JPS62128024A - Photomagnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To easily and surely rewrite only a part of a disc by moving an optical system accurately to specify the irradiated position of a laser light. CONSTITUTION:An erasing head 2, a recording and reproducing head 8, objective lens actuators 4 and 10, and bias coils 14 and 15 are fixed to a base, which can be moved in the radial direction of the disc, as a head block. Means (actuators 4 and 10) which read an address indicating the track position of a photomagnetic disc 1 recorded in accordance with the ruggedness of the presence/absence of a tracking groove 20 of the photomagnetic disc 1 and move respective beams of two optical systems to prescribed positions are provided to specify irradiated positions of beams 3 and 9 accurately. Thus, only a part of the disc is easily and surely rewritten.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magneto-optical disk for recording and reproducing information, particularly audio signals.

2. Description of the Related Art In recent years, optical discs that use light to digitally record and reproduce information have attracted attention. There are optical discs that use various principles, and one that is rewritable is one that uses the magneto-optical effect.

For recording, the coercive force is almost zero when the recording medium is heated to a temperature above one Curie with a laser beam, etc., and the coercive force is reversed by a small external magnetic field. This method uses the Kerr effect, in which the plane of polarization of laser light rotates.

By the way, when recording new information on a magneto-optical disk on which information has already been recorded, the following two methods can be considered. That is, the first method is a method based on magnetic field modulation, in which the direction of the magnetic field is changed depending on recorded information, and laser light is irradiated to erase previously recorded information and record new information at the same time. This is not practical because it is difficult to change the magnetic field of a magnitude that allows erasing and recording in accordance with the recorded information.

The second method is to first erase the previously recorded information by irradiating a laser beam with an erase magnetic field that is opposite to the direction of the magnetic field during recording.
This method then applies a recording magnetic field and irradiates laser light to record new information.

Although this method is feasible, it requires twice as much time to record the recorded information, and real-time recording is not possible, so it is not suitable for recording audio signals.

As a means to solve these drawbacks, for example, as shown in Japanese Unexamined Patent Publication No. 59-217250, a recording optical system for recording information on a magneto-optical disk and a recording optical system for recording information on a magneto-optical disk are proposed. Playback/Erasing
It has been considered to include two optical systems, including an erasing optical system. In this method, new information is recorded by the recording optical system immediately after the information that has already been recorded is erased by the reproducing/erasing optical system, and real-time recording is possible.

Problems to be Solved by the Invention However, with the above configuration, it is difficult to move the two systems of optical systems to the same position on the disk accurately, so it is difficult to erase only a portion of the disk and rewrite it with new information. There were m points in between.

In view of the above-mentioned problems, the present invention provides a magneto-optical recording and reproducing apparatus that is capable of erasing and recording in real time and has an optical system that allows accurate rewriting of only a portion of a disk.

Means for Solving the Problems In order to achieve this object, the magneto-optical recording and reproducing apparatus of the present invention includes two optical systems having multiple functions of recording, reproducing, and erasing information on a magneto-optical disk. Each of the two optical systems is equipped with means for reading an address indicating the track position of the disk and moving the laser beam to a predetermined position.

Function: With the above-described configuration, the present invention can accurately move the optical system and determine the irradiation position e% of the laser beam by means of each of the two optical systems reading the track position of the disk and moving the laser beam to a predetermined position. , it is easy to rewrite only a portion of the disc. Furthermore, since real-time recording is possible, the magneto-optical recording and reproducing apparatus is suitable for recording and reproducing audio signals.

