JPS59185074A - Disc device - Google Patents

Abstract

PURPOSE:To obtain accurately a track number by reading the track number for plural number of times at the accessing of a head and discriminating that the track number is correct when the result of reading is coincident with the prescribed number of times. CONSTITUTION:An object track number and a sector number are supplied from an external device, e.g., a host computer to a control circuit 29. The control circuit 29 reads a value where the content of a track number register 16 is revised at first and a value revised next and compares whether or not they are coincident with each other. When the access to a prescribed track is read or the track number is read by the 1st scale access, the control circuit 29 calculates the difference between the track number of a position to be accessed and the read track number. Then if the difference is larger than 70 tracks' share, the control circuit 29 sets a flag requesting pitch recalculation, calculates the scale number difference from the track number difference and corrects the scale position to be accessed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disk device for storing or reproducing information on an optical disk in which information is stored, for example, in a spiral or concentric pattern.

[Technical background of the invention]

In recent years, a large amount of image information such as documents is generated using two-dimensional optical scanning or photoelectric conversion, and the photoelectrically converted image information is stored in an image storage device, or it can be retrieved as needed. Recently, optical disk devices have been used as image storage devices in image information file devices that can reproduce and output images as hard copies or soft copies.

Conventionally, such optical disk devices have used optical disks that store information in a spiral or concentric form, and track numbers are recorded by an optical head that moves linearly in the radial direction of the optical disk using a linear motor. While storing the information, the information is stored or the information on the optical head is reproduced.

[Problems with background technology]

However, in the above-mentioned apparatus, when a predetermined track is accessed during recording or reproduction, the track number is read only once. For this reason, there is a problem in that reading only once like this may result in misreading.

C. Object of the Invention This invention has been made in view of the above circumstances, and its object is to provide a disk device that can obtain accurate track numbers.

[Summary of the invention]

In this invention, when accessing the head, the track number is read a plurality of times, and if the reading results match a predetermined number of times, it is determined that the track number is correct.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a disk device, such as an optical disk device, according to the present invention. It has a spiral information storage section with a constant pitch, and is driven by a motor 2 for multiple rotations. As shown in FIG. 2, the optical disc 1 has a donut-shaped coating layer of a recording material such as tellurium or bismuth on the surface of a circular substrate made of, for example, noflas or plastic. A notch base position mark 11 is provided near the center of the recording material coating layer. Each round on the optical disk 1 is called a track, and each track is assigned a track number (position information), and each track is numbered from 0 to 31, with the base position mark 11 being 0. It is divided into 32 sectors.

Data is read and written to the optical disk 1 by an optical head (head). carried out by This optical head 3 is fixed to a movable part 5 of a DC linear motor 4 which is composed of a movable part and a fixed part, and is linearly moved in the radial direction of the optical disc 1 and in the AjB direction shown in the figure by the movement of the movable part 5. be done. 6 is an optical scale fixed to the movable part 5; 7 is a detector for detecting the position of the optical scale 6; It outputs two types of detection signals with different phases (this phase relationship changes depending on the direction) depending on the amount. On the other hand, the optical head 3 fixed to the linear motor 4 includes a laser diode, a collimator lens, a beam snorter, an objective lens, a focus drive coil that drives the objective lens in the direction of the optical disk, and a tracking drive coil that drives the objective lens in the radial direction of the optical disk. ,
It consists of a focusing detector having a pair of photodetectors that detects whether the laser beam is focused on the optical disk, and a tracking detector having a pair of photodetectors that detects whether the laser beam is tracking on the information track. There is. Each photodetector outputs a detection signal to a signal circuit, and each drive circuit supplies power to each drive coil and radar diode.

The linear motor drive circuit 8 drives the linear motor according to a target position signal supplied from a control circuit 29, which will be described later, an output signal from the detector 7, and eccentricity correction data supplied from a D/A controller 25, which will be described later. 4.

The track number insertion circuit 9 inserts a track number in a track number register 16, which will be described later, into recording input data from an external device (not shown) and outputs the same. The modulation circuit 10 converts the data from the track number insertion circuit 9 into MF.
It is output after performing M modulation. The laser drive circuit 11 drives and controls the laser oscillator in the optical head 3 in accordance with the output signal supplied from the modulation circuit 10.

