JPS61265750A - Optical disk - Google Patents

Abstract

PURPOSE:To minimize the influence of an information pit part by providing a continuous track guide part having the 1st phase depth to the land parts between tracks and the information pit part having the 2nd phase depth to part of the track guide part and making the groove width of the information pit part narrower than the grovoe width of the track guide part. CONSTITUTION:The continuous track guide part 2 having the 1st phase depth d1 is provided to the land part 1 between the guide tracks and the information pit part 3 having the 2nd phase depth d2 is provided to at least part on the track guide part 2. The pit width WD2 of the information pit part 3 is made narrower than the groove width WD1 in the guide track part. The ill effect of the information pit part on the tracking error signal is thereby decreased and the groove constitution interchangeable with the conventional grooves is made possible. The groove constitution which decreases the ill effect of the information pit part and can increase the amplitude of an address signal is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical disk system for recording information such as digital data 7 files on an information recording layer by optical means, or for reproducing or erasing recorded information. This invention relates to the optical disc used.

2. Description of the Related Art A schematic diagram of the structure of an example of a conventional optical disc is shown in FIG.

In the figure, numeral 2 indicates a track guide portion of the information recording/reproducing area, and numeral 3 indicates an information pit portion such as an address signal. 1 indicates a land between tracks. Truck guide section 2. The groove depth of the information pit portion 3 is usually set to a depth that maximizes the tracking error detection signal by the ear field method.

Problems to be Solved by the Invention When optically reading an optical disc configured as described above, when a recording/reproducing beam crosses an information pit, a tracking error signal or a focus error signal is generated in the information pit. This has the problem that the amplitude decreases and the servo gain decreases as a result.

:・Aya Gai. . To Kai, 71-'. In the method of counting and detecting the number of grooves crossed by Yuya□, h5 marking error signal, by crossing the information pit part,
The tracking error signal fluctuates.

Another problem was that it gave an error in counting the number of grooves.

In view of the above problems, the present invention provides a method for configuring an optical disc that minimizes the influence of information pits.

Means for Solving the Problems In order to solve the above problems, the optical disc of the present invention includes a continuous track guide portion having a first phase depth with respect to a land portion between tracks, and at least one of the track guide portions. The information pit part has an information pit part having a second phase depth, and the groove width of the information pit part is narrower than the track guide part groove width.

Function: With the above-described structure, the information pit part is conventionally formed by the land part and the groove depth of the mirror, whereas the information pit part is formed by the part of the continuous track guide part of the groove depth of the mirror. By configuring the information pit part with a groove depth of
This means that the influence on the tracking error of the address signal of the information peer) section can be significantly reduced.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings regarding the groove structure.

FIG. 1 shows a schematic diagram of a groove configuration in an embodiment of the present invention. In Fig. 1, 1 is a land portion, 2 is a guide groove portion,
An information pit portion 3 is formed in a part of the guide groove portion. In the figure, P indicates the track pitch, which is usually 1.6 to 2.5μ.
It is m. In the figure, WDl.

dl indicates the groove width and groove depth of the guide track portion, respectively, and VV
D2. d2 indicates the pit width and pit depth of the information pit portion.

FIGS. 2 and 3 show the tracking error signal amplitude characteristics and the reflectance characteristics from the disk, respectively, constructed according to an embodiment of the present invention. In each case, the vertical axis is the relative tracking error signal amplitude,
The relative reflectance is shown, and the horizontal axis shows the guide groove line width. In the same figure, A shows only a guide groove with a groove retention level, and B shows a guide groove with a groove depth of about 1 and a groove depth of 6 degrees, with a pit width of 0.
A case is shown in which there is an information pit region of about 3 μm. C is similar to B, and shows the case where the information pit width is about 0.4 μm.

In the case of the groove configuration described in the conventional example, the tracking error signal amplitude (hereinafter abbreviated as TK) is approximately 0.4, and the reflectance is approximately 0.6.
It is 6. Since the address signal amplitude is proportional to the reflectance between the information pits and the pits, it is approximately 0.36 in this case. The TE signal fluctuation when crossing the land part of the information pit part (hereinafter referred to as address influence) is 0.36 because the TE signal width at the land part is 0 in the far field detection method. Become.

On the other hand, if we consider case B, which is an embodiment of the present invention, when the guide groove width is approximately 111 m, the curves A and B in Fig. 3 cross each other, and there is an information pit area. There is a condition in which the TEE signal amplitude does not change regardless of whether or not the TEE signal is used.

In this case, the TEE signal amplitude is approximately 0.2 and the address signal amplitude is approximately 0.23.The OTE signal amplitude and address signal amplitude can be amplified several times using an amplifier as long as the S/N of the signal is good. It is.

In addition, considering the effect when the guide groove width is made the same as that of the conventional one in the groove configuration B of the embodiment of the present invention, the TE amplitude is approximately 0.33, the address amplitude is approximately 0.26, and the address influence degree is approximately 0.33. It is about 0.09, and the influence of the information pit part is about 1 compared to the conventional one.
reduced.

In addition, in the groove configuration C of another embodiment of the present invention, if the guide part groove width is selected to be about 0.9 μm, the TE amplitude is about 0.
．． 23. The address amplitude is about 0.66 and the address influence is about 0.2, which means that the address influence can be reduced by about 40% and the address signal amplitude can be increased by about 60%.

Another configuration example of the present invention will be explained using FIG. 4.

The numbers given in the figure are the same as in FIG. 1, and 1 is the land portion, 2 is the guide groove portion, and 3 is the pit information portion. In the case of this single structure, the groove width of the continuous guide section varies between the pit section and the information recording/reproducing section, but the groove depth is constant. As mentioned above, the amplitudes of the tracking error signals of the information recording/reproducing section and the guide groove section including the pit information sentinel are made to be the same in terms of amplitude. In order to do this, it has a blind groove configuration.

Effects of the Invention As described above, the present invention provides continuous t-rack guide portions having a first phase depth and a second phase depth on at least a portion of the track guide portion for one part of the run between guide tracks. By forming an information pit portion having a depth and configuring the pit width of the information pit portion to be narrower than the groove width of the third guide trough, the adverse effect of the information pit portion on the tracking error signal can be reduced, and the conventional groove It is possible to provide a groove configuration that is compatible with the following. In addition, it is possible to provide a new technology that reduces the negative effects of the information pit area and increases the amplitude of the address signal.

[Brief explanation of the drawing]

FIGS. 1A and 1B are a plan view, a sectional view, and FIG. 2 showing the groove structure of an optical disc in an embodiment of the present invention. Fig. 3 shows the relative tracking error signal output and relative reflectance changes with respect to the guide track groove width. 6A and 6B are a plan view and a sectional view showing the groove structure of a conventional optical disc. 1...Land section, 2...Track guide section, 3...Information pit section. Name of agent: Patent attorney Toshio Nakao and one other person ``Figure 1 3... Pit A Kurahobu Yoi 2 Zukan Kakumizo Tsuyoshi Figure 3 Guidance Mizo Yamasa

Claims (2)

[Claims] (1) An information recording medium having an information recording layer for optically recording desired information or reproducing or erasing recorded information has an information pit area such as an optically readable guide track and an address. an optical disc, comprising: a land between the tracks; a continuous track guide having a first phase depth with respect to the land;
An optical disc comprising an information pit part having a second phase depth on at least a part of the track guide part, and a pit width of the information pit part is narrower than a groove width of the guide track part. (2) The optical disc according to claim 1, wherein the pit width of the information pit portion is approximately 1/2 or less of the 1/e^2 intensity diameter of the read or write spot.