JPH0514975B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an information recording and reproducing apparatus that records information on a disk-shaped recording medium or reproduces information from a disk-shaped recording medium and erases the recorded information using an erasing magnet.

An example of this type of device is to record information by irradiating a light beam onto a magneto-optical disk with a ferromagnetic thin film to change the direction of magnetization, and to record information using the magneto-optical effect. Magneto-optical disk devices that reproduce . FIG. 1 shows an outline of such a magneto-optical disk device. 1 is a magneto-optical disk, for example, Tb.
It supports a ferromagnetic thin film made of an alloy such as Gd.Fe. Information is recorded by collimating the light beam emitted from the laser light source 2 according to the information into parallel light using the collimator lens 3, passing it through the beam splitter 4, and then collimating the light beam using the condenser lens 5. This is carried out by focusing a light beam spot with a diameter of 1 μm on the surface of the magnetic disk 1.
That is, although the ferromagnetic thin film on the magneto-optical disk 1 is magnetized in advance so that the direction is aligned in the vertical direction, the portion where the light beam spot is illuminated is heated to a high temperature by the energy of the light beam, and the ferromagnetic material When the temperature of the thin film reaches the Curie point or higher, the magnetization direction becomes disordered. When the light beam spot moves to another position as the magneto-optical disk 1 rotates, the temperature of that part where the magnetization direction is disordered decreases, and at this time, the external magnetic field causes it to move in the opposite direction to the surrounding area. Become magnetized. In this way, information is recorded in the ferromagnetic thin film as recording bits 6 (see FIG. 2) whose magnetization is reversed.

On the other hand, reproduction is performed as follows. A light beam whose output intensity is weaker than that during recording is emitted from a laser light source 2, linearly polarized by a polarizer 7, and then irradiated onto a bit string formed on a ferromagnetic thin film. The irradiated light is reflected by the ferromagnetic thin film, and this reflected light is rotated according to the direction of magnetization of the recording bits 6. The direction of this reflected light is changed by a beam splitter 4, the direction of magnetization is detected by an analyzer 8, and then guided to a light receiving element 9. Information is then reproduced from the output signal of the light receiving element 9 by the signal processing circuit 10.

A feature of such a device is that the distance P (track pitch) between signal strings on the magneto-optical disk 1 is less than 2 μm, and the recording density is 1 to 2 orders of magnitude higher than that of conventional magnetic disk devices. , large-capacity recording is possible. Furthermore, by configuring the optical head (consisting of the laser light source 2 to the light receiving element 9) to be movable in the radial direction of the magneto-optical disk 1, arbitrary retrieval (random access) of information recorded on the magneto-optical disk 1 can be performed. be able to.

If you take advantage of the above features of magneto-optical disk devices,
It can be used as a collation device for electronic copying devices such as facsimile machines. That is, as shown in FIG. 3, an image reading device 12 is connected to the input side of the magneto-optical disk device 11, and a printer 13 is connected to the output side, and the image information read by the image reading device 12 is transmitted to the magneto-optical disk device 11. The information is temporarily recorded on the magneto-optical disk device 11, and the information is reproduced as needed and sent to the printer 13 to print out the required number of copies. Now, assuming that the diameter of magneto-optical disk 1 is 200 mm and the diameter of the recording area is 100 mm, approximately
It has a storage capacity of 2G bits, and can record approximately 125 A4-sized documents on each side without data compression.

Incidentally, the storage capacity of the magneto-optical disk device 11 also has a certain limit, and previously recorded information may have to be erased as necessary.
That is, the remaining recording area after subtracting the already used recording area from the total recording area on the magneto-optical disk 1 becomes the usable recording area, but this remaining recording area alone cannot record all new information. This is because there is.

Therefore, in order to erase the previous information, conventionally the erasing magnet was moved in the radial direction of the magneto-optical disk 1 by a dedicated motor (Japanese Patent Application No. 58-16899).
(No.), efforts are being made to align the magnetization direction of ferromagnetic thin films to the initial magnetization direction. However, when a dedicated motor is used to move the erasing magnet in this way, there is a problem that the device becomes expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide an information recording and reproducing apparatus that solves the above-mentioned problems and can move an erasing magnet at low cost and with a simple configuration.

