JPS62219342A - Optical recorder - Google Patents

Abstract

PURPOSE:To make a device small in size, and to prevent recording information from being discontinued by an address signal, by providing separately a recording track and a control track in which an address is recorded. CONSTITUTION:A laser diode array 10 has three radiation points, and outputs an erasing beam B1, a recording/reproducing beam B2, and a controlling beam B3. An address signal can be obtained as the sum output of a 2-split photosensor 24, and in such a case, the reflected light of the recording beam B2 is not made incident on the photosensors 24, 21, therefore, an accurate address signal can be obtained. By switching the polarity of a bias magnetic field at every recording track, based on said address signal, recording of new information by the recording beam B2 can be executed, being under an erasion of already recorded information by the erasing beam B1.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an optical recording device that is capable of writing new information while erasing information.

Naka) #: For example, a device for recording and reproducing psychic information using the magneto-optical effect of the future technology is
It is disclosed in Japanese Unexamined Patent Publication No. 57-117106. According to this conventional technique shown in FIG. 9, the information signal and the address signal 4+ are recorded on the same recording track (for example, the address signal is recorded on the same recording track for each rotation of the disk, that is, in one radial direction). The previous erasing beam [records new information with the subsequent recording beam while erasing the previously recorded information]. I can do it. That is, the erasing beam and the recording beam are irradiated to adjacent tracks or two or more tracks apart, and by detecting the address with the erasing beam and switching the magnetism of the bias magnetic field for each track, the erasing beam is used. This makes it possible to record new information using the recording beam while erasing previously recorded information.

By the way, in the conventional technology shown in FIG. 9, which is disconnected, the laser diode (1) for erasing beam and the laser diode (2) for recording beam are separate, making the device complicated and large. There is a problem with doing so. Furthermore, during erasing and recording, the erase beam and recording beam reflected from the disk reach the beam splitter (3), but if the wavelengths of both beams are close to each other, the beam splitter (3) The two beams are not separated sufficiently,
The reflected light of the recording beam that has been modulated based on the recorded information also reaches the photo sensor (4), which should normally receive only the reflected light of the erasing beam and detect the address signal 9, and thus the address signal is detected. There was a drawback that the reading could not be performed accurately.

In addition, in FIG. 9, the symbol (6) is the objective lens, and (D)
(6) is a half mirror, and (7) is a photo sensor for detecting a reproduced signal. Laser diode (2
) can also be used as a reproduction beam by reducing its oscillation output, and during reproduction, the reproduction beam output from the laser diode (2) is incident on the photosensor (7). , a reproduced signal can be obtained from this photosensor (7).

(c) Problems to be Solved by the Invention The present invention solves the above-mentioned drawbacks of the prior art, simplifies the configuration of the optical system, downsizes the device, and enables accurate readout of address signals during recording. This is what we intend to do.

(b) Means for solving the problem Raded diode means having at least three radiation points for a recording beam, an erasing beam and a control beam, and at least seven radiation points for said control beam from a recording medium. A photosensor means for receiving reflected or transmitted light is provided. And the sbyra μ where the address signal is recorded
When the #width control beam is irradiated onto a control track in the form of a spiral or concentric circle, a Kfi information signal is recorded.For a recording track in the form of a spiral or concentric circle, the recording beam and the erasing beam are different from each other. The photosensor means for detecting an address signal is arranged at a position that irradiates the track and corresponds to the reflected light or transmitted light from the recording medium of the control beam. By utilizing laser diode means having at least three emission points for the beam, the erasing beam and the control beam, the recording beam and the erasing beam are arranged not on the same recording track but on adjacent tracks (tracks separated by one pitch). ) Alternatively, it is possible to irradiate the next recording track two or more tracks apart, and at the same time, the control beam can be irradiated to the control track. The reflected light or transmitted light from the recording medium of the recording beam does not reach the photosensor means provided at the position corresponding to the reflected light or transmitted light from the disk of the control beam, and the With this seven-point sensor means, it is possible to read out an accurate address signal that is not affected by the recording beam that is modulated by the information to be recorded.

