JPH05205287A - Track jump controller and information recording medium - Google Patents

Abstract

PURPOSE:To provide a track jump controller for information recorder/reproducer in which track jump is stabilized by solving a problem that a defect such as scratch or distortion of information track causes instable jumping. CONSTITUTION:A jump command output means 6 reads out scanning position information of a scanner 8 from a scanning position detecting means 1 and delivers a jump command to a scanning position stored in a scanning position memory means 7 at a timing causing no overlap of track jump. A jump waveform monitoring means 4 takes out a zero-cross signal representing the movement of scanning track from a tracking error signal at the time of track jump. A jump abnormality detecting means 5 compares the number of zero-cross signals with the number of jump commands thus detecting jump abnormality. Thus detected jump abnormality is fed to the scanning position memory means 7 and the position of abnormal scanner 8 is stored in a memory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording / reproducing information on / from an information recording medium having an information track, and particularly controlling the execution position of a track jump for moving the scanning track of a scanner. It relates to the device.

[0002]

2. Description of the Related Art In an information recording medium having information tracks (hereinafter referred to as a disk), the recording density has become higher and the track pitch has become narrower. It is impossible to control to scan. In particular, a disk-shaped optical information recording medium having spiral information tracks (hereinafter referred to as an optical disk) has a track pitch of 1.6 μm, and an information recording / reproducing apparatus for irradiating a light beam on the optical disk to record / reproduce information. In the above, the tracking control means for the scanning element to correctly scan the information track is indispensable. Also, in the field of magnetic disks, tracking control means have been introduced to realize high density. Further, a technique for moving a scanning track accurately and quickly in order to retrieve a large amount of information is also important, and one of them is a track jump technique. The track jump is used for a fine search that is performed while confirming the track address when searching for information. Further, in a device for reproducing an image such as a video disc, it is used for trick reproduction such as still reproduction and fast reproduction.

A conventional track jump control device will be described below. FIG. 11 shows a conventional track jump control device which is generally used. Reference numeral 1 is a scanning position detecting means for detecting the scanning position of the scanning element 8 on the disk 9. Reference numeral 2 denotes a tracking control means, which controls the scanner 8 to scan the information track. A jump pulse generating means 3 moves the scanning track of the scanning element 8. Reference numeral 6 denotes a jump command means, which outputs a jump command at an appropriate timing based on the information from the scanning position detecting means 1. A scanner 8 scans the information track of the disk 9 to record and reproduce information. Reference numeral 9 is a disc having information tracks. Reference numeral 10 is a disk motor for rotating the disk.

The operation of the track jump control device configured as described above will be described below. First, the jump command output means 6 outputs a jump command at a predetermined timing based on the information on the scanning position of the scanning element 8 from the scanning position detecting means 1. Upon receiving the jump command, the jump pulse generating means 3 cuts the control loop of the tracking control means 2 and outputs a jump pulse to the tracking coil drive stage of the tracking control means 2 to move the scanning track of the scanning element 8.

[0005]

However, a medium such as an optical disk is a removable medium and may be soiled or scratched depending on the installation environment and handling method, and a disk having a relatively large diameter may be slightly distorted during the manufacturing process. May occur on the outer track. These scratches, stains, and track distortion are not a problem in normal reproduction in many cases, but the track jump is a short time of several hundreds of μsec, but the tracking control is in an unstable state, and the track jump malfunctions. Since a track jump is performed at a predetermined position in the above-described conventional configuration, if there is a defect such as the scratch at the track jump execution position, the track jump cannot be performed on the defective information track. There are problems that the device performance is deteriorated and troubles are caused such that the device becomes stable, the still reproduction cannot always be performed, the search time becomes long, and information cannot be read due to the inability to search.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a track jump control device capable of stably moving a scanning track of a scanning element even on a disk having scratches, dirt, or track distortion. ..

[0007]

In order to achieve this object, a track jump control device of the present invention comprises a jump pulse generating means for outputting a track jump signal and a scanning position detecting means for detecting a scanning position of a scanning element. A jump abnormality detecting means for detecting an abnormality of the track jump, a scanning position storing means for storing the scanning position of the scanning element in which the abnormality of the track jump occurs, and a track at the scanning position of the scanning element stored by the scanning position storing means. The jump command output means outputs a track jump command at a timing when the jumps do not overlap.

