JP2683030B2 - Disk device - Google Patents

Description

The present invention relates to a drive device having a servo mechanism for tracking by a servo pattern formed on a data recording surface.

[Conventional technology]

2. Description of the Related Art In recent years, disk devices such as floppy discs have been remarkably miniaturized and high-density recorded, and the narrow track and high density have been promoted even for a disk as a recording medium. However, when the density is increased in this way, it becomes difficult to accurately set the head position with respect to the recording track by conventional head feeding using a simple step motor or the like. As a method for solving this problem, a method has been adopted in which servo information for tracking is recorded on a recording medium and head tracking is performed based on this information.

As a result, as described above, the medium in which the tracking servo information is recorded and the conventional medium in which the servo information is not present are mixed, and in the device that handles these media, the compatibility is raised as one problem. There is.

Then, in a device equipped with a servo mechanism that performs heading tracking from information, a method of reading a medium without servo information (hereinafter referred to as a conventional medium) is as follows: (1) Open loop control of a stepping motor or the like as a tracking actuator. If you are using one that can be positioned, move the head to a position that is thought to be the center of the track and read it.

(2) If there is an error in the data information read by moving the head to a position that seems to be the target track position, for example, ID information or data part, if there is an error, move the head position slightly Find a position that does not exist.

Etc. can be roughly divided into two methods.

[Problems to be solved by the invention]

However, in the case of the above method (1), open loop control simply moves to a position that is considered to be the target track position and reads, so if the accuracy of the stepping motor or the like is poor, it will cause a track shift and cannot be read correctly. there were.

In the case of the method (2), it is difficult for the system side to control the head position on the drive device because it is determined by the system side to which the drive device is connected whether or not there is an error in the data. The processing time becomes long, and if a circuit for judging an error in data is added in the drive device, the circuit scale becomes large and the cost of the device becomes high.

[Means for solving the problem]

The present invention has been made for the purpose of solving the above-mentioned problems, and is a disk device for controlling the position of a head with respect to a track by servo information recorded on a recording medium. Means and
The recording medium is provided with the servo information based on the head moving means for moving the head according to the output of the detecting means to correct the deviation with respect to the target track, and the presence or absence of the detection of the servo information by the detecting means. And the determination means determines that there is no servo information, the detection means determines the amplitudes of the reproduction signals of the target and the track at a plurality of locations on the track. A recording medium having servo information and a servo medium having servo information by measuring and controlling the operation of the head moving means to move the head in a direction in which the amplitude level of the reproduction signal increases. This makes it possible to provide compatibility without preparing a dedicated circuit for each of both media which are not conventional media.

〔Example〕

An embodiment of the disk device according to the present invention will be described in detail below with reference to the drawings.

1 to 6 are diagrams for explaining an embodiment of the present invention and its description. FIG. 1 is a block diagram showing the configuration of a disk device of the present invention, and FIGS. 2 (a) and 2 (b) are FIG. 3 is a comparison diagram of track layouts of a medium having a track servo pattern and a conventional medium, FIG. 3 is an operation flow chart of the apparatus of the present invention, FIG. 4 is a diagram showing a timing relationship with a format, and FIG. 5 is a signal timing. And FIG. 6 are diagrams showing the measurement results from the amplitude measuring circuit. Embodiments of the present invention will be described below with reference to the drawings.

First, before describing the circuit operation according to the present invention, the positional relationship between the track layout and the head on the time disk as the recording medium considered as a target will be described with reference to FIG. The track format shown in FIG. 2 (a) shows an example of a servo pattern system called sector servo which becomes servo information for head tracking when recording / reproducing is mainly performed in the drive apparatus of the present invention ( Japanese Patent Application No. 62-4020 filed by the applicant earlier
No.), when traveling in the direction of the arrow AA in the figure by the magnetic head 6, signals of two different frequencies of F1 and F2 are detected, and the subsequent patterns A to D are sampled with this as the start timing of the servo pattern. , A, B, C, D, the amplitudes of two of them are compared to operate to correct the track deviation. The circuit block at this time is shown in FIG. 1, and the details are disclosed in the above-mentioned Japanese Patent Application No. 62-4020.

The track layout shown in FIG. 2 (b) is a conventional recording medium having no servo information, and is composed of 1/3 pitches of the track pitch of FIG. 2 (a), and the track width is about 2 as well.
Doubled (this is called the conventional medium. As a concrete value, for example, in the case of a 3.5-inch PRO disk, the track pitch of the conventional medium is 135 TPI, FIG. 2 (a).
The servo pattern of is 405 TPI. ).

In the figure, the track 00 and the head position a indicate that the head is completely within the track width (on-track state), or the track 01 and the head position b indicate that the head is within the track width. It shows a state in which it is displaced. When the reading operation is performed in the state of the track 01 in which the track deviation occurs, the recorded data cannot be correctly read, that is, an error occurs due to the output reduction due to the track deviation. Therefore, in the disk of FIG. 2 (a), the head position can be correctly controlled with respect to the track by the servo information.
When the head is accessed to the disk of FIG. 2 (b),
Since the track servo does not work, the track shift as shown by the head position b occurs. Therefore, the operation according to the present invention will be described below. The circuit block shown in FIG. 1 is originally a block diagram configured to perform a track servo targeting a medium having the track servo pattern. In the present invention, this hardware is used and the processing is performed by a microprocessor. By changing the flow, the conventional media on-track operation is performed.