On the other hand, the rotary motor drive circuit 12 determines the speed according to the rotation clock from the motor 2, and performs speed control to a set speed of a control circuit 29, which will be described later. The riot position mark 11 of the optical disc 1 is detected by the detector 13, and this detection signal is binarized by the binarization circuit 14 and then sent to the sector number counter 15 and the track number register 1.
6. The sector number counter 15 counts the number of sectors by counting the rotation clock from the motor 2 every time a signal is supplied from the binarization circuit 14. The track number register 16 stores a track number from a track number discrimination circuit 28, which will be described later, each time a signal from the binarization circuit 14 is supplied.

Further, the focus pull drive circuit 17 is connected to the optical head P.
The focus of the movable lens in the optical head 3 is adjusted according to the detection signal from the detector in the optical head 3, and the focus pull-in circuit 18 is used to adjust the focus of the movable lens in the optical head 3 in accordance with the detection signal from the detector in the optical head 3. It appears as if focusing is to be performed. The tracking servo drive circuit 19 moves the movable lens to the optical disc so that the beam emitted through the movable lens (objective lens) in the optical head 3 is in the center of the track in accordance with the detection signal from the detector in the optical head 3. radially. In addition, the tracking servo drive circuit 19 temporarily stops the servo operation and generates a track jump and drive pulse from the tracking jump pulse generation circuit 2θ to move the objective lens according to the track jump pulse and generate a beam of light for one track. The bit signal envelope detection circuit 2) and the pit signal envelope binarization circuit 22 perform envelope detection on the detection signal from the photodetector of the optical head 3, and then convert it into binary data. By doing so, it is detected whether or not the area being read by the beam light is an area on the optical disc I where bits are generated.

On the other hand, the eccentricity detection circuit 23 detects the eccentricity of the optical disc 1 according to the detection signal from the photodetector in the optical gutter 3, and the eccentricity data is stored in the eccentricity storage circuit 2.
4 is stored. The eccentricity-Jk data (correction data) in the eccentricity storage circuit 24 is converted into an analog signal by the D/A converter 25 and supplied to the linear motor drive circuit 8. Further, the bit signal binarization circuit 26 binarizes the detection signal from the photodetector in the optical head 3. The demodulation circuit 27 is for translating the MFM modulated output of the bit signal binarization circuit 26. Track number discrimination circuit 28
is for discriminating the data demodulated by the demodulation circuit 27 into image information and track numbers.The track number is supplied to the track number register 16, and the image information is output as playback data. It has become.

The control circuit 29 controls each of the above sections. The control circuit 29 monitors time using a timer 3θ.

Next, in such a configuration, FIG. 3(a).

The operation will be explained with reference to the flowcharts shown in FIGS. 5(b) to 5(b). For example, a target track number and a sector number are now supplied to the control circuit 29 from an external device (not shown), such as a host computer. Then, the control circuit 29 starts the timer 30. At this time, the optical disc 1 is rotating at a constant speed. Therefore, the contents of the track number discriminator circuit 28) and the track number register 16 are sequentially updated with the track numbers recorded in a plurality of locations on a predetermined track. Accordingly, the control circuit 29 reads the first updated value and the next updated value of the track number register 16, and compares them to see if they match. If they match, control circuit 2
9 determines the track number reading range based on the rotational speed of the rotary motor 2, and determines whether the read track number is within the track number reading range. Multi-control circuit 2
If it is determined that 9 is within the range, it is determined that the read track number is correct. Note that when the timer 3o times out, the control circuit 29 notifies an error.

Then, the control circuit 29 calculates the difference between the correctly read track number and the track number to be accessed.

When the difference is within 70 tracks, or when it is determined that the track number cannot be read, the control circuit 2
9 reads the scale number in the linear motor and drive circuit 8, and calculates the difference between it and the scale number corresponding to the track number to be accessed. When this difference is not within the "4" scale, and when the difference in track numbers is greater than r70J) racks, the control circuit 2g uses its scale signal linear motor drive circuit 8 to move the linear motor 4.

