JP2005190630A - Optical disc drive and optical pickup start positioning method - Google Patents

Abstract

An optical disk drive capable of positioning an optical pickup at a desired start radius position with high accuracy without depending on dimensional accuracy of a stopper.
In order to move an optical pickup from a position in contact with a stopper to a start radius position where a signal can be read from a lead-in area on an optical disc, a value of a feed control amount stored in a nonvolatile memory is read. In the optical disc drive that drives the feed mechanism based on the read feed control value, the radial position on the optical disc when the optical pickup is moved by a predetermined feed control amount in the learning process using the reference disc is determined. Measure and obtain learning data of the feed control amount from this measurement value (or the average value of several measurement results). Based on this feed control amount learning data, the desired start radius from the position where the optical pickup is in contact with the stopper Move to position.
[Selection] Figure 2

Description

  The present invention relates to an optical disc drive apparatus that records or reproduces data on an optical disc and a start positioning method of an optical pickup.

  CD (compact disk) -R (Recordable), CD-RW (Read / Write), DVD (Digital Versatile disk) -RAM (Random Access Memory), DVD-R, DVD-RW, etc. When the disc tray loaded with the disc is inserted, the optical pickup is moved to the lead-in area on the disc. Subsequently, a signal is read out from the lead-in area, for example, various adjustments for focus servo and tracking servo, disc type (DVD-RAM revision number, etc.) and diameter recognition, write strategy data Acquiring etc.

  When positioning the optical pickup to the lead-in area on the disk, first, the optical pickup is pressed against a physical stopper provided on the inner peripheral side of the disk. Thereafter, the optical pickup is moved in the outer peripheral direction so as to reach the lead-in area by sending a certain amount of control pulses to a feed motor for transferring the optical pickup.

As this kind of known technique, there is, for example, Patent Document 1. In this patent document 1, a specific distance from the disk rotation center of the position where the optical pickup is moved is defined.
JP 2003-331436 A (paragraph 0008 etc.)

  However, due to the mechanical dimensional tolerance of the stopper, the position of the optical pickup at the start has a variation for each product. This variation becomes a problem particularly in the case of a DVD-RAM disk.

  That is, in the case of a DVD-RAM disc, between a BCA (Burst Cutting Area) area in which a barcode for CPRM (Content Protection for Recordable Media), which is information relating to copy restrictions, is engraved, and a wobble groove area as a user area Further, a control track corresponding to the lead-in area is provided, and the width of the control track in the radial direction of the disk is less than 0.5 mm. For this reason, high dimensional accuracy of the stopper has been required. However, there is a problem in that it is expensive to manufacture and attach a stopper with high dimensional accuracy.

  In view of such circumstances, the present invention provides an optical disc drive and an optical pickup start positioning method capable of positioning an optical pickup at a desired start radius position with high accuracy without depending on the dimensional accuracy of a stopper. To do.

  In order to solve the above problems, an optical disc drive of the present invention includes an optical pickup that irradiates an optical disc with a light beam and extracts a reflected light signal thereof, a feed mechanism that sends the optical pickup in a radial direction of the optical disc, A stopper for defining a limit position on the inner circumference side of the optical disc in the feeding direction of the optical pickup by the feeding mechanism; and for reading a signal from a predetermined area on the optical disc, the optical pickup is connected to the stopper. A storage unit that stores a feed control amount when the optical disc is moved from the contact position toward the outer periphery of the optical disc, and a moving position of the optical pickup on the optical disc when the feed mechanism is operated at a predetermined feed control amount Then, the predetermined feed control amount is corrected based on the measurement result, and the corrected feed control is corrected. The amount in which and a control unit for controlling so as to set in the storage unit.

  In this invention, the movement position of the optical pickup on the optical disk when the feed mechanism is operated with a predetermined feed control amount is measured, and the predetermined feed control amount is corrected based on the measurement result. The feed control amount thus set is set in the storage unit. When reading a signal from a predetermined area on the optical disk, the optical pickup is moved from the position in contact with the stopper toward the outer periphery of the optical disk according to the correction feed control amount stored in the storage unit. Thus, the optical pickup can be positioned with high accuracy at the intended start radius position without depending on the dimensional accuracy of the stopper.

  Further, the control unit uses the reference disc on which address information is recorded at least for each radial position as an optical disc for feed control amount learning, and controls the feed of the optical pickup when the optical pickup is moved by a predetermined feed control amount. The moving position of the optical pickup is measured by reading the address information on the optical disk for quantity learning.

  As a result, the movement position of the optical pickup on the optical disk when the optical pickup is moved by a predetermined feed control amount can be accurately measured.

  According to the optical disk drive and the optical pickup start positioning method of the present invention, the optical pickup can be positioned at an intended start radius position with high accuracy without depending on the dimensional accuracy of the stopper.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an optical disc drive according to an embodiment of the present invention.

