JPS6332771A - Disk device - Google Patents

Abstract

PURPOSE:To improve the compatibility of a recording and reproducing data with a simple device by providing an encoder means recorded with servo information leading a head to a prescribed track position to one end of a means 7 moving the recording/reproducing head so as to use the servo information thereby controlling the head position. CONSTITUTION:A magnetic disk 9 is contained in a cassette 9a, which is mounted on a prescribed position of a base 7 of a disk device. Further, the disk 9 is exposed externally from a head window provided to the cassette 9a to form an opening 7a corresponding to the window. A magnetic head 8 is moved along the opening 7a and positioned to a track position on a prescribed radius of the disk 9. Further, a head holder 8a is fixed to a carriage 6 and a steel belt wound on a drive shaft 3 of the motor 5 is fixed along its side face. Further, an encoder plate 1 is provided on one end of the carriage 6 moved to the head 8 and the position of the head 8 is controlled by track servo information from the encoder plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk device, and particularly to a disk device that controls the position of a recording/reproducing head based on servo information recorded on a predetermined member in advance.

[Prior Art] Optical disk devices and magnetic disk devices are known as disk devices as described above.

Magnetic disk drives are widely used as external storage systems for computer systems, word processors, image processing devices, and the like.

In magnetic disk equipment, multiple information tracks are formed on the disk by positioning magnetic heads in stirrups on multiple disk surfaces and reading and writing information at those positions. Ru.

The track position l on the disk, that is, the position of the magnetic head, may vary depending on conditions such as the expansion and contraction of the disk depending on environmental conditions, the manufacturing accuracy of the disk, and so on. We must expect clear skies.

For this reason, in devices that control track positions using an oven loop, in order to reduce crosstalk between tracks,
Techniques such as setting guard bands between tracks and performing tunnel erasure are used.

[Problem to be solved by the invention] Also. A method is also known in which a servo signal for positioning a magnetic head, that is, a track servo signal, is recorded on a magnetic disk, and this servo signal is reproduced to control the head position.

According to such a system, the position of the tracker 2 can be controlled with high precision, and by omitting a guard band or the like, it is possible to increase the density of recording. However, with this type of device, only media that has been formatted in advance with a dedicated formatter and recorded with ID information and track servo signals can be used. It must be formatted and used.

Since the cost of a formatted disk is naturally higher, there is a problem in that the running cost of the medium increases.

[Means for Solving the Problems 5] In order to solve the above problems, in the present invention, a track servo information is placed at a predetermined position on a rotationally driven recording/reproducing disk based on track servo information pre-recorded on the recording/reproducing disk. In a disk device that positions a recording/reproducing head and records/reproduces information on a predetermined track of a recording/reproducing disk, a drive means for moving the recording/reproducing head; It has an encoder means in which servo information for guiding the head to a predetermined track position is recorded, and when formatting a recording/reproducing disk, the servo information of this encoder means is used to control the position of the recording/reproducing head, and track servo information is written on the recording/reproducing disk. A recording configuration was adopted.

[Sakukawa] According to the above configuration, even if no information is recorded on the recording/reproducing disk, after the recording/reproducing head is positioned at the approximate track position, the servo information recorded on the encoder of the drive system can be read. It is possible to control the track position with high precision using this method, and to write track servo information with high precision. By using the track servo information written in this way, it is possible to drive the disk between devices, such as when the disk is not previously formatted with a dedicated formatter and is formatted including the servo information on each user device. Track deviations and other inconveniences caused by variations in conditions can be eliminated.

[Example] The present invention will be described in detail below based on an example shown in one drawing. An embodiment relating to a magnetic disk device will be described below as an example of a disk device.

FIG. 1 is a perspective view showing the configuration of a floppy disk device employing the present invention. In this embodiment, a magnetic disk 9 is housed in a cassette 9a. Cassette 9a
is loaded at a predetermined position on the base 7'' of the magnetic disk device, and in this state, the center hub 9b of the disk 9 middle and the spindle 11 of the motor 10 attached to the base 7 are engaged, and the magnetic disk 9 is held at a constant position ( or variable) rotational speed.

The magnetic disk 9 can be exposed to the outside through head windows provided on the upper and lower surfaces of the cassette 9a, and a rectangular opening 7a is formed in the base 7 at a position corresponding to the head window. The magnetic helad 8 moves along this opening 7a and is positioned at a track position on a predetermined radius of the magnetic disk 9.