[0008]

[Action]
With this configuration, the jump command output means outputs the jump command at a predetermined scanning position based on the information of the scanning position of the scanning element from the scanning position detecting means. At this time, when the timing of the track jump overlaps the scanning position stored in the scanning position storage means, the jump command output is delayed until the stable track jump can be performed. According to the jump command, a jump pulse is output from the jump pulse generating means to the drive stage of the tracking control means to move the scanning track of the scanning element. The jump abnormality detecting means detects the jump abnormality from the address of the information track after the track jump or the waveform of the tracking error signal at the time of the track jump. The scanning position where the jump abnormality occurs is stored in the scanning position storage means. The scanning position stored in the scanning position storage means is used when the next track jump is executed such as a retry. In this way, a stable track jump can be performed, and the scanning track of the scanner can be reliably moved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a scanning position detecting means for detecting the scanning track address of the scanning element 8 and the elapsed time from the track address information, and 2 is a tracking control for controlling the scanning element 8 to scan the information track. Means 3 is a jump pulse generating means for outputting a jump pulse for moving a scanning track, 4 is a jump waveform monitor means for detecting a zero cross of a tracking error signal at the time of track jump, and 5 is a mismatch between the jump command and the number of zero crosses. A jump abnormality detecting means, 6 is a jump command output means for outputting a jump trigger and a jump direction signal as a jump instruction, 7 is a scanning position storing means for storing the scanning position where the jump abnormality occurs, and 8 is optical information. Scanner for reading and writing, 9 is a disc for optically recording information, and 10 is a disc. A disk motor for rotating the click 9.

The operation of the track jump control device constructed as described above will be described below. First, the jump command output unit 6 outputs a jump command at a predetermined scanning position based on the information on the scanning position of the scanning element 8 from the scanning position detecting unit 1. At this time, when the execution position of the track jump overlaps the scanning position stored in the scanning position storage means 7, the timing of the jump command output is delayed by a time period in which a stable track jump can be performed. In this embodiment, the timing is delayed by the time required for the track jump. By the jump command,
Jump pulses are output from the jump pulse generating means 3 to the drive stage of the tracking control means 2 to move the scanning track of the scanning element 8. The tracking error signal from the scanner 8 at the time of track jump is input to the tracking control means 2. The tracking error signal is amplified and enters the jump waveform monitoring means 4, and a zero cross signal indicating the movement of the scanning track is extracted from the jump waveform of the track error signal at the time of track jump. The jump abnormality detecting means 5 detects the jump abnormality by comparing the number of the zero-cross signals with the number of jump commands. The detected jump abnormality is input to the scanning position storage means 7, and the scanning position of the scanner 8 at the time of outputting the jump command in which the jump abnormality has occurred is stored in the memory.

FIG. 2 shows the configuration of the scanning position detecting means 1 in this embodiment. The RF signal reproduced by the scanner 8 is amplified by the amplifier 11, the track address information is extracted by the bandpass filter 12, and converted into a digital signal by the binarization circuit 13. The read clock demodulation circuit 14 demodulates the read clock from the binarized track address information, and the data demodulation circuit 15 demodulates the address data.
The demodulated address data is a serial / parallel conversion circuit 1 configured by a shift register using the read clock.
It is converted into parallel information at 6 and output to the input port 56 of the microcomputer. Further, the sync pattern of the address data converted into the parallel information is detected by the sync pattern detection circuit 17, and the timer 18 for counting the output of the oscillator (OSC) 19 is cleared. Timer 18
Is output to the input port 56 as the elapsed time from the track address information.

FIG. 3 shows the configuration of the tracking control means 2 in this embodiment. The signals from the two-divided photodetectors A and B of the scanner 8 are supplied to the buffer amplifier 2 respectively.
The differential signal passing through 0 and 21 is detected by the differential amplifier 22 as a tracking error signal. The sum signal obtained by the addition amplifier 23 is put into the denominator of the divider 24 to normalize the tracking error signal. The normalized tracking error signal is phase-compensated by the equalizer 25, enters the drive amplifier 27 through the switch 26, and drives the tracking coil of the scanning element 8. The low-frequency component of the tracking error signal is extracted by the low-pass filter 28, passes through the drive amplifier 29, drives the linear motor, and performs radial feed of the scanning element 8. The jump period signal from the jump pulse generating means 3 enters the switch 26, cuts off the control loop of the tracking control means 2, outputs a jump pulse to the drive amplifier 27, and moves the scanning track of the scanner 8.