When the scale access is completed, the control circuit 29 reads the contents of the track number register 16, performs the track number reading process described above, and determines whether the correct track number has been read. If the trunk number cannot be read, the control circuit 29 moves the optical head 3 to the unrecorded area.
is accessed, and causes the linear motor drive circuit 8 to cause the linear motor 4 to seek inward. At this time, the control circuit 29 (ti timer 30 is started.Then, the control circuit 29 judges whether the scale number from the linear motor drive circuit 8 is also inside the scale number of the innermost track, and if it is inside, The linear motor 4 is caused to seek outward.Then, before the timer 30 times out, the track number is stored in the track number register 16, and the track number reading process described above is performed.
When the control circuit 29 reads the correct track number, the timer 30 determines whether a predetermined time or more has elapsed, and if so, it stops the seek operation and sets a flag requesting pitch recalculation. , within a predetermined time, the seek operation is stopped. Note that when the timer 30 times out, the control circuit 29 notifies you of an error.

In this way, when an access to a predetermined track is read, or when a track number is read in the first scale access, the control circuit 29 calculates the difference between the track number at the position to be accessed and the read track number. calculate.

When the difference is greater than 70 tracks, the control circuit 29 sets a flag requesting pitch recalculation, calculates the scale number difference from the track number difference, and corrects the scale position to be accessed. In this case, the control circuit 29 uses the scale signal and the linear motor drive circuit 8 to move the linear motor 4. After this access, the above-described track number reading process is performed again, and the operation starts from determining whether or not the correct track number can be read.

Further, when the difference between the track number of the position to be accessed and the read track number is between 20 and 70 tracks, the eccentricity is outputted from the eccentricity storage circuit 24, and the tracking sensor yl? The drive circuit 19 is turned off and tracking servo is no longer performed. Then, the control circuit 29 causes the linear motor drive circuit 8 to operate the linear motor 4 based on the track number difference. after that,
Upon completion of the access, the control circuit 29 reads the contents of the track number register 16, performs the track number reading process described above, and determines whether the correct track number has been read. If the correct track number is read, the control circuit 29 outputs the difference between the track number of the position to be accessed and the read track number.

Then, when this difference is within 20 tracks, and when the difference between the above-mentioned accessed power position no-track number and the read track number is calculated, and the difference is within 20 tracks, the control circuit 29 Eccentricity memory circuit 2
4 is turned on, and the tracking circuit 19 is also turned on. This is the track difference, tracking sir d? The 4FiK dynamic circuit 19 performs a track jump using the track jump pulse from the track jump pulse generating circuit 2o. Next, the control circuit 29 determines whether the track number of the track to which the track has been jumped matches the track number determined to be correct by the track number reading process described above and the track number to be accessed. If they do not match, The difference between the track number to be accessed and the read track number is calculated, and the track jump is performed again as described above. Furthermore, if it is determined that they match, it means that a normal access has been made.

In the above embodiment, the track number is determined to be correct if two reading results match at the time of the 7th access, but the present invention is not limited to this. It may be determined that the track number is correct when a predetermined number of reading results match.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a disk device that can obtain accurate track numbers.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a diagram schematically showing the overall configuration, FIG. 2 is a plan view showing an optical disk, and FIGS. 3 to 5 are for explaining the operation. This is a flowchart. DESCRIPTION OF SYMBOLS 1... Optical disk (disk), 3... Optical head (head), 4... Linear motor, 5... Optical scale, 7... Detector, 8... Linear motor 1 drive circuit, 16... Track number register, 26... Focus signal binarization circuit, 27... Demodulation circuit, 28... Track number discrimination circuit, 29... Control circuit.

Claims (2)

[Claims] (1) In a disk device having a head for recording information on a disk or reproducing information on a disk, when accessing the head, the track number is read multiple times), and if the reading result matches a predetermined number of times, the track number is A disk device characterized by being provided with a track determining means for determining that b is correct. (2) Claims characterized in that the track determining means reads track numbers at different positions on the disk and compares the reading results to determine whether or not the PB track number is correct. The disk device according to item 1.