JPH0528600Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is applicable to a device that performs recording by irradiating a plurality of beams onto a disk surface, such as a magneto-optical disk recording and reproducing device that can record, read, and erase. The present invention relates to an available optical head transport device.

(b) Conventional technology In recent years, magneto-optical disks have been developed as high-density, large-capacity recording media (Journal of the Television Society of Japan).
(See 1985, April issue VoL.39.No.4, pages 365-373). Such a magneto-optical disk is made of a magnetic material, and has the property that when an external magnetic field is applied in a high temperature state, its magnetization direction can be easily made to match the magnetization direction of the external magnetic field. Using this method, binary digital information is recorded on an information track formed on a disk depending on the direction of an external magnetic field. Furthermore, during reproduction, a linearly polarized beam is irradiated onto the information track, and the deflection direction of the reflected beam from the disk surface is rotated by a predetermined angle depending on the magnetization direction of the irradiated portion. The binary information is read by detecting the deflection state of the reflected beam.

When recording information on the above-mentioned disk, it is necessary to raise the temperature of the recording portion on the information track, and a laser beam is generally used as a means for this purpose.

Now, in order to record digital information on the above-mentioned disk, the magnetization direction of the area on which information is to be recorded must be aligned in one direction in advance.In other words, the information track to be recorded must be set to an erased state. Must be. Therefore, during recording, at least two beams, a recording beam and an erasing beam, are required, and a magnet that magnetizes the irradiated part of the erasing beam in one direction, and a magnet that magnetizes the irradiated part of the recording beam in a binary information format. A magnet that magnetizes according to is required. Furthermore, the erasing beam and magnet must always be located on a track ahead of the recording beam and magnet.

In order to satisfy such requirements, a method using an optical head that generates a recording beam and a magnetic field and an optical head that generates an erasing beam and magnetic field is considered. The concept of such a method was published in Japanese Patent Application Laid-Open No. 1986-
It is disclosed in Publication No. 217250.

(c) Problems to be solved by the invention When two optical heads are used to record information on a disk, the invention proposes a method for each optical head so that the erasing head is always in a position ahead of the recording head. The aim is to realize a device that drives the motor with a simple configuration.

(d) Means for Solving the Problems In order to provide the above-mentioned device, the present invention includes two optical heads that irradiate beams onto the disk surface, and two optical heads that slide in the radial direction of the disk. The optical head is configured to have a shaft that freely supports the optical head, and a drive mechanism that simultaneously drives both optical heads while keeping the distance difference in the radial direction between the respective optical heads constant.

(E) Effect According to the present invention, the two optical heads are simultaneously driven in the same radial direction by the drive mechanism, and furthermore, the distance difference in the radial direction of each optical head is kept constant during driving. If two optical heads are used for erasing and recording, and the erasing head is set ahead of the recording head, the erasing head will always move ahead of the recording head when the optical head is moved. .

(f) Examples The figure shows one embodiment of the present invention.

Reference numerals 1 and 2 denote a recording head and an erasing head, respectively, which include a semiconductor laser as a light source, an objective lens for converging the laser beam onto the magneto-optical disk surface D, and an electromagnet for applying a magnetic field to the converging portion of the laser beam. Furthermore, the erasing head 2 is configured to have a reproducing function for reading information recorded on the disk by reducing the output level of the laser beam in the reproducing mode.

Further, a spiral information track is formed on the magneto-optical disk D, and during recording, the disk D is rotated at a constant angular velocity, and the recording head and erasing head are scanned from the innermost periphery to the outer periphery of the information track. It is used for recording.

3 is a shaft that supports the recording head 1 and the erasing head 2 in a slidable manner in the radial direction of the disk;
It is inserted into a through hole provided at one end of the recording head 1 and the erasing head 2.

Numeral 4 is a worm gear that supports the ends of the recording head 1 and erasing head 2 and transmits driving force to each head. Gear portions 5 and 6 are provided alternately and with the same pitch, and track portions 7 and 8 disposed on the recording head 1 and the erasing head 2 mesh with the gear portions 5 and 6. Here, the recording head 1 and the erasing head 2 are arranged to sandwich a spindle motor 9 as shown in the figure, and the erasing head 2
is arranged slightly ahead of the recording head 1 in the direction of the outer circumference of the disk.

In this embodiment configured as described above, when the worm gear 4 is rotationally driven by the drive motor, the recording head 1 and the reproducing head 2 are rotated in opposite directions due to the difference in the threading directions of the gear parts 5 and 6. That is, it is moved in the outer circumferential direction or the inner circumferential direction with respect to the disk. Furthermore, since the gear parts 5 and 6 of the worm gear 4 have the same pitch, each head moves at the same speed when the worm gear 4 is rotated, and when the heads move, the erasing head 2 is faster than the recording head 1. It is always moved slightly ahead in the outer circumferential direction.

As described above, in this embodiment, when the worm gear is driven during recording, the recording head scans the information track that has been erased by the erasing head, thereby recording information.

In this example, a worm gear with opposite thread cutting directions was used as the drive mechanism for the two heads, but the invention is not limited to this. For example, by combining a plurality of gears, two types of worm gears with different rotation directions can be used. A configuration may also be adopted in which a driving gear is formed and the driving gear is meshed with the rack portion of each head to obtain the driving force.

(g) Effects of the invention According to the invention, two optical heads driven simultaneously by the drive mechanism are driven in the same radial direction while keeping the distance difference in the radial direction constant. If the head that precedes the information track on the inner disk in the radial direction is set as the erasing head and the other head is set as the recording head, the recording head will always scan the information track erased by the erasing head during recording. I decided to do it,
Thus, the head can be moved during recording simply by driving the drive mechanism.

[Brief explanation of the drawing]

All drawings show one embodiment of the present invention.
FIG. 1 is a plan view of the main part, and FIG. 2 is a side view of the main part. 1... recording head, 2... erasing head, 3
...Shaft, 4...Worm gear, 7, 8...
Rack part [forms a drive mechanism together with 4], D...disc.

Claims (1)

[Claims for Utility Model Registration] An erasing optical head and a recording optical head that irradiate a beam onto a disk surface, a shaft that supports the two optical heads so as to be slidable in the radial direction of the disk, and the two optical heads. A drive for simultaneously driving the recording heads and moving the recording optical head linearly in the opposite direction to the erasing optical head when the erasing optical head moves linearly from the inner circumference to the outer circumference of the disk. An optical head feeding device comprising: a mechanism for causing the erasing optical head to precede the recording optical head by a very small amount in the outer circumferential direction.