JP2017208154A - Optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk drive capable of properly reducing time for moving an optical pickup to a target area of an optical disk.SOLUTION: An optical pickup 3 is driven to move by the number of tracks, which is determined based on a statistical data of at least one of the disk eccentricity amount prescribed in an optical disk standard and the eccentricity amount due to the mechanism of an optical disk drive 1 to get out of a PIC area where no address information is read.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical disc apparatus that reproduces or records information recorded on an optical disc such as a BD (Blu-ray Disc; registered trademark; hereinafter omitted).

  Conventionally, in a seek for moving an optical pickup to a target position of an optical disc, a technique for shortening a seek completion time when the optical pickup is significantly deviated from the target position has been proposed. For example, the optical disc apparatus described in Patent Document 1 performs a focus search by returning the optical pickup to the inner peripheral side by a predetermined distance when the optical pickup is moved to the outer peripheral side from the target position.

JP-A-11-265512

  However, Patent Document 1 does not clearly indicate how the distance for returning the optical pickup is the calculated value, and may not be able to set an appropriate distance that can shorten the seek completion time. For example, if the distance for returning the optical pickup is too long or too short, it takes time to complete the seek to the final target position.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disc apparatus capable of appropriately shortening the time for moving an optical pickup to a target area of an optical disc.

An optical disc apparatus according to the present invention includes an optical pickup, a drive unit, and a control unit.
The optical pickup reads the recorded information by irradiating the optical disk with light.
The drive unit moves the optical pickup to the inner and outer circumferences of the optical disc.
When the control unit controls the drive unit to move the optical pickup to the first area of the optical disc, if the optical pickup moves to the second area where recording information cannot be read out, the control unit is defined in the optical disc standard. For each track number determined from statistical data of at least one of the disc eccentricity and the optical eccentricity of the optical disc apparatus, the optical pickup is moved toward the first area to move from the second area. Let go.

  According to the present invention, the recording information is obtained by moving the optical pickup for each track number determined from statistical data of at least one of the disc eccentricity specified in the optical disc standard and the eccentricity on the mechanism of the optical disc apparatus. Is separated from the second area where reading of the data is impossible. Thereby, the time for moving the optical pickup to the target area of the optical disc can be shortened appropriately.

1 is a block diagram showing a configuration of an optical disc device according to Embodiment 1 of the present invention. 3 is a flowchart showing the operation of the optical disc device according to the first embodiment. It is a figure which shows the operation | movement which seeks an optical pick-up to a disk management area | region.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus 1 according to Embodiment 1 of the present invention. The optical disk device 1 is a disk drive device mounted on a moving body such as a vehicle, for example, and includes a main control unit 2, an optical pickup 3, a motor driver 4, a stepping motor 5, and a spindle motor 6. In FIG. 1, only the configuration for driving the optical pickup 3 in the circumferential direction of the optical disk d is shown, and the configuration for realizing other functions is omitted.

The main control unit 2 is a component that embodies the control unit in the present invention, and is realized by, for example, a microcomputer or a digital signal processor (DSP).
The main control unit 2 controls the entire optical disc device 1. For example, rotation control of the optical disk d, servo drive control of the optical pickup 3, signal processing from the optical pickup 3 and the like can be mentioned.

The optical pickup 3 reads the recorded information by irradiating the optical disk d with light.
The motor driver 4 is a component that embodies the drive unit in the present invention, and rotates the stepping motor 5 and the spindle motor 6 in accordance with control from the main control unit 2.
The stepping motor 5 is a motor that moves the optical pickup 3 in the inner circumferential direction or the outer circumferential direction of the optical disk d. The spindle motor 6 is a motor that rotates the optical disk d. The control signal of the main control unit 2 is amplified by the motor driver 4 and then transmitted to each motor.

  When the optical disc d is BD-R or BD-RE, when the optical disc apparatus 1 is activated, the management information recorded in the disc management area (hereinafter referred to as DMA) in the inner periphery of the optical disc d is read. There is a need. For this reason, the main control unit 2 controls the motor driver 4 to execute a so-called seek process to the DMA in which the optical pickup 3 is moved to the DMA by the stepping motor 5.

  The seek process ends when the address information recorded on the optical disk d is read after the optical pickup 3 is moved and the read address matches the seek target address. The address information is position information of the optical pickup 3 with respect to the optical disc d. In the case of seek processing to DMA, the DMA address is the seek target address.

