JP2006294174A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an "optical disk device" in which higher-speed seek operation is performed by considering the number of rotations of the disk. <P>SOLUTION: When the optical disk device receives an instruction for seek operation of an optical pickup (Step S101), move time Tj by track jump from a present address to a target address and the move time Ts by trace move (Step S 102, 103) is calculated. The move time Tj and the Ts is compared, the move shorter in the move time is chosen (Step S 104-106), and the optical beam is moved to the target address by the chosen trace move or the chosen track jump (Step S107). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention optically reads and / or reads data recorded on a disk-shaped recording medium (hereinafter referred to as an optical disk) such as a CD (Compact Disk), a CD-R, a CD-RW, and a DVD (Digital Versatile Disk). The present invention relates to an optical disk apparatus that enables writing, and more particularly to a track jump method during a seek operation.

  Optical disc apparatuses such as CDs and DVDs optically read data recorded in a spiral shape on an optical disc, convert it into electronic signals, and reproduce music and video. In an optical disk reproducing apparatus, when reading or writing data of a target track or target sector, a seek operation for moving an optical beam to a target position is frequently performed. Normally, when the distance from the current address to the target address is far away, a so-called track jump is performed in which the optical pickup is moved in the disc radial direction to jump a plurality of tracks.

  Japanese Patent Application Laid-Open No. 2004-228561 moves a pick movement of a disk type recording / reproducing apparatus to a target position at high speed. Access from a current position to a target position is roughly moved, finely moved, and waited as shown in FIG. The three steps are realized. In step 1, if the number of tracks to be jumped from two points of the current address and the target address is greater than or equal to a certain value, the table data is referred to and moved greatly. Next, in step 2, the current address after movement is detected, the number of tracks to be jumped is calculated by accurate calculation, and the pick is moved. In the final step 3, the pick is made to wait while following the disk data until the current address matches the target address.

Japanese Patent Laid-Open No. 10-112037

  As described above, the seek operation of the optical pickup includes a track jump for moving the light beam in the radial direction of the optical disk and a trace movement for causing the light beam to follow the track on the optical disk. In the conventional case, as shown in Patent Document 1, when the number of tracks to the target address is larger than a certain value, track jump is automatically selected and seek movement is performed.

  The track jump requires a time proportional to the number of tracks to be jumped regardless of the number of revolutions of the disk. On the other hand, in the trace movement, the time to the target track changes according to the number of revolutions of the disk. For this reason, even if the number of tracks to the target track is larger than a certain value, depending on the number of revolutions of the disk, the time due to the track jump becomes longer than the time due to the trace movement, and the seek operation is delayed. There is a problem.

  For example, as shown in FIG. 6, when the current address A0 of the light beam is on the track R0 and the target address A1 is on the track R1, if the number of tracks to jump is larger than a certain number, the seek operation by the track jump is performed. Done. When Tj is the time required for the track jump and Ts is the time required for the trace movement, there is no problem if Tj <Ts. However, the time Ts required for the trace movement differs depending on whether the disc is 1 × speed, 2 × speed, 4 × speed, 8 × speed or the like, and in some cases, Tj> Ts.

  Further, when the rotation of the disk becomes high speed, the stability of convergence of the light beam after the track jump or the optical pickup to the target address is lowered, and as a result, the seek time to the target address is delayed.

The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an optical disc apparatus that performs a higher-speed seek operation in consideration of the rotational speed of the disc.
It is another object of the present invention to provide an optical disc apparatus that stabilizes convergence to a target address by track jump according to the number of revolutions of the disc.

  The optical disk apparatus according to the present invention can select the number of rotations of the optical disk from a plurality of settings, and can read and / or write the optical disk rotated at the selected number of rotations. Calculating means for calculating a first time required for the trace movement and a second time required for the track jump at the selected number of revolutions of the optical disc before moving to the target address, and the calculated first time and first time A selection means for comparing the two times and selecting a trace movement or track jump having a shorter time and an execution means for moving the light beam to the target address by the selected trace movement or track jump are provided.

  The calculating means calculates the first and second times from the current address of the optical pickup and the target address by calculation. Alternatively, a table prepared in advance may be referred to and a time selected therefrom may be used. The track jump includes not only a mode in which the optical pickup is moved in the disc radial direction but also a mode in which only the objective lens is moved in the disc radial direction.