In order to achieve this object, the present invention provides a recording medium that records information on a disc-shaped recording medium or reproduces it from a disc-shaped recording medium while moving in the radial direction of the disc-shaped recording medium in which recorded information can be erased. In an information recording and reproducing apparatus that includes a reproducing head and an erasing magnet that erases information by applying a magnetic field substantially perpendicular to the recording area surface of a disk-shaped recording medium, the recording and reproducing head is connected to the disk-shaped recording medium. a first moving means for moving in the radial direction of the medium; and when the recording/reproducing head is moved out of the recording area of the disk-shaped recording medium by the first moving means, the moving means is interlocked with the evacuation operation. and second moving means for moving the erasing magnet radially across the recording area of the disk-shaped recording medium.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.

Figures 4 and 5 show an embodiment of the present invention.
4a and 4b are a plan view and a side view showing the configuration of the magneto-optical disk device, and FIG. 5 is a diagram showing the positional relationship between the optical head and the erasing head mechanism shown in FIG. 4 and its control system. Reference numeral 14 denotes an optical head for recording information with a light beam on the recording area A of the magneto-optical disk 15 or reproducing information from the magneto-optical disk 15, one end of which slides on a guide shaft 16 fixed to the main body of the device. The other end is supported by the guide rail 17 via a cam follower 18. Further, the optical head 14 has a protrusion 14a on the other end side. 19 is a rack attached to the lower part of the optical head 14 (see FIG. 4b), 20 is a head motor for the optical head 14, and the driving force of the head motor 20 is provided by the pinion 2.
1 to the rack 19, thereby
The optical head 14 moves in the radial direction of the magneto-optical disk 15 while being guided by a guide shaft 16 and a guide rail 17. 22 is a light beam irradiation port, and the optical head 14 is movable until the light beam emitted from the light beam irradiation port 22 irradiates at least the innermost track of the recording area A of the magneto-optical disk 15 (see two points in FIG. 4). The position where the light beam irradiation port 22 reaches the outermost peripheral edge of the magneto-optical disk 15 (the solid line position in FIG. 4) is the home position of the optical head 14. 23
is a spindle motor that rotates the magneto-optical disk 15.

24 is an erasing head fixed to one end of an L-shaped link 26 rotatably supported on a shaft 25;
As shown in Figure b, it is formed by a permanent magnet that generates a magnetic field in the direction of arrow B, and therefore the north pole is on the side facing the ferromagnetic thin film surface, and the south pole is on the opposite side. Here, the radial width of the magneto-optical disk 15 having a ferromagnetic thin film made of Gd.Tb.Fe is 1μ.
Experiments have shown that in order to reverse the magnetic field of m recording bits, the strength of the magnetic field on the ferromagnetic thin film needs to be 1 KOe (Oersted) or more, and Alnico is a material for a magnet that satisfies this condition. Examples include cobalt-based or rare earth cobalt-based magnets.

The link 26 mentioned above comes into contact with the stopper 28 by the clockwise biasing force of the torsion coil spring 27 while the optical head 14 is recording/reproducing (note that the erasing head 24 is in the recording area A of the magneto-optical disk 15). The stopper 28 is provided at a position further away from the optical head 14. Conversely, the optical head 14 is held at a position outside the solid line position in FIG. When the optical head 14 moves in a direction away from A, the other end 26a is pushed to the left in FIG. One end with 24) begins to do so. 29 is a support plate that holds the shaft 25 and one end of the torsion coil spring 27. An erasing head mechanism 30 is comprised of the erasing head 24 to the support plate 29 described above.

31 controls the position of the optical head 14 (in the radial direction of the magneto-optical disk 15) via the head motor drive circuit 32 and the head motor 20;
A control circuit that controls the rotational speed of the magneto-optical disk 15 via the spindle motor drive circuit 33 and the spindle motor 23. When a copy number input signal is input from an image reading device (not shown), the head motor drive circuit 32 and the spindle motor are driven. circuit 3
When the erase end signal I is input from the microswitch 34, a head movement stop signal J is generated to the head motor drive circuit 32. The micro switch 34 causes the erase head 24 to move to the recording area A of the magneto-optical disk 15.
The optical head 14 is placed in such a position that it turns on (by contacting the optical head 14) when the optical head 14 has completely traversed the area, that is, when erasing has completed completely.

