EP0387052A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magneto-optical recording apparatus having means for delaying an input signal for preventing bit shift
Assignee: Canon Inc
•
Filing: 1990-03-08
•
Granted: —
•
Expires: 2010-03-08
Abstract
Abstract An apparatus for recording an input signal on a magneto-optical recording medium comprises an optical head for applying a light beam to the medium, a circuit for delaying the input signal by a time for preventing a bit recorded on the medium from shifting relative to the input signal, a magnetic head for applying a magnetic field modulated in conformity with the delayed signal to that portion of the medium to which the light beam is applied, and a mortor for moving the medium relative to the light beam.
Inventors
- 👤 Mitsuhiro Otokawa
- 👤 Shunpei Canon Daini Fujigaokaryo Kimura
- 👤 Yasuyuki Miyaoka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:15
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/10508; G11B11/1053
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
83 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for delaying said input signal by a time for preventing a bit recorded on said medium from shifting relative to said input signal; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 2
Independent Claim
83 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for delaying said input signal by a time for preventing a bit recorded on said medium from shifting relative to said input signal; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 3
Dependent Claim
23 words
An apparatus according to Claim 1, wherein said magnetic field applying means alternately applies to said medium pulse-like magnetic fields having opposite polarities.
Claim 4
Dependent Claim
39 words
An apparatus according to Claim 2, further comprising means for making the magnetic field intensity during a period corresponding to the rear end portion of said pulse-like magnetic fields smaller than the magnetic field intensity during the other period.
Claim 5
Independent Claim
88 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for detecting the temperature of said medium; means for delaying said input signal by a time determined in conformity with the temperature detected by said temperature detecting means; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 6
Independent Claim
88 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for detecting the temperature of said medium; means for delaying said input signal by a time determined in conformity with the temperature detected by said temperature detecting means; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 7
Dependent Claim
20 words
An apparatus according to Claim 4, wherein said temperature detecting means detects the temperature of the atmosphere near said medium.
Claim 8
Independent Claim
95 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for moving said medium relative to the light beam; means for judging the relative line speed of said medium and the light beam; means for delaying said input signal by a time determined in conformity with the line speed judged by said speed judging means; and means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied.
Claim 9
Independent Claim
95 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for moving said medium relative to the light beam; means for judging the relative line speed of said medium and the light beam; means for delaying said input signal by a time determined in conformity with the line speed judged by said speed judging means; and means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied.
Claim 10
Dependent Claim
48 words
An apparatus according to Claim 6, wherein said medum is a magneto-optical disk, said moving means rotates said disk at a predetermined angular speed, and said speed judging means judges the line speed by the disk radial position of that portion to which the light beam is applied.
Claim 11
Independent Claim
93 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for judging the power of the light beam applied to said medium; means for delaying said input signal by a time determined in conformity with the power judged by said power judging means; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 12
Independent Claim
93 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for judging the power of the light beam applied to said medium; means for delaying said input signal by a time determined in conformity with the power judged by said power judging means; means for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and means for moving said medium relative to the light beam.
Claim 13
Dependent Claim
43 words
An apparatus according to Claim 8, further comprising means for judging the relative line speed of said medium and the light beam and wherein said delay means varies the delay time in conformity with the line speed judged by said speed judging means.
Claim 14
Dependent Claim
48 words
An apparatus according to Claim 9, wherein said medium is a magneto-optical disk, said moving means rotates said disk at a predetermined angular speed, and said speed judging means judges the line speed by the disk radial position of that portion to which the light beam is applied.
Claim 15
Dependent Claim
36 words
An apparatus according to Claim 9, further comprising means for detecting the temperature of said medium and wherein said delay means varies the delay time in conformity with the temperature detected by said temperature detecting means.
Claim 16
Dependent Claim
20 words
An apparatus according to Claim 11, wherein said temperature detecting means detects the temperature of the atmosphere near said medium.
Claim 17
Independent Claim
115 words
An apparatus for recording a signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for applying a magnetic field modulated in conformity with said signal to that portion of said medium to which the light beam is applied; means for moving said medium relative to the light beam; means for recording a test signal on said medium by said magnetic field applying means; means for reproducing the test signal recorded on said medium; means for detecting bit shift from said reproduced signal; and means for delaying a data signal input to said magnetic field applying means by a time necessary to compensate for the detected bit shift.
