JPS5930250A - Tracking controlling method of optical information recording device - Google Patents

Abstract

PURPOSE:To perform tracking control which allows information recording at recording bit density, by scanning and detecting a track after recording near a track position to be recorded by a tracking beam, and obtaining the tracking signal of a write beam. CONSTITUTION:Only one circular reference track 6 is recorded on a recording medium 1 and while the track is irradiated by the tracking beam 7 whose level is lower than that of the write beam, the tracking signal is detected by its reflected light to control the beam 7, tracing the reference track 6. Simultaneously, a recording bit string (track) 9 is formed by the write beam 8 controlled by the tracking signal to record information. Then, the track 9 after the recording is scanned and detected by the tracking beam 7 to perform recording to a recording track 9' by the write beam 8 controlled simultaneously by the tracking beam 7 according to the tracking signal. Consequently, the tracking control is formed at the recording bit density.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information recording apparatus that records information on a disc-shaped recording medium using an original beam, and a method for tracking and controlling the optical beam.

Conventionally, in optical information recording devices such as S magneto-optical disks, a method as shown in FIG. 1 has been used as a tracking control method. That is, a position detection track 2 consisting of a recording pit train of a specific signal or a specific line υ is provided concentrically on a disk-shaped recording medium 1 in advance, and a recording track 3 is formed on the position detection track. . Here, the recording medium is irradiated with a tracking beam 4 and a writing beam 5 spaced apart from the tracking beam in the radial direction of the recording medium. This device has means for receiving the reflected light of the tracking beam 4 with a divided light-receiving element and detecting a tracking signal based on the difference in reflectance between the position detection track 2 and the recording medium 1. and scanning control of the tracking beam according to the tracking signal,
At the same time as tracing the position detection track correctly,
The writing beam 5 is tracked and controlled by the same tracking signal, and the recording track 6 is formed by penetrating the position detection track as described above.

This method corrects eccentricity and positional deviation due to the loading and unloading of the disk, and allows information to be recorded without causing accidents such as recording tracks crossing each other. Further, even when recording in a spiral shape on a recording medium, it is possible to perform tracking control in the same way by providing a spiral position detection track in advance.

However, the above-mentioned conventional method requires space for a position detection track on the recording surface of the recording medium, separate from the area where information is recorded, and the recording bit density is lower than that of a recording medium for re-use only, such as a video disc. It had the disadvantage of being low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tracking control method for an optical information recording device that is capable of recording information at a constant recording bit density.

The present invention achieves the above object by scanning and detecting a recorded track in the vicinity of a track position to be recorded using a tracking beam having a weaker intensity than the writing beam to obtain a tracking signal of the writing beam.

Hereinafter, the present invention will be specifically explained based on Examples.

FIGS. 2(a) and 2(b) are schematic diagrams each showing an embodiment of the present invention. In FIG. 2(a), a reference track 6 for only one round is recorded in advance on the disc-shaped recording medium 1. As shown in FIG. A tracking beam 7 is irradiated onto the reference track 6, a tracking signal is detected from the reflected light of the beam, and the tracking signal is used to control the tracking beam 7 so as to move the tracking beam 7 onto the reference track 6 according to the rotation of the recording medium. trace. At the same time, the tracking beam 7
A recording bit string (track) 9 is formed by a writing beam, which is irradiated at a constant interval a in the radial direction of the recording medium and whose tracking is controlled simultaneously with the tracking beam by the tracking signal, to record information.

When the writing of recording track 9 is completed, the next step is as shown in Fig. 2 (b).
), the recorded track 9 is scanned and detected by the tracking beam 7, a tracking signal is generated, and the write beam 8, which is tracked simultaneously with the tracking beam 7 according to the tracking signal, is used to write the recording medium. Information is recorded on recording track 1 like recording track 9'.

Furthermore, information is recorded using a writing beam while sequentially performing tracking control on the recorded tracks using a tracking beam 7. Here, the writing beam 8 naturally has a light intensity higher than the recording sensitivity of the recording medium 1, but the tracking beam 7 has a light intensity lower than the recording sensitivity so as not to erase the recorded information when scanning the recorded track. The light intensity is kept to a low level. In addition, in FIG. 2 (al (b)), the diameter of the writing beam 8 is shown to be smaller than that of the tracking beam 7, but the diameter of the writing beam 8 is larger than the recordable energy level, and the tracking beam 7 is It shows the range of light detection for tracking control.

