JPS61236051A - Recording method for information of optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To make possible recording and erasing simultaneously by irradiating two light beams onto a recording medium while giving magnetic field of one direction to the recording medium by an electromagnet and making recording of information by modulated light beam and making erasing of information by unmodulated light beam. CONSTITUTION:As shown in the figure (a), in adjoining track C and track D of a recording medium 1, the track C is magnetized upward and erased as initial state, while information of '1' and '0' is recorded in the track D. In the figure (b), downward magnetic field is given to the recording medium by an electromagnet 7, a laser driver 25 is driven to modulate a light beam A and the light beam A is irradiated onto the track C, and at the same time, a light beam B is irradiated onto the track D without modulation. Then, information is recorded successively in the track C by the light beam A, and information is erased successively in the track D by the light beam B. As shown in the figure (c), information is recorded in the track C and information in the track D is erased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an information recording method for an optical information recording/reproducing device that performs recording and erasing simultaneously.

[Conventional technology]

Generally, information recording, reproduction, and erasing of information in an optical information recording/reproducing apparatus such as a magneto-optical disk apparatus is performed in the following manner.

When recording information, the recording medium is uniformly magnetized in one direction in advance, and a modulated light beam is irradiated onto the recording medium while applying a magnetic field in the opposite direction to the magnetization direction using an electromagnet. Recording is performed by reversing the direction of magnetization of the area irradiated with the light beam. When reproducing information, a linearly polarized light beam is irradiated onto the recording medium, and the rotation of the plane of polarization caused by the magnetic Kerr effect is transmitted through a polarizing plate. Information is reproduced by detection with a photodetector.

In addition, when erasing information, a strong magnetic field is applied to the recording medium to make it uniformly magnetized, or an electromagnet is used to apply a magnetic field in one direction to the recording medium with no modulation. Information is erased by irradiating the recording medium with a light beam.

[Problems with conventional technology]

However, in such an optical information recording/reproducing device, in order to renew the information recorded on the recording medium, it is necessary to first erase the information on the recording medium and then record new information. .

At this time, if you want to rewrite all the information on the recording medium, you can erase the information by applying a strong magnetic field as described above before recording, but if you want to rewrite part of the information on the recording medium, then write the information. However, it is necessary to sequentially erase predetermined portions with a light beam and then record anew with a modulated light beam, which is problematic in that the processing is troublesome and time-consuming.

For this reason, it is conceivable to perform recording and erasing at the same time using dedicated heads for recording and erasing, but this has the disadvantage that the apparatus for doing so becomes complicated and increases costs.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by providing an information recording method for an optical information recording/reproducing apparatus that can perform recording and erasing simultaneously with a simple configuration.

[Summary of the invention]

In order to achieve the above object, the present invention provides a recording medium for recording binary signals in the direction of magnetization, an electromagnet capable of switching the direction of a magnetic field applied to the recording medium in two directions, and generating two light beams. a light source that selects and modulates one of the two light beams; and a modulation means that selects and modulates either of the two light beams; This is an information recording method for an optical information recording/reproducing apparatus, characterized in that information is recorded with a modulated light beam and information is erased with an unmodulated light beam.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram showing the configuration of an optical information recording/reproducing apparatus showing one embodiment of the present invention.

A recording medium 1 such as a magneto-optical disk records binary signals of +11 and IQ+ depending on the direction of magnetization.
Where 1+ is recorded and the magnetization is downward, +
□+ is recorded. This recording medium 1 is rotated by a spindle motor 3.

An optical head 5 and an electromagnet 7 are provided above and below the recording medium 1 so as to be movable in the radial direction of the recording medium 1.

The optical head 5 includes a semiconductor laser 9 and a collimator lens 11.
．． It consists of a polarizing beam splitter 13, an objective lens 15, a lens 17, a cylindrical lens 19, a polarizing plate 21, and a photodetector 23.

A radar driver 25, 27 is connected to the semiconductor laser 9 of this optical head 5. The laser drivers 25 and 27 modulate the light beams A and BK emitted from the semiconductor radar 9 according to signals sent from the control section 29, respectively. That is, during recording (erasing), a recording signal is sent from the control unit 29 to one of the laser drivers 25 and 27, and one of the light beams A and H emitted from the semiconductor laser 9 is modulated in accordance with this recording signal. receive. Also, during playback, the laser driver 2
From 5.27 onwards, a reproduction driving signal is sent to the semiconductor radar 9.

The semiconductor radar 9 emits two light beams A and B. These light beams A and B are irradiated onto different parts of the recording medium 1 via a collimator lens 11, a polarizing beam splitter 13, and an objective lens 15, and the reflected light is Objective lens 15. The light is detected by a photodetector 23 via a polarizing beam splitter 13, a lens 17, a cylindrical lens 19, and a polarizing plate 21.

