JPS63306536A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To add and rerecord new information while reproducing previously recorded information by setting up time order radiating three optical beams to an optional specific point on a medium in accordance with the movement of the medium to the order of 1st-3rd optical beams, i.e. the order of reproducing, erasing and recording. CONSTITUTION:The 1st optical beam 14 for reproducing information recorded on the information recording medium, the 2nd optical beam 12 for erasing the information and the 3rd optical beam 15 for recording new information are projected on respectively different positions on the medium. Information previously recorded on the medium is reproduced by the 1st beam 14, decoded by a decoder 42 and mixed with new information by a mixer 40, the mixed information is encoded again by an encoder 48 and the encoded information is recorded on the original position of the medium by the 3rd beam 15. The information is erased by the 2nd beam 12 within the decoding and encoding time. Consequently, new information can be added and rerecorded while reproducing the previously recorded information.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording/reproducing device which can be particularly preferably used as a digital audio disk device, and in particular to a book that can use a magneto-optical disk or a phase change optical disk. The present invention relates to the configuration of a replaceable optical information recording/reproducing device.

The present invention will be described below with reference to a rewritable digital audio disc device, but it is not limited to this.

[Conventional technology]

Playback-only digital audio discs have been commercialized as ``compact discs,'' and the development of rewritable information is underway. Rewritable optical data
There are two types of disks known, one that utilizes the magneto-optical effect and one that utilizes a crystal-amorphous phase change. Symposium 18
A specific example is shown in 6 collections of papers P, P, 87-92 (hereinafter referred to as ``Literature 1''). Although there are few presentations on the application of the latter in the digital audio field, for example, at the AE8 Japan Chapter regular meeting held on August 28, 1985, there was an experimental example in which CD signals were recorded using a Ge-Te alloy as a recording medium. It has been reported. FIG. 3 is an override format diagram of the conventional rewritable digital audio disc device shown in Document 1.

In the figure, (11) is a recording/reproducing laser beam, (1
2) is the erasing laser beam, (13) is the control laser beam, (21) is the groove portion of the pre-group, (23) is the land portion, and (22) is the track address signal portion. Further, (30) indicates the polarity of the external magnetic field applied in the direction perpendicular to the plane of the paper.

Next, the operation will be explained.

The disc has a spiral pre-group (21).
is engraved, and a one-time disk rotation (one track) K1-times track address signal (22) is also engraved. The control laser beam (13) is controlled in focus and tracking so as to trace the pre-group (21), and furthermore, the track address signal (22) is read to recognize the track number.

The recording/reproducing laser beam (1t) runs on the land portion (23) that is half a track behind the control laser beam (13), and the erasing laser beam (12) runs on the land portion (23) that is half a track behind the control laser beam (13). The alignment of the three beams is set so that they run on the land portion (23) that is half a track ahead, and as a result, the erasing laser beam (12) is only one track longer than the recording/reproducing laser beam (11). You will be running ahead. The polarity (30) of the applied magnetic field is alternate when the control laser beam (13) runs on the n-1th track (state A in the figure) and when it runs on the nth track (state B in the figure). Since it can be switched, the control laser beam (13
) is running on the n-1th track, the land portion (23) between the n-1st and nth tracks magnetized in one direction by the erasing laser beam (12) is used for primary control. When the laser beam (13) runs on the nth track, the recording/reproducing laser beam (
11) K enables recording. With this 5K, it becomes possible to substantially override continuous information.

[Problem that the invention seeks to solve]

By the way, when recording or editing in a music studio, it is extremely rare for all the performers to come together and record at once; generally, the rhythm section such as the drums is recorded first, and then the melody instruments are recorded. A song is completed by recording the song and finally recording the singing. In such a case, the user will listen to the previously recorded performance of another part and play his/her own part over it. Therefore, in a recording/editing device used in a music studio, etc., it is necessary to have a function to add new information and re-record while playing back pre-recorded information. This function could not be achieved with digital audio disc devices. The reason for this comes from the recording/playback principle of erasable optical disk devices. In other words, in magneto-optical recording, the magnetic reluctance is lowered by laser heating the medium to around the Curie point, the direction of magnetization is reversed using a relatively weak external magnetic field, and recording is performed by reversing the direction of magnetization after cooling. The magneto-optical effect (Kerr effect or Faraday effect) is used to obtain reproduction signals, so when irradiated with a strong laser beam such as an erasing laser beam, the temperature of the medium increases and magnetization decreases, making signal detection impossible. It becomes difficult. In addition, in phase change optical disks, the recording/erasing principle is crystallization or amorphization due to the difference in the cooling process after heating the medium, and generally the crystalline state due to slow cooling is the erased state. . Because of this slow cooling, the erasing laser beam has a long circular shape that is long in the direction of medium movement, and cannot reproduce information with a short spatial wavelength.