  The optical disc drive 100 includes a system control unit 1 that controls the overall operation, a ROM 2 that stores a control program and various parameters of the system control unit 1 as firmware, and operations of the system control unit 1. It has a RAM 3 used as a region and a nonvolatile memory 21 such as a flash memory.

  The optical disc drive 100 has an optical pickup 4 for writing and reading information to and from the optical disc D. The optical pickup 4 condenses a light source including a laser light source, a four-divided photodetector, and the like, a laser emitted from the laser light source on the recording surface of the optical disc D, and detects light reflected from the recording surface of the optical disc D. It comprises an optical system (not shown) that leads to the light receiving surface of the device.

  The optical disk drive 100 includes a feed mechanism 5 including a feed motor that drives the optical pickup 4 in the radial direction of the disk, a disk motor 6 that rotates the optical disk D, and an actuator that supplies a drive signal to each of the motors. A driver 7 and a disk motor driver 8 are included.

  The optical disk drive 100 includes a servo controller 9 that performs processing for various servos such as tracking, focusing, and disk rotation speed.

  Further, the optical disk drive 100 includes an RF amplifier 10, a signal processing circuit 11, an error correction / descramble circuit 12, a parity generation / scramble circuit 13, a modulation / write strategy circuit 14, a wobble PLL circuit 15, and a laser in the optical pickup 4. A laser driving circuit 16 that drives the light source, a data buffer 17, a data buffer circuit 18 that controls reading and writing of data with respect to the data buffer 17, and the like are provided.

  The output of the optical detector of the optical pickup 4 is amplified to a signal of a level suitable for the subsequent processing by the RF amplifier 10 and sent to the signal processing circuit 11 and the wobble PLL circuit 15. The signal processing circuit 11 generates a focus error (FE) signal (FE detection), generates a tracking error (TE) signal (TE detection), generates a read clock by a PLL (Phase Locked Loop) (synchronous signal reproduction), RF This is a circuit that performs signal processing such as signal binarization (data slice), for example, demodulating 8-bit unit data from 8/16 modulated data.

  The wobble PLL circuit 15 generates, as a wobble signal, a difference signal for each radial half surface obtained from each output of the quadrant photodetector of the photodetector inputted through the RF amplifier 10, and uses the wobble signal for recording. This circuit generates a clock and an address on the optical disc D.

  The focus error signal and the tracking error signal generated by the signal processing circuit 11 are supplied to the servo controller 9, and the servo controller 9 controls the actuator driver 7 based on these error signals to perform the focus servo and the tracking servo. Do. The servo controller 9 is detected by, for example, the wobble clock generated by the wobble PLL circuit 15 or the signal processing circuit 11 so as to drive the optical disc D at a predetermined rotation speed designated by the system control unit 1. The disk motor driver 8 is controlled based on the synchronization signal.

  At the time of reading, the signal processing circuit 11 binarizes the RF signal and demodulates the 8/16 modulated data from the binarized data, thereby obtaining 8-bit unit data. This data is subjected to error correction and descrambling processing by the error correction / descrambling circuit 12, converted into data that can be handled by the host device, and temporarily stored in the data buffer 17 via the data buffer circuit 18. Thereafter, the data is transferred to an external host device in predetermined block units.

  At the time of recording, data transferred from an external host device is stored as data for recording in the data buffer 17 via the data buffer circuit 18. The data stored in the data buffer 17 is read out in predetermined block units by the data buffer circuit 18 and sent to the parity generation / scramble circuit 13. The parity generation / scramble circuit 13 adds parity for error correction and scramble processing to the recording data, and sends the data to the modulation / write strategy circuit 14. The modulation / write strategy circuit 14 modulates the 8-bit unit data subjected to the parity addition and the scramble with the recording clock generated by the wobble PLL circuit 15 using, for example, the 8/16 modulation method. A signal waveform for controlling the irradiation time of the recording laser beam is generated according to the modulation data. The generation of the signal waveform is performed based on the write storage parameters (for example, laser power value, laser irradiation time, irradiation timing, etc.) set by the system control unit 1. The signal waveform generated in this way is sent to the laser drive circuit 16. The laser drive circuit 16 generates a drive signal corresponding to the signal waveform from the modulation / write strategy circuit 14 and supplies it to the laser light source. As a result, the laser light source is driven, and pits are formed on the recording surface of the optical disc D.

  In addition, the optical disk drive 100 is transported between the optical disk D or a tray on which the optical disk D is mounted so that the user can hold the optical disk D and the position state where recording / reproduction is performed. A mechanism 19 for loading / unloading is provided.

