KR20100112702A - Method for recording optical disc and optical disc apparatus - Google Patents

Abstract

PURPOSE: An optical disc recording method and an optical disc device are provided to accurately compensate for a transfer error of a sled motor when a label is printed on a disc. CONSTITUTION: An optical disc recording method comprises the following steps. A movement error for each step in which a location error of an objective lens when measuring a movement error of a sled motor is compensated is checked. A label is recorded on a label surface of an optical disc while compensating for the checked movement error by an actuator. A location error of an objective lens is compensated based on an actuator operating value when sensitivity of the actuator and a movement error for each step of the sled motor are measured.

Description

Method for recording optical disc and optical disc apparatus

The present invention relates to an optical disc recording method, and more particularly, to a method of reducing a transfer error that occurs when an optical pickup is moved outward when recording a label on a label recording disc.

Label recording discs and optical disc devices, such as Light Scribe discs, which are capable of label printing on the opposite side of the data side on which data is recorded, are becoming popular. The side on which a label is printed on a label recording disc is called a label side.

On the data side of the recording optical disc, lands / grooves for performing the tracking servo operation are formed in the data recording process, and ATIP information for detecting the current position is recorded in the form of a wobble land / groove. Accordingly, the optical disc recording apparatus may perform a tracking servo operation by a feedback method using a push-pull signal generated from a land / groove, determine a current position based on ATIP information, and randomly access a desired position. Can be.

However, since the tracking servo and the wobble land / groove for random access are not formed on the label surface of the label recording disc, the tracking servo by the feedback method is impossible based on an error signal such as a push-pull signal. Random access to the location is also impossible. Only the labels can be recorded sequentially from the inner circumference to the outer circumference of the disc in a feed forward manner.

Since the movement from the inner circumference to the outer circumference is due to the movement of the sled motor and the movement of the tracking actuator, the label printing on the label side is sensitive to the dynamics characteristic of the actuator of the sled mote and the optical pickup with respect to the tracking servo. Have no choice but to. In particular, when the optical pickup is moved to the outer periphery, the unprinted blank or the overprinting of the label may occur due to the transfer error generated from the sled motor, thereby degrading the recording quality.

However, the conventional optical disk device does not correct the feed error of the sled motor, or even if the accuracy of the measurement of the position of the data plane in the process of checking the feed error of the sled motor is corrected, even if it is corrected. There was not much effect.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a method for improving the label printing quality of a label recording disk.

A specific object of the present invention is to provide a method for accurately compensating for a transport error of a sled motor generated when a label is printed on a label recording disk.

In the optical disk recording method according to an embodiment of the present invention for achieving the above object, to determine the movement error for each step of correcting the position error of the objective lens generated when measuring the movement error of the sled motor Making; And recording the label on the label side of the optical disc while compensating for the identified movement error through an actuator for moving the objective lens in and out.

In the above embodiment, the position error of the objective lens may be corrected based on an actuator driving value checked when measuring the sensitivity of the actuator and the movement error for each step of the sled motor. In this case, the sensitivity may be calculated based on the position detected in the state where the objective lens is moved in the inner and outer circumferential directions and the driving value of the actuator, respectively, and the sensitivity is the position and the driving of the objective lens near the center of the optical pickup. The value is further measured and based on this, the sensitivity in the inner circumferential direction and the sensitivity in the outer circumferential direction can be calculated separately, and the sensitivity can also be calculated based on the drive value detected at the same circumferential position of the disc.

In the above embodiments, when compensating for the movement error, when the objective lens is sequentially moved in the outer circumferential direction, or when the objective lens is moved in the inner circumferential direction after step movement by a sled motor, the actuator The calculated sensitivity can be applied.

In this embodiment, the movement error can be detected in the manufacturing process of the optical disk device and stored in the memory of the optical disk device, and can be updated periodically while using the optical disk device.

An optical disc apparatus according to another embodiment of the present invention includes an optical pickup for reading data from an optical disc data side and recording data on the data side or label side of the optical disc; A sled motor for moving the optical pickup in and out; A memory for storing a movement error for each step of correcting a position error of an objective lens generated when measuring a movement error of a sled motor; And a control unit which checks a movement error for each step from the memory and controls to write a label on the label side of the optical disc while compensating the identified movement error through an actuator for moving the objective lens in and out. It is characterized by.

