk (3, 30, 33, 55) that records information and an optical head (15) that records reproduces said information recorded by the irradiation of a light beam to this disk, comprises an inclination shift element (16) that shifts the relative inclination between said disk and head by applying a forced inclination in alternately positive and negative directions with respect to either of said optical disk (3, 30, 33, 55) and said optical head (15), a signal change detection element (18) that detects the change of an output signal of an optical head (15) generated when a relative inclination is forcedly changed by said inclination shift element (16), a synchronization detection element (17) that detects synchronization of a forced change of said relative inclination, and an inclination detect element (19, 20) that detects the relative inclination between said disk and head on the basis of the cycle of forced inclination detected by said synchronization detection element (17) and the change in signals detected by said signal change detection element (18).
Inventors
- 👤 Senji Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:05
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/095; G11B7/0956
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
179 words
A system for the detection of relative inclination of an optical disk (3, 30, 33, 55) that records information and an optical head (15) that records reproduces said information recorded by the irradiation of a light beam to this disk, comprising; an inclination shift means (16) that shifts the relative inclination between said disk and head by applying a forced inclination in alternately positive and negative directions with respect to either of said optical disk (3, 30, 33, 55) and said optical head (15); a signal change detection means (18) that detects the change of an output signal of an optical head (15) generated when a relative inclination is forcedly changed by said inclination shift means (16); a synchronization detection means (17) that detects synchronization of a forced change of said relative inclination; and an inclination detect means (19, 20) that detects the relative inclination between said disk and head on the basis of the cycle of forced inclination detected by said synchronization detection means (17) and the change in signals detected by said signal change detection means (18).
Claim 2
Dependent Claim
134 words
The detection system of claim 1, comprising: a disk inclination shift mechanism (16) as said inclination shift means that forcedly changes an inclination of said disk with respect to said optical head by applying an inclination in alternately positive and negative directions at a constant cycle; said signal change detection means (18) detecting a change in an output signal of an optical head and generated when an inclination of said disk has been forcedly changed by said change mechanism; said cycle detection means (17) detecting a cycle of forced change of an inclination of said disk by said change mechanism; and said inclination detection means (19, 20) that detects an inclination of said disk with respect to said head on the basis of said inclination change cycle and said optical head output signal change.
Claim 3
Dependent Claim
41 words
The detection system of claim 2, wherein: said signal change detection means (19) performs detection of an envelope detect wave with respect to output signals of said optical head, and comprising a detect circuit that detects a change of a signal.
Claim 4
Dependent Claim
39 words
The detection system of claim 2, wherein: said signal change detection means (19) performs detection of a jitter component contained in output signal of said optical head, and comprising a detect circuit that detects a change of a signal.
Claim 5
Dependent Claim
64 words
The detection system of claim 2, wherein: in addition to said disk inclination change mechanism, said inclination shift means is further provided with an object lens drive mechanism that drives an object lens configuring said optical head at a rotational cycle of said optical disk and so that a radial change direction becomes an eccentric direction and a reverse direction of an information track.
Claim 6
Dependent Claim
69 words
The detection system of claim 2, wherein: said inclination shift means is further provided with an object lens drive mechanism so that an aberration component of an object lens comprising said optical head in addition tos aid disk inclination change mechanism and generated by radial shift at the rotation cycle of said optical disk, is multiplied with the X direction inclination component generated accompanying rotation of an optical disk.
Claim 7
Dependent Claim
48 words
The detection system of claim 1, wherein: said inclination shift means comprises an optical system shift means that relatively shifts an objective optical system (54) that irradiates said light beam to said optical disk, from the center (L A ) of said light beam to a peripheral region.
Claim 8
Dependent Claim
164 words
The detection system of claim 7, wherein: said detection system comprises a laser oscillator (50) that generates said light beam, a diffraction grating (51) that diffracts laser light from said laser oscillator (50), a beam splitter (52) that reflects in the direction of an optical disk (55) the diffracted light that passes through said diffraction grating (51), a collimator (53) that makes parallel light beams of the light that is reflected by said beam splitter (52), an objective lens (54) that focusses at a specific point of said disk (55) the parallel light beams passing through said collimator (53), a detection lens (56) that focusses and detects laser light that is reflected by said disk (55) and irradiated via said objective lens (54), said collimator (53) and said beam splitter (52) in order to detect information, a photodetector that detects information recorded on said disk (55) on the basis of light that is focussed by said detection lens (56) and an optical head (15).