FIG. 4 shows the configuration of the jump waveform monitoring means 4 in this embodiment. A low-pass filter (LPF) 40 extracts low-frequency components of the tracking error signal a from the tracking control means 2 and a comparator 4
In step 1, the zero cross for tracking at the time of a track jump, which indicates that the scanning track of the scanner 8 has moved, is extracted as a zero cross pulse signal, input to the exclusive OR circuit 42, and the jump direction signal c from the jump command output means 6 Then, the polarity of the edge of the zero-cross pulse signal at the time of zero-cross becomes constant in the forward and backward jumps, and is output as the zero-cross pulse signal b.

FIG. 5 shows the configuration of the jump pulse generating means 3 in this embodiment. By the jump trigger from the jump command output means 6, mono-multi (MM)
30 produces a pulse of period T1. At the leading edge of the output of the monomulti 30, the monomulti 31 outputs the jump period signal e of the period T2, and the monomulti 32 outputs the jump accelerator signal of the period T3. At the trailing edge of the output of the mono-multi 30, the mono-multi 33 outputs the jump stop signal of the period T4. The jump accelerator signal and the jump stop signal enter the exclusive OR circuits 34 and 35, the pulse polarity is determined by the direction signal c from the jump command output means 6, and the pulse polarities are added by the resistors 36 and 37 and the capacitor 38. The jump pulse signal f whose level has been adjusted in 39 is output.

FIG. 6 shows a hardware structure for realizing the jump abnormality detecting means 5, the jump command outputting means 6 and the scanning position storing means 7 in this embodiment. Reference numeral 50 denotes a central processing unit (hereinafter referred to as CPU), which is interfaced with peripheral devices by an address bus AB, a data bus DB and a control bus CB for reading and writing. An address decoder 52 decodes the content of the address bus AB and generates a device select signal used for selecting a peripheral device. Reference numeral 53 is a read-only memory (hereinafter referred to as a ROM), which stores a control program of the CPU 50 that realizes the jump abnormality detection means 5, the jump command output means 6, the scanning position storage means 7, and the like. An arbitrary access memory (hereinafter referred to as RAM) 54 is used as a data memory of the CPU 50 such as the scanning position storage means 7. An oscillator circuit (OSC) 51 supplies the CPU 50 with a reference clock for program execution. A counter 55 counts the zero-cross pulse signal b from the jump waveform monitor 4.
Reference numeral 56 is an input port for inputting information such as the track address from the scanning position detecting means 1 and the elapsed time from the track address. An output port 57 outputs a jump trigger d and a direction signal c.

FIG. 7 shows the contents of the scanning position stored in the memory which constitutes the scanning position storage means 7 in this embodiment. The memory uses a part of the RAM 54. The data number N of the scanning position stored in the head address A is written, and thereafter, the track address and the timer value from the track address information are each written in 2 bytes.

FIG. 8 shows a program for realizing the jump abnormality detecting means 5 in this embodiment, which is executed after the jump instruction is outputted from the jump instruction outputting means 6. First, in step 510, the counter 55 that counts the zero-cross pulse signal of the track jump from the jump waveform monitor 4 is cleared. In step 520, execution of the next step is delayed by the time required for the track jump. In step 530, the count value of the counter 55 is read, compared with the commanded number of jumps, if they match, step 540 is executed, and if they do not match, step 550.
To execute. At step 540, the jump abnormality flag is cleared, and at step 550, the jump abnormality flag is set and the program of the jump abnormality detecting means 5 is terminated.