In the figure, only the lower side of the magnetic head 8 is shown, and the illustration of the upper magnetic head is omitted. The lower magnetic helad 8 is fixed to a head bolder 8a having a size that allows it to move within the opening 7a of the base 7, and the head holder 8a is fixed on the carriage 6. The steel belt 4 fixed along the side surface of the carriage 6 with screws 4b is connected to a motor 5 consisting of a step motor or the like.
is wound around the drive shaft 3, and a part of it is fixed to the drive shaft 3 with a screw 4a.

Therefore, when the motor 5 is rotated by a predetermined amount, the carriage 6
is translated in the P or Q direction in the figure via the steel belt 4.

A disk-shaped encoder plate l is attached to the tip of the drive shaft 3 of the motor 5, and the position of the carriage 6, that is, the magnetic helad 8 is attached to this encoder plate l.
A slit is cut so that the absolute position of can be detected with a predetermined resolution. This slit is detected by a sensor 2 using a photocoupler or the like.

FIG. 2(A) explains a detection method using the encoder plate 1 and photosensor 2 of FIG. 1, and in the figure, reference numeral IA indicates a slit in the encoder plate l. This slit IA is configured to run through the positions of slits 2A and 2B of a slit plate attached to the photosensor 2. Each slit 2A, 2B is arranged in front of two light receiving elements of the photosensor 2. The width W of the slits 2A and 2B is set equal to the width W of the slit 1A of the encoder plate 1. Also, slit 2
As shown in the figure, the positions of A and 2B are set to be shifted by half the pitch of the slit IA along the direction of entry of the slit IA.

As a result, the light source of the photosensor 2 is turned on.

When the motor 5 is rotated, the photosensor 2 outputs an output signal formed by the slit 2A and an output signal formed by the slit 2B, as shown by reference numeral 10.11 in FIG. 2(B). . These output signals are pseudo sine waves, and their phases are shifted by 180'' from the above slit arrangement.

On the other hand, the slit pitch of the encoder plate 1 is one slit per one track movement of the magnetic head 8).
A is set so that it passes through the position of the photosensor 2.

On the other hand, the recording format of the magnetic disk 9 is as shown in FIG. Up to n sectors are formed.

Each sector is identified by sector ID information (not shown), as in the past. In addition, track servo information having two recording frequencies f, . The servo information on both sides of the track having these two frequencies is reproduced by the magnetic helad 8, detected by a tuning circuit having the respective corresponding frequencies, and their levels are compared. When the magnetic head 8 is placed at the center of a predetermined track, the servo information is shifted by half a track pitch, so the frequencies fl,
The reproduction levels of the two servo information having f2 become equal. If the reproduction level of any of the servo information is large, the magnetic head 8 is not correctly positioned at the track center, so the magnetic head is moved in the direction where the reproduction levels are equalized, and as a result, it is not accurately positioned at the track center position. be guided. However, as shown in figure f53, the frequency ft.

Since the servo information of f2 is arranged alternately, it is necessary to control the moving direction of the magnetic head in the opposite direction for the even-numbered tracks and the odd-numbered tracks to correspond to the magnitude relationship of the servo information.

Next, the operation when writing the servo information shown in FIG. 3 in the above configuration will be explained.

In this case, the magnetic head position is controlled by counting the number of steps in the drive signal of the motor 5, which is a step motor, and by performing closed-loop control to confirm the magnetic head position using an encoder device consisting of an encoder plate 1 and a photosensor 2. .

As shown in FIG. 2(B), the output levels of the two systems of the photosensor 2 coincide with each other at the normal track position and the positions 10 and 11 shifted by a half track before and after the normal track position. By utilizing this fact and monitoring both the number of driving steps of the motor 5 and the output of the photosensor 2,
The magnetic head 8 can be accurately positioned on the recording surface of the magnetic disk 9 at a half-track pitch.

A head 8 corresponding to a feed amount less than the step amount of the motor 5
As is well known, the minute position correction can be performed by changing the balance of the current of the excitation phase of the motor 5. The operation of feeding the magnetic head 8 by a small amount and comparing the outputs of the two systems of the photosensors 2 is repeated to advance the magnetic head to a predetermined track position, and when the outputs of the two photosensors match, the driving current of the motor is fixed. In this state, servo information is written.

As described above, it is possible to advance the magnetic head in half-track pitch increments and store servo information.