  According to the optical disk apparatus of the present invention, when performing the seek operation to the target address, either the trace movement or the track jump movement is selected in consideration of the rotation speed of the optical disk. Time can be optimized. Furthermore, when the optical disk is rotated at a higher speed, the stability of the track jump convergence is reduced. However, in the present invention, when the optical disk is rotated at a high speed, the probability that the trace movement is selected increases and the high-speed rotation is performed. It is possible to reduce a decrease in the stability of convergence of the track jump at the time.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention. The optical disk apparatus 1 includes a spindle motor 12 that rotates an optical disk 10 such as a CD or a DVD, an optical pickup 14 that irradiates a rotated optical disk with a light beam and converts the reflected light into an electrical signal, and an electrical signal from the optical pickup 14. The RF circuit 16 that generates a reproduction signal (RF signal), a tracking error signal (TE signal) and the like based on the above, and a signal processing unit that decodes the RF signal from the RF circuit 16 and generates an audio signal and a video signal 18, the tracking of the optical pickup is controlled based on the TE signal from the RF circuit 16 or the like, the servo circuit 20 that controls the focusing, the track jump of the optical pickup 14 based on the drive signal TD from the servo circuit 20, and the spindle motor 12 Driver 22 to drive, sys to control seek operation, etc. It includes a beam controller 24.

  The optical pickup 14 includes an objective lens that focuses the light beam on the recording surface of the optical disc, and a tracking actuator such as a thread motor that moves the optical pickup in the radial direction of the optical disc. There are two types of track jumps: a lens jump that moves the objective lens in the radial direction of the optical disc 10 and a jump that moves the optical pickup by a thread motor (hereinafter referred to as a thread jump). The lens jump or thread jump is selected by a drive signal from the driver 22.

  When reading or writing data, the system controller 24 rotates the disk 10 at a rotation speed selected from a plurality of rotation speeds such as a double speed, a quadruple speed, and an 8 speed. For example, at the time of ripping for reading data recorded on an optical disk at a high speed and transferring the data to another electronic device, a high-speed rotation mode is selected to shorten the transfer time. This selection may be an instruction from the user, or the system controller 24 may select a predetermined rotation mode. The rotation of the optical disk 10 is performed by the spindle motor 12 based on the drive signal from the driver 22.

  Further, the system controller 24 controls the seek operation of the optical pickup 14. When the user selects a desired music piece or the like, a seek operation instruction is given to the system controller 24. The system controller 24 recognizes the current address of the optical pickup 14 from the RF signal, calculates the time required to move from the current address to the target address by calculation, and selects track jump or trace movement as will be described later. Then, the optical pickup or the light beam is moved to the target address.

  Next, the seek operation of the optical disk apparatus according to the present embodiment will be described with reference to the flowchart of FIG. Upon receiving the seek operation instruction (step S101), the system controller 24 reads the current address of the optical pickup 14 based on the RF signal (step S102). Next, the system controller 24 calculates a travel time for reaching the target address from the current address (step S103). This calculation is performed for each of the movement time Tj due to the track jump and the movement time Ts due to the trace movement. The target address here is a concept including a target sector or a target track, and should not be interpreted in a limited manner.

  For example, as shown in FIG. 3, when the movement is from the current address A0 to the target address A1, if it is a track jump, the number of tracks existing between the current address A0 and the target address A1 is calculated. The travel time Tj is calculated. On the other hand, in the case of trace movement, the movement time is determined from the data existing between the current address A0 and the target address A1, for example, the number of sectors (1, 2,..., 12) and the peripheral speed determined by the rotation speed of the optical disk. Ts is calculated. Note that the track jump movement time Tj is not directly affected by the rotational speed of the optical disc, and therefore it is not necessary to consider the rotational speed. On the other hand, since the trace movement is a movement that follows the track, the movement time Ts is inversely proportional to the rotation speed of the optical disk, and the movement time Ts to the target address becomes shorter as the rotation speed is higher.

  Next, the system controller 24 compares the movement time Tj and the movement time Ts (step S104), and selects the track jump or the trace movement with the shorter movement time (step S105). For example, if the movement time Tj due to the track jump is shorter than the movement time Ts due to the trace movement, the track jump is selected (step S106), and if the opposite is true, the trace movement is selected (step S107).

  Next, the system controller 24 outputs a control signal to the servo circuit 20 to move the optical pickup 14 or the light beam to the target address in accordance with the selected movement. The servo circuit 20 moves the optical pickup 14 or the light beam to the target address via the driver 22 (step S108).

  By performing the track control as described above, the speed of movement of the optical pickup or light beam to the target address can be increased in consideration of the number of rotations of the disk. As described above, there are two modes of track jumping: lens jumping and thread jumping. In this case, the travel time of both is calculated, and the shorter travel time and the travel time due to trace movement You may make it compare with Ts. Alternatively, either lens jump or thread jump is selected according to the number of tracks jumping from the current address to the target address, and the movement time Tj by the selected jump is compared with the movement time Ts by the trace movement. Also good.

Next, the seek operation according to the present embodiment will be described in comparison with the conventional seek operation. When the conventional seek operation reads 6 or more data to the target address, a track jump is performed. For example, as shown in FIG. 3, the movement from the current address A0 to the target address A1 (the number of data is 12) To do.
Movement A: The movement time when data is read by trace movement (flow-reading) to the target address at 1 × speed is 20 msec,
Movement B: The movement time when moving by track jump to the target address at 1 × speed is 10 msec.
In this case, the track jump by the movement B is selected, but there is no problem because the movement of the track jump is faster than the trace movement.