FIG. 9 shows a program for realizing the jump command output means 6 and the scanning position storage means 7 in this embodiment. Steps 610 to 670 show the jump command output means 6, and steps 690 and 700 show the scanning position. The storage means 7 is shown. RAM5 in step 610
The data number i of the scanning position data read from 4 is initialized. In step 620, the scanning position P of the scanning element 8 is read from the scanning position detecting means 1 through the input port 56. In step 630, the data number i is incremented. In step 640, the scanning position Ji of the scanner 8 in which the track jump abnormality designated by the data number i has occurred is stored in the RAM 5
4 and the scanning position P is (Ji
−Jump time) and (Ji + jump time) are inspected for entering the jump prohibition period. If the jump prohibition period is entered, the process returns to step 610 and steps 610 to 650 are repeated. If the scanning position P is outside the jump prohibition period, it is checked in step 660 whether the comparison with all the scanning position data is completed, and if it is not completed, the process returns to step 630 to compare with the next scanning position data. I do. When the comparison with all the scanning position data is completed, the process proceeds to step 670, and the jump command including the jump trigger and the jump direction signal is output from the output port 57. The jump abnormality detecting means 5 is executed in step 680, and when the jump abnormality is detected in step 690, the scanning position P is written in the RAM 54 in step 700. If there is no jump abnormality in step 690, the program of the scanning position storage means 7 is terminated without doing anything.

FIG. 10 shows the disk 9 used in this embodiment.
91 shows the position of the address information pre-recorded on the information track, 92 is the rotation reference mark used for rotation control of the disc motor, and 93 is the jump abnormality recorded on the outer peripheral portion of the disc 9. The generated scanning position information, 94 is a synchronization signal (SYNC) preceding the address data in the address information, and 95 is the address data. Also, g
Is a reproduction RF signal of the scanning position information 93, and h is a binarized signal obtained by binarizing the reproduction RF signal g. The address information 91 of the information track is a PE-modulated signal, and one block is recorded for each information track. Further, one image is recorded per one information track. The scanning position information 93 is FM
The modulated image signal is recorded by intermittently recording according to 1 and 0 of data.

As described above, according to this embodiment, the scanner 8
Scan position detecting means 1 for detecting the elapsed time from the scan track address and track address information, jump waveform monitoring means 4 for detecting the zero cross of the tracking error signal at the time of track jump, and detecting the mismatch between the jump command and the number of zero cross. Jump abnormality detection means 5, jump command output means 6 for outputting a jump trigger and a jump direction signal as a jump command at the timing when the track jump does not overlap with the scanning position where the track jump abnormality has occurred, and the scanning position when the jump command is output. By providing the scanning position storage means 7 for storing, the track jump abnormality can be detected almost at the same time as the track jump execution, and the scanning position where the track jump abnormality occurs can be accurately detected. As a result, the next track jump such as the retry performed immediately after the occurrence of the track jump abnormality can be surely performed, and the next track jump can be executed near the regular jump position. It is also possible to minimize image quality deterioration due to jump noise during trick playback.

In this embodiment, the jump abnormality detecting means 7 detects a track jump abnormality due to a mismatch between the jump command and the zero cross number. However, one round is divided into a plurality of sectors like a disk used for recording digital information. Therefore, when using a disc in which track addresses are written in each sector, a track jump abnormality may be detected at the scan track address after the track jump, and the positive and negative peak values of the jump waveform and the jump waveform itself may be detected. The abnormality may be detected by comparing with the normal one. Further, the scanning position detecting means 1 uses the address information of the information track as a reference for detecting the scanning position in the rotation direction and the track address as the scanning position information in the radial direction, but detects the rotation reference mark 92 on the disc. Means may be provided to serve as a reference for detecting the scanning position in the rotational direction, or position information of the scanner 8 such as a linear encoder may be used as the radial scanning position information. Further, in this embodiment, the scanning position information in which the jump abnormality has occurred is stored in the RAM 5.
4, the information is recorded in a specific position such as the inner circumference or the outer circumference of the disc 9 as shown in FIG. 10, and the information is read at the time of reproduction, so that the scanning position information can be obtained even if the disc is replaced. Can be left, and the reliability of the track jump of the device can be further improved. Further, by recording the scanning position information of the tracking abnormality during the disc shipping inspection, the yield of the disc can be improved.

Although this embodiment has been described by using the optical disk device, the present invention is not limited to the optical disk device and can be applied to a magnetic disk device, an optical card device, a video tape recorder and the like.