However, in this seek process, permanent information and control data (hereinafter, referred to as the optical pickup 3) that is located on the inner peripheral side of the DMA due to the influence of the eccentricity of the optical disk d or the eccentricity of the mechanism of the optical disk apparatus 1. It may move to the area (denoted as PIC).
Note that information is recorded in the PIC area by a recording method different from that of DMA, and the recording information cannot be read by the optical pickup 3 when seeking to DMA.
That is, when the optical pickup 3 moves to the PIC area, the current position information of the optical pickup 3 cannot be acquired, and the seek process cannot be completed normally.

On the other hand, the main control unit 2 uses the optical pickup for each track number determined from statistical data of at least one of the disk eccentricity specified in the optical disk standard and the eccentricity on the mechanism of the optical disk device 1. 3 is moved away from the PIC area.
More specifically, when the optical pickup 3 is moved to the PIC area when the optical pickup 3 is moved to the DMA of the optical disk d, the main control unit 2 cannot acquire the address information, so the counter 2a is incremented by 1. . When the value of the counter 2a is equal to or less than the threshold value, the main control unit 2 forcibly moves the optical pickup 3 in the outer circumferential direction for each of the tracks so as to leave the PIC area. Hereinafter, this process is referred to as a dedicated retry process. The value of the counter 2a is called a retry count.

  When the address information can be acquired after executing the dedicated retry process, the main control unit 2 clears the retry count. In this way, even if address information acquisition fails again at the next seek, the number of dedicated retry processes can be secured.

  In order to avoid an infinite loop in the dedicated retry process, when the value of the counter 2a exceeds the threshold value, the main control unit 2 clears the retry count and shifts to a normal retry process. Here, the normal retry process is a process of returning to the movement start position of the optical pickup 3 and executing the DMA seek again.

Next, the operation will be described.
FIG. 2 is a flowchart showing the operation of the optical disc apparatus 1 and shows a series of processes related to seeking to the target address.
First, the main control unit 2 performs a seek to the target address (step ST1).
Specifically, the main control unit 2 controls the motor driver 4 to move the optical pickup 3 toward the target address of the optical disk d by the stepping motor 5.

Next, the main control unit 2 checks the state of focus servo control and tracking servo control of the optical pickup 3 after being moved (step ST2).
If there is an abnormality in each servo control (step ST2; NG), the process proceeds to step ST11, the retry count is cleared, and the process proceeds to a normal retry procedure. If there is no problem in servo control (step ST2; OK), the process proceeds to step ST3.

In step ST <b> 3, the main control unit 2 confirms whether or not address information has been acquired based on a signal from the optical pickup 3.
If the address information can be acquired (step ST3; YES), the main control unit 2 moves to step ST9 and clears the value of the counter 2a because at least the current position of the optical pickup 3 is not in the PIC area. .

Thereafter, the main control unit 2 determines whether or not the position indicated by the acquired address information matches the target address, that is, whether or not the optical pickup 3 has reached the target address (step ST10).
If the optical pickup 3 has reached the target address (step ST10; YES), the seek process is completed because the seek has been completed.
If the optical pickup 3 has not reached the target address (step ST10; NO), the process returns to step ST1, and seek processing is repeated until the target address is reached.

On the other hand, when the address information cannot be acquired (step ST3; NO), the main control unit 2 confirms whether or not the medium to be reproduced is BD-R / RE (step ST4).
If it is not BD-R / RE (step ST4; other than BD-R / RE), it is considered that the main control unit 2 cannot acquire address information due to a factor other than the movement to the PIC area. After clearing the retry count, proceed to the normal retry procedure.

When it is BD-R / RE (step ST4; BD-R / RE), the main control unit 2 checks whether or not the seek target address is DMA (step ST5).
Here, if the target address is not DMA (step ST5; NO), it is considered that the main control unit 2 cannot acquire the address information due to a factor other than the movement to the PIC area, so the retry count is calculated in step ST11. After clearing, proceed to normal retry procedure.

On the other hand, when the target address is DMA (step ST5; YES), the main control unit 2 determines that the optical pickup 3 has moved to the PIC area, and proceeds to the process of step ST6.
In step ST6, the main control unit 2 adds 1 to the retry count.
Next, the main control unit 2 checks whether or not the retry count is equal to or greater than a threshold value (step ST7). If the retry count is equal to or greater than the threshold (step ST7; YES), the main control unit 2 clears the retry count in step ST11, and then proceeds to a normal retry procedure. Note that the threshold value may be set to a sufficiently large value because it avoids falling into an infinite loop when the retry process does not function normally.

