JP2869146B2 - Optical information recording medium - Google Patents

Description

The present invention relates to a write-once or rewritable optical information recording medium having a guide groove.

[Conventional technology]

An optical disc as a write-once or rewritable optical information recording medium has, for example, guide grooves formed for tracking, and addresses in the form of concave and convex pits at predetermined intervals in or between the guide grooves. Information, clock information, and the like are provided in advance.

However, an area where uneven pits such as address information are formed cannot be used as an information recording area.

It is desirable that the address information is recorded as much as possible. However, if the address information is recorded as much as possible, the information recording area is reduced and the amount of recordable information is reduced.

Therefore, recently, as shown in FIG. 4, the optical disc D of the write-once with a guide groove G ₁ which is meandering in response to the carrier signal which is frequency modulated with the address information signals has been proposed.

The horizontal width of the guide groove wherein G ₁ is fixed, the undulation of the opposite edges g _11, g ₁₂ of the guide groove G ₁ is identical.

The optical disk D having such a guide groove can be created by using the optical disk or compact disk creating process substantially as it is.

That is, a photoresist was spin-coated on a glass substrate with a predetermined thickness, and irradiated with a light beam such as an argon laser meandering by a deflector in accordance with a carrier signal frequency-modulated by an address signal, and then developed to obtain. By forming a stamper from the master and forming a recording layer, a protective layer, and the like on a synthetic resin disk substrate formed by the stamper, the above-described optical disk D with a guide groove can be obtained.

[Problems to be solved by the invention]

Incidentally, in the optical disc D of the conventional write-once type as described above, by using the frequency of the additional information carrier signals that can be multiplexed in the guide grooves G ₁ as timing information, although the two types of address and timing information, different than these It is desired to improve the recording density by multiplex-recording the above information.

SUMMARY OF THE INVENTION The present invention has been made in order to meet the above-mentioned demand, and provides an optical information recording medium in which a plurality of types of information are multiplex-recorded on both edges of a guide groove to improve a recording density. .

[Means for solving the problem]

An optical information recording medium according to the present invention is an optical information recording medium in which a guide groove is formed on a surface where information is to be optically written, and information is recorded in or between the guide grooves. One edge of the groove is meandered with a first carrier signal frequency-modulated by the first additional information, and the other edge of the guide groove is a second carrier signal frequency-modulated by the second additional information. To meander.

(Operation)

In the optical information recording medium according to the present invention, both edges of the guide groove are undulated according to the carrier signal frequency-modulated by the respective additional information. A plurality of types of information can be respectively detected from the unit.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 1 is a plan view of a portion of the optical information recording medium according to one embodiment of the invention, G ₂ represents a guide groove formed on the optical disc D, and one edge g ₂₁ first additional information is meandering in response to a first carrier signal frequency-modulated, and are allowed to meander in response to a second carrier signal by frequency-modulating the other edge g ₂₂ in the second additional information.

The frequencies of the first and second carrier signals are selected so as not to interfere with the servo signal and the data.

Next, an optical information recording apparatus for producing an optical information recording medium master according to the present invention will be described with reference to FIG.

First, a laser beam L emitted from a laser light source 1 such as an argon laser is split into two by a first beam splitter 2 such as a half mirror, and one laser beam L is split into a first light beam deflector such as an ultrasonic deflector. 4A, the other laser beam L is reflected by the first mirror 3 and supplied to a second light beam deflector 4B such as an ultrasonic deflector.

Then, the divided laser beams L are given minute vibrations by the first or second light beam deflectors 4A and 4B in accordance with the first or second additional information signal.

That is, the first carrier wave signal f _C1 (FIG. 3A) from the first carrier wave signal generation circuit 5A and the first additional information signal f _V1 (third wave) from the first additional information signal generation circuit 6A. (B) is supplied to the first FM modulation circuit 7A, and the first FM modulation circuit 7A converts the first carrier signal f _C1 into the first additional information signal f.
_Since the first carrier signal F _FM1 (FIG. 3 (c)) frequency-modulated by _V1 is output, the first gate signal generation circuit 8A
From the outputs of the first gate signals S ₁ ON signal to the first gate circuit 9A (FIG. 3 (d)), the first carrier signal f
_FM1 (FIG. 3 (e)) is supplied to a first light beam deflector 4A via a first gate circuit 9A and a first amplifier circuit 10A.