 Here, the circuit configuration shown in FIG. 1 will be described.

FIG. 1 is a block diagram showing the structure of a disk device of the present invention. In FIG. 1, Di is a magnetic disk as a recording medium, 1 is a disk rotating motor for rotating a disk D at a predetermined speed, and 2 is described later. A motor drive circuit that rotationally drives the motor 1 according to a command from the microprocessor, 3
Is an index sensor for detecting the disk rotation, for example, an index hole of the disk, and 4 is a detection circuit for supplying a signal to the microprocessor 18 in accordance with the detection output of the index sensor 3 according to the rotational status of the disk.
Reference numeral 5 is a disc identification switch for detecting whether the disc has sovo information or a conventional medium through an identification hole or the like of the cassette.

6 is a magnetic head for recording / reproducing data on / from a recording track on the magnetic disk Di, 7 is a recording circuit for supplying a recording current to the magnetic head for recording data, and 8 is a magnetic head 6 for magnetic recording. In the reproducing circuit for outputting the data read from the disk D, the reproducing circuit 8 outputs the data signal and the servo information signal shown in FIG. 2 from the reproduced signal. Reference numeral 9 controls the recording circuit 7 in accordance with the data signal supplied via the external host computer connected to the disk device and the input / output interface 10 to perform data recording, and the reproduction circuit 8 supplies the reproduced data. A control logic circuit for supplying a data signal to an external host computer through an input / output interface 10. The recording circuit 8 and the control logic circuit 9 are controlled by the microprocessor 18 to execute each operation at a predetermined timing.

Reference numeral 11 is a servo signal detection circuit for detecting the servo information shown in FIG. 2 which is detected and output by the reproduction circuit 8, and 12 is an integration for integrating the servo information signal according to the instruction of the microprocessor 18 and outputting the average level thereof. An integrator circuit as a gate, 13 is a sample and hold circuit that samples and holds the output level of the integrator circuit in response to a command from the microprocessor 18, and 14 is a digital signal that converts the output of the sample and hold circuit 13 into a microprocessor. Supply A /
It is a D converter. That is, the servo signal detection circuit 11
When the _first two-frequency signals f ₁ and f _{2 of the} servo information shown in FIG. 2A are detected by the microprocessor 18, the microprocessor 18 operates the integrating circuit 12, and the sample-hold circuit causes the subsequent patterns A to D to be output. Is generated to hold the amplitudes at the positions of the respective patterns A to D. Then, the level of each signal pattern is converted into a digital signal by the A / D converter 14 and supplied to the microprocessor 18, so that the positional deviation of the head with respect to the track is detected.

The servo operation itself is described in detail in Japanese Patent Application No. 62-4020.

Reference numeral 15 is a head that moves the magnetic head 6 in the radial direction of the disk, that is, to each recording track, and the head position can be finely adjusted according to the amount of deviation between the head 6 and the recording track detected based on the servo information described above. A moving actuator, which is driven by, for example, a stepping motor or the like. 16 is a drive circuit which drives the actuator 15 for moving the head, 17 is a D / A which converts the control signal supplied from the microprocessor 18 into an analog signal and supplies a signal to the drive circuit 16 according to the amount of movement of the actuator. It is a converter.

Further, as described above, the microprocessor 18 records and reproduces data on and from the motor drive circuit 2 for rotating the magnetic disk, the drive circuit 16 for the actuator for moving the head, and the disk according to the information from each sensor and the control information from the outside. A control logic circuit for performing the operation, an integrated circuit (integration gate) 12 for detecting servo information detected on the disk, a sample hold circuit 13 and the like are collectively controlled, and hereinafter referred to as a CPU. .

Next, the operation of the disk device of the present invention will be described with reference to the flow chart of FIG.

First, when a cassette such as a floppy disk as a magnetic disk is inserted into the drive device (step 1), a medium identification hole or the like (not shown) provided in the cassette is identified by the cassette detection switch 5 (step 2). As a result, if the disk has servo information, the process proceeds to step 3, and the head tracking servo operation is performed according to the above-mentioned servo information. If it is a conventional medium, the control program enters the processing routine of step 4 and thereafter.

When a seek command to the target track is issued from the system side such as the host computer to read the data (step 4), the microprocessor 18 causes the target track of the head 6 through the D / A converter 17 and the drive circuit 16. A seek operation is performed (step 5). After the seek, for example, an index signal generated once per one rotation of the disk is detected by the index sensor, and 1 is synchronized with this.
Measure the playback amplitude in the rotating track. The measurement timing at this time is, as shown in FIG. 4, after detecting the index signal of FIG. 4 (a), as shown in FIG. 4 (b), the gear portion existing between the respective sectors in the recorded format. The amplitude of Gap is configured to be measured by the sampling pulse shown in (d) of the figure, which is generated at the timing shown in (c) of the figure. This is to reduce the influence of the recording density and the like by measuring the same recording pattern portion.

