JPH04355285A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a head or a recording medium from being damaged or sucked by stopping a rotation of the recording medium after a floating type head separates from a disk-like recording medium, and separating the head from the recording medium, when a rotating speed becomes a prescribed value or below. CONSTITUTION:An ascending/descending means 6 allows a floating type magnetic head 5 to ascend and descend in the vertical direction against the surface of a magnetic disk 3, and also, is provided with a position detecting sensor for detecting whether the head 5 is in the most adjacent state to the disk 3 or not. A spindle motor 2 drives to rotate the disk 3, and a revolution speed detecting means 4 detects a rotating speed of the disk 3. A control part 1 controls the ascending/descending means 6 so that the rotation of the disk 3 is stopped after the head 5 separates from the disk 3, and also, the head 5 is separated from the disk 3, when the rotating speed of the disk becomes a prescribed value or below. In such a manner, damage of the head 5 or the disk 3, and suction of the head to the disk 3 can prevented.

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 equipped with a floating head such as a floating magnetic head or a floating optical head, and particularly relates to the raising and lowering of the floating head.

0002

2. Description of the Related Art In recent years, magneto-optical disks have been developed as optical memory devices capable of recording, erasing and reproducing information. A magneto-optical disk uses a perpendicularly magnetized film whose magnetization direction is perpendicular to the film surface as a recording medium.The perpendicularly magnetized film is heated by laser beam irradiation to reduce its coercive force, and then an external magnetic field is applied to the perpendicularly magnetized film. By applying the magnetic field, the direction of magnetization is made to match the direction of the external magnetic field, and information is recorded.

[0003] Recording methods for magneto-optical disks include an optical modulation method in which the intensity of laser light is modulated according to the information to be recorded while continuously applying an external magnetic field in a fixed direction, and a light modulation method in which the intensity of laser light is modulated according to the information to be recorded. It is broadly classified into a magnetic field modulation method, which reverses the direction of the external magnetic field depending on the information to be recorded.

By the way, when rewriting recorded information, the magnetic field modulation method is seen as a promising method for realizing so-called overwriting, in which new information is directly recorded over the old information without going through the process of erasing the old information. ing. In this case, in order to increase the switching speed of the direction of the external magnetic field and improve the transfer rate, it is necessary to reduce the inductance of the magnetic head, but this will reduce the magnetic field strength, so the magnetic head It must be placed as close to the magnetic disk as possible.

However, as a substrate for a magneto-optical disk,
Particularly when using a resin such as polycarbonate, the surface of the substrate has considerable surface runout, that is, unevenness in the circumferential direction. If the magnetic head is brought too close to the magneto-optical disk, the magnetic head will be affected by the surface runout. The head may come into contact with the magneto-optical disk, causing damage to the magnetic head or the magneto-optical disk. Therefore, it is necessary to leave a certain distance between the magnetic head and the magneto-optical disk.
There was a problem that the magnetic field strength tended to be insufficient. Furthermore, as the distance between the magnetic head and the perpendicularly magnetized film changes due to surface runout, the magnetic field strength tends to change.

[0006] Therefore, a floating magnetic head, which is used in magnetic disks, etc., is adopted, and the magnetic head is biased toward one surface of the magneto-optical disk by a suspension made of a leaf spring, etc. When stopped, the floating magnetic head is brought into contact with the surface of the magneto-optical disk, and as the magneto-optical disk rotates, the floating magnetic head follows the surface runout and is floated at a nearly constant minute distance from the magneto-optical disk, thereby recording. It is possible to do so.

[0007] On the other hand, in order to make the optical head smaller, lighter, and more integrated, it is also being considered to form it as a floating head and float it above a magneto-optical disk.