The photodetector 23 includes a first detection section 23a that detects the light beam A and a second detection section 23b that detects the light beam B.

Reference numerals 31 and 33 indicate preamplifiers for reproducing information using light beams A and B, respectively.

The reference numeral 35 is a focus detection circuit that detects the focus state of the light beams A and B, and the reference numeral 37 is a tracking detection circuit that detects the tracking states of the light beams A and B.

The electromagnet 7 applies a magnetic field to the recording medium 1, and the driver 3
By controlling 9, the direction of the magnetic field applied to the small recording medium 1 is switched between upward and downward.

Next, a method for recording on the recording medium 1 using the apparatus shown in FIG. 1 will be explained. FIG. 2 is a schematic diagram of a track of the recording medium 1, in which the shaded portion is magnetized upward and represents the track 111, and the white portion is magnetized downward and represents the track 101.

As shown in FIG. 2 (&), in the adjacent tracks C and D of the recording medium 1, in the initial state, track C is all magnetized upward and erased, while track D is +111! :+01 information is recorded.

In FIG. 2(b), the electromagnet 7 applies a downward magnetic field to the recording medium, drives the radar driver 25 to modulate the light beam A, and irradiates the track C with the light beam A, while the light beam B Irradiates track D without modulation.

Then, information is sequentially recorded on the track C by the light beam A, and information is sequentially erased from the track D by the light beam BI/c.

As shown in FIG. 2(c), information is recorded on track C and information on track D is erased.

Then, in order to erase track C and record on track D again, as shown in FIG. B is modulated and this light beam B is irradiated onto track D, while light beam A remains unmodulated and irradiated onto track C.
irradiate.

Then, information is sequentially recorded on the track D by the light beam B, and information is sequentially erased from the track C by the light beam AK.

As shown in FIG. 2 (-), the information on track C is erased and information is recorded on track D.

Therefore, it is possible to erase the recording medium 1 with one of the light beams while recording with the other light beam.

A reproduction signal at the time of information reproduction can be obtained by irradiating the recording medium with the light beams A and B without modulation, detecting the reflected light with the detector 23, and amplifying it with the preamplifiers 31 and 33. In this case, Fig. 2(a), Fig. 2(C),
As shown in FIG. 2(e), since KFi information is not recorded on one of the pair of tracks C and D, information is recorded in the reproduced signal obtained by the light beams A and B). All you have to do is choose one. Alternatively, it is also possible to store in advance in another device or the like which of the pair of tracks C and D information is recorded on, and to reproduce only the track on which information is recorded.

Focus control and tracking control are performed during recording, playback, and
Although erasing is performed at the same time, it may be performed using one of the light beams A and B, or may be performed by combining signals from both light beams A and BK.

The light beams A and B may be emitted so as to be shifted back and forth as shown in FIG. 2, or may be emitted side by side.

In this embodiment, a disc-shaped disk is used as the recording medium 1, but the recording medium is not limited to this, and may be a card-shaped, tape-shaped, or other arbitrary shape.

Also, the tracks of the recording medium may be either concentric or spiral.

Furthermore, in this embodiment, the light beams A and B are connected to the adjacent track C.
, D, the tracks on which recording and erasing are performed at the same time do not necessarily have to be adjacent, and may be spaced apart, for example, by one track.

When the tracks serving as surface seals are provided adjacently, even if the distance between the paired tracks is small, crosstalk occurs less during signal reconstruction, and the recording density can be increased.

Furthermore, in this embodiment, the two light beams share an optical device such as a lens, so the configuration is simple.

〔Effect of the invention〕

As described above in detail, according to the present invention, recording and erasing can be performed simultaneously with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical information recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of tracks on a recording medium. DESCRIPTION OF SYMBOLS 1... Recording medium, 7... Electromagnet, 9... Semiconductor radar, 25.27... Radical driver, 29... Control part, 39... Driver. Agent Patent Attorney Seki Hirahani
Law to 1st ward

Claims (1)

[Claims] A recording medium that records a binary signal depending on the direction of magnetization, an electromagnet that can switch the direction of a magnetic field applied to the recording medium in two directions, a light source that generates two light beams, and a light source that generates one of the two light beams. a modulating means for selectively modulating the recording medium, irradiating the recording medium with the two light beams while applying a magnetic field in one direction to the recording medium by the electromagnet, recording information with the modulated light beam, and recording information without recording. An information recording method for an optical information recording/reproducing device, characterized in that information is erased with a modulated light beam.