Next, the operation of the erase head mechanism 30 according to the present invention will be explained in detail with reference to the timing chart of FIG. First, when the number of copies input signal is input, the control circuit 31 generates a recorded information erasure signal H (see FIG. 6). In response to this signal, the head motor drive circuit 32 outputs a drive signal to the head motor 20, and the head motor 20 drives the optical head 1.
4 moves in the radial direction of the magneto-optical disk 15 (in the direction of arrow C in FIG. 4a) (see FIG. 6). At this time,
The protruding plate 14a of the optical head 14 pushes the other end 26a of the link 26, so that the link 26 rotates about the shaft 25 against the biasing force of the torsion coil spring 27, that is, the link 26
The erasing head 24, which is fixed at one end, begins to move in the direction of arrow D (see FIG. 4a). The recorded information erase signal H is also input to the spindle motor drive circuit 33, and the spindle motor drive circuit 33 is connected to the magneto-optical disk 15 via the spindle motor 23.
(see Fig. 6) in the direction of arrow E (see Fig. 5). Here, there is a certain relationship between the rotational speed of the spindle motor 23 and the moving speed of the optical head 14, and if the rotational speed of the spindle motor 23 is P [rps] and the width of the erasing head 24 is _l1 , then
The moving speed of the optical head 14 is set so that the erasing head 24 moves toward the center of the magneto-optical disk 15 at a speed less than P·l ₁ . Due to this moving speed, the erasing head 24 moves toward the magneto-optical disk 15.
The maximum width of the erasing head 24 during one rotation is l ₁
Since the erase head 2 travels only a distance corresponding to
4 crosses the recording area width l on the magneto-optical disk 15, the magnetization directions of the ferromagnetic thin films on the magneto-optical disk 15 are all aligned in the direction of arrow B. When the optical head 14 moves until it comes into contact with a microswitch 34 installed in the main body of the apparatus, the microswitch 34 is turned on and an erasure completion signal I is input to the control circuit 31. As a result, the control circuit 31
outputs a head movement stop signal J (see FIG. 6) to the head motor drive circuit 32, which causes the head motor drive circuit 32 to stop moving the optical head 14 in the direction of arrow C via the head motor 20. At this time, the erasing head 24 has reached at least the innermost track of the recording area A of the magneto-optical disk 15, as shown in FIG. Through the above operations, it becomes possible to erase the information recorded on the magneto-optical disk 15.

Thereafter, when the control circuit 31 generates a signal to the head motor drive circuit 32 to move the optical head 14 to a desired recording area (recording start position), the head motor drive circuit 32 causes the head motor drive circuit 32 to move the optical head 14 to a desired recording area (recording start position).
0 to move the optical head 14 to the desired recording area. At this time, erase head 24 (link 2
6) is rotated clockwise by the biasing force of the torsion coil spring 27 and stops when it hits the stopper 28. The moving speed of the erasing head 24 at this time may be P·l ₁ or more. Thereafter, a series of recording and reproducing sequences are performed.

The recording and reproducing sequence when the magneto-optical disk device of the present invention is connected to the image reading device 12 and printer 13 as shown in FIG. 3 and used as a collating device will be explained with reference to FIG. for example,
When you want a copy of a part of the image, after setting the predetermined initial conditions, start by pressing the button (step
101) Let. The image information signal read by the image reading device 12 is output to the printer 13 via a coaxial cable without going through the magneto-optical disk device (because only a part of it is), and is read by the printer 13 ( Step 102), and only a portion of the image is printed out as a copy image (Step 103). At this time, the previous recorded information in the magneto-optical disk device (on the magneto-optical disk 15) is not erased. When a plurality of copies is desired, a predetermined number of copies is inputted (step 104), and in conjunction with this, the erase head mechanism 30 erases the previously recorded information in the magneto-optical disk device (step 105).
That is, when image information is input to the magneto-optical disk device, the recording area A of the magneto-optical disk 15 is always completely erased, so the operator is guaranteed to use the maximum storage capacity. Furthermore, if you specify the page order (for example, output the printer 13 in the reverse order of image information input or every other page), you can
106), the read image information signals are once recorded in the recording area A of the magneto-optical disk 15 in a predetermined order (step 107). When the recording is completed, the recorded information recorded in the recording area A of the magneto-optical disk 15 is reproduced a necessary number of times (step 108), and sequentially outputted to the printer 13 via the coaxial cable. The printer 13 prints the copied images in the specified order (step 109), and when the necessary number of copies have been printed (step 110), the sequence ends.