The first light beam deflector 4A deflects the laser beam L according to the first carrier signal f _FM1 when the frequency-modulated first carrier signal f _FM1 (FIG. 3E) is supplied. together, to generate a first first-order diffracted light beam L ₁₁ with reduced vibration in a direction orthogonal to the guide groove forming direction.

Similarly, the second carrier signal f _C2 from the second carrier signal generation circuit 5B and the second additional information signal f _V2 from the second additional information signal generation circuit 6B are supplied to the second FM modulation circuit 7B. Then, the second FM modulation circuit 7B converts the second carrier signal f _C2 to the second
The second carrier signal f frequency-modulated with the additional information signal f _V4 of
Since output _FM2, and outputs the second on-signal of the gate signal S ₂ to the second gate circuit 9B from the second gate signal generating circuit 8B, the second carrier signal f _FM2 second gate circuit
9B, the second light beam deflector 4 via the second amplifier circuit 10B.
Supplied to B.

When the frequency-modulated second carrier signal _fFM2 is supplied, the second light beam deflector 4B deflects the laser beam L in accordance with the second carrier signal _fFM2, and _crosses the laser beam L in a direction perpendicular to the guide groove forming direction. generating a second first-order diffracted light beam L ₂₁ obtained by fine vibrations in the direction.

Note that L ₁₀ and L ₂₀ are the first and second 0s generated simultaneously
These are the secondary light beams, but these are not used.

First light beam deflector first first-order exiting 4A diffracted beam L ₁₁ and the second beam splitter such as a half mirror 1
2 and exits from the second light beam deflector 4B.
Order diffracted light beam L ₂₁ is incident on the second beam splitter 12 via the second mirror 11, is reflected.

The first and second first-order diffracted light beams L ₁₁ and L ₂₁ are:
The photoresist is arranged on the glass disk via the mirror 13a and the objective lens 13b, which are arranged in the direction orthogonal to the guide groove forming direction, are adjusted by the second mirror 11 and the like so as to partially overlap each other, and constitute the recording optical system 13 and the objective lens 13b. An image is formed on the photoresist surface of the applied master R.

The master R is mounted on a turntable 14a driven by a motor 14b, and a motor drive circuit 14c that receives a reference signal from a reference signal generation circuit 14e generates a drive signal and supplies the drive signal to the motor 14b. Master R attached
Is rotating.

Further, the recording optical system 13 is moved in the radial direction of the rotating master R by the feed mechanism part 14d which has received the reference signal from the reference signal generation circuit 14e.

In this manner, two beams vibrated slightly in accordance with different additional information signals are arranged in a direction orthogonal to the guide groove forming direction, and an image is formed on a photoresist surface so as to partially overlap and exposure is performed. Accordingly, meandering guide grooves G ₂ can be formed as shown in Figure 1.

〔The invention's effect〕

As described above, according to the present invention, since both edges of the guide groove are independently meandered according to the additional information, a plurality of types of information can be multiplex-recorded on both edges of the guide groove. Density can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a part of an optical information recording medium according to an embodiment of the present invention, and FIG. 2 is a configuration of an optical information recording apparatus for forming a master of the optical information recording medium shown in FIG. 3 (a) to 3 (e) are waveform diagrams showing some signals in FIG. 2, and FIG. 4 is a plan view showing a part of a conventional optical information recording medium. D ...... optical disc, G ₂ ...... guide groove, g _12, g ₂₂ ...... edge.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/24

Claims (1)

(57) [Claims] 1. An optical information recording medium in which a guide groove is formed on a surface on which information is to be written optically and information is recorded in or between the guide grooves, one edge of the guide groove. Is meandered by a first carrier signal frequency-modulated by the first additional information, and the other edge of the guide groove is meandered by a second carrier signal frequency-modulated by the second additional information. Characteristic optical information recording medium.