[0008]

[Problem to be Solved by the Invention] However, using a floating head as described above, it is difficult to force the floating head to come into contact with the surface of the magneto-optical disk from the stopped state of the magneto-optical disk using the same method as for magnetic disks. As the magneto-optical disk rotates, the floating head follows the surface runout and floats, and the floating head comes into contact with the magneto-optical disk as the rotation of the magneto-optical disk decelerates or stops.
So-called CSS (Contact Start and
If the CSS is repeated, the magneto-optical disk and floating head may be worn out or damaged, and the magneto-optical disk and floating head may attract each other, causing the spindle motor to become magneto-optical. There were problems such as the inability to rotate the disk.

These problems become even more serious when a floating head is used for a magneto-optical disk cartridge of the ISO standard, which is being defined without assuming the use of a floating head.

0010

[Means for Solving the Problems] An information recording and reproducing apparatus of the present invention is an information recording and reproducing apparatus that records information using a floating head on a disk-shaped recording medium that is rotationally driven by a rotational drive means. a lifting means for raising and lowering the floating head relative to the disk-shaped recording medium; a position detecting means for detecting the position of the floating head; a rotation speed detecting means for detecting the number of rotations per unit time of the disk-shaped recording medium; The rotation driving means is controlled so that the rotation of the disk-shaped recording medium is stopped after the disk-shaped recording medium leaves the disk-shaped recording medium, and when the number of rotations per unit time of the disk-shaped recording medium becomes equal to or less than a predetermined value, the floating head and control means for controlling the elevating means so as to separate the disc-shaped recording medium from the disc-shaped recording medium.

[0011]

[Operation] With the above configuration, in an information recording and reproducing apparatus that uses a floating head to record information on a disk-shaped recording medium that is rotationally driven by a rotational drive means, the floating head is raised and lowered with respect to the disk-shaped recording medium. an elevating means, a position detecting means for detecting the position of the floating head, a rotation speed detecting means for detecting the number of rotations per unit time of the disk-shaped recording medium, and a position detecting means for detecting the position of the floating head; The rotation driving means is controlled to stop the rotation of the disk-shaped recording medium, and when the number of rotations per unit time of the disk-shaped recording medium becomes less than a predetermined value, the floating head is moved up and down to move away from the disk-shaped recording medium. The floating head and the disk-shaped recording device are equipped with a control means for controlling the floating head and the disk-shaped recording device when the rotational drive of the disk-shaped recording medium is stopped or when the rotational speed of the disk-shaped recording medium falls below a predetermined value due to malfunction or the like. Contact of the media is largely avoided. This makes it possible to prevent damage to the floating head or the disk-shaped recording medium, and to prevent the floating head from adhering to the disk-shaped recording medium.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 3 shows a schematic configuration of a magnetic disk device using a floating magnetic head 5 (floating head). This device is placed on the top side of a magnetic disk 3 (a disk-shaped recording medium), and records information by applying a magnetic field to the magnetic disk 3, and also records information by detecting leakage magnetic flux from the magnetic disk 3. The floating magnetic head 5 for reproduction and the floating magnetic head 5 are moved up and down in a direction perpendicular to the surface of the magnetic disk 3, and it is checked whether the floating magnetic head 5 is in the closest state to the magnetic disk 3. An elevating means 6 equipped with a position detection sensor (position detection means, not shown) for detection, a spindle motor 2 (rotation drive means) that rotationally drives the magnetic disk 3,
The rotational speed detection means 4 detects the rotational speed of the magnetic disk 3, that is, the number of rotations per unit time, and the elevating means 6 raises and lowers the levitation based on detection signals from the position detection sensor and the rotational speed detecting means 4 of the elevating means 6. The apparatus includes a control section 1 (control means) that controls the vertical movement of the magnetic head 5 and the rotation of the spindle motor 2.

The floating magnetic head 5 is composed of, for example, a magnetic head, a slider to which the magnetic head is attached, and a suspension that supports the slider and urges the magnetic head toward one surface of the magnetic disk 3. ing. When the rotational speed of the magnetic disk 3 exceeds a predetermined value, the slider is moved by balancing the levitation force generated by the air flow between the bottom surface of the slider and the surface of the magnetic disk 3 and the biasing force by the suspension. At the same time, the magnetic head is designed to stably fly above the magnetic disk 3 while maintaining a substantially constant distance from the magnetic disk 3.