The reference track 6 may be one having a concave surface formed on the disc surface like an optical disc, or any other track that can be detected by a tracking beam can be used. In addition, the reference track 6 is not provided, and the recording track is formed for only one revolution without first performing tracking control on the recording medium.
From the second round, it is also possible to perform Ill&next recording while controlling the tracking flilJ on the recorded track as described above. In addition, the present invention provides that the recording trunk has a concentric circular acid (・
can be used in any case where data is recorded in a spiral manner.

In the present invention, as shown in FIG.
If a gentle force envelope occurs due to eccentricity of the recording medium, etc., the tracking beam 7
Since a recording track is always formed at a distance in the radial direction of the recording medium from the previous recording track while tracking is controlled by Also, the fourth
As shown in the figure, if the recording track 98 is distorted due to some kind of impact that makes it impossible for the tracking beam 7 to follow, the next recording track 98 will be moved by the tracking beam 7.
The amount of deviation or distortion that can be followed is adjusted to a distortion below the frequency, and there is no problem with recording from recording track 9B onwards, and even during playback, recording track 9z cannot be reproduced, but recording track 9s and onward can be reproduced. becomes.

Next, FIG. 5 shows an example of an optical information recording device used in the present invention. In FIG. 5, 18 is a writing optical system including a semiconductor laser 12, a diffraction grating 16, and a tracking mirror 14.
, an imaging lens 15, and an information processing section 10. A coherent light beam is irradiated onto a disk, and information is scanned and recorded by rotating the disk. Also, 20 is a reproducing optical system which, like the recording optical system, irradiates a light beam onto the disk and detects the reflected light to reproduce information recorded on the disk. Here, the light emitted from the semiconductor laser 12 is passed through a tracking beam 16 by a diffraction grating 13.
and a writing beam 17, and these two beams reach the recording medium 11 via the information processing section 10, the tracking mirror 14, and the imaging lens 15. Here, the tracking beam irradiates the recorded track 19, and the reflected light is again transmitted to the imaging lens 15 and the tracking mirror 1A.
and enters the information processing unit. A tracking signal is obtained by detecting the reflected light, and the tracking mirror is driven in accordance with the signal to correctly trace the recorded track 19 using the tracking beam.

At the same time, the recording medium 11 is
The writing beam that irradiates the recording beam is also tracking controlled by the signal, and a recording track 19' is formed along the recorded track 19.

Furthermore, detection of tracking signals from the tracking beam 16 will be explained with reference to FIG. A tracking beam 16 and a writing beam 17 emitted from a semiconductor laser 12 and divided by a diffraction grating 13 are irradiated onto a recording medium 11 .

The reflected light 21 from the recording medium is separated from the tracking beam 16 by a beam sinter 22 and enters two divided light receiving elements 23 and 24. Then, electrical signals generated according to the amount of light received by each of the light receiving elements 2 and 24 are compared to obtain a tracking signal 25.

In the above example, the diffraction grating 13 was used to obtain the tracking beam and the cutting beam, but it is also possible to use a semiconductor laser unit or two semiconductor lasers that oscillate two beams with different intensities. It serves a similar function. In such a case, by stopping the oscillation of the tracking beam, the writing beam can be used for reproduction, and a configuration in which the optical system is shared for recording and reproduction is also possible.

As explained above, in the conventional tracking control method of an optical information recording device, the present invention does not involve throwing a position detection track on the recording surface (i.e., it performs tracking control of a recording beam by scanning and detecting recorded tracks). This has the effect of improving recording density.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining a conventional tracking control method, FIGS. 2(a) and 2(b) are diagrams for explaining a tracking control method according to the present invention, and FIGS. FIG. 5 is a schematic diagram showing the formation of tracks; FIG. 5 is a schematic diagram showing an example of an optical information recording device used in the present invention; FIG.
The figure is a diagram illustrating an example of a method for obtaining a tracking signal. 1...0 Disc-shaped recording medium 6...φ・Measure standard track 7...-Tracking beam 8...Writing beam 9, 9'@116+1@Recording track Applicant Canon Corporation

Claims (1)

[Claims] (1) In a tracking control method for an optical information recording device that rotates a disc-shaped recording medium and records information concentrically or spirally on the recording medium using an original beam, the recording medium is omitted. At least two C beams (including a recording beam and a tracking beam) having different intensities are irradiated at regular intervals in the radial direction of the recording medium, and the tracking beams are used to illuminate the vicinity of the track position to be recorded. A certain recorded track is detected as a running hill, a tracking signal is obtained, and the tracking-W 43
A tracking control method for an optical information recording apparatus, characterized in that information is recorded on the recording medium by a writing beam that is tracked simultaneously with a tracking beam according to the method.