Thus, when recording a label on the label side of the optical disk, a transfer error caused by the sled motor can be reduced, thereby improving the recording quality of the label.

EMBODIMENT OF THE INVENTION Hereinafter, an optical disc recording method and an optical disc apparatus which concern on this invention are demonstrated in detail based on attached drawing.

In the label recording disc, a saw-teeth area is allocated in the Control Feature Outer Ring (CFOR) area. The CFOR region is formed on the label surface in the shape of a circular band having a width of 650 um, and the tooth region is divided into two regions facing each other in the CFOR region in consideration of the eccentricity of the disk.

In the saw tooth region, a portion having a high reflectance and a portion having a low reflectance are engaged with each other in a triangular sawtooth shape. If the disk is rotated with the laser beam centered in the CFOR region, the duty ratio of the reflected signal is 50%. However, when the disk is rotated while applying a predetermined voltage to the actuator in the track direction to bias the objective lens in the inner circumferential direction or the outer circumferential direction, i.e., the laser beam is rotated in the inner circumferential direction or the outer circumferential direction from the center of the CROF region, The duty ratio of the resulting signal is lower or higher than 50%.

Accordingly, the optical disc apparatus capable of label recording measures the actual sensitivity of the track direction actuator in this manner, that is, the magnitude of the voltage to be applied to the actuator in order to move the outer periphery by a predetermined distance, and based on the feed forward method Perform the tracking servo.

In connection with moving the objective lens for recording the label on the label side of the optical disk, a feed forward tracking servo by movement in the outer circumferential direction of the actuator supporting the objective lens and the movement of the sled motor will be briefly described.

In order to print the labels in order from the inner circumference to the outer circumference of the label zone of the optical disk, the optical disk apparatus largely moves the entire optical pickup by a predetermined distance to the outer circumference by a predetermined distance using a sled motor. Slowly move the actuator supporting the objective lens to the outer circumference.

As the objective lens deviates from the center of the optical pickup toward the inner or outer circumferential direction, the optical electrical performance of the optical pickup decreases. Therefore, when the objective lens is moved outward from the center of the optical pickup by a predetermined distance, the sled motor is driven to move the entire optical pickup in the outer circumferential direction. During the center of the optical pickup or in the inner circumferential direction of the optical pickup.

For example, if the optical performance is significantly degraded to the extent that the objective lens is inward or outward from the center of the optical pickup by 100um, the entire optical pickup must be moved when it is inclined inward or outward by less than 100um, for example 75um. . In this case, the minimum unit by which the sled motor can move the optical pickup may be determined to be 150um, which is twice the 75um. That is, when the objective lens is shifted by 75um in the circumferential direction, the sled motor moves the entire optical pickup 150um in the circumferential direction, and simultaneously drives the actuator to move the objective lens based on the current position of the objective lens in the optical pickup. Direction (150um-track pitch) (75um-track pitch) from the center of the optical pickup. That is, when the actuator is deviated in the outer circumferential direction by a predetermined distance, the entire optical pickup must be moved to the outer circumference by the minimum unit and the actuator must also be moved in the inner circumferential direction.

1 is a configuration of an optical disk apparatus including an optical pickup including an actuator for moving an objective lens and a sled motor for moving the objective lens. As shown in FIG. 1, the sled motor is composed of a mechanism device that transmits the rotational motion of the stepper motor and the stepper motor in a linear motion, and typically includes an angular error of the frame / yoke value and an uneven internal diameter of the frame / yoke value. Step errors can occur due to mechanical factors, such as unevenness between winding resistance, inductance, and unbalance of magnetic flux generated on each tooth surface.

Even if the optical disk device configured as shown in Fig. 1 compensates the dynamic characteristics of the actuator by the operation in the tooth area of the label recording disk, the transfer generated from the sled motor when the optical pickup is moved to the outer periphery. If the error is not properly compensated for, as shown in FIG. 2, blanks without labels may be generated or overprinted.