Next, writing of sector ID and normal writing and reading operations will be explained. In these cases, positioning is not performed using the encoder plate l and the photosensor; in this case, the positioning of the magnetic helad 8 is performed by detecting servo information on the disk and monitoring the number of drive steps of the motor 5. In order to guide the magnetic heald 8 to a predetermined track position on the disk 9, first rotate the motor 5 by a predetermined step M, and guide the magnetic heald 8 onto the regular track.
Roughly position. Furthermore, when the servo information of the frequency fl+f2 shown in FIG. 3 is generated by +IT in this state, a composite output of two frequencies is obtained from the magnetic herad 8 as described above. By separating these signals using a tuning circuit, comparing their levels, and controlling the motor 5 by a small amount in accordance with the difference signal, the magnetic head can be correctly positioned on a regular track.

According to the above configuration, when writing track servo information on the magnetic disk 9, the magnetic head is moved by closed-loop control based on position detection, so it is much more expensive than writing with a conventional open-loose magnetic disk device. Accurate servo information can be written into WiNj.

As a result, variations in servo information written between user devices can be suppressed, and a high degree of compatibility in recording and reproduction can be ensured.

On the other hand, during normal recording and playback, the magnetic head position is controlled based on servo information written on the magnetic disk, so even if the disk expands or contracts due to temperature and humidity, there is high compatibility in terms of data recording and playback. It is possible to ensure sex.

According to the above configuration, since a raw magnetic disk can be formatted and used in each user device without using a dedicated formatter, there is an excellent effect that the cost of the recording medium can be reduced.

In the above embodiment, an optical encoder is used, but the method of detecting one position is not limited to the optical type, and may be a magnetic type.Also, it is not limited to the rotary encoder, and the linear encoder is fixed to a carriage etc. It can also be used as

Furthermore, a linear motor can also be used as the driving means for moving the magnetic head. Alternatively, the motor is not limited to the stepping motor, and a direct current motor, voice coil motor, or the like may be used.

Furthermore, regarding track servo control, the above embodiment does not use an encoder attached to the motor shaft during normal data access, but at the initial stage of head positioning, instead of monitoring the motor step amount, Positioning may be performed using an encoder attached to the motor shaft, or when a DC motor or the like is used, the encoder attached to the motor shaft is used for initial positioning. Further, in the above embodiment, a method of writing servo information for each sector as shown in FIG. 3 was shown, but the method of writing track servo information is not limited to this sector servo method. Various methods can be applied, such as writing information.

The above technique is not limited to magnetic disk devices, but can also be applied to optical disk devices and the like.

Further, the servo information may be constructed by recording signals of the same frequency with a time difference instead of signals of two frequencies.

[Effects] As is clear from the above configuration, according to the present invention, a recording/reproducing head is placed at a predetermined position on a rotationally driven recording/reproducing disk based on track servo information recorded in advance on the recording/reproducing disk. In a disk device for positioning and recording/reproducing information on a predetermined track of a recording/reproducing disk, there is provided a driving means for moving the recording/reproducing head, and a driving means provided in a part of the driving means to move the recording/reproducing head to a predetermined track. It has an encoder means that records servo information that leads to the position, and when formatting a recording/reproducing disk, the servo information of the encoder means is used to control the position of the recording/reproducing head, and track servo information is recorded on the recording/reproducing disk. As a result, each user device can write track servo information with high precision, and can also record and reproduce data with high precision based on the written servo information, and can record and reproduce 771 pieces of recorded and reproduced data.
This has the excellent effect of greatly improving convertibility and reducing the cost of the recording medium.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main part configuration of a magnetic disk device adopting the present invention, FIG. 2 (A) is an explanatory view showing the configuration of the position detection means in FIG. 1, and FIG. 2 (B) 1 is a diagram showing the output of the photosensor shown in FIG. 1, and FIG. 3 is an explanatory diagram showing the recording format of the magnetic disk shown in FIG. 1... Encoder plate 2... Photo sensor 4... Steel belt 5...
...Motor 6...Carriage 7...Base 8...Magnetic head 9...Magnetic disk

Claims (1)

[Claims] A disk in which a recording/reproducing head is positioned at a predetermined position on a rotationally driven recording/reproducing disk based on track servo information recorded in advance on the recording/reproducing disk, and information is recorded/reproduced on a predetermined track of the recording/reproducing disk. The apparatus includes a driving means for moving the recording/reproducing head, and an encoder means provided as a part of the driving means and recording servo information for guiding the recording/reproducing head to a predetermined track position, and the encoder means is provided as a part of the driving means and records servo information for guiding the recording/reproducing head to a predetermined track position. A disk device characterized in that the position of the recording/reproducing head is controlled using the servo information of the encoder means, and the track servo information is recorded on the recording/reproducing disk.