When the retry count is less than the threshold value (step ST7; NO), the main control unit 2 causes the optical pickup 3 to leave the PIC area.
Specifically, the main control unit 2 controls the motor driver 4 to execute a so-called track jump that moves the optical pickup 3 by a predetermined number of tracks in the outer circumferential direction of the optical disc d (step ST8). ).
Thereafter, the main control unit 2 returns to the process of step ST2 in order to confirm whether or not the optical pickup 3 has left the PIC area.

Next, a method for calculating the number K of tracks for moving the optical pickup 3 in the outer peripheral direction by a dedicated retry process will be described.
FIG. 3 is a diagram illustrating an operation of seeking the optical pickup 3 to the DMA. As shown by an arrow A in FIG. 3, the optical pickup 3 moves to the PIC area due to the eccentricity of the optical disk d or the mechanical mechanism of the optical disk apparatus 1 itself when seeking to the target address, that is, the head address of the DMA. To do.

As shown by an arrow B in FIG. 3, the number J of tracks necessary for detaching the optical pickup 3 from the PIC area is determined by the eccentric amount of the optical disc d and the eccentric amount of the mechanism of the optical disc apparatus 1 itself. The
Here, T is the number of tracks from the seek target address, that is, the head address of the DMA to the address closest to the DMA in the PIC area. Further, the eccentricity of the optical disk d is set to Disc_ECC, the mechanical eccentricity of the optical disk apparatus 1 is set to Mecha_ECC, and the track pitch is set to N. In this case, the number of tracks J required to leave the PIC area is obtained by the following equation (1).
J = {(Disc_ECC + Mecha_ECC) ÷ N} −T (1)

In the above equation (1), T and N are values determined by the specifications of the optical disc d, and Mecha_ECC is a unique value determined for each optical disc apparatus 1.
As a result, if the above formula (1) is used, the number of optical pickups 3 that can be reliably detached from the PIC area in one retry even if the optical disk d has the largest eccentricity in the market. It is also possible to set the number of track movements K of the optical pickup 3.

However, when such a number of tracks is set, the optical pickup 3 moves to the outside of the seek target address in the optical disc d having a small eccentricity. This delays the time until the seek process is finally completed.
Therefore, in the optical disc device 1 according to the first embodiment, the track movement number K of the optical pickup 3 at the time of retry is set so that the time from the retry until the seek is completed is as short as possible.
That is, the track movement number K of the optical pickup 3 at the time of retrying is determined from statistical data of at least one of the eccentric amount of the optical disk d and the eccentric amount on the mechanism of the optical disk apparatus 1 on the market.

For example, it is assumed that the maximum eccentricity of a BD-RE disc existing in the market is 150 μm. In the case of the BD-RE, N is 0.32 μm and T is 188 from the disc specification.
For simplicity of explanation, Mecha_ECC is zero, that is, there is no mechanical eccentricity of the optical disk apparatus 1, and the disk having the maximum eccentricity is calculated once from the PIC area using the above equation (1). The number of tracks J required to leave on retry is calculated.
J = {(Disc_ECC + Mecha_ECC) ÷ N} −T
= {(150 μm + 0 μm) ÷ 0.32 μm} −188 lines = 280.75 lines According to the above calculation results, if the number of track movements K of the optical pickup 3 at the time of retry is set to 281, all BD− existing in the market In the RE disk, it is possible to reliably leave the PIC area with one retry.

However, for example, in the case of a BD-RE disc having an eccentricity of 75 μm, the number of tracks J required for detaching from the PIC area in one retry is approximately 47. For this reason, when the number of track movements K of the optical pickup 3 at the time of retry is set to 281, KJ = 281 lines−47 lines = 234 lines more than the seek target address in one retry. As a result, the optical pickup 3 moves to the track on the outer peripheral side by 234 lines. That is, it will return too far outside the target address.
As a result, as shown by an arrow C in FIG. 3, after the retry is executed, it is necessary to move 234 tracks to the target address. This means that a total of 515 tracks (= number of movements for one retry K + 234) needs to be moved.

