Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
  • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B21/00—Head arrangements not specific to the method of recording or reproducing
  • G11B21/02—Driving or moving of heads
  • G11B21/10—Track finding or aligning by moving the head ; Provisions for maintaining alignment of the head relative to the track during transducing operation, i.e. track following
  • G11B21/106—Track finding or aligning by moving the head ; Provisions for maintaining alignment of the head relative to the track during transducing operation, i.e. track following on disks
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
  • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
  • G11B7/0946—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for operation during external perturbations not related to the carrier or servo beam, e.g. vibration

Definitions

• the present invention relates to a disk-shaped recording medium (hereinafter referred to as a disk) that is driven to rotate, and to a tracking control device of a recording disk reproducing apparatus that reproduces information recorded one after another by pick-up means.
• the pickup means is used to scan information tracks on a disc with good tracking performance, and to keep the tracking performance stable against external impacts. It is composed.
• Fig. 1 is a diagram illustrating the principle of a servo system that uses three beams, which is one type of tracking disc on an optical disc that obtains a reproduced signal using an optical beam.
• T 2 Ts is the information collected by racks of de Lee disk
• 2 is read] 9 optical beam, 1 and 3 in the auxiliary bi chromatography beam for preparative rats key in g signal detector A] 9.
• the tracking signal 4 shown in Fig. 1 can be obtained.
• Remind as in FIG. 1 3 ⁇ 4 preparative rats King signal 4 is obtained.
• Range ⁇ bets rats King signal 4 the beam 1, 2, 3 force S preparative rats indicates that scanning the click T 2, the range of ⁇ is. DOO rack T 2 and the This corresponds to scanning between spaces.
• FIG. 1 shows the configuration of the tracking servo. 1 ⁇
• the Day scan click, 1 1 a motor for rotating the disk 1 0, 1 2 read Les emission's, 1 3 source Der! ), Irradiate the tracking auxiliary beams 1, 2 , and 3 shown in Fig. 1 onto the disc 1 ⁇ with the diffraction grating 14 ⁇ 15 is a beam splitter and 16 is a beam splitter. It is a racking mirror!
• the position of the light beam is controlled so that the reading light beam focused on the lens 1 2 is always kept on the track of the disk 1).
• Numerals 1 and 18 denote optical detectors for receiving the reproduced output of the auxiliary beams 1 and 3 in FIG. 1, respectively.
• the output of the differential amplifier 19 and the tracking signal 4 in FIG. ⁇ 20 is an equalizer, which is a filter to optimize the characteristics of the tracking servo system.
• an equalizer which is a filter to optimize the characteristics of the tracking servo system.
• the eccentricity of the disk 1 ⁇ has a harmonic component whose fundamental wave is 3 ⁇ .
• the King Mirror 16 follows the eccentricity and always moves the reading optical beam 2 shown in Fig. 1 to the information track of the disk 1 1. Therefore, it is necessary to cover at least the eccentric total harmonic component in at least the tracking servo band because it is necessary to move the scanning servo.
• Fig. 3 shows a block diagram of the tracking servo system described in Fig. 2.
• R is a signal indicating the position of the disc information track.
• C is a signal indicating the position of the reading light beam! ),
• the Figure 4 a shows the Lee co riser and preparative rats Kingumi error, and third frequency characteristic, DG amplifier (J 2 is for simplicity of explanation, the frequency characteristic is off rats.
• Fig. 4b shows the open-loop characteristics of the block diagram shown in Fig. 3, where ⁇ is the open-loop gain.
• FIG. Fig. 5 corresponds to Fig. 1!
• the center line of the information collected by rack is 2, is represented by T 5.
• the areas ⁇ and ⁇ in Fig. 1 correspond to the areas ⁇ and ⁇ in Fig. 5.
• the reading light beam 2 power; track ⁇ 2 is scanned in the direction of arrow 5 by a tracking servo. 6 indicates a defect on the track.In this defect 6 part, the switch SW in Fig. 3 is cut off and the tracking servo malfunctions. Jump in the direction of the arrow or 8 depending on the special resident of Sabo. At this time
• the present invention has been proposed in view of this point, and is stable against a defect of a disc information track and sufficiently stable against disturbances such as vibration to a disc breaker.
• D is used for the purpose of the present invention.
• the reproducing apparatus includes a pickup means for reproducing an information signal and an information track on a disk driven in rotation, and a track corresponding to a relative position between the pickup means and the information track. Means for generating a tracking control signal; pickup driving means for displacing the pickup means in accordance with the tracking control signal; and output corresponding to the displacement of the pick-up means. It has means for detecting, and means for returning a detection power corresponding to the displacement amount to the pick-up driving means.
• Fig. 1 shows the relationship between the irradiation position of the optical beam irradiated on the information track and the tracking control signal.
• Fig. 2 shows the basics of a conventional tracking control device.
• Fig. 3 is a block diagram illustrating the configuration, Fig. 3 is a block diagram for explaining the operation, Fig. 4a is a characteristic diagram for explaining the operation, and Fig. 5 is a tracking diagram.