Implementation Arrangement The implementation arrangement of the present invention will be explained below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, 1 is a magneto-optical disk that records information by changing the direction of magnetization, and 2 is a magneto-optical disk 1.
An erasing head 3 erases information recorded on the magneto-optical disk 1, an erasing beam 3 made of a laser beam is irradiated from the erasing head 2 to the magneto-optical disk 1, and 4 is an erase beam 3 so that the erase beam 3 is accurately irradiated onto the magneto-optical disk 1. an objective lens actuator for adjusting the focus and position of the erase beam; 5 an address decoder for reading an address indicating the position of the erasing beam 3 on the magneto-optical disk 1 by changes in the intensity of the reflected light from the magneto-optical disk 1; An analog/digital converter 7 converts the digital audio signal into a 16-bit parallel digital signal, and 7 converts the digital signal from the analog/digital converter 6 into a magneto-optical disk.
An encoder 8 records information according to a signal from the magneto-optical disk IKCD encoder 7 and reproduces information recorded on the magneto-optical disk 1. A recording/reproducing head 9 is a recording/reproducing beam such as a laser beam irradiated from the recording/reproducing head 8 onto the magneto-optical disk 1; 1o is a focal point and position so that the recording/reproducing beam 9 is accurately irradiated onto the magneto-optical disk 1; 11 is an address decoder that reads an address indicating the position of the recording/reproducing beam 9 on the magneto-optical disk 1 by changing the intensity of the reflected light from the magneto-optical disk 1; 12 is an address decoder from which the recording/reproducing head 8 13 is a digital/analog converter that converts the digital signal from the CD decoder 12 into an audio signal, and 14 erases information recorded on the magneto-optical disk 1. A bias coil 15 generates a magnetic field for recording information on the magneto-optical disk 1. A bias coil 16 inputs a control signal for operating the magneto-optical recording/reproducing apparatus of this embodiment. A keyboard 17 is a control circuit that controls the device using control signals from the keyboard 16, addresses from address decoders 6.11, and the like. In this example, erase head 2. Recording/playback head8. Objective lens actuator 4, 10. The bias coils 14, 15 are fixed as hend blocks on a base which is not shown in the figure but can be moved in the radial direction of the disk.

FIG. 2 is a perspective sectional view showing the recording state of the addresses of this embodiment on the magneto-optical disk 1. FIG. In Figure 2, 18
19 is a protective film for protecting the recording medium 18; 20 is a trunking groove; 21 is a magnetization direction reversal portion; The recorded address, 23 is the incident direction of the laser beam, and 24 is the rotation direction of the magneto-optical disk 1. Although not shown in FIG. 2, a transparent disk substrate exists on the side of the recording medium 18 in the laser beam incident direction 23.

The entire operation of the magneto-optical recording/reproducing apparatus configured as described above during information recording will be explained according to the flowcharts shown in FIGS. 3 and 4.

FIG. 3 is a flowchart showing the entire operation when starting recording, and FIG. 4 is a flowchart showing the entire operation when ending recording. Address A indicates the position on the magneto-optical disk 1 where recording is to start.
1. Let A2 be the address where recording ends.

First, when starting recording, rough access to the head block is performed (step 31). This is to move the entire Henodopronoku to the vicinity of the entire recording start address A1.

At this time, current is applied to the bias coils 14 and 15 to erase the
Generate the magnetic field necessary for recording. Next, erase beam 3
location address A.

are read from the address decoder 5 and the position address Are of the recording/reproducing beam 1Q from the address decoder 11 (step 31), and the control circuit 17 compares A6 with the recording start address A1 (step 33), Ae
The irradiation position of the erasing beam 3 is adjusted by moving the objective lens actuator 4 or the hendo block until A1 becomes equal to A1 (step 34). At the same time, Ar≦
The irradiation position of the recording and reproducing beam 9 is adjusted by the objective lens actuator 1o so that the position becomes A1. Erasing is started by increasing the intensity of the erasing beam 3 from when A and A1 become equal (step 35).

Then, the recording/reproducing head position address Ark is read (step 36). Next read addresses Ar and A
+e is compared (step 37), and the irradiation position of the recording/reproducing beam 9 is adjusted by the objective lens actuator 10 until the addresses Ar and A1 are equal.Step 3
8) When Ar becomes equal to A1, recording is started by increasing the intensity of the recording/reproducing beam 9 (step 39).

This state of erasing and recording continues until the recording stop address A2 is reached.