According to this embodiment, the driving force of the optical head 14 (head motor 20) is used as the driving source for the erasing head 24 for erasing previously recorded information on the magneto-optical disk 15. The erase head mechanism 30 for moving the erase head 24 radially across the recording area A of the magneto-optical disk 15 can be made inexpensive.

In this embodiment, the head motor 20 corresponds to the first moving means of the present invention, and the shaft 25 and the link 2
6, the torsion coil spring 27, the stopper 28, and the support plate 29 correspond to the second moving means of the present invention.

In the embodiments of FIGS. 4 and 5, a permanent magnet is used as the erasing head 24, but an electromagnet may also be used. In addition, the home position of the optical head 14 was set as the position where the light beam irradiates the outermost peripheral edge of the magneto-optical disk 15, but the position where the micro switch 34 is turned on is set as the home position, and the series of recording and reproducing sequences ends. After returning to the home position, the data may be erased on the way back to the home position. Further, although the link 26, the other end 26a, the torsion coil spring 27, etc. are used to move the erasing head 24, the same effect can be obtained by using a wire or the like.

Furthermore, although this embodiment has been described using a magneto-optical disk device as the information recording/reproducing device, it is also possible to apply the present invention to a magnetic disk device.

As explained above, according to the present invention, information is recorded on or reproduced from a disc-shaped recording medium while moving in the radial direction of the disc-shaped recording medium from which recorded information can be erased. In an information recording and reproducing apparatus that includes a reproducing head and an erasing magnet that erases information by applying a magnetic field substantially perpendicular to a recording area surface of a disk-shaped recording medium, the recording and reproducing head is connected to the disk-shaped recording medium. a first moving means for moving in the radial direction of the medium; and when the recording/reproducing head is moved out of the recording area of the disk-shaped recording medium by the first moving means, the moving means is interlocked with the evacuation operation. and a second moving means for moving the erasing magnet radially across the recording area of the disk-shaped recording medium, the erasing magnet can be moved using the drive source of the recording/reproducing head. Since the erasing magnet is moved by using the same method, the erasing magnet can be moved at low cost and with a simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a general magneto-optical disk device, Fig. 2 is a plan view of the magneto-optical disk shown in Fig. 1, and Fig. 3 is the input side of the magneto-optical disk device shown in Fig. 1. FIG. 4 is a perspective view showing an example in which an image reading device is connected to the output side and a printer is connected to the output side, respectively.
Figures a and b are a plan view and a side view showing the positional relationship between an optical head and an erasing head mechanism arranged in a magneto-optical disk device according to an embodiment of the present invention, and Figure 5 is an optical head shown in Figure 4. Figure 6 is a time chart showing the signals generated in the control circuit shown in Figure 5 and the operation of each motor at that time; Figure 7 is a diagram showing the control system that controls the head, erase head mechanism, and its operation; This is a flowchart of each device when a magneto-optical disk device according to an embodiment of the invention is used as a collating device as shown in FIG. 3. 14...Optical head, 14a...Protrusion, 15
...Magneto-optical disk, 19...Lack, 20...
Head motor, 23...Spindle motor, 24
... Erase head, 25 ... Axis, 26 ... Link,
26a...other end, 27...torsion coil spring,
28...stopper, 29...support plate, 30...erasing head mechanism, 31...control circuit, 32...head motor drive circuit, 33...spindle motor drive circuit, A...recording area, H...recording information Erasing signal, J...Head movement stop signal.

Claims (1)

[Claims] 1. A recording/reproducing head that records information on or reproduces information from the disc-shaped recording medium while moving in the radial direction of the disc-shaped recording medium from which recorded information can be erased, and a recording area of the disc-shaped recording medium. In an information recording and reproducing apparatus equipped with an erasing magnet that erases information by applying a magnetic field substantially perpendicular to the surface thereof, a first movement of moving the recording and reproducing head in the radial direction of the disk-shaped recording medium. and when the recording/reproducing head is retracted out of the recording area of the disk-shaped recording medium by the first moving means, the erasing magnet is moved toward the disk-shaped recording medium in conjunction with the retracting operation. an information recording/reproducing apparatus comprising: second moving means for moving the recording area in a radial direction;