  When receiving a signal indicating the completion of loading from the load / unload mechanism 19, the system control unit 1 can read the signal from the lead-in area on the optical disc D from the position where the optical pickup 4 is in contact with the stopper 20. In order to move to the position, the value of the feed control amount stored in the nonvolatile memory 21 is read, and control is performed so as to drive the feed mechanism (feed motor) 5 based on the read value of the feed control amount. .

  In the optical disk drive 100 of this embodiment, the optical pickup 4 is mounted on the basis of a learning program stored in the ROM 2 in order to absorb variations in the start radius position of the optical pickup 4 due to the dimensional tolerance of the stopper 20 and the like. The following learning correction is performed on the feed control amount for moving from the position in contact with the stopper 20 to the desired start radius position.

  FIG. 2 is a flowchart showing an operation flow for obtaining the learning data of the feed control amount.

  First, a reference disc for feed control amount learning is inserted (step 201). The reference disc may be any disc as long as address information is recorded so as to correspond to at least the disc radial position, and the address information can be reproduced by the optical disc drive 100. For example, a general CD-ROM can also be used. Is possible.

  When loading of the reference disk is completed by the load / unload mechanism 19, a signal indicating completion of loading is sent from the load / unload mechanism 19 to the system control unit 1. Upon receiving this signal, the system control unit 1 drives and moves the optical pickup 4 toward the inner peripheral side of the optical disc D and feed mechanism 5 including a feed motor until it hits the stopper 20 in accordance with the learning program (step 202). 203).

  Thereafter, the system control unit 1 drives the feed mechanism 5 including the feed motor by a predetermined feed control amount, and moves the optical pickup 4 from the position in contact with the stopper 20 to the outer peripheral side of the optical disc D (step). 204).

  Subsequently, the system control unit 1 activates the disk motor 6 (step 205), and starts reading signals from the optical disk D and reproducing address information (step 206). At this time, the system control unit 1 replaces the address information first reproduced from the optical disk D with the radial position on the optical disk D (step 207), and stores the result in the RAM 3.

  The same processing is repeated a specified number of times (step 208), each time an average value of the obtained radial positions on the optical disc D is obtained (step 209), and the optical pickup 4 is operated based on the obtained average value of the radial positions. The correct feed control amount for moving from the position in contact with the stopper 20 to the desired start radius position is calculated (step 210), and the correction result of this feed control amount is recorded in the nonvolatile memory 21 as learning data ( Step 211).

  Here, in order to obtain a feed control amount correction result with higher accuracy, the feed control amount of the optical pickup 4 is corrected from the average value of each radial position repeatedly calculated a plurality of designated times using the reference disk. Although the result is calculated, the correction result of the feed control amount of the optical pickup 4 may be calculated from the calculation result of one radial position.

  Next, when the optical pickup 4 is moved from the position in contact with the stopper 20 to the intended start radius position on the disk D based on the learning data of the feed control amount of the optical pickup 4 recorded in the nonvolatile memory 21. The operation will be described.

  FIG. 3 is a flowchart showing an operation flow when the optical pickup is moved to the intended start radius position on the disk based on the learning data.

  First, the optical disk D is inserted (step 301). When loading to the position state where recording / reproduction is performed by the load / unload mechanism 19 is completed, a signal indicating the completion of loading is sent from the load / unload mechanism 19 to the system control unit 1. Upon receiving this signal, the system control unit 1 drives and moves the optical pickup 4 to the inner peripheral side of the optical disk D until it contacts the stopper 20 (steps 302 and 303).

  Next, the system control unit 1 reads learning data that is a correction result of the feed control amount of the optical pickup 4 from the nonvolatile memory 21 (step 304), and drives the feed mechanism 5 including the feed motor by the feed control amount. Then, the optical pickup 4 is moved from the position in contact with the stopper 20 toward the outer periphery of the optical disc D (step 305).

  Thereafter, the system control unit 1 starts reading signals from the control track, which is the lead-in area on the optical disc D, and performs various adjustments for focus servo and tracking servo, and the type of the optical disc D (DVD-RAM Revision number, etc.), diameter recognition, acquisition of write strategy data, etc. (step 306).

  As described above, after the initial operation in the optical disc drive 100 is completed, the disc activation processing for accessing the user area is started (step 307).

  According to the optical disk drive 100 of the present embodiment described above, the optical pickup 4 is positioned with high accuracy from the position in contact with the stopper 20 to the intended start radius position without depending on the dimensional accuracy of the stopper 20. Can do. As a result, the cost for manufacturing and attaching the stopper 20 can be reduced, and the initial operation time can be shortened by making it difficult for a retry to occur in reading a signal from a lead-in area such as a control track.

  In particular, the start positioning method of the optical pickup 4 of this embodiment is effective in the optical disc drive 100 that handles an optical disc having a very narrow control track such as a DVD-RAM disc.