The floating magnetic head 5 is moved in the radial direction of the magnetic disk 3 by a moving means (not shown) such as a linear motor.

The rotational speed detecting means 4 includes, for example, a pulse generator consisting of a small piece of magnet attached to the rotating shaft of the spindle motor 2 and a fixed magnetic head, or
A frequency generator is used.

In the magnetic disk device described above, the floating magnetic head 5 when the rotation of the magnetic disk 3 is stopped.
The elevating and lowering operations will be explained based on the flowchart of FIG.

When stopping the rotation of the magnetic disk 3, first step 1 (hereinafter, step 1 is expressed as S1) is performed.
, whether the floating magnetic head 5 is in a position where it can record and reproduce information on the magnetic disk 3, that is, whether the floating magnetic head 5 is in the closest position to the magnetic disk 3. In order to check whether this is the case, the position information of the floating magnetic head 5 detected by the position detection sensor provided in the elevating means 6 is read into the control section 1. Based on this position information, the control unit 1 determines whether the floating magnetic head 5 is closest to the magnetic disk 3 (S2).

When the floating magnetic head 5 is not in the closest position, the control section 1 stops the rotation of the magnetic disk 3 by stopping the spindle motor 2 (S7), and ends the process. When the floating magnetic head 5 is in the closest position,
In order to separate the floating magnetic head 5 from the magnetic disk 3,
The control unit 1 causes the lifting means 6 to start raising the floating magnetic head 5 (S3). Then, in order to check again whether the floating magnetic head 5 is in the closest state to the magnetic disk 3, the position information of the floating magnetic head 5 detected by the position detection sensor provided in the elevating means 6 is determined. is read into the control unit 1 (S4). The control unit 1 determines whether the floating magnetic head 5 is closest to the magnetic disk 3 based on the position information (S5).

When the floating magnetic head 5 is in the closest position, the process returns to S4. Then, S4 to S5 are repeated until the floating magnetic head 5 is no longer in the closest state, in other words, until the floating magnetic head 5 is separated from the magnetic disk 3. When the floating magnetic head 5 is no longer in the closest state, the controller 1 moves the floating magnetic head 5 using the lifting means 6.
(S6). The control unit 1 stops the rotation of the magnetic disk 3 by stopping the spindle motor 2 (S7), and ends the process.

As described above, the magnetic disk device of this embodiment is configured to stop the spindle motor 2 and stop the rotation of the magnetic disk 3 after the flying magnetic head 5 leaves the magnetic disk 3. Contact between the floating magnetic head 5 and the magnetic disk 3 when the rotation of the magnetic disk 3 is stopped is almost avoided. Thereby, damage to the floating magnetic head 5 or the magnetic disk 3 and adsorption of the floating magnetic head 5 to the magnetic disk 3 can be prevented.

Next, when the floating magnetic head 5 is closest to the magnetic disk 3, the rotational speed of the magnetic disk 3 becomes lower than a predetermined value due to a malfunction or the like. The elevating operation will be explained based on the flowchart of FIG. 2.

In order to constantly check the rotational state of the magnetic disk 3, the control unit 1 reads the rotational speed of the magnetic disk 3 from the rotational speed detection means 4 through interrupt processing or the like (S11), and makes sure that the magnetic disk 3 rotates at a predetermined level. It is determined whether or not it is rotating at a speed higher than the speed (S12).

[0024] If the rotational speed of the magnetic disk 3 is equal to or higher than a predetermined value, the process ends without doing anything. On the other hand, if the rotational speed of the magnetic disk 3 is below a predetermined value,
The controller 1 immediately causes the lifting means 6 to start raising the floating magnetic head 5, and moves the floating magnetic head 5 away from the magnetic disk 3 (S13). Then, in order to check whether the floating magnetic head 5 is closest to the magnetic disk 3, the position information of the floating magnetic head 5 detected by the position detection sensor provided in the lifting means 6 is controlled. Part 1 is read (S14). Based on this position information, it is determined whether the floating magnetic head 5 is closest to the magnetic disk 3 (S15
).