Claim 9
Dependent Claim
156 words
The detection system of claim 1, wherein; said signal change detection means comprises an aberration generation component detection circuit (18) that receives reproduced signals from said optical head (15) and detects a change component by aberration generated due to inclination of an optical disk (3) from said reproduced signals, said cycle detection means comprising a vibration signal generation circuit (17) that receives focus drive signals applied to said optical head (15) and generates vibration signals synchronous with an inclination status of an optical disk (3), and said inclination detect means comprises an in-phase synchronous detector (19) and a 90° phase synchronous in detector (20) that respectively perform synchronous wave detect for the same phase and a 90° shifted phase on the basis of aberration change component of said reproduced signals output from said aberration component detection circuit (18) and vibration signals generated from amounts said focus drive signals by said disk vibration signal generation circuit (17).
Claim 10
Dependent Claim
112 words
The detection system of claim 9, wherein: said in-phase synchronous detector (19) outputs a same phase wave detect component to an X regulation amplifier (21) that performs regulation of the inclination (in the X direction) of an optical disk (3), and that also outputs X direction inclination adjustment commands to an inclination adjustment mechanism (16) via a drive amplifier (23), said 90° phase synchronous detector (20) outputs a 90° shift phase wave detect component to a Y regulation amplifier (22) that performs adjustment in the direction (the Y direction) perpendicular to said X direction, and outputs Y direction inclination adjustment commands to said inclination adjustment mechanism (16) via a drive amplifier (24).
Claim 11
Dependent Claim
93 words
The detection system of claim 1, wherein: said signal change detection means comprises a jitter change component detection circuit (35) that detects a jitter change component of an RF signal, a burst noise suppressor circuit (37) that suppresses burst noise from this detected jitter change component for this jitter change component detection circuit (35), and a change component selector circuit (36) that selectively outputs a jitter change component of said detection circuit (35) by signals that have had noise suppression processing and which have been output from said burst noise suppresses circuit (37).
Claim 12
Dependent Claim
107 words
The detection system of claim 11, wherein: said synchronization detection means comprises a vibration signal generation circuit (38) that receives focus drive signals output from said optical head (15) and generates vibration signals synchronous with an inclination status of an optical disk (3) from amongst these focus drive signals, and said inclination detection means comprising a synchronous signal generation circuit (39) and a synchronous signal in 90° shifted phase generation circuit (40) that respectively perform synchronous wave detect at the same phase and the 90° shifted phase, on the basis of vibration signals generated from amongst said focus drive signals by said vibration signal generation circuit (38).
Claim 13
Dependent Claim
74 words
The detection system of claim 12, wherein: said synchronous signal generation circuit (39) outputs a same phase detect wave component to an X component detection circuit (41) that detects an inclination direction (X direction) component of an optical disk (3), and said synchronous signal in 90° shifted phase generation circuit (40) detects a component in a direction (the Y direction) perpendicular to said X direction from amongst the 90° phase shifted wave detect component.
Claim 14
Dependent Claim
134 words
The detection system of claim 1, wherein: said signal change detection means comprises a change component detection circuit (61) that detects a change component from said output signal of said optical head, a burst noise suppressor circuit (63) that suppresses noise of a component detected by this circuit (61), and a change component selector circuit (62) that selects a component from said circuit (61) by suppressed noise, said signal change detection means comprising a synchronous signal generation circuit (64) that generates signals synchronous with drive signals, and said inclination detection means comprising an X component detection circuit that detects a component in an inclination direction (X direction) of an optical disk (55) on the basis of the synchronous signal output from said circuit (64) and the output of said change component selection circuit (62).
Claim 15
Dependent Claim
44 words
The detection system of claim 14, wherein: said inclination detection means has a low-pass filter (66) and a meter amplifier (67) and an inclination of an optical disk (55) from an X direction component output detected via these is displayed on a meter (68).
References Cited (Backward Citations)
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