  FIG. 4 shows the positional relationship in the disc radial direction between the BCA area 41, the control track 42, and the wobble groove area 43 in the inner periphery of the DVD-RAM disc. Since the control track 42 does not move to an area having a width of only about 0.5 mm between the BCA area 41 and the wobble groove area 43, whether or not the optical pickup 4 can be correctly moved to the intended start radius position is determined. Until now, it has largely depended on the dimensional accuracy of the stopper 20.

  On the other hand, in the optical disc drive 100 of the present embodiment, the radial position on the optical disc D when the optical pickup 4 is moved by a predetermined feed control amount is measured in the learning process using the reference disc, and this measurement is performed. Learning data of the feed control amount is obtained from the value (or the average value of several measurement results), and the optical pickup 4 is moved from the position in contact with the stopper 20 to the desired start radius position based on the learning data of the feed control amount. By doing so, the optical pickup 4 can be accurately moved to the desired start radius position even for the narrow control track 42 having a width of about 0.5 mm.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

  In the above-described embodiment, the learning of the feed control amount for moving the optical pickup 4 from the position in contact with the stopper 20 to the lead-in area (control track) has been described. However, it is necessary to move the optical pickup 4 initially. The present invention can also be applied to learning of a feed control amount when the optical pickup 4 is moved from a position in contact with the stopper 20 to an area other than the lead-in area (control track) in a certain area. .

1 is a diagram illustrating an overall configuration of an optical disc drive according to an embodiment of the present invention. 6 is a flowchart showing a flow of an operation for obtaining learning data of a feed control amount for moving the optical pickup to an intended start radius position in the optical disk drive of the present embodiment. The flowchart showing the flow of operation when the optical pickup is moved to the desired start radius position on the disk based on the learning data of the feed control amount of the optical pickup recorded in the nonvolatile memory in the optical disk drive of this embodiment. It is. It is a figure which shows the positional relationship of the disc radial direction with the BCA area | region, control track, and wobble groove area | region in the disk inner peripheral part of a DVD-RAM disk.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... System control part, 2 ... ROM, 3 ... RAM, 4 ... Optical pick-up, 5 ... Actuator, 6 ... Disc motor, 7 ... Actuator driver, 8 ... Disc motor driver, 9 ... Servo controller, 10 ... RF amplifier, 11 Signal processing circuit 12 Error correction / descrambling circuit 13 Parity generation / scramble circuit 14 Modulation / write strategy circuit 15 Wobble PLL circuit 16 Laser drive circuit 17 Data buffer 18 Data Buffer circuit, 19: Load / unload mechanism, 20: Stopper, 21: Non-volatile memory, 100: Optical disk drive, D: Optical disk.

Claims (6)

An optical pickup that irradiates an optical disk with a light beam and extracts a reflected light signal;
A feeding mechanism for sending the optical pickup in the radial direction of the optical disc;
A stopper that defines a limit position on the inner circumference side of the optical disc in the feeding direction of the optical pickup by the feeding mechanism;
A storage unit for storing a feed control amount when moving the optical pickup from a position in contact with the stopper in the outer circumferential direction in order to read a signal from a predetermined area on the optical disc;
The movement position of the optical pickup on the optical disk when the feed mechanism is operated at a predetermined feed control amount is measured, and the predetermined feed control amount is corrected based on the measurement result. An optical disc drive comprising: a control unit that performs control so as to set a feed control amount in the storage unit.   The control unit uses a reference disc on which address information is recorded at least for each radial position as an optical disc for feed control amount learning, and moves the optical pickup by the predetermined feed control amount. 2. The optical disc drive according to claim 1, wherein the moving position of the optical pickup is measured by reading address information on the optical disc for feeding control amount learning.   3. The optical disk drive according to claim 1, wherein the predetermined area on the optical disk is a lead-in area. A feeding mechanism for feeding the optical pickup in the radial direction of the optical disc, a stopper for defining a limit position on the inner circumference side of the optical disc in the feeding direction of the optical pickup by the feeding mechanism, and reading of a signal from a predetermined area of the optical disc To store the optical pickup, a storage unit for storing a feed control amount when moving the optical pickup from the position in contact with the stopper in the outer peripheral direction of the optical disc is provided,
Measuring the movement position of the optical pickup on the optical disc when the feed mechanism is operated with a predetermined feed control amount;
Correcting the predetermined feed control amount based on the measurement result;
And a step of setting the corrected feed control amount in the storage unit.   Learning the feed control amount of the optical pickup when the optical pickup is moved by the predetermined feed control amount using a reference disc on which address information is recorded at least for each radial position as an optical disc for feed control amount learning 5. The start positioning method of an optical pickup according to claim 4, wherein the moving position of the optical pickup is measured by reading address information on an optical disc for use.   6. The optical pickup start positioning method according to claim 4, wherein the predetermined area on the optical disc is a lead-in area.

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