[0024]

As described above, according to the present invention, the jump pulse generating means for outputting the track jump signal, the scanning position detecting means for detecting the scanning position of the scanning element, and the jump abnormality detecting means for detecting the abnormality of the track jump are provided. And a scanning position storage means for storing the scanning position of the scanning element in which an abnormality of the track jump has occurred, and a jump command at a timing at which the scanning position of the scanning element stored in the scanning position storage means and the track jump do not overlap. By providing a jump command output means for outputting, an excellent track jump control device capable of performing a track jump while avoiding a portion having scratches, dirt, or track distortion and stably changing the scanning track of the scanning element. It can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a track jump control device according to an embodiment of the present invention.

FIG. 2 is a block diagram of scanning position detecting means in the present embodiment.

FIG. 3 is a block diagram of tracking control means in this embodiment.

FIG. 4 is a block diagram of jump waveform monitoring means in this embodiment.

FIG. 5 is a block diagram of jump pulse generating means in this embodiment.

FIG. 6 is a block diagram of hardware that realizes a jump or more detection means, a jump command output means, and a scanning position storage means in the present embodiment.

FIG. 7 is a diagram showing stored contents of a scanning position storage means in the present embodiment.

FIG. 8 is a flowchart showing a program of jump abnormality detecting means in the present embodiment.

FIG. 9 is a flowchart showing a program of a jump command output means and a scanning position storage means in this embodiment.

FIG. 10 is a plan view showing the shape of the disc in this embodiment.

FIG. 11 is a block diagram showing a configuration of a conventional track jump control device.

[Explanation of symbols]

 1 Scanning Position Detection Means 2 Tracking Control Means 3 Jump Pulse Generation Means 4 Jump Waveform Monitors 5 Jump Abnormality Detection Means 6 Jump Command Output Means 7 Scanning Position Storage Means 8 Scanners 9 Disks 93 Scanning Position Information

Claims (12)

[Claims] 1. An information recording medium having an information track is used,
Scanning position detecting means for detecting a scanning position of a scanning element for scanning an information track and recording and reproducing information, tracking control means for controlling the scanning element to scan the information track, and track jumping of the scanning element for scanning. Jump pulse generating means for outputting a track jump signal for moving a track to an adjacent information track to the tracking control means, jump abnormality detecting means for detecting abnormality of the track jump, and scanning of a scanner having the abnormality of the track jump. A track jump control device, comprising: a scanning position storage means for storing a position. 2. The track jump control according to claim 1, wherein the jump error detecting means includes jump error detecting means for detecting an error in the track jump based on scanning position information from the scanning position detecting means after the track jump. apparatus. 3. A jump waveform monitor means for extracting a characteristic of a tracking waveform at the time of a track jump, and a jump for detecting an abnormality in tracking control at the time of a track jump by a signal from the jump waveform monitor means to the jump abnormality detection means. The track jump control device according to claim 1, wherein the abnormality detection means is used. 4. The track jump control device according to claim 3, wherein a zero cross detector for detecting movement of a scanning track due to a track jump is used as the jump waveform monitor means. 5. An information recording medium having address information of an information track is used, and a scanning position detecting means for detecting address information of an information track on the information recording medium is used as the scanning position detecting means. Track jump controller. 6. A disk-shaped recording medium is used as the information recording medium, and a scanning position detecting means for detecting a radial scanning position of a scanning element on the disk-shaped recording medium is used as the scanning position detecting means. 1. The track jump control device according to 1. 7. A disk-shaped recording medium is used as the information recording medium, and scanning position detecting means for detecting the scanning position in the radial direction and the scanning position in the rotational direction is used as the scanning position detecting means. Track jump controller. 8. A scanning position using the disk-shaped recording medium having address information of an information track, and including a scanning device for scanning the address information and a timer for measuring an elapsed time from the address information as scanning position detecting means. 8. The track jump control device according to claim 7, wherein the detection means is used. 9. A phase for detecting a rotational phase from the address information reading device and the rotation reference information, using the disk-shaped recording medium having address information of an information track and rotation reference information as scanning position detecting means. 8. The track jump control device according to claim 7, wherein the scanning position detecting means is provided with a detecting means. 10. A jump command output means for outputting a track jump command to the jump pulse generation means at a timing when the track jump does not overlap the scanning position of the scanning element stored in the scanning position storage means.
The described track jump control device. 11. The track-jump control device according to claim 1, wherein the information stored by the scanning position storage means is recorded on an information recording medium. 12. An information recording medium characterized in that the information on the abnormal position of the jump stored in the scanning position storage means is recorded at a specific position on the information recording medium.