US5293365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Track control circuit for optical card recording/reproducing apparatus
Assignee: Olympus Corp
•
Filing: 1993-07-12
•
Granted: 1994-03-08
•
Expires: 2013-07-12
Abstract
Abstract In a track control circuit for an optical car recording/reproducing apparatus, a light beam for optically recording or reproducing information is incident on a desired track of an optical card having a plurality of tracks through a focusing lens. A beam reflected by a desired track of the optical card is detected by a photosensor, and a track error signal is generated as a signal representing a deviation of the reflected beam. A track actuator moves the focusing lens in horizontal and vertical directions so as to position the focusing lens on the track of the optical card in accordance with a track error signal gain-controlled by a variable gain amplifier. The variable gain amplifier receives a control signal from a CPU so as to change the gain of the track error signal in accordance with the amplitude of the generated track error signal.
Inventors
- 👤 Takao Rokutan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:03
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0941; G11B7/0948
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
353 words
A track control circuit for an optical card recording/reproducing apparatus, comprising: light beam means for emitting a light beam for optically recording/reproducing information onto a card-like optical recording medium having a plurality of tracks; focusing means for focusing the light beam emitted from said light beam means onto said card-like optical recording medium; photosensing means for detecting a beam reflected by a desired track of said card-like optical recording medium; error signal generating means for generating a track error signal output in accordance with a deviation of the reflected beam detected by said photosensing means; actuator means having a moving member which is movable across said tracks; track scanning means for driving said actuator means by transmitting a track scanning signal to said actuator means, in a state wherein said actuator means is stopped relative to said card-like optical recording medium, thereby to perform a track scanning operation wherein the light beam moves across said tracks; track servo means for holding the light beam on said desired track, by transmitting the track error signal to said actuator means so that said actuator means uses the track error signal in replacement of the track scanning signal; gain setting means for setting a gain of the track error signal; determining means for determining that the track error signal is abnormal when an amplitude level of the track error signal differs from a predetermined amplitude level during the track scanning operation, and for determining that the track error signal is normal when the amplitude level of the track error signal is equal to the predetermined amplitude level during the track scanning operation; and control means for outputting to said gain setting means a control signal for controlling the gain set by said gain setting means, only when said light beam means is stopped relative to said card-like optical recording medium and when said determining means determines that the track error signal is normal, and, when said determining means determines that the track error signal is abnormal, moving the light beam across said tracks again after moving said actuator means relative to said card-like optical recording medium.
Claim 2
Dependent Claim
353 words
A track control circuit for an optical card recording/reproducing apparatus, comprising: light beam means for emitting a light beam for optically recording/reproducing information onto a card-like optical recording medium having a plurality of tracks; focusing means for focusing the light beam emitted from said light beam means onto said card-like optical recording medium; photosensing means for detecting a beam reflected by a desired track of said card-like optical recording medium; error signal generating means for generating a track error signal output in accordance with a deviation of the reflected beam detected by said photosensing means; actuator means having a moving member which is movable across said tracks; track scanning means for driving said actuator means by transmitting a track scanning signal to said actuator means, in a state wherein said actuator means is stopped relative to said card-like optical recording medium, thereby to perform a track scanning operation wherein the light beam moves across said tracks; track servo means for holding the light beam on said desired track, by transmitting the track error signal to said actuator means so that said actuator means uses the track error signal in replacement of the track scanning signal; gain setting means for setting a gain of the track error signal; determining means for determining that the track error signal is abnormal when an amplitude level of the track error signal differs from a predetermined amplitude level during the track scanning operation, and for determining that the track error signal is normal when the amplitude level of the track error signal is equal to the predetermined amplitude level during the track scanning operation; and control means for outputting to said gain setting means a control signal for controlling the gain set by said gain setting means, only when said light beam means is stopped relative to said card-like optical recording medium and when said determining means determines that the track error signal is normal, and, when said determining means determines that the track error signal is abnormal, moving the light beam across said tracks again after moving said actuator means relative to said card-like optical recording medium.
Claim 3
Dependent Claim
87 words
A circuit according to claim 1, wherein said light beam driving means moves said focusing means in horizontal and vertical directions so as to position said focusing means on a given track of the card-like optical recording medium in accordance with the track error signal controlled by said gain setting means and moves said focusing means onto a track different from the given track of the card-like optical recording medium responsive to said determining means determining that the track error signal is less than the predetermined level.