Therefore, in order to prevent deterioration of the label print quality such as stripe, the transport error can be detected and stored for each step of the sled motor and the label can be printed by compensating the stored transport error through the actuator. In order to do this, the sled motor is driven in units of steps on the data side of the disk on which the data is recorded, and the transfer error for each step can be obtained by reading the address while converting the pick-up to a radius.

FIG. 3 shows an equation for reading an address (PSN: Physical Sector Number) on the recording side of an optical disc, for example, a DVD-ROM, and converting it into a radius of the disc.

The radius r (x) at the position where PSN is x is calculated as ((S (x) + S (0) / π) ^ (1/2), where S (0) is LBA (Logical Block Address) 0h (PSN 30000h) The area of the circle to position r (s) is πxr (s) ^ 2, and S (x) is the area of the donut between r (s) and r (x) (xpsn 0 x 30000) x Sa, Sa is an area of one sector (um ^ 2).

The optical disk device may drive the sled motor in units of one step to read the address at the moved position while moving the optical pickup in the circumferential direction, and obtain the radius corresponding to the read address using the above equation.

In order to find the exact transport error of the sled motor, it is necessary to read the address when the objective lens is in the center of the optical pickup at the position where the optical pickup is stepped by the sled motor. However, as shown in FIG. 4, when the tracking servo is turned on to read the address of the optical disk, the optical lens moves in the X direction (internal and circumferential directions) to follow the track, so that the objective lens is located at the center position instead of the center position of the optical pickup. You may be tracking on at a slightly off-site location and reading the address from that location. Therefore, the center position of the optical pickup can be known only by correcting the moving distance of the objective lens moved in the X direction at this time.

To correct the degree of deviation of the objective lens of the optical pickup from the center of the optical pickup, the tracking actuator of the optical pickup is moved as shown in FIG. The position value refers to a position converted from an address of a disc read out from the shifted position, and the actuator driving value indicates a voltage applied to the tracking actuator while shifting the objective lens.

As shown in FIG. 5, the ratio R of the difference between the position values L_left and L_right after the objective lens shift and the tracking actuator driving values D_left and D_right can be obtained. ) Is used to eliminate the positional error of the objective lens when the actual position is obtained after the sled movement.

R = (L_left L_right) / (D_left D_right)

The position error of the objective lens generated when reading the address can be corrected by stepping the optical pickup by driving the sled motor, reading the address, measuring the actuator driving value at this time, and multiplying the ratio obtained above.

The actual position = L_current D_current x R, where the actual position refers to the center position of the optical pickup (the center position of the objective lens when zero voltage is applied to the tracking actuator), and L_current is the position value converted from the read address. , D_current indicates the voltage applied to the current actuator.

Therefore, while driving the pickup by driving the sled motor in steps, the tracking servo is turned on at each movement position to read the address, and the voltage applied to the actuator at this time is obtained to calculate the actual position value of the movement position using the above equation. You can get it.

Theoretically, the same distance is moved for each step driving, but the moving distance for each step may be changed by the mechanical and electrical factors of the above-described step motor. Therefore, it is necessary to find the step error, which is the difference between the theoretical moving distance (same for all steps) and the actual moving distance for all the steps required to rotate the step motor one revolution. The actual moving distance for each step can be obtained from the actual position for each step obtained above, and this can be compared with the theoretical moving distance to obtain a transfer error for each step.

When the optical pickup is moved step by step while printing the label on the label surface of the disc, the transfer error for the step movement can be checked and the transfer error confirmed through the tracking actuator can be compensated.

In this way, when calculating the transfer error for each step, by reading the address of the data plane, the degree of deviation of the objective lens from the center of the optical pickup is more precisely corrected. The fall can be prevented.

The optical disc recording method according to the present invention can be applied to a disc recording apparatus capable of recording a label on a disc for label recording. FIG. 6 shows an embodiment of the configuration of an optical disc apparatus to which the present invention is applied. .