When recording is to be stopped, the position address Ae of the erasing beam 4 read in step 41 is the recording stop address A.
2 (step 42), erasing is completed by reducing the intensity of the erasing beam 4 (step 43). Next, when the position address Ar of the recording/reproducing beam 9 read in step 44 becomes equal to A2 (step 45)
In step 46), the recording is terminated by reducing the intensity of the recording and reproducing beam 90, and the current in the bias coils 14 and 15 is stopped, thereby stopping the generation of the magnetic field. Recording is performed as described above. For reproduction, only operations related to the recording/reproducing head 8, recording/reproducing beam 9, and objective lens actuator 10 are performed.

As described above, according to this embodiment, the address 22 indicating the track position of the magneto-optical disk 1 recorded by the unevenness of the tracking groove 20 of the magneto-optical disk 1 is read, and the address 22 indicating the track position of the magneto-optical disk 1 is read, and Beam 4.10'
i By providing a means for moving the disk to a predetermined position, the irradiation position of the beam 4.10 can be accurately specified, and therefore only a portion of the disk can be rewritten easily and reliably.

In this example, after generating a magnetic field by preparatory bias coils 14 and 15 during erasing or recording,
Erasing or recording is started by increasing the intensity of the erasing beam 4 or the recording/reproducing beam 90, but it is also possible to generate the entire magnetic field by simultaneously generating the magnetic field and increasing the beam force, or by increasing the beam intensity in advance. It is also possible to start erasing or recording. In addition, the address 22 is determined not only by the unevenness of the tracking groove 20 but also by the unevenness of the tracking groove 20.
It is also possible to record by changing the groove depth or groove width. Further, the two-system optical system includes two systems, an erasing head and a recording/reproducing head, but it may also include two systems of an erasing/reproducing head and a recording head, or two systems of erasing/recording/reproducing heads having the same function. In addition, the two optical systems are fixed on the same base as Henodopronok, but each of the two optical systems can be independently connected to the magneto-optical disk.
It is also possible to fix it on two bases that can be moved in the radial direction.

Effects of the Invention As described above, the present invention includes two optical systems having multiple functions of recording, reproducing, and erasing information on a magneto-optical disk, and each of the two optical systems indicates the track position of the disk. Since it is equipped with means for reading the address and moving the laser beam to a predetermined position, it is possible to accurately move the optical system and specify the irradiation position of the laser beam, making it possible to easily and reliably rewrite only a portion of the disk. Furthermore, since old information can be erased and new information can be recorded simultaneously, real-time recording is possible, and a magneto-optical recording and reproducing apparatus suitable for recording and reproducing audio signals is realized.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of a magneto-optical recording and reproducing device in an embodiment of the present invention, Fig. 2 is an FMT diagram showing the recording state of the same address, and Fig. 3 is a case where the same recording is started. FIG. 4 is a flowchart showing the operation when the recording is finished. DESCRIPTION OF SYMBOLS 1...Magneto-optical disk, 2...Erasing head, 3...Erasing beam, 4...Objective lens actuator, 5...Address decoder, 6
...Analog/digital converter, 7...
・CD encoder, 81. . ...recording/reproducing head, 9...recording/reproducing beam,
10...Objective lens actuator, 11...
... Address decoder, 12 ... CD decoder, 13 ... Digital/analog converter, 14
...Bias coil, 15°°...Bias coil, 16...Keyboard, 17...
Control circuit, 18... Recording medium, 19...
Protective film, 2o...Tracking groove, 21...
... Magnetization direction reversal part, 22 ... Address, 23
. . . Incident direction of the laser beam, 24 . . . Rotation direction of the magneto-optical disk.

Claims (1)

[Claims] (1) Equipped with two optical systems that have multiple functions of recording, reproducing, and erasing information on a magneto-optical disk, and each of the two optical systems reads an address indicating the track position of the disk and emits a laser beam. 1. A magneto-optical recording and reproducing device characterized by comprising means for moving it to a predetermined position. (2) The address is recorded in advance by changing the shape of the tracking groove, and the address is read by changing the intensity of reflected light from the disk.
The magneto-optical recording and reproducing device described in .