JPS62164237A - Optical recording disk - Google Patents

Abstract

PURPOSE:To attain stable and satisfactory recording and reproduction of information by setting the depth, the inner end width and the width of the middle part between said inner end and the surface of a substrate of a pre-group formed on the substrate at the prescribed value respectively. CONSTITUTION:A mirror surface part A, a guide address PA part B, a guide groove PG part C, and the reflected light quantity D obtained when the PG part is recorded are shown in a diagram as long as the reflection factor of the part A of an optical recording disk is set at 100. The parts B and a recording part D serve as the system control signal and the signal which records and reproduces information respectively. These signals are delivered centering on the part C. Thus the level of the part C drops when the amplitude of the part B is increased and therefore the amplitude of the part D is reduced. The depth of a groove 2 serves as a main factor to decide the level of the part C. Here the depth of the groove 2 is set at 105+ or -5nm together with the inner end width set at 0.2mum and the width of the middle part between the inner end and the surface of a substrate set at 0.45+ or -0.05mum respectively. Thus it is possible to set the difference of return light quantity between the PA and PG of the system signal and the tracking error of the PG at the optimum value respectively in relation to all recording signals.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention forms grooves called bri-greaps (hereinafter abbreviated as PG) on the surface of a base forming a disk, and forms bits with different reflectances in the bri-greaps. This invention relates to an optical recording disc on which signals are recorded.

[Conventional technology]

Optical recording discs have guide grooves (PG) and guide addresses (hereinafter referred to as PA) on the disc in advance in order to greatly simplify the recording and reproducing device and achieve high density. omitted) needs to be formed.

Here, the cross-sectional shapes of the grooves 2 of the PG and PA shown in FIG. 2 are theoretically calculated as being rectangular, and the grooves 2
The depth of 1 groove 2 is 0.6±0.02μm, and 1/8 of the wavelength λ of the laser beam used is 1/8 of λ for PG.
4 was considered optimal for PA.

[Problem that the invention seeks to solve]

When actually forming a PG, it is impossible to create groove widths and groove depths that meet the above-mentioned theory for the following reasons.

First of all, in the mastering process in which the photoresist on the glass master is exposed to a laser beam and then developed, the exposure of the photoresist depends on the intensity distribution of the laser beam itself, so it has an intensity distribution that can be returned by the glass distribution. Since it uses a laser beam, it is extremely difficult to create sharp edges.

Next, even if it is possible to form a rectangle, PG
The width of the groove 2 is thin and the pinch is narrow in order to achieve high density, so if the cross-sectional shape of the groove 2 of the PC is rectangular, there is a risk of damaging the PG during the transfer process of removing it from the metal stamper. can be given.

Due to the above two reasons, the cross-sectional shape of the PC groove 2 could not be made according to the above-mentioned theoretical value, and had to have a shape that was unsuitable for practical use.

[Purpose of the invention]

The present invention aims to eliminate the above-mentioned drawbacks of conventional optical recording discs, and maximizes the quality of various signals obtained by adjusting the width and depth of the PG and its degree of taper, thereby providing information. The purpose is to perform stable and high-quality recording and reproduction.

[Summary of the invention]

In order to achieve the above object, the present invention reduces the actual demand of PG by 0.2 p when the depth of PG is 105±5 nm.
m, 0.8μm at the entrance, median value 0.45±0.05μ
The gist of this is that m.

[Embodiments of the invention]

FIG. 1 shows a cross section of an optical recording disk formed with the PG of the present invention. Note that the same reference numerals as in FIG. 2 indicate the same parts.

In an optical recording disk, the reflectance of the mirror surface is 10
In the case of 0, the amount of reflected light when recording is performed on the mirror surface area A, PA area B, PG area C, and PC area is assumed to be D, and the situation is shown in FIG. PAA3B is a signal that controls the system, and the recording section is a signal that records and reproduces information.
Since both are output with the I)G section C as the boundary, the PAA3B amplitude, which is the signal that controls the system, is large.
If so, the level of C will be lowered, and the amplitude of D will therefore be smaller. In other words, B and D are in a contradictory relationship with C as the boundary. Here, where to set the level of C depends on which signal and how much the system requires.
The main factor determining the level of C is the depth of groove 2,
We adopted IO3nm±5nm.

In addition, the return light amount difference (hereinafter abbreviated as ΔL R), which is a type of system control signal due to changes in the reflectance of the mirror surface, and the PC
The relationship between the two is shown in Figure 4, and the return light amount difference is the difference when the system jumps tracks when searching for a specific address, and when the tracking is pulled into that specific address.
ΔLR plays a very important role in determining the moving direction of pink-up, and even if the recording film reflectance changes as shown in the figure, in both cases, when the groove is 0.4 to 0.5 μm, It can be seen that it takes the maximum value.

Further, FIG. 3 shows the relationship between tracking error (hereinafter abbreviated as TE), which is also a type of system control signal, and groove width.

TE and amplitude are signals used when a big amplifier traces a certain trunk, and the larger the better, but in this system, the output at 0.4 to 0.5 μm in the groove is sufficient. A wide range of results has been obtained.

From this point of view, in the present invention, since the PG of an optical recording disk becomes a trapezoid during manufacturing, the width and depth of the trapezoid are changed, and the PA of the system control signal is changed.
, PG ΔLR, PC TE, and the recording section signal, the JWJ value was determined and the above value was obtained.

〔Effect of the invention〕

As mentioned above, the present invention maintains each system control signal in the direction of maximum output, and also harmonizes the levels of each signal by maximizing the output of contradictory recording characteristics. This allows information to be stably and efficiently recorded and reproduced. Since the shape of the PG is trapezoidal, the substrate on which the PG is formed can be manufactured in the conventional manner, so that mass production is not hindered.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional dimensional diagram of the PC of the present invention, and FIG.
A cross-sectional dimension diagram when a recording film is created and bits are formed on the PC shown in the figure. Figure 3 shows PG due to changes in reflectance.
Relationship diagram between medium and TE, Figure 4 shows PGI due to changes in reflectance
11 and ΔLR, and FIG. Patent applicant: Pioneer Corporation Figure 1 Figure 3 PG width (, um) Figure 4-1, Ll Figure 5

Claims (1)

[Claims] The depth of the pregroove formed on the base is 105 ± 5 nm.
, an optical recording disk characterized in that the width at the rear end is 0.2 μm, and the intermediate width between the rear end and the base surface is 0.45±0.05 μm.