Naturally, if the number of tracks K to which the optical pickup 3 is moved in one retry is less than 281, the number of retries increases, but the amount of return to the outside of the target address decreases. For this reason, the total number of tracks to which the optical pickup 3 is moved before the seek is completed can be reduced.
However, since it takes time to check the address information for each retry, even if the total number of movements is reduced, it takes time if the number of retries increases. Therefore, it is necessary to reduce the number of retries as much as possible.

  Assuming that the number of tracks K is 100, in the case of a BD-RE disc with an eccentricity of 75 μm, the total number of optical pickups 3 is 153 (= number of tracks for one retry + number of tracks that have returned too much in a retry = 100). The target address can be reached by moving the track by +53). As a result, the track movement time for 362 tracks can be shortened even when the number of retries is the same, compared with the case where the number K of track moves during the retry is 281.

On the other hand, in the case of a disc having an eccentricity of 150 μm, the optical pickup 3 reaches the target address with a total of 320 tracks (= the number of movements for three retries + the number of tracks returned by retry = 300 + 20). To do.
For this reason, the number of retries is increased twice compared with the case where the number of tracks K is 281, and an additional movement time of 39 tracks is required.

  Here, if there are more optical discs d with an eccentricity of 75 μm on the market than discs with an eccentricity of 150 μm, it is highly likely that many users have the optical disc d with an eccentricity of 75 μm. In this case, if the number of tracks J is set to 100, which is advantageous with respect to the optical disc d having an eccentricity of 75 μm, it is more likely that the time required from retry to completion of seek can be shortened.

Therefore, in the present invention, the number of tracks K to which the optical pickup 3 is moved by retry is set in consideration of the statistical data of the eccentricity of the optical disk d existing in the market.
As the eccentricity amount of the optical disk d existing in the market, if there is data that is open to the public as statistical data, it may be used, or uniquely collected data may be used.

  Although the case where there is no mechanical eccentricity of the optical disc apparatus 1 has been described as an example, the mechanical eccentricity statistical data on the eccentric amount on the mechanism of the optical disc apparatus 1 collected independently is used. The number of tracks may be set in consideration of the core.

As described above, in the optical disc apparatus 1 according to the first embodiment, the track is determined from statistical data of at least one of the disc eccentricity defined in the optical disc standard and the eccentricity on the mechanism of the optical disc apparatus 1. The optical pickup 3 is moved for each number, and is separated from the PIC area where address information cannot be read.
With this configuration, it is possible to appropriately shorten the time for moving the optical pickup 3 to the target area of the optical disk d.

  Further, the optical disc apparatus 1 according to Embodiment 1 includes a counter 2a that counts the number of times address information cannot be read. When the value of the counter 2a becomes equal to or greater than the threshold value, the main control unit 2 clears the value of the counter 2a, returns to the movement start position of the optical pickup 3, and re-executes the movement to the DMA. By configuring in this way, it is possible to avoid falling into an infinite loop even when the retry process does not function normally.

  Furthermore, in the optical disc device 1 according to the first embodiment, the main control unit 2 clears the value of the counter 2a when the address information is successfully read. In this way, the number of dedicated retry processes can be ensured even if address information acquisition fails again at the next seek.

  In the present invention, any component of the embodiment can be modified or any component of the embodiment can be omitted within the scope of the invention.

  1 optical disk device, 2 main control unit, 2a counter, 3 optical pickup, 4 motor driver, 5 stepping motor, 6 spindle motor.

Claims (4)

An optical pickup that reads recorded information by irradiating the optical disc with light;
A drive unit for moving the optical pickup to the inner and outer circumferences of the optical disc;
When the optical pickup moves to the second area where reading of recorded information is impossible when the drive unit is controlled to move the optical pickup to the first area of the optical disk, the optical disk standard defines The optical pickup is moved to the first area side for each track number determined from statistical data of at least one of the disk eccentricity and the mechanical eccentricity of the optical disk device. An optical disc apparatus comprising: a control unit configured to leave the area. The first area is a disk management area of the optical disk;
2. The optical disk apparatus according to claim 1, wherein the second area is a permanent information and control data area on the inner circumference side of the disk management area. With a counter that counts the number of times recording information could not be read,
The control unit clears the counter value when the counter value is equal to or greater than a predetermined threshold, returns the optical pickup to the movement start position, and re-executes the movement to the first area. The optical disk apparatus according to claim 1 or 2, wherein With a counter that counts the number of times recording information could not be read,
4. The optical disc apparatus according to claim 1, wherein the control unit clears a counter value when recording information is successfully read. 5.

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