• Fig. 6 is a block diagram showing the basic configuration of the tracking control device of the present invention, Fig. 6A is a side sectional view of the essential parts, and Fig. 6B is the same part.
• FIG. 8 is a block diagram of an embodiment of the tracking control device of the present invention.
• FIG. E shows a configuration diagram of an embodiment of the present invention. Blocks having the same reference numerals as those in FIG. 2 are the same as those in FIG.
• the optical detectors 1 and 18 receive the reflected light from the disk of the tracking optical beam shown in 1 and 3 in Fig. 1. Input.
• a tracking signal is obtained at the output of the first differential amplifier 19.
• the tracking signal is applied to one input terminal 32 a of the second differential amplifier 32 after optimizing the response characteristics of the tracking servo by the equalizer 20. It is input and drives the tracking mirror 16 via the drive amplifier 31.
• the angle detector 3 O in preparative rats Kin grayed Mi La one 1 6 runout ⁇ is ⁇ .
• the angle of the tracking mirror 16 is controlled such that the output of the angle detector 30 also reaches 17. If this time. Disturbance such as vibration is applied to the tracking mirror 16 . If the angle fluctuates, the optical detectors-1, 18, 1st differential amplifier 19, equalizer 20, 2nd differential amplifier 32, drive Amplifier 31, tracking mirror 16] 9-tracking servo-motor open-loop gain G 10 and angle detector 30, 2nd differential amplifier 3 2 of the drive a down-flops 31, door rats key in g mirror 1 6! ) Due to the configured position servo system's open loop gain & 1 ⁇ ];), a restoring force is generated and attempts to counter the disturbance.
• FIG. 7 shows a pickup device in which the reading and the ?? lens 12 and the tracking mirror 16 in FIG. 6 are integrated.
• 4 1 reads and Contact this optical system tube 4 O attached taken in the optical system barrel 4 O in Les emission figure 3 ⁇ 4 by the support shaft 4 2 to the action of an annular magnetic circuit 4 6 and Coil le 4 4 Move in the direction of ⁇ and read! )
• Lens 1 reads and Contact this optical system tube 4 O attached taken in the optical system barrel 4 O in Les emission figure 3 ⁇ 4 by the support shaft 4 2 to the action of an annular magnetic circuit 4 6 and Coil le 4 4 Move in the direction of ⁇ and read!
• the rotation angle of the optical cylinder 4 mm can be detected as a voltage value. That is, this voltage value corresponds to the output of the angle detection means 30 in FIG.
• FIG. 8 shows a block diagram of an embodiment of the present invention.
• Fig. 8 corresponds to Fig. 6]>
• the output of the 15 beam splitter: light is read through a fixed mirror of 16F]) incident on lens 41 * Irradiates on the disc 1 O track.
• Disk 1 O of the reflected light is fixed Mi La one 1 6 F, bi one beam Splitter 1 5 via the optical de te Selector Selector - 1 ⁇ enters a 1 8, the first differential A down-flop 1 Input to 9 to operate the above-mentioned tracking servo.
• a current of about SO fflz is applied to the coil 52 shown in Fig.
• a DC signal indicating the rotation angle change of 41 is obtained. That is, 30a,
• the angle detector 3 O is configured.
• the output of the differential amplifier 30 C is input to the second differential amplifier 32, and is input to the tracking and drive coil 45 via the amplifier 31.
• Doo rats key in g error signal of the first differential A down-flops 1 9 is input to the I co-La Adviser one 2 ⁇ through the second differential amplifier 3 2. If the two inputs of the second differential amplifier 32 are 32a and 32b, the voltage of 32b operates so that it always matches the tracking error signal of 3233 While the tracking sensor is moving, the voltage at 32a and the voltage at 32b are almost equal.
• a magnetic circuit is used as an element for detecting the position in the tracking direction, but it is also possible to detect optically! ), 'It can also be used for any type of pickup device as long as it can detect the displacement in the tracking direction.
• the tracking direction (Shown by B in the figure) has no sensitivity such as springs, but has a large neutral point. * The position of the reading lens in the rotation direction is not fixed. However, in the present invention, since the position servo system is added, the above neutral point can be electronically determined. This is also an advantage of the present invention.
• the magnetic circuit 50 for detecting the position in the tracking direction shown in FIG. 7 detects the displacement in the direction of arrow B without error even when the optical system tube 4 O is displaced in the direction of arrow A. It is configured so that the magnetic material 49 always exists within the operating range for the magnetic circuit 5 O 0

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• Optical Recording Or Reproduction (AREA)
• Moving Of The Head To Find And Align With The Track (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=12234092

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (8)

Citations (4)

Family Cites Families (20)

• 1983
  • 1983-02-22 JP JP58027912A patent/JPS59154677A/ja active Granted
• 1984
  • 1984-02-22 DE DE8484900885T patent/DE3485307D1/de not_active Expired - Lifetime
  • 1984-02-22 WO PCT/JP1984/000065 patent/WO1984003387A1/ja active IP Right Grant
  • 1984-02-22 US US06/667,485 patent/US4799206A/en not_active Expired - Lifetime
  • 1984-02-22 EP EP84900885A patent/EP0145787B1/en not_active Expired

Patent Citations (4)

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