(f) Example In FIG. 1, the laser diode array +101 has three radiation points, and the erasing beam (B
), recording/reproducing beam (B2), and control beam (B8
) is output. The beam passes through a collimator, a mirror (1υ), a beam splitter LJ, and is focused onto the magneto-optical disk +Di surface by an objective lens.

As shown in Figure 2, the erasing beam (B1) takes the lead, and the recording/reproducing beam (B2) that follows tracks the recording track (TI) where the erasing beam (B1) is focused.
It is focused on an adjacent recording track (T2) (it may be focused on a track two or more tracks apart).

On the other hand, a control beam (B8) is focused on a control track (AT) of the disk (D), and a specific portion of this control track (e.g. on one radial line of the disk).
The K address signal is recorded. control track (
The other part of AT) serves as a guide groove for tracking.

The recording track and the control track are formed in a spiral shape or a concentric shape with respect to the disk fD).

The beam reflected by the disk (D+) passes through the objective lens (1), the beam splitter (0), the narrow wavelength plate 11 and the condensing lens (10), and then reaches the polarizing beam splitter (161).

It is separated into each polarization component (P component and S component) by the i-light beam splitter θ4, and one is separated by the cylindrical lens θ
η, and the other directly to the photosensor means (181
Coming to Q.

The configuration of the end of the photosensor means is as shown in Fig. 3.The photo sensor has one photo sensor at the position receiving the erasing beam (B1) (EM has a photosensor 21 at the position receiving the recording/reproducing beam (B2)). e241 is the control beam (
B8) They are respectively arranged at t-receiving positions.

Photosensor @1) It is an H4-split photosensor, and an example of the photosensor is a 2-split photosensor.

Now, during recording, the control beam (B3) is incident on the photosensor example (24j), but as is well known in the art, the focus error signal is transmitted from the 4-split photosensor circle and the tracking beam is sent from the 2-split photosensor (24j). An error signal can be obtained.The address signal 8 can be obtained as the sum output of the 2-split photosensor system (also the sum output of each 4-split photosensor), and at this time, the recording beam The reflected light of (B2) is the photo sensor t&41.21
1, so the correct address signal 8
can be obtained. Based on this Abirev No. 48, by switching the polarity of the bias magnetic field for each recording track, 1. While erasing the previously recorded information with the erasing beam (B1), the analysis information with the recording beam (B2) IC is can be recorded.

Furthermore, a control signal for detecting scratches, etc. on the disc CDl is obtained from a photosensor (a photosensor* may be used) to which the erasing beam (B1), which precedes the recording beam (B2), is incident. Control signals are used to control the loop gain of tracking servo circuits, focus servo circuits, etc.
Frequency characteristics etc. may be controlled by 'jt.

On the other hand, during reproduction, by reducing the oscillation output of the laser diode (JO), a reproduction beam can be obtained from the laser diode +101 instead of the recording beam. In this case, photosensort photosensor (
Although a reproduced signal can be obtained from one of the 251, a configuration in which the difference output between these is obtained from an operational amplifier (OPl) allows a reproduced signal 8fc with a better S/N ratio to be obtained. Further, the focus error signal, tracking error signal, address signal, and control signal can be obtained using the same configuration as that used during recording.

FIG. 4 shows another embodiment in which only the photosensor α barrel has t-2 digits. In this case, an address signal can be obtained from the operational amplifier (OPg), a tracking error signal can be obtained from (OPg), and a focus error signal can be obtained from (OF2). However, since the differential output between the two photosensors (22□□□) which are in a push-pull relationship as shown in FIG. 3 is not utilized, the SN ratio of the obtained reproduced signal is lowered.

'That is, the reproduction beam that enters the polarizing beam splitter OI is polarized in the P polarization direction or the Ss direction depending on the previous recording, and this is separated by the polarizing beam splitter α (2), so the photo sensor . , 22 (251) as the reproduced signal, the SN ratio is twice as good.

