JPS5817974B2 - Kirokusai Seisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording/reproducing device that sequentially records or reproduces signals concentrically or spirally on a disk-shaped recording medium, and the present invention relates to a recording/reproducing device that sequentially records or reproduces signals concentrically or spirally on a disc-shaped recording medium. ) is intended to automatically reduce the difference in the relative positional relationship between the scanning body for signal recording and reproduction and the recording medium.

In a device that records and reproduces information signals on a disk-shaped information medium 1 as shown in FIG. For example, when recording is stopped midway, the information medium 1 being recorded is removed from the recording/playback device, and then inserted into the device again to start recording. When recording is performed with a recording/reproducing device, the disc-shaped information medium 1 is attached to the recording/reproducing device because there is play between the hole 3 and the rotating shaft of the recording/reproducing device. Eccentricity occurs because the center of rotation 4 is different between the time of reinstallation or attachment to another device and the time of previous recording, and when rerecording, as shown in FIG. If the expected amount of eccentricity is a, then if recording is not restarted from position 2' with a margin of at least b=2a, a new signal will be recorded overlapping the previously recorded portion, which will be inconvenient.

However, taking such a margin is not necessary for information medium 1.
This is undesirable as it drastically reduces the efficiency of use.

The present invention provides a method for minimizing the amount of margin required during re-recording.

An embodiment of the present invention is shown in FIG.

In FIG. 3, a disk-shaped information medium 5 is placed on a turntable 8 attached to a rotating shaft 7 of a drive motor 6, and is driven at a constant rotation speed.

The drive motor 6 is moved in the direction indicated by an arrow 8 by a shaft screw (not shown) or the like, and as shown in FIG. .

A portion 10 surrounded by a dotted line is a tracking guide signal recording/reproducing device for recording and reproducing a circular track without a signal on the information medium 5. When the information medium 5 is started to be used, a circular track as shown in FIG. Record the reference track of
It is something to be regenerated.

That is, the light beam 13 from the light source 12 is transmitted through the beam splitter.
14, it is bent in a substantially right angle direction by a vibrating mirror 15, and is irradiated onto the information medium 5 through a lens 16. The reflected light passes through the lens 16 and the vibrating mirror 15, and is bent by a beam splitter 14, and is transmitted to a detection device 17. projected onto the top.

The detection device 17 detects the degree of convergence of the light beam 13 on the information substrate 5 and the amount of tracking deviation. When recording the circular track 11, a signal representing the degree of convergence by the detection device 17 is applied to the focusing control circuit 18. , the signal of the control circuit 18.

The drive element 19 that moves the position of the lens 16 is operated to focus and converge the light beam 13 onto the information medium 5, thereby recording a circular track 11 for a tracking guide.

Recording on the information tracks 2 and 2' will be performed based on the circular track 11 from now on.

. To record the information track, a recording signal 22 is added to the light beam 25 from the information recording light source 21, and an optical modulator 24 and a beam splitter 26 whose polarization angle is controlled by adding the output of the modulation circuit 23 through the R terminal of the switch S2. , an information vibrating mirror 21, and an objective lens.

28 onto the information medium 5, the detection device 34 detects the degree of convergence of the irradiated light, and the control circuit 35 controls the drive element 29 that moves the objective lens to focus it on the information medium 5. .

On the other hand, the tracking guide signal recording and reproducing device 10! After recording the circular track 11, when recording the information track 2 or 2, the intensity of the light source 120 is weakened and the light beam 13 is
is not recorded even if it is focused on the information medium 5, the detection device 17 detects the discrepancy between the spot position on the information medium and the previously recorded circular track 11, and the amplification circuit 20 amplifies it. Vibrating mirror 1
5 to scan the circular track 11.

In this way, when the information medium 5 is removed and then reinstalled, or when the information medium 5 that is being recorded on another device is attached to this device and recorded, the eccentricity may cause the rotational axis 70 of the drive motor 6 to On the other hand, when the circular track 11 has an eccentric trajectory, the output of the amplifier circuit 20 generates a signal according to the eccentricity, and the vibrating mirror 15 is moved to the center 111L,
In order to cause the light beam 13 to scan on an eccentric circular track, the output of this amplifier circuit 20 is sent to a tracking control circuit 3.
In addition to the information vibrating mirror 27 through the vibrating mirror 1
If the spot of the light beam 25 on the information medium 5 is controlled to move by an approximately equal amount in the same direction as the amount of movement of the spot on the information medium 5, the recorded information track will always be as shown in FIG. The tracks 2, 2' are concentric circles or spirals having substantially the same shape as the circular track 11, and the margin shown in FIG. 2 can be extremely reduced.