The optical disk apparatus according to the present invention includes an optical pickup 20, an optical driver 21, a spindle motor 23, a sled motor 25, a channel bit encoder 30, a digital recording signal processor 40a, and a digital device. The reproduction signal processor 40b, the R / F unit 50, the servo unit 60, the driving unit 70, the control unit 80, the memory 90 and the like can be configured.

The digital recording signal processor 40a adds an error correction code (ECC) or the like to the digital data to be converted into a recording format, and the channel bit encoder 30 reconverts the data converted into the recording format into a bit stream. The optical driver 21 outputs a light quantity driving signal according to the input signal, and the optical pickup 20 records data on the data surface of the optical disk 10 in accordance with the light quantity driving signal and further includes an optical disk ( Read data from the data side of 10).

The R / F unit 50 filters the signal detected by the optical pickup 20 to output a binary signal by shaping the filter, and also generates and outputs a tracking error signal TE, a focus error signal FE, and an RF signal. The digital reproduction signal processor 40b restores the binary signal to the original data using its own clock synchronized with the binary signal, and the servo unit 60 receives the signal from the R / F unit 50. Generates servo signals necessary for focusing servo, tracking servo, sled servo, and spindle servo, and the driving unit 70 drives the spindle motor 23 for rotating the optical disk 10 and the optical pickup 20. Drive the sled motor 25 to move in the inner and outer circumferential direction, and drive the current required for the focusing servo and tracking servo of the objective lens in the optical pickup 20.

The control unit 80 controls each element to write data to or read data from the optical disc. The optical drive unit 21 controls the optical pickup to read data from the optical disc 10. The laser diode in 20 is driven with reproducing power or the laser diode is driven with recording power for recording data on the optical disc 10.

In addition, the controller 80 controls the servo unit 60 and the driver 70 based on the RF signal and the servo signal detected by the optical pickup 20 and output from the R / F unit 50. Control, driving the spindle motor 23 to rotate the disk 10 at a desired speed, driving the spindle motor 25 to move the optical pickup 20 to a desired position, and also the optical pickup 20 A current is applied to the actuator supporting the objective lens in the lens to perform the focusing servo and the tracking servo.

When recording a label on the label surface, the digital recording signal processing unit 40a converts the label recording data into a label recording format, and the channel bit encoder 30 can bypass the converted label data. The controller 80 controls the servo unit 60 and the driving unit 70 to perform a focusing servo in a feedback manner, and the rotation of the disk, the movement of the sled motor 25, and the movement of the tracking actuator are performed. Control by feed forward method.

The control unit 80 controls the servo unit 60 and the driving unit 70 to drive the tracking actuator of the optical pickup 20 to shift the objective lens in the inner and outer circumferential directions as described in FIG. 5. Read the address at each shifted position, calculate the position of the shifted objective lens therefrom, check the voltage applied to the tracking actuator while the objective lens is shifted, and calculate the sensitivity of the tracking actuator based on this. This is stored in the memory 90.

At this time, the voltage applied to the tracking actuator at the inner and outer circumference at the same rotation angle (or circumferential position) of the disk can be checked or the address can be read out so as to exclude the influence of the disk eccentricity. Since 23 pulses can generate 20 pulses from 0 to 19 in one rotation, checking the voltage applied to the tracking actuator when the same number of pulses occurs can reduce the influence of the disk eccentricity.

In addition, the controller 80 may calculate the sensitivity of the tracking actuator by dividing the sensitivity of the inner circumferential direction and the sensitivity of the outer circumferential direction. For this purpose, the objective lens is shifted to the inner circumference and the outer circumference to read an address, and also an optical pickup. In the vicinity of the center of 20, the tracking servo is turned on, and at this time, the voltage applied to the actuator is checked and the address is read, and the sensitivity in the inner circumferential direction and the sensitivity in the outer circumferential direction can be calculated based on this.

In addition, the control unit 80 controls the servo unit 60 and the driving unit 70 to turn on the focusing servo and turn off the tracking servo by one step to the sled motor 25. Input the drive signal to move the optical pickup 20 to the outer periphery, turn on the tracking servo at each moved position to detect the address at that position, and the radius at that position using the equation described with reference to FIG. In this case, when the address is detected, the voltage applied to the tracking actuator is checked, and using the obtained radius and sensitivity, the center position of the optical pickup 20 (when zero voltage is applied to the tracking actuator) The actual radius of the center of gravity).