When the rotation speed of the optical disc is changed from 1x to 4x,
Movement C: The movement time when the data read is performed by the trace movement to the target address at the quadruple speed is 5 msec.
Movement D: The movement time when moving by track jump to the target address at 4 × speed is 10 msec.

  The relationship between the movement time Ts due to the trace movement and the movement time Tj due to the track jump is reversed at the 1 × speed and at the 4 × speed. That is, the time for the trace movement at the quadruple speed is shorter than the time for the track jump.

  In the conventional method, movement B and movement D (both track jumps) are adopted for both 1 × speed and 4 × speed, but in this embodiment, the track jump of movement B is selected at 1 × speed, and the trace of movement C is selected at 4 × speed. Move is selected. As a result, the seek time can be optimized according to the rotational speed of the disk. Further, when the disk is rotating at a high speed, there is an advantage that the trace movement can converge more stably on the target address than the track jump.

  In the above embodiment, the movement times Tj and Ts from the current address to the target address are calculated by calculation. In addition to this, a table is prepared for the number of tracks to be jumped and the data amount for each rotation speed. The travel time can also be calculated with reference to this. FIG. 4 shows an example of the travel time calculation table. FIG. 4A shows the relationship between the number of tracks to jump and the movement time Tj at the time of lens jump. FIG. 4B shows the relationship between the number of data reads (for example, the number of sectors) and the movement time Ts at 1 × speed. When the double speed of the optical disc is changed to double speed or quadruple speed, the movement time Ts in FIG. The system controller 24 searches the range of the corresponding number of tracks and selects the movement time Tj. Similarly, the range of the corresponding data read number is searched, and the movement time Ts is selected.

  Furthermore, the initially set moving time value in the table shown in FIG. 4 may be updated by the learning effect. For example, the travel time when the seek operation is actually performed is stored in the memory as history information, and the average of the travel time actually taken is reflected every time a fixed number of seeks or a certain time elapses. If the number of tracks is in the range of 1-10, an average value Ta of actual travel times may be calculated, and the travel time T1 of the table may be updated to Ta. Thereby, the error range of the calculated movement time can be reduced.

  Furthermore, in the case of an optical disc such as a DVD-RAM, there is a half jump mode from land to pitch or from pitch to land. The present invention can also be applied to such a jump mode. In particular, half-jump control is difficult, so when the optical disk is rotated at high speed, the more frequently the trace movement is selected, the more the frequency of half-jumps decreases. Convergence is stabilized and seek time is shortened.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible.

  The optical disk apparatus according to the present invention can be used in a reproducing or writing apparatus for optical disks such as CD, CD-R, CD-RW, and DVD.

It is a block diagram which shows the structure of the optical disk reproducing device based on the Example of this invention. It is a flowchart explaining the seek operation | movement of the optical disk apparatus of a present Example. It is the figure which showed notionally the track jump or trace movement from a present address to a target address. FIG. 4A is a table for calculating a movement time. FIG. 4A shows the movement time due to a lens jump, and FIG. 4B shows the movement time due to a 1 × speed trace movement. It is a figure which shows the step of the conventional seek operation | movement. It is a figure explaining the conventional subject.

Explanation of symbols

1: Optical disk device 10: Optical disk 12: Spindle motor 14: Optical pickup 16: RF circuit 20: Servo circuit 22: Driver 24: System controller

Claims (7)

An optical disk apparatus capable of selecting the number of rotations of an optical disk from a plurality of settings and enabling reading and / or writing of an optical disk rotated at a selected number of rotations,
Calculating means for calculating a first time required for trace movement and a second time required for track jump, respectively, before moving the light beam of the optical pickup to the target address;
A selection means for comparing the calculated first time with the second time and selecting a trace movement or track jump with a smaller time;
Execution means for moving the light beam to the target address by the selected trace movement or track jump;
An optical disc apparatus having 2. The optical disc apparatus according to claim 1, wherein the calculating means calculates the first and second times from the current address and the target address of the optical pickup by calculation. The optical disk apparatus according to claim 1, wherein the calculation means selects the first and second times from a table prepared in advance. The optical disc apparatus according to claim 1, wherein the track jump includes a jump for moving the objective lens of the optical pickup in the disc radial direction. The optical disk apparatus according to claim 1, wherein the trace movement is a movement that follows a track on the disk. A seek method for an optical disk device that enables reading and / or writing of an optical disk,
Calculating a first time required for trace movement and a second time required for track jump, respectively, before moving the light beam of the optical pickup to the target address;
Comparing the calculated first and second times and selecting the trace move or track jump with the smaller time;
Moving the light beam to the target address by a selected trace move or track jump; and
Having a seek method. The seek method according to claim 7, wherein the trace movement is performed while reading data on a track of the disk.

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