When reproducing a signal from the recorded information medium 5, switch s1. S2 is connected to the husband P terminal, and the information light source 21 whose intensity is weakened is also emitted, and the light modulator 24, beam splitter 25, information vibrating mirror 27, and objective lens 2
8 is focused on the information medium 5 by the detection device 34, the control circuit 35, and the drive element 29 in the same way as during recording, and a signal corresponding to the track deviation detected by the detection device 34 is output from the amplifier circuit 37. amplify, switch S1
is sent to the tracking control circuit 36 along with the output signal of the amplifier circuit 20 representing a correction signal corresponding to eccentricity when the circular track 11 is tracked by the light beam 13, and also controls the information vibrating mirror 27. The spot of the light beam 25 on the information medium 5 is made to accurately track the recorded information 2, 2'.

The information vibrating mirror 27 is roughly controlled by the signal from the amplifier circuit 20 so as to scan a spiral track that is approximately the same shape as the circular track 11, and subsequent fine control is performed by the signal from the detection device 34. , high-precision control becomes possible.

The reflected light of the light beam 25 on the information medium 5 is detected by the detection element 31, demodulated into the original signal by the demodulation circuit 32, and sent to the output terminal 3.
Take out according to 3.

In the above explanation of FIG. 3, the method of recording the circular trunk 11 for tracking shown in FIG. 4 using the tracking guide signal recording/reproducing device 10 prior to recording has been described, but the circular track 11 has already been recorded. Alternatively, the information medium 5 may be used, and when recording circular tracks, the drive motor may be driven at a slower speed than usual, so that the light source 12 with low output can perform recording.

In addition, when reproducing using the circular track 11 and the light beam 13, the light beam 13 is not focused on the information medium 5, but is irradiated over a slightly wider width than the expected eccentricity of the circular track 11, as shown in FIG. , a triangular detection device 1
It is also possible to form an image on the detection element 41 in 7 and generate a voltage between the terminals 39 and 40 according to the track position.

As described above, according to the present invention, it is possible to record and reproduce signals without being greatly affected by eccentricity that occurs when a recording medium is attached to a device, and therefore, the compatibility of recording media is improved. be.

Further, in the present invention, during playback, the first light beam is
In order to track the second light beam using the sum signal of the tracking signal and the second l tracking signal corresponding to the difference between the information track and the irradiation position of the second light beam, the second For the tracking signal, it is essentially necessary to correct only the minute error after control by the first tracking signal, and extremely high-precision tracking can be achieved without configuring a high-precision tracking servo system. It is something.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of recording tracks on a disk-shaped recording medium, FIG. 2 is a diagram showing differences in recording tracks due to eccentricity of the recording medium, and FIG. 3 is a block diagram showing an embodiment of the present invention. 4 are diagrams showing recording tracks on a recording medium according to the present invention, and FIG. 5 is a diagram showing an example of a tracking detection device. 1...Recording medium, 2,2'...Recording track, 5...Recording medium, 11...Reference track, 15°27...・・Vibration mirror, 16
, 28...Objective lens.

Claims (1)

[Claims] 1. In a recording and reproducing apparatus that irradiates a rotationally driven disc-shaped recording medium with a light beam and sequentially records and reproduces signals as concentric or spiral recording trajectories using the light beam, there is no signal on the disc-shaped recording medium during recording. A first recording locus that has already been recorded is scanned with a first light beam, and a first tracking signal is used to scan a second recording locus based on the difference between the irradiation position of the first light beam and the first recording locus. The irradiation position of the light beam on the recording medium is controlled, and the second light beam records a new signal as a second recording locus on the disk-shaped recording medium, and during reproduction, the second light beam Based on the difference between the irradiation position and the second recording trajectory (according to the addition output of the second tracking signal and the first tracking signal) A recording/reproducing device characterized by causing tracking.