Claim 18
Independent Claim
115 words
An apparatus for recording a signal on a magneto-optical recording medium, comprising: means for applying a light beam to said medium; means for applying a magnetic field modulated in conformity with said signal to that portion of said medium to which the light beam is applied; means for moving said medium relative to the light beam; means for recording a test signal on said medium by said magnetic field applying means; means for reproducing the test signal recorded on said medium; means for detecting bit shift from said reproduced signal; and means for delaying a data signal input to said magnetic field applying means by a time necessary to compensate for the detected bit shift.
Claim 19
Independent Claim
114 words
A method of recording a signal on a magneto-optical recording medium, comprising the steps of: scanning said medium by a light beam and at the same time, applying to said medium a magnetic field modulated in conformity with a test signal, thereby recording the test signal on said medium; reproducing the test signal recorded on said medium; detecting bit shift from the reproducing signal; delaying a data signal by a time necessary to compensate for the detected bit shift; and scanning said medium by the light beam and at the same time, applying to said medium a magnetic field modulated in conformity with said delayed signal, thereby recording said data signal on said medium.
Claim 20
Independent Claim
114 words
A method of recording a signal on a magneto-optical recording medium, comprising the steps of: scanning said medium by a light beam and at the same time, applying to said medium a magnetic field modulated in conformity with a test signal, thereby recording the test signal on said medium; reproducing the test signal recorded on said medium; detecting bit shift from the reproducing signal; delaying a data signal by a time necessary to compensate for the detected bit shift; and scanning said medium by the light beam and at the same time, applying to said medium a magnetic field modulated in conformity with said delayed signal, thereby recording said data signal on said medium.
Claim 21
Independent Claim
90 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a delay circuit for delaying said input signal by a time for preventing a bit recorded on said medium from shifting relative to the input signal; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 22
Independent Claim
90 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a delay circuit for delaying said input signal by a time for preventing a bit recorded on said medium from shifting relative to the input signal; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 23
Dependent Claim
18 words
An apparatus according to Claim 15, wherein said magnetic head alternately applies pulse-like magnetic fields having opposite polarities.
Claim 24
Dependent Claim
44 words
An apparatus according to Claim 16, further comprising a magnetic field waveform adjusting circuit for making the magnetic field intensity during a period corresponding to the rear end portion of said pulse-like magnetic fields smaller than the magnetic field intensity during the other period.
Claim 25
Independent Claim
95 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a detector for detecting the temperature of said medium; a delay circuit for delaying said input signal by a time determined in conformity with the temperature detected by said temperature detector; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 26
Independent Claim
95 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a detector for detecting the temperature of said medium; a delay circuit for delaying said input signal by a time determined in conformity with the temperature detected by said temperature detector; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 27
Dependent Claim
19 words
An apparatus according to Claim 18, wherein said temperature detector detects the temperature of the atmosphere near said medium.
Claim 28
Dependent Claim
19 words
An apparatus according to Claim 19, wherein said temperature detector comprises a thermistor disposed in proximity to said medium.
Claim 29
Dependent Claim
147 words
An appartus for recording an input signal on a magneto-optical disk on which a plurality of tracks are formed concentrically or spirally, comprising: a spindle motor for rotating said disk at a predetermined angular speed; an optical head for applying a light beam to said disk; a head feeding motor for moving said optical head radially of said disk; a control circuit for outputting a command to said head feeding motor so as to move said optical head to a position at which the light beam is applied to a desired track on said disk; a delay circuit for delaying said input signal by a time determined by the disk radial position of the desired track commanded by said control circuit; and a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to around at least the desired track of said disk.
Claim 30
Dependent Claim
147 words
An appartus for recording an input signal on a magneto-optical disk on which a plurality of tracks are formed concentrically or spirally, comprising: a spindle motor for rotating said disk at a predetermined angular speed; an optical head for applying a light beam to said disk; a head feeding motor for moving said optical head radially of said disk; a control circuit for outputting a command to said head feeding motor so as to move said optical head to a position at which the light beam is applied to a desired track on said disk; a delay circuit for delaying said input signal by a time determined by the disk radial position of the desired track commanded by said control circuit; and a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to around at least the desired track of said disk.