This invention was made in order to solve the above-mentioned problems, and provides an optical information recording and reproducing device that has the function of reproducing prerecorded information while adding new information to it and rerecording it. The purpose is to obtain.

[Means for solving problems]

The rewritable optical information recording/reproducing device according to the present invention includes a first light beam for reproducing information recorded on an information recording medium, a second light beam for erasing the information, and a second light beam for recording new information. emitting at least three light beams including a third light beam to different positions of the information recording medium;
As the recording medium rotates, the time order of the light beams irradiated onto any same point on the medium is 1st. Second. The third light beam is arranged in the order of reproduction, erasure, and recording.

[Effect]

The rewritable optical information recording/reproducing device according to the present invention reproduces information previously recorded on an information recording medium using a first light beam, decodes the information, and then mixes the information with new information. It is encoded again and recorded at the original position on the medium by a third light beam. Also, erasure is performed by the second light beam during the decoding and re-encoding time.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows the relationship between the time of three laser beams and the position on the medium, and FIG. 2 is a schematic diagram of recording and reproduction in this apparatus. In the figure, (14) is a laser beam as a first light beam for reproducing information pre-recorded on a disc as an information recording medium (not shown), and (12) is a laser beam as a second light beam for erasing the above information. , (15)
is the laser beam as the third light beam that records new information, and looking at the position k on the medium, the period from when the first laser beam is irradiated until when the third laser beam is irradiated is The time difference is tH.

Incidentally, since known devices such as a disk drive device, an optical device, a detection device for playback signals and control signals, a servo circuit, etc. can be used as appropriate, illustrations and explanations are omitted.

The reproduced signal (41) reproduced by the first laser beam (14) is subjected to dinterleaving and error correction decoding by the decoding circuit (42) IC, and the mixing circuit (40
) is mixed with a newly input signal (44) from the outside, and then encoded and interleaved again in an encoding circuit (48) to produce a new recording signal (49) as a third laser beam (15). ) is then re-recorded at its original location on the medium. When the time required for the decoding circuit is tl, and the time required for the encoding circuit is t, the time difference between the first and third laser beams tH>1H>1. +12 is fine. Furthermore, since the second laser beam (12) used for erasing is located between the first and third laser beams, the predetermined position on the medium is erased before new information (49) is recorded. There is.

Next, the actual operation will be explained in more detail.

The mixing circuit (40) includes a first attenuator (43) that attenuates the decoded reproduction signal, a second attenuator (45) that attenuates a new information signal (44) input from the outside, and an adder. (46), and the attenuation amounts of the first and second attenuators are changed in a complementary manner in conjunction with each other.

When writing information to a new disk, the attenuation amount of the first attenuator (43) is set to the maximum, and the amount of attenuation of the second attenuator (43) is set to the maximum.
5) is set to zero, only the external input signal (44) appears in the addition result of the adder (46), which is encoded by the encoding circuit (48) and transmitted to the third laser beam ( 1
Recording is done in step 5).

Next, consider a case where new information input from the outside is added to the information recorded above. In this case, when playback is started with the attenuation amount of the first attenuator (43) set to zero and the amount of lft and is corrected, encoded again as it is by the encoding circuit (48), and recorded at the original position on the medium by the third laser beam (15). If the attenuation amounts of the first and second attenuators are changed at the time when new information (44) from the outside is to be added, the output of the adder (46) will contain the reproduced information from the disk and the information from the outside. The new information appears mixed at an arbitrary mixing ratio, and by encoding this, a new recording signal (49) is obtained. The mixing state can be confirmed by the monitor output (47). By speeding up or slowing down the rate of change of the attenuation amount of the attenuator, an arbitrary cross-fade (fading in one of the two while fading the other, 2+) characteristics can be obtained.