When the floating magnetic head 5 is in the closest position, the process returns to S14. Then, the floating magnetic head 5
S14 and S15 are repeated until the state is no longer in the closest state. When the floating magnetic head 5 is no longer in the closest state, the control unit 1 stops the lifting means 6 from raising the floating magnetic head 5 (S16), and ends the process.

As described above, when the floating magnetic head 5 is in the closest position to the magnetic disk 3, the magnetic disk device of this embodiment always checks the rotational state of the magnetic disk 3 and performs some kind of operation. If the rotational speed of the magnetic disk 3 falls below a predetermined value for some reason, the floating magnetic head 5 is immediately separated from the magnetic disk 3. Therefore, contact between the floating magnetic head 5 and the magnetic disk 3 due to malfunction or the like is almost avoided. Thereby, damage to the floating magnetic head 5 or the magnetic disk 3 and adsorption of the floating magnetic head 5 to the magnetic disk 3 can be prevented.

Furthermore, since a position detection sensor is provided to detect whether the floating magnetic head 5 is closest to the magnetic disk 3, it is possible to accurately detect when the floating magnetic head 5 has separated from the magnetic disk 3. can be confirmed.

In the above embodiment, a magnetic disk device equipped with a floating magnetic head 5 has been described, but the present invention can also be applied to an information recording/reproducing device such as a magneto-optical disk device. Furthermore, similar effects can be obtained not only for the floating magnetic head 5 but also for various floating heads such as floating optical heads.

[0029]

As described above, the information recording and reproducing apparatus of the present invention includes a lifting means for raising and lowering a floating head with respect to a disk-shaped recording medium, a position detecting means for detecting the position of the flying head, and a disk-shaped recording medium. a rotational speed detection means for detecting the number of rotations per unit time of the disk-shaped recording medium; and a rotational drive means that controls the rotation of the disk-shaped recording medium so as to stop the rotation of the disk-shaped recording medium after the flying head leaves the disk-shaped recording medium. and control means for controlling the lifting means to move the flying head away from the disk-shaped recording medium when the number of revolutions per unit time of the disk-shaped recording medium becomes equal to or less than a predetermined value. Contact between the flying head and the disk-shaped recording medium is almost avoided when the rotational drive of the disk-shaped recording medium is stopped or when the rotational speed of the disk-shaped recording medium falls below a predetermined value due to malfunction or the like. Thereby, it is possible to prevent damage to the floating head or the disk-shaped recording medium, and to prevent the floating head from adhering to the disk-shaped recording medium.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the up-and-down operation of a floating magnetic head when rotation of a magnetic disk is stopped in a magnetic disk device according to the present invention.

[Fig. 2] In the magnetic disk device according to the present invention, when the floating magnetic head is in the closest state to the magnetic disk, the rotational speed of the magnetic disk becomes lower than a predetermined value due to a malfunction or the like. 5 is a flowchart for explaining the elevating and lowering operations of the magnetic head.

FIG. 3 is a schematic configuration diagram of a magnetic disk device.

[Explanation of symbols]

1 Control part (control means) 2 Spindle motor (rotation drive means) 3
Magnetic disk (disk-shaped recording medium) 4 Rotation speed detection means 5 Floating magnetic head (levitating head) 6
Lifting means

Claims (1)

[Claims] 1. An information recording and reproducing apparatus for recording information with a floating head on a disk-shaped recording medium that is rotationally driven by a rotational drive means, comprising a lifting means for raising and lowering the floating head with respect to the disk-shaped recording medium. , a position detection means for detecting the position of the floating head; a rotation speed detection means for detecting the number of rotations per unit time of the disk-shaped recording medium; control the rotation drive means to stop the rotation of the disk-shaped recording medium, and control the elevating means to move the floating head away from the disk-shaped recording medium when the number of rotations per unit time of the disk-shaped recording medium becomes less than a predetermined value. An information recording/reproducing device characterized in that it is equipped with a control means for controlling.