Claim 31
Independent Claim
105 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a control circuit for commanding said optical head about the power of the light beam applied to said medium; a delay circuit for delaying said input signal by a time determined in conformity with the power commanded by said control circuit; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 32
Independent Claim
105 words
An apparatus for recording an input signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a control circuit for commanding said optical head about the power of the light beam applied to said medium; a delay circuit for delaying said input signal by a time determined in conformity with the power commanded by said control circuit; a magnetic head for applying a magnetic field modulated in conformity with said delayed signal to that portion of said medium to which the light beam is applied; and a motor for moving said medium relative to the light beam.
Claim 33
Dependent Claim
69 words
An apparatus according to Claim 22, wherein said control circuit comprises a photodetector for receiving part of the light beam emitted from said optical head, a comparing circuit for comparing the output of said photodetector with a target value, a feedback circuit for feeding back the output of said comparing circuit to said optical head, and a setting circuit for changing over the target value of said comparing circuit.
Claim 34
Dependent Claim
45 words
An apparatus according to Claim 22, further comprising a judging circuit for judging the relative line speed of said medium and the light beam and wherein said delay circuit varies the delay time in conformity with the line speed judged by said speed judging circuit.
Claim 35
Dependent Claim
47 words
An apparatus according to Claim 24, wherein said medium is a magneto-optical disk, said motor rotates said disk at a predetermined angular speed, and said speed judging circuit judges the line speed by the disk radial position of that portion to which the light beam is applied.
Claim 36
Dependent Claim
36 words
An apparatus according to Claim 24, further comprising a detector for detecting the temperature of said medium and wherein said delay circuit varies the delay time in conformity with the temperature detected by said temperature detector.
Claim 37
Dependent Claim
19 words
An apparatus according to Claim 26, wherein said temperature detector detects the temperature of the atmosphere near said medium.
Claim 38
Independent Claim
123 words
An apparatus for recording a signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a magnetic head for applying a magnetic field modulated in conformity with the signal to that portion of said medium to which the light beam is applied; a motor for moving said medium relative to the light beam; a controller for recording a test signal on said medium by said magnetic head; a reproducing circuit for reproducing the test signal recorded on said medium; a detecting circuit for detecting bit shift from said reproduced signal; and a delay circuit for delaying a data singal input to said magnetic head by a time necessary to compensate for the detected bit shift.
Claim 39
Independent Claim
123 words
An apparatus for recording a signal on a magneto-optical recording medium, comprising: an optical head for applying a light beam to said medium; a magnetic head for applying a magnetic field modulated in conformity with the signal to that portion of said medium to which the light beam is applied; a motor for moving said medium relative to the light beam; a controller for recording a test signal on said medium by said magnetic head; a reproducing circuit for reproducing the test signal recorded on said medium; a detecting circuit for detecting bit shift from said reproduced signal; and a delay circuit for delaying a data singal input to said magnetic head by a time necessary to compensate for the detected bit shift.
Claim 40
Independent Claim
59 words
A method or apparatus for recording information on a medium by a magneto-optic effect, in which a radiation beam illuminates a spot on the medium while a magnetic field applies a data signal to the spot, characterised in that the magnetic field signal is delayed relative to a synchronising signal to compensate for the non-zero size of the spot.
Claim 41
Independent Claim
59 words
A method or apparatus for recording information on a medium by a magneto-optic effect, in which a radiation beam illuminates a spot on the medium while a magnetic field applies a data signal to the spot, characterised in that the magnetic field signal is delayed relative to a synchronising signal to compensate for the non-zero size of the spot.
Claim 42
Independent Claim
62 words
A method or apparatus for recording information on a medium by a magneto-optic effect, in which a radiation beam illuminates a spot on the medium while a magnetic field applies a data signal to the spot, characterised in that the magnetic field is weakened towards the end of at least some data periods to compensate for the non-zero size of the spot.
Claim 43
Independent Claim
62 words
A method or apparatus for recording information on a medium by a magneto-optic effect, in which a radiation beam illuminates a spot on the medium while a magnetic field applies a data signal to the spot, characterised in that the magnetic field is weakened towards the end of at least some data periods to compensate for the non-zero size of the spot.
Claim 44
Dependent Claim
39 words
A method or apparatus according to claim 29 or claim 30 in which the extent of the said delay or weakening is varied in accordance with variations in one or more physical parameters of the circumstances of the recording.
Claim 45
Dependent Claim
34 words
A method or apparatus according to claim 31 in which the physical parameter comprises the temperature of the medium and/or the speed of relative movement between the medium and the position of the spot.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.