The controller 80 repeats the above process a predetermined number of times or more to obtain an actual position and an actual moving distance according to each step input, and calculates an error (difference between the theoretical moving distance and the actual moving distance) for each step. Can be obtained and stored in the memory 90.

When the label is recorded on the label surface of the disc, the controller 80 checks the sensitivity of the tracking actuator from the memory 90 and the error of the movement distance for each step, and the servo unit 60 and the driver unit. 70, the tracking actuator is driven by applying the identified sensitivity to move the objective lens to the outer circumference, and when the optical pickup 20 moves to the outer circumference, moves to the inner circumference as necessary, and the sled motor 25. When the optical pickup 20 is moved to the outer periphery, the transfer error for each identified step is compensated by the tracking actuator.

7 is a flowchart illustrating an operation of an optical disk recording method according to an embodiment of the present invention.

When the optical disk 10 is seated, the controller 80 of the optical disk device checks whether the seating surface of the optical disk 10 is a data surface and recognizes a disk (for example, a DVD-ROM) (S701). This is because address information on the data side of the optical disc 10 is required to detect the sled travel distance for each step. If the optical disc 10 is recognized as a DVD-ROM, for example, the controller 80 may drive the optical pickup 20 through the servo unit 60 and the drive unit 70 to the optical disc 10. It moves to a predetermined initial position of the image (for example, LBA 0h or PSN 30000h) near (S702).

The controller 80 controls the servo unit 60 and the drive unit 61 to drive the tracking actuator of the optical pickup 20 to shift the objective lens in the inner circumferential direction to measure the voltage applied to the tracking actuator. And read the address to calculate the first position therefrom, and also shift the objective lens in the circumferential direction to measure the voltage applied to the tracking actuator, and also read the address to calculate the second position therefrom, from which the tracking actuator The sensitivity is calculated and stored in the memory 90 (S703).

Thereafter, the controller 80 controls the servo unit 60 and the drive unit 61 to turn on the tracking servo (S804), read address information from the position on the moved optical disk 10, and At this time, the voltage applied to the actuator is measured (S705). The control unit 80 calculates the position (radius information) on the disk of the objective lens included in the optical pickup 20 based on the read address information (S706).

Since the position (position of the objective lens) in the tracking direction of the actuator changes little by little each time the tracking servo is turned on, the controller 80 corrects the position error of the objective lens to correct the actual position of the optical pickup 20. (The center position of the objective lens when zero voltage is applied to the tracking actuator) (S707), wherein a value obtained by subtracting the product of the voltage obtained in step S705 and the sensitivity obtained in step S703 is calculated from the position calculated in step S706. The actual position of the optical pickup 20 can be calculated.

Thereafter, the control unit 80 turns off the tracking servo and applies a driving voltage corresponding to one step to the sled motor 25 through the servo unit 60 and the drive unit 61, thereby transmitting the sled. The motor 25 is rotated by an angle corresponding to one step, and thus the optical pickup 20 is moved outwardly by a distance corresponding to one step from the initial position (S708).

The control unit 80 repeats the process of obtaining the actual position (radius) of the optical pickup 20 moved from the position where the optical pickup 20 is moved through the steps S704 to S707 and again moving by a distance corresponding to one step. In order to sufficiently obtain the moving distance according to each step input, the predetermined number of times or more are repeated (S709). If the sled motor 25 is to be rotated once, for example, 16 step inputs are required, the steps S704 to S708 may be repeated so that the sled motor rotates at least three or five rotations.

Thereafter, the controller 80 obtains an average of actual moving distances according to each step input, calculates a movement error for each step input, and stores the movement error in the memory 90 (S710).

As such, the operation of storing the movement error for each step input of the sled motor 25 in the memory 90 may be performed during manufacturing of the optical disk device, or may be performed while the user uses the optical disk device. It may be. In both cases, the controller 80 may periodically update the movement error of each step input of the sled motor 25 in order to reflect a change in performance over time.