In addition, in a digital audio disk device that time-division multiplexes audio information of two or more channels and records and edits it as a serial signal, the decoding circuit (42) performs serial-to-parallel conversion so that each audio channel becomes parallel when decoding. By operating the mixing circuits (40) in parallel for the number of audio channels, independent mixing can be performed for each channel. In this case, it is natural to perform parallel-to-serial conversion and return to a serial signal before encoding in the encoding circuit (48). With this configuration, the method normally used for multichannel recording and editing, in which only some of the multiple audio channels are recorded during the first recording, and then other information is recorded on the remaining channels, can also be used for digital audio. It can be implemented using a disk device.

Note that the operation of the mixing circuit (40) described above may be performed analogously or digitally without any problem.

Furthermore, in the digital audio disc device according to an embodiment of the present invention, the second laser beam (12) may be located between the first laser beam (14) and the third laser beam (15). Therefore, the three laser beams may be emitted from independent optical heads, for example, the first and second laser beams (14),
(12) may be configured to be emitted from the same optical head; in the latter case, the configuration of the apparatus is simplified as the number of optical heads is reduced.

Furthermore, since reproduction is performed before erasing, it is possible to preserve the original information by separately recording the reproduction signal.

Further, when a magneto-optical disk is used as the medium, in the apparatus according to the present invention, the recording laser beam and the erasing laser beam are independent, so the direction of the external magnetic field required for each is always constant. Therefore, by using an electromagnet to reverse the magnetic field, there is no need to mechanically move the permanent magnet to change the direction of the magnetic field, and the fixed permanent magnet can be used as an external magnetic field source, reducing the possibility of equipment cave-ins. It is also effective for Furthermore, even in magneto-optical disks, the thermomagnetic effect due to laser heating is used for recording and erasing, and polarization accuracy is important only for the reproduction laser beam. In systems where the purposes of use of the beams are independent, the optical system that emits the recording and erasing laser beams is a conventional one-time write type (W
rite 0nce) The same optical disc as that of the optical disc can be used, and it also has the effect of simplifying the optical system.

Incidentally, in the above embodiment, the case where the present invention is applied to a digital audio disc has been described, but it goes without saying that it can be applied to recording and reproducing other types of information. Further, the laser beam may be any other light beam.

〔Effect of the invention〕

As described above, according to the present invention, there is a first light beam for reproducing information recorded on an information recording medium, a second light beam for erasing false information, and a third light beam for recording new information. At least three light beams are emitted to different positions on the medium, and as the medium moves, any specific point on one medium is
The time order in which the books are irradiated with the light beam is 1st, 2nd, 2nd. Third
Since the light beam order is 5, that is, the order of reproduction, erasure, and recording, it is possible to reproduce previously recorded information while adding new information to it and re-recording it.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the time of three laser beams and the position on the information recording medium in an optical information recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing the rewriting according to the above embodiment. FIG. 3 is a block diagram illustrating the principle of recording and playback of a conventional rewritable digital audio disc device. FIG. 3 is a diagram showing an override format of a conventional rewritable digital audio disc device. In the figure, (14) is a laser beam as a first light beam, (12) is a laser beam as a second light beam, (15) is a laser beam as a third light beam, (
40) is a mixing circuit, (42) is a decoding circuit, (48) is an encoding circuit, (41) is a reproduction signal from a disk,
(44) is a signal newly input from the outside, and (49) is a recording signal recorded on the disk. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. j# & bee circle (smell)

Claims (2)

[Claims] (1) At least three light beams: a first light beam for reproducing information previously recorded on an information recording medium, a second light beam for erasing the above information, and a third light beam for recording new information. A time sequence in which the three light beams are emitted to different positions on the information recording medium, and any specific point on the information recording medium is irradiated with the three light beams as the information recording medium moves. An optical information recording/reproducing apparatus characterized in that the first, second, and third light beams are arranged in this order. (2) The time interval from when the first light beam is irradiated to a specific point on the information recording medium until the third light beam is irradiated is the encoding time and decoding time of the digital information to be recorded and reproduced. 2. The optical information recording/reproducing device according to claim 1, wherein the optical information recording/reproducing device is larger than the sum of the following.