That is, after the index signal is detected by the index sensor 3 in step 6, the reproduction signal level output by the integration circuit 12 is held by the sample hold circuit 13 after a predetermined time has elapsed by the timer 1, and then by the A / D converter 14. Import to CPU18 (step
7,8). The operation timing chart at this time is shown in FIG. The figure (a) shows the relationship between the sector and the inter-sector gap.
(B) is an integration gate pulse for operating the integration circuit 12,
(C) is a hold pulse, (d) is a waveform of the output point P of the integrating circuit 12, and (e) is a sample-held pulse signal.

Next, in step 9, the timer 2 increments the measurement counter by +1 after a lapse of a predetermined time in step 10, and it is checked in step 11 that the scheduled number of times (N times) has been reached, and if it has not reached N times, it goes to step 8 again. Return and measure until N times. When the measurement is performed N times, the process proceeds to step 12 and N
The measurement data is checked once.

FIG. 6 is for explaining the check operation of the measurement data, and shows the case of 9 sectors per track. FIG. 7A shows the case where the head 6 is on-track with respect to the target track, and all the measurement levels are above a predetermined judgment level. FIG. 7B shows the case where the off-track is performed, and the determination level has not been reached at any measurement level. This makes it possible to discriminate between on-track and off-track (step 13).

Also, since the reproduction amplitude decreases from the outside to the inside depending on the track position of the disk, a coefficient that reduces the head output due to the decrease in relative velocity and the output decrease due to the increase in linear recording density at each track position with the amplitude of the outermost track as a reference. Is used to set the judgment level for each track.

That is, if it is on track at step 13, st
Proceeding to ep14, a seek complete output signal indicating that the seek operation has been completed is output to the system side to enable control on the system side (step 15). After that, when a seek operation command is issued again on the system side, the process returns to step 4 and the above operation is repeated.

On the other hand, if it is off-track in step 13, shift to step 16, compare the previous amplitude data measurement value with the current measurement value, and refer to the head movement direction at the last measurement, The head 6 is micro-stepped in the direction of increasing amplitude, and the head moving actuator 15 is controlled so as to be in the on-track state (steps 17, 18, 1).
9).

If there is no measured value at the first measurement of this time, the head is moved in any one direction, and the head position is detected by the next measurement.

Incidentally, the microstepping operation is generally used for minute feed of a rotary or linear stepping motor, and it drives by changing the current balance of the drive coil.

The off-track described in the above embodiment refers to the case where the track position is deviated, but in the case of eccentricity due to the tracking deviation of the cassette, for example, the amplitude is one revolution as shown in FIG. 6 (c). There is a part that increases and a part that decreases in the cycle.

As a method for this case, it is also possible to perform a microstepping command for each sector and perform tracking servo like a medium having a servo pattern. However, in this case, it may be necessary to measure the amplitude for one rotation or more and then perform learning control processing based on this.

〔The invention's effect〕

As described above, according to the disk apparatus of the present invention, the processing means for reading the conventional medium having no servo information is added by using the control circuit provided for the track servo for the disk having the servo information. By doing so, it is possible to realize complete compatibility control with the conventional medium with common hardware, and to reliably read the conventional medium without increasing the manufacturing cost.

Further, since the tracking control method is switched depending on the presence or absence of servo information, for example, even if the recording medium is not capable of accurate tracking control due to defective or missing servo information, accurate tracking operation is possible. It becomes possible to do.

Incidentally, according to the present embodiment, the case of the magnetic disk device and the magnetic head has been described as an example, but the present invention is not limited to this, and the present invention can be applied to, for example, an optical detecting device. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the structure of a disk device according to the present invention, FIGS. 2 (a) and 2 (b) are views for explaining a track and servo information pattern formed on the disk, and FIG. 4 is a flow chart for explaining the operation of the present invention, FIG. 4 is a timing chart for explaining the timing of the signal detection operation of the present invention, and FIG. 5 is a timing and waveform for explaining the signal detection operation of the present invention. FIG. 6 and FIG. 6 are waveform diagrams of measurement signals.

Claims (1)

(57) [Claims] 1. A disk device for controlling the position of a head with respect to a track based on servo information recorded on a recording medium, the detecting device detecting the servo information, and the head according to the output of the detecting device. A head moving unit that moves and corrects a deviation with respect to a target track; and a determining unit that determines whether or not the recording medium includes the servo information based on whether or not the servo information is detected by the detecting unit; When the determination unit determines that the servo information does not exist, the detection unit measures the amplitude of the reproduction signal of the target track at a plurality of points on the track,
A disk device comprising: a control unit that controls the operation of the head moving unit to move the head in a direction in which the amplitude level of the reproduction signal increases.