Figures 5 and 6 show recording beam (Bl), erasing beam (B2) and two control beams (B8a) (B8b)
Another example using a laser diode array with four radiation points for the control beam (B8a) (
B8b) is irradiated onto the control track (AT) as shown in FIG. In the case of this embodiment, the photosensors (l(6), (19)) are configured as shown in FIG.
24a) (24b) is calculated using the arithmetic intensifier ('0P5
), this difference output becomes a tracking error signal called the 3-beam system in compact disc players. The address signal and focus error signal can be obtained in the same manner as in the embodiment shown in FIG. Approximately half of the control beams (B8a) and (B8b) are in a state where the two control tracks (CT) and L are emitted, but this does not interfere with the detection of the #F filter signal.

Figures 7 and 8 show three control beams (B 8 a) (
This is yet another example using Bib) (B8c).

In this embodiment, the tracking error signal can be obtained from the operational amplifier (OF2) as in the embodiment shown in FIG. Beam (B8b)
It can be made with the same configuration as the embodiment shown in FIG. 4 from the 4-split photosensor (21b) which receives the reflected light. In the case of this embodiment, if conditions such as track pitch match, the photosensors (21a, 21b).

21c) enables playback on a compact disc player. That is, in a compact disc, the control track shown in FIG. 7 becomes a recording track, and the recording track becomes a guard band, but the photo sensor (21a
, 21c) In the track tree invention, since the recording track on which information is recorded and the control track on which address signals are recorded are separate, information can be recorded continuously without interruption. I can do it. In the case of a method in which an address is formed in a part of a recording track, information cannot be recorded in the address part, but the present invention does not have this problem. Width of recording track m (Wl
) and the width (W2) of the control track (CT) is (Wl>W2
) (see Figure 2, m). This is because, in the case of magneto-optical recording and reproduction, the polarization plane changes depending on the direction of magnetization.
This is because the width of the recording track ('11) is preferably as wide as possible since the information is detected and reproduced.

Although the embodiment described above is an example of magneto-optical recording, it is also applicable to a type of recording information by changing the reflectance or transmittance of the disk. In short, a laser diode array having at least three radiation points for erasing beam, recording beam, and control beam is used, and the erasing beam and recording beam are irradiated onto the recording track of phase A, and the control beam is emitted. The present invention is characterized in that the control track on which the address signal is recorded is irradiated, and an odometer (for detecting the address signal) is arranged at a position corresponding to the control beam.

(g) Effects of the Invention According to the present invention described above, the optical system is simplified, the apparatus can be downsized, and a positive mz address signal can be detected during recording. Since the recording track and the control track on which the address is recorded are separate tracks, the recording information is not interrupted by the address signal.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the optical recording device of the present invention, FIG. 2 is a diagram showing the relationship between a beam and a track, FIG. 3 is a diagram showing the relationship between a photosensor and a beam, and FIG. 4 is a diagram showing another embodiment. Figure 5 is a diagram showing the relationship between the track and the beam when an erasing beam, recording beam, and two control beams are used. @6 Figure #i
! A diagram showing the relationship between the photosensor and the beam corresponding to the embodiment shown in FIG. FIG. 8 is a diagram showing the relationship between the 7-point sensor and the beam corresponding to the embodiment shown in FIG. 7, and FIG. 9 is a diagram showing the conventional system rItt. +101 is a laser diode array, 01 is a polarizing beam splitter, state α@□2υ (2) 1231f241 (to) is a photosensor, (81) is an erasing beam, (B2)
hafi! , useless beam, and (B8) is the control beam.

Claims (1)

[Claims] (1) Laser diode means having at least three radiation points for a recording beam, an erasing beam, and a control beam, and a photodiode for receiving at least the reflected light or transmitted light from the recording medium of the control beam. A spiral or concentric control track having a sensor means and having an address signal recorded thereon is irradiated with the control beam and a spiral or concentric recording track on which an information signal is recorded. The recording beam and the erasing beam are irradiated onto different recording tracks, and the photosensor means for detecting an address signal is arranged at a position corresponding to the reflected light or transmitted light from the recording medium of the control beam. An optical recording device characterized by