Subsequently, when a label recording request is received from the user (S711), the controller 80 controls each element of the optical disk device to record a label on the label surface of the disk (S712). Check the sensitivity of the stored tracking actuator and the movement error for each step input, and apply the identified sensitivity to drive the tracking actuator to move the objective lens to the outer periphery, and the objective lens from the center of the optical pickup 20 If out of the outer circumferential direction by a predetermined distance or more, the step input is applied to the sled motor 25 to move the optical pickup 20 in the outer circumferential direction to perform a label recording operation.

The control unit 80 controls the servo unit 60 and the driving unit 70 when the optical pickup 20 is moved in the outer circumferential direction to compensate for the transfer error with respect to the corresponding step input through the tracking actuator. Also, by applying the identified sensitivity, the objective lens is moved in the inner circumferential direction so that the objective lens can be accurately moved to the position after label recording is stopped.

The above-described preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art can improve, change, and substitute various other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims below. Or addition may be possible.

1 shows a configuration of an optical disk device including a sled motor for moving an optical pickup,

2 illustrates an example in which blanks without labels printed or overprinted due to a transport error of a sled motor are generated.

FIG. 3 illustrates a method of reading an address (PSN: Physical Sector Number) in terms of an optical disk and converting it into a radius of the disk.

4 shows an example in which the position of the objective lens moves away from the center of the optical pickup in the X direction (inner and outer circumferential direction) when the tracking servo is turned on to read the address of the optical disk.

5 shows an example of shifting the objective lens in and out around to measure the sensitivity of the tracking actuator,

6 illustrates an embodiment of a configuration of an optical disk device to which the present invention is applied;

7 is an operation flowchart for an optical disc recording method according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

20: optical pickup 21: optical drive unit

23: spindle motor 25: sled motor

30 channel bit encoder 40 digital signal processor

50: RF unit 60: servo unit

70: drive unit 80: control unit

90 memory

Claims (12)

Confirming a movement error for each step of correcting a position error of an objective lens generated when the movement error of the sled motor is measured; And And recording the label on the label side of the optical disc while compensating for the identified movement error through an actuator for moving the objective lens in and out. The method of claim 1, And the position error of the objective lens is corrected based on an actuator driving value checked when measuring the sensitivity of the actuator and the movement error for each step of the sled motor. 3. The method of claim 2, And the sensitivity is calculated based on the position detected in the state where the objective lens is moved in the inner and outer circumferential directions and the driving value of the actuator, respectively. The method of claim 3, wherein And the sensitivity is further measured by measuring the position and the driving value of the objective lens near the center of the optical pickup, and calculating the sensitivity in the inner circumferential direction and the sensitivity in the outer circumferential direction based on this. The method according to claim 3 or 4, And the sensitivity is calculated based on a drive value detected at the same circumferential position of the disc. The method of claim 3, wherein And the calculated sensitivity is applied to the actuator when compensating for the movement error. The method according to claim 3 or 6, And wherein the calculated sensitivity is applied to the actuator when the objective lens is sequentially moved in the outer circumferential direction or when the objective lens is moved in the inner circumferential direction after stepping by a sled motor. The method of claim 1, And the movement error is detected in a manufacturing process of the optical disk device and stored in the memory of the optical disk device. The method of claim 1, And wherein the movement error is periodically updated while using the optical disk device. An optical pickup for reading data from the optical disc data side and recording the data on the data side or label side of the optical disc; A sled motor for moving the optical pickup in and out; A memory for storing a movement error for each step of correcting a position error of an objective lens generated when measuring a movement error of a sled motor; And And a controller configured to check a movement error for each step from the memory and to control recording of the label on the label surface of the optical disc while compensating the identified movement error through an actuator for moving the objective lens in and out. Disk device. The method of claim 10, And wherein the movement error is detected in a manufacturing process of the optical disk device and stored in the memory. The method of claim 10, And the control unit periodically updates the movement error and stores the movement error in the memory while using the optical disk device.

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