Claim 4
Dependent Claim
104 words
A circuit according to claim 1, wherein said light beam means, said focusing means, and said photosensing means constitute an optical system, and wherein said light beam driving means moves said optical system in horizontal and vertical directions so as to position said optical system on a given track of the card-like optical recording medium in accordance with the track error signal controlled by said gain setting means and moves said optical system onto a track different from the given track of the card-like optical recording medium responsive to said determining means determining that the track error signal is less than the predetermined level.
Claim 5
Dependent Claim
41 words
A circuit according to claim 1, wherein said control means supplies a control signal to said gain setting means so as to reduce a gain when an amplitude of the track error signal is larger than a predetermined target amplitude level.
Claim 6
Dependent Claim
41 words
A circuit according to claim 1, wherein said control means supplies a control signal to said gain setting means so as to increase a gain when an amplitude of the track error signal is smaller than a predetermined target amplitude level.
Claim 7
Dependent Claim
51 words
A circuit according to claim 1, wherein said light beam driving means moves a light beam emitted from said light beam means responsive to said determining means determining that a number of cycles for determining that the track error signal is less than the predetermined level falls within a predetermined number.
Claim 8
Dependent Claim
45 words
A circuit according to claim 2, wherein said light beam driving means moves said focusing means responsive to said determining means determining that a number of cycles for determining that the track error signal is less than the predetermined level falls within a predetermined number.
Claim 9
Dependent Claim
45 words
A circuit according to claim 3, wherein said light beam driving means moves said optical system responsive to said determining means determining that a number of cycles for determining that the track error signal is less than the predetermined level falls within a predetermined number.
Claim 10
Dependent Claim
28 words
A circuit according to claim 1, wherein said determining means includes a means for comparing an amplitude of said track error signal with a predetermined reference amplitude level.
Claim 11
Dependent Claim
28 words
A circuit according to claim 1, wherein said determining means includes means for comparing a differentiated amplitude of said track error signal with a predetermined reference amplitude level.
Claim 12
Dependent Claim
99 words
A circuit according to claim 1, wherein said control means includes a second determining means for determining whether a difference between the amplitude of the track error signal generated by said error signal generating means and that of a second level showing a suitable level of the track error signal is more than a predetermined value, and means for outputting a control signal to control the gain set by said gain setting means when the track error signal generated by said error signal generating means is determined to be more than the predetermined level by said second determining means.
Claim 13
Dependent Claim
210 words
A track control method for an optical card recording/reproducing apparatus, comprising: a first step of focusing a light beam used for optical recording/reproducing information onto a desired track of a card-like optical recording medium having a plurality of tracks, and detecting the beam reflected by the desired track to output an electrical signal corresponding to the detected reflected beam; a second step of generating a track error signal output in accordance with a deviation of the reflected light beam on the basis of the electrical signal; a third step of determining whether the track error signal is less than a predetermined level; a fourth step of moving the light beam to a track different from the given track of the card-like optical recording medium when the track error signal is determined to be less than the predetermined level; a fifth step of performing the third step after the moving of the light beam to a track different from the given track of the card-like optical recording medium by the fourth step; and a sixth step, performed after said fifth step, of outputting a control signal to control a gain of amplification of the track error signal when the track error signal is determined to be more than the predetermined level.
Claim 14
Dependent Claim
210 words
A track control method for an optical card recording/reproducing apparatus, comprising: a first step of focusing a light beam used for optical recording/reproducing information onto a desired track of a card-like optical recording medium having a plurality of tracks, and detecting the beam reflected by the desired track to output an electrical signal corresponding to the detected reflected beam; a second step of generating a track error signal output in accordance with a deviation of the reflected light beam on the basis of the electrical signal; a third step of determining whether the track error signal is less than a predetermined level; a fourth step of moving the light beam to a track different from the given track of the card-like optical recording medium when the track error signal is determined to be less than the predetermined level; a fifth step of performing the third step after the moving of the light beam to a track different from the given track of the card-like optical recording medium by the fourth step; and a sixth step, performed after said fifth step, of outputting a control signal to control a gain of amplification of the track error signal when the track error signal is determined to be more than the predetermined level.
Claim 15
Dependent Claim
56 words
A method according to claim 12, further comprising executing a further step when the track error signal is determined in said third step to be more than the predetermined level, said further step comprising outputting a control signal to control a gain amplification set by a gain setting means, without executing said fourth and fifth steps.
Claim 16
Dependent Claim
38 words
A method according to claim 13, further comprising conducting a predetermined error processing when the track error signal is not determined to be more than the predetermined level after performing said third step a predetermined number of times.
References Cited (Backward Citations)
US4616353A
Cited
US4890273A
Cited
US5023860A
Cited
US5138596A
Cited
JPH02285523A
Cited
US5048002A
Cited
US5109367A
Cited
US5146443A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |