JPH103699A - Disk shaped optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk shaped optical information recording medium capable of visually discriminating the presence of absence of the eccentricity or the eccentric quantity between plural information recording layers in the case of reproducing plural information recording layers from one side. SOLUTION: Eccentricity judging area 3 is provided in the area of the area of the inside or the outside of the recording area 2 of an optical disk 1. The eccentricity judging area 3 is constituted of the line of plural lines of eccentricity judging track being a concentric form or the line of plural turns of eccentricity judging tracks being a helical form and these tracks are respectively arranged on first and second information layers. The eccentricity judging track 11 are arranged at intervals (d) and respectively tracks are tracks in which 5-20 lines of concentric or helical grooves or pit columns are gathered. When a relative eccentricity due to the sticking of them is present in the optical disk 1, moire fringes are visually observed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped optical information recording medium such as a digital video disc (DVD) for reproducing information recorded on a plurality of information recording layers from one side.

[0002]

2. Description of the Related Art In recent years, various disc-shaped optical information recording media have been put to practical use. As a playback-only type, a compact disk (CD), an optical video disk, and the like are widely used. Examples of the recording / reproducing devices include a hole-type optical disk capable of recording only once by melting and sublimating a metal recording layer with a laser beam, an amorphous-crystal phase change optical disk, and thermomagnetic recording. Also, magneto-optical disks and the like using the magneto-optical effect have been steadily put into practical use. Among them, CD based on CD format
-ROMs are expanding rapidly, mainly in the distribution of software applications for computers and game consoles. Also, with the development of image compression technology such as MPEG, CD
Video CDs capable of recording one-hour moving images on one sheet are also on the market.

As a next-generation medium of CD and CD-ROM, DVD (Digital Video Disc) is used.
k). The DVD is a large-capacity optical disk for recording data having a larger amount of information such as a digitalized video signal. The DVD employs some new technologies to increase the recording density on the optical disk as compared with the conventional technology in order to secure a large capacity. For example, the thickness of the base is 0.6 mm, and the two bases are bonded to each other to have a thickness of 1.2 mm.
mm optical disk. In this case, information can be recorded on each substrate, and single-sided reproduction, double-sided reproduction, single-sided double-layer reproduction, and the like can be performed.

FIG. 4 is a sectional view of an optical disk for explaining the structure of a DVD-5. In the figure, 21 is a first transparent substrate, 22 is a reflective film, 23 is a second transparent substrate, 24 is an adhesive layer, and 25 is a pickup. This structure is a DVD
It represents the structure of DVD-5 as a draft standard, and is an optical disk having a single-layer single-sided structure. A pit row is formed on the upper surface on the first transparent substrate 21 side, and is covered with the reflection film 22.
The pit train is modulated by data to be recorded.
The second transparent substrate 23 on which no pit row is formed is
They are attached via an adhesive layer 24. The single-sided reproduction is performed by the pickup 25.

FIG. 5 is a sectional view of an optical disk for explaining the structure of a DVD-10. In the figure, the same parts as those in FIG. 31 is a reflection film. This structure represents the structure of DVD-10 of the proposed DVD standard, and is a single-layer double-sided optical disk.

[0006] A pit row is formed on the upper surface of the first transparent substrate 21 and is covered with a reflection film 22. Similarly, the pit row is formed on the upper surface on the second transparent substrate 22 side, and the second transparent substrate 23 is covered with the reflection film 31. The first transparent substrate 21 and the second transparent substrate 23 are bonded via an adhesive layer 24. Pickup 2
5 is reproduced on both sides, or the optical disk is turned over to be reproduced on one side by the pickup 25.

FIG. 6 is a cross-sectional view of the optical disk for explaining the structure of the DVD-9. In the figure, the same parts as those in FIG. 41 is a translucent reflective film, 42 is a transparent adhesive layer, and 43 is a reflective film. This structure represents the structure of DVD-9 of the proposed DVD standard.
This is a two-layer single-sided optical disk.

A pit row is formed on the upper surface of the first transparent substrate 21 and is covered with a translucent reflection film 41. A pit row is also formed on the upper surface of the second transparent substrate 23, and the reflection film 4 is formed.
3 is covered. The first transparent substrate 21 and the second transparent substrate 23 are bonded via a transparent adhesive layer 42. The first information recording layer composed of pit rows on the upper surface of the first transparent substrate 21 covered by the semi-transparent reflective film 41 is reproduced by the pickup 25, and the second transparent substrate covered by the reflective film 43 by the pickup 25 is reproduced. The second information recording layer composed of a pit row on the upper surface of the 23 is reproduced.

FIG. 7 is a cross-sectional view of the optical disk for explaining the structure of the DVD-18. In the figure, the same parts as those in FIG. 51 and 54 are translucent films, 52 and 55 are reflection films, 53 is an adhesive layer,
57 is a transparent resin layer. This structure represents the structure of the DVD-18 of the proposed DVD standard, and is a two-layer double-sided optical disk.

[0010] A pit row is formed on the upper surface of the first transparent substrate 21 and is covered with a translucent film 51. On this semi-transparent film 51, 2P (photo polymerizer)
A pit array is also formed on the transparent resin layer 56 formed of an ultraviolet curable resin by the Tion method, and is covered with the reflective film 52. The same applies to the second transparent substrate 23, in which pit rows are formed on the upper surface of the second transparent substrate 23,
The transparent resin layer 57 which is covered with the translucent film 54 and is
A pit row is formed by the P method, and is covered with the reflection film 55. The first transparent substrate 21 and the second transparent substrate 23 are bonded via an adhesive layer 53 with the readout surface facing outward.

A first information recording layer composed of a pit row on the first transparent substrate 21 covered by the translucent film 51 is reproduced by the pickup 25, and the translucent film covered by the reflection film 52 by the pickup 25 is reproduced. The second information recording layer composed of a pit row on the lower surface of 51 is reproduced. Similarly, the pickup 25 reproduces the first information recording layer composed of the pit rows on the second transparent substrate 23 covered by the translucent film 54 by the pickup 25, and the pickup 25 reflects the first information recording layer. The second information recording layer composed of the pit rows on the lower surface of the translucent film 54 covered by 55 is reproduced.
In this manner, four layers are reproduced on both sides, or two layers are reproduced on one side by turning over the optical disc.

[0012] Of the above-mentioned DVDs, the DVD shown in FIG.
In -9, the first information recording layer and the second information recording layer are formed on different first transparent substrates 21 and second transparent substrates 23, respectively. First transparent substrate 22
When the second transparent substrate 23 and the second transparent substrate 23 are attached to each other, the centers of the two may be shifted from each other.

In the DVD reproducing apparatus, when chucking the optical disk to the spindle, the optical disk is positioned by a centering ring on a turntable using the center hole of the first transparent substrate 21 on the read side. Therefore, if the bonding is displaced, the eccentricity of the second information recording layer on the side of the second transparent substrate 23 on the side opposite to the positioned substrate becomes large. As a result, jitter when reading the second information recording layer becomes large, and there is a possibility that a reading error increases.

On the other hand, in the DVD-18 shown in FIG. 7, a semi-transparent film 51 is laminated on a base on which a first information recording layer is cut, and a second layer pit is formed thereon by a 2P method. Is formed, but the center of the track of the first layer is deviated from the center during the formation of the resin layer, so that the second layer is formed similarly to the DVD-9. In reading the information recording layer, the error may increase.

According to the draft DVD standard, DVD-9 and DV
In both cases, the maximum eccentricity of the first information recording layer near the laser light incident surface is 70 μm and the maximum eccentricity of the second information recording layer far from the incident surface is 100 μm with respect to the center hole of the substrate.
m.

That is, when the eccentric direction of the DVD-9 is 180 ° different from that of the first and second information recording layers by lamination and the 2P method, the relative eccentricity of the DVD-18 is 2P. The maximum amount is 100 μm + 70 μm = 17
It is allowed up to 0 μm. When the eccentric directions of the first and second information recording layers are the same, the relative amount of eccentricity is allowed up to a maximum of 100 μm−70 μm = 30 μm, and if it exceeds this, the standard value will not be satisfied. .

However, in practice, the eccentric component of the first information recording layer is almost determined by the eccentricity at the time of stamper punching and the tolerance of the punched hole. At the current general technical level, the amount of eccentricity during stamper punching is 5 to 10 μm.
m, the tolerance of the punched hole is about 10 μm. Therefore, the amount of eccentricity of the first information recording layer is usually 15 to 20 μm.
It is about. Therefore, the above-mentioned numerical value of 70 μm can be replaced with 20 μm, and the set value of the maximum allowable eccentricity is 100 μm ± 20 μm. That is, when the eccentric direction is different by 180 °, the relative eccentricity is allowed up to 120 μm, and when the eccentric direction is the same direction, the relative eccentricity is allowed up to 80 μm. It is. Therefore, the above-described allowable range itself or the amount of eccentricity within this allowable range may be set as an inspection standard (for example, an in-house standard).

Conventionally, in order to measure the presence or absence of eccentricity between information recording layers of a bonded optical disk or an optical disk having a plurality of information recording layers on one surface, a completed optical disk is reproduced by an eccentricity measuring device to measure the amount of eccentricity. Was.
Therefore, it is not possible to visually inspect the eccentricity of the completed optical disc and whether the amount of eccentricity is within the standard value, and the eccentricity is measured by an eccentricity measuring device or the like. Had been healed.

As described in Japanese Patent Application Laid-Open No. 7-249238, an information recording layer is provided on both sides of an optical disk substrate. It is known that a reference mark is provided on each of the substrates, and the reference marks are adhered to each other while observing them with an individual CCD camera so that the positions of the centers of the two substrates coincide with each other. As the reference marks, a dot-shaped first reference mark and a circular second reference mark centered on the substrate center of each transparent substrate are used.

However, in such a reference mark, the position (orientation) of each transparent substrate must be precisely adjusted in order to align the position of the reference mark at the time of bonding. It is necessary to use four CCD cameras and the like in order to confirm whether or not the positions of the reference marks on the substrate match. Furthermore, this method cannot be used for centering between information recording layers of an optical disc having two or more information recording layers on one side and for measuring eccentricity.

[0021]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been developed for DVD-9, DVD-18.
A disc-shaped optical information recording medium for reproducing information from a plurality of information recording layers from one side, such as laminating a substrate having an information recording layer, or forming a plurality of information recording layers on the same substrate An object of the present invention is to provide a disc-shaped optical information recording medium that can visually determine the presence or absence of eccentricity or the amount of eccentricity, and that improves productivity.

[0022]

According to a first aspect of the present invention, there is provided an information processing apparatus comprising: a first and a second information recording areas each having an information recording area;
In the disc-shaped optical information recording medium for reproducing the first and second information recording layers from one side, an area excluding the information recording area in the first information recording layer, and
A pattern in which moiré fringes occur due to eccentricity between the first information recording layer and the second information recording layer is formed in an area of the second information recording layer other than the information recording area. It is assumed that.

According to a second aspect of the present invention, there are provided first and second information recording layers each having an information recording area.
In a disc-shaped optical information recording medium for reproducing the second information recording layer from one side, an area excluding the information recording area in the first information recording layer and an area excluding the information recording area in the second information recording layer In addition, at least one row of a plurality of concentric circular eccentricity determination tracks or a row of a plurality of spiral eccentricity determination tracks is provided.

According to a third aspect of the present invention, in the disk-shaped optical information recording medium according to the second aspect, the row of the eccentricity determination tracks is concentric, and each eccentricity determination track is concentric or It is characterized by being formed of a plurality of tracks identical to those for spiral information recording.

According to a fourth aspect of the present invention, in the disk-shaped optical information recording medium according to the third or fourth aspect, the eccentricity determination track includes a first and a second eccentricity determination track. , The interval between the rows of the first eccentricity determination tracks and the interval between the rows of the second eccentricity determination tracks are different.

[0026]

FIG. 1 is an external view of a disc-shaped optical information recording medium according to an embodiment of the present invention. In the figure, 1 is an optical disk, 2 is a recording area, and 3 is an eccentricity determination area.
The eccentricity determination area 3 is provided in at least one area inside or outside the recording area 2 of the optical disc 1. DVD
According to the draft standard, the start position of the lead-in area located at the innermost circumference is 45.2 mm, and the outermost circumference of the lead-out area or the middle area located at the outermost circumference is 116 mm. Therefore, the eccentricity determination area 3 is 45.2.
mm or at least one outside of 116 mm. When exposing two glass masters of the optical disc 1 by the master exposure apparatus, the eccentricity determination area 3 is also exposed by the same beam as the beam for cutting information in the recording area.

FIG. 2 is a schematic diagram of the eccentricity determination area shown in FIG. Reference numeral 11 denotes an eccentricity determination track. The eccentricity determination area 3 shown in FIG. 1 is constituted by a row of a plurality of eccentricity determination tracks in a concentric circle or a row of a plurality of eccentricity determination tracks in a spiral shape. FIG. 2 shows a row of seven concentric eccentricity determination tracks 11. The individual eccentricity determination tracks 11 are arranged at intervals d. In the case of a row of spiral eccentricity determination tracks having a plurality of turns, the interval between adjacent spirals is d. When the eccentricity determination track row is provided in a spiral shape, it is necessary to align the orientations of the substrates so that the spiral eccentricity determination track rows formed on the respective substrates coincide when bonding.

The length of the interval d is determined based on the relative allowable eccentricity between the first and second information recording layers. The row of the eccentricity determination tracks 11 is formed on each of the first and second information recording layers. When viewed from the reproduction side of the first and second information recording layers, the row of the eccentricity determination tracks 11 formed on the first information recording layer and the eccentricity determination tracks formed on the second information recording layer It is formed in a pattern such that the 11 columns match.

Each eccentricity determination track 11 is a collection of 5 to 20 concentric or spiral grooves or pit rows when viewed microscopically. Since the track is composed of a plurality of tracks as described above, the difference between the reflectance and the transmittance between the eccentricity determination track 11 and its peripheral portion becomes large, and the eccentricity determination track 11 can be easily observed. This groove or pit row is the same as the groove or pit row of the information recording track. Therefore,
The interval between the grooves or pit rows is set to 0.74 μm, which is the track pitch of the DVD. Therefore,
It can be formed in the same manner as the information recording track. However, it is not necessary to record information in the groove or the pit row. When forming the pit row, the pit row may have a random pattern as appropriate.

The maximum allowable amount of eccentricity between the first information recording layer and the second information recording layer is 18
0 ° is different from the case of displacement in the opposite direction. Therefore, when it is necessary to detect both of these cases separately, two types of eccentricity determination tracks 11 with different intervals d are provided in one optical disc 1. A column may be used. Eccentricity judgment track 11
As described above, it is easy to manufacture a glass master if it is formed of the same material as the information recording track, but this is not always necessary, and it may be formed separately on the glass master.

FIG. 3 is a schematic diagram of an eccentricity determination area for explaining eccentricity determination. FIG. 3A shows a state where there is no eccentricity between the first information recording layer and the second information recording layer.
FIG. 3B shows a state in which an eccentricity having a length not exceeding the distance b between both information recording layers is present in the left-right direction in the drawing, and FIG. It shows a state where the eccentricity is in the horizontal direction in the figure. Reference numeral 12 denotes moire fringes.

In FIG. 3A, when the first and second information recording layers are viewed from the reproducing side, the row of the eccentricity determination tracks 11 formed on the first information recording layer and the second And the row of the eccentricity determination tracks 11 formed on the information recording layer are visually observed at the same time.

In FIG. 3B, since there is an eccentricity between the two information recording layers that does not exceed the distance b, one eccentricity in the circumferential direction occurs.
A pair of moiré fringes 12 occurs. In FIG. 3C, since there is an eccentricity having a length exceeding the interval b between the two information recording layers, three pairs of moiré fringes 12 are observed in the circumferential direction.

When the relative eccentricity due to the bonding corresponds to the length of the interval d, two pairs of moiré fringes 12 are formed in the circumferential direction, and when the relative eccentricity increases more than this, the moiré fringes 12 The number of pairs increases. That is, when the length of the interval b is determined so that the displacement due to bonding is within the range of the maximum eccentricity when the number of moire fringes is one pair or less, two or more pairs of moire fringes are obtained when the distance exceeds the maximum eccentricity. Is visually observed, and eccentricity can be instantaneously determined.

The amount of displacement can be determined from the number of pairs of moiré fringes 12, and the relative direction of displacement can be determined from the angle direction at which the moiré fringe pairs are formed. The moiré fringes 12 depend on the relative deviation between the first and second track rows. If the absolute amount of eccentricity or the range of eccentricity of the first information recording layer is known, Based on this, the absolute amount of eccentricity or the range of eccentricity of the second information recording layer can be determined. Not only by visual observation, if the moire fringes 12 are detected as dark and light using the photoelectric conversion element while rotating the optical disk, the presence or absence of an eccentric state is detected from the presence or absence of a pair of dark and light, and the amount of eccentricity is detected from the number of pairs. You can also.

In the above description, the pattern in which moire fringes are generated is a row of a plurality of eccentricity determination tracks 11 in a concentric circle or a row of a plurality of eccentricity determination tracks 11 in a spiral shape. It is desirable that the concentric circles and spirals are continuous over the entire circumference of 360 degrees in that the eccentricity in all angular directions from the center of the base can be clearly determined. There may be a break that cannot be determined. The pattern is not limited to the pattern described above, and may be any pattern that has a periodic repetition such that moire fringes occur according to the eccentricity when viewed from one side reproduced.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the disc-shaped optical information recording medium of the present invention will be specifically described for the case of DVD-9. A glass substrate having a diameter of 200 mm and a thickness of 6.0 mm whose surface was flattened by a method such as polishing was 120
Dehydration bake at 5 ° C for 5 minutes.
A positive photoresist for i-line (trade name “ST11” manufactured by Zeon Corporation) was applied by spin coating to prepare a glass master. In accordance with a signal to be recorded, a laser beam is subjected to light intensity modulation using an EO modulator or the like, and is then narrowed down by an objective lens to irradiate the glass master.

Recording is performed with a recording diameter of 45 to 116 mm as a data recording area, and eccentricity determination tracks consisting of five grooves are spaced at intervals d in the areas of 40 to 44.5 mm and 116.5 to 118 mm. It was made concentrically. As an example of the length of the interval d, the interval d
Of the first eccentricity determination track having a distance of 170 μm and the second eccentricity determination track having an interval d of 30 μm. After post-baking and development, Ni electroforming and injection molding were carried out.
Was obtained. The first transparent substrate 21 is sputtered to a thickness of 10 nm as a translucent reflective film 41.
Were laminated to obtain a first disk.

Using a glass master which has been cut from the outer circumference to the inner circumference or from the inner circumference to the outer circumference in a spiral opposite to that of the above-mentioned glass master, a thickness of 0.
A second transparent substrate 23 of 6 mm of polycarbonate was obtained, and was used as a reflective layer 43 by sputtering to a thickness of 100 mm.
A second disk was obtained by laminating Al of nm. The first disk and the second disk were bonded with an ultraviolet curable resin adhesive, and the resin thickness of the adhesive layer 42 was set to 40 μm.

When the line of the first eccentricity determination track and the line of the second eccentricity determination track are both in the state shown in FIG. 3A or FIG. It is determined that the amount is within the standard value (in-house standard value). Only the row of the first eccentricity determination track in which the length of the interval d is long, d = 170 μm, is shown in FIG.
In the case of (B), if it is found from another inspection method that the eccentric directions of the first information recording layer and the second information recording layer are the same, the amount of eccentricity becomes the standard value. It turns out that it is settled.

In this case, only the second eccentricity determination track row having the shorter interval d of 30 μm may be formed.
When the row of the second eccentricity determination track is in the state shown in FIG. 3A or FIG. 3B, it can be seen that the second eccentricity determination track is always within the standard value even if the eccentric direction is not known.
Of course, the interval d between the rows of the eccentricity determination tracks may be set to less than 30 μm to narrow the allowable range at the time of inspection.

As described in the section of the prior art, the eccentricity of the first information recording layer is usually about 15 to 20 μm at the present general technical level. The distance d between the rows of the eccentricity determination tracks is 120 μm
And the distance d between the rows of the second eccentricity determination tracks is 80 μm.
It may be. As in the above-described example, the rows of the first and second eccentricity determination tracks are both shown in FIG.
In the case of (B), it is determined that the amount of eccentricity is within the standard value (in-house standard value). The interval d is 80μ
Only the second eccentricity determination track row shorter than m may be formed.

When the maximum allowable eccentricity of the optical disk 1 is determined by the logarithm of the moiré fringes 12 and the optical disks 1 are selected, a good reproduction signal is obtained from the optical disk 1 having the moiré fringes 12 within one pair. It has been found that the maximum allowable eccentricity can be determined by the method described above.

[0044]

As is apparent from the above description, according to the first aspect of the present invention, the area other than the information recording area in the first information recording layer, and the information recording in the second information recording layer. Since a pattern in which moire fringes occur due to the eccentricity between the first information recording layer and the second information recording layer is formed in each of the regions except the region, the moire fringes can be performed without using a special device. Accordingly, the presence or absence of eccentricity or the amount of eccentricity between the first and second information recording layers can be visually determined, and the moiré fringes can be easily read mechanically.

In the case of a bonded optical disk, it is possible to determine whether or not the two information recording layers satisfy the relative maximum eccentric allowance. In addition, even in an optical disc in which the information recording layer is formed in two layers from the beginning by the 2P method or the like, it is possible to determine whether or not the two information recording layers satisfy the relative maximum eccentric allowance. As a result, it is possible to improve the productivity of the disc-shaped optical information recording medium in which the jitter when reading the second information recording layer is reduced.

According to the second aspect of the present invention, a plurality of concentric circles are formed in an area excluding the information recording area in the first information recording layer and an area excluding the information recording area in the second information recording layer. Since there is at least one row of eccentricity determination tracks or a plurality of rows of spiral eccentricity determination tracks, the same effect as the invention according to claim 1 can be obtained, and the narrowness inside or outside the information recording area can be obtained. There is an effect that it is easy to provide an eccentricity determination track in the area.

According to the third aspect of the invention, the row of the eccentricity determination tracks is concentric, and each eccentricity determination track is composed of a plurality of concentric or spiral tracks for recording information. Since it is formed, there is an effect that a row of eccentricity determination tracks that can be easily viewed can be easily formed by using a conventional glass master disc producing apparatus.

According to the fourth aspect of the present invention, the first and second eccentricity determination track rows are provided as the eccentricity determination track row, and the distance between the first eccentricity determination track row and the second eccentricity determination track row are provided. Since the interval between the rows of the eccentricity determination tracks is different, different eccentricities can be observed simultaneously.

For example, if the interval between the rows of the first eccentricity determination tracks is 170 μm and the interval between the rows of the second eccentricity determination tracks is 30 μm, the amount of eccentricity is equal to the eccentricity of the first and second information recording layers. It can be seen whether the direction is within the range of the maximum allowable eccentricity when the direction is the same direction or the opposite direction. Further, for example, the interval between the rows of the first eccentricity determination track is set to 12
0 μm, and the interval between the rows of the second eccentricity determination track is 80
μm, the eccentricity of the first information recording layer is usually about 15 to 20 μm at the current general technical level, and the eccentricity is set to the first and second information recording layers. It can be seen whether or not the eccentric direction is within the range of the maximum allowable eccentricity when the eccentric direction is the same direction or the opposite direction.

[Brief description of the drawings]

FIG. 1 is an external view of a disc-shaped optical information recording medium according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of an eccentricity determination area shown in FIG.

FIG. 3 is a schematic diagram of an eccentricity determination area for explaining eccentricity determination.

FIG. 4 is a cross-sectional view of an optical disc for describing the structure of a DVD-5.

FIG. 5 is a cross-sectional view of an optical disc for explaining the structure of a DVD-10.

FIG. 6 is a cross-sectional view of an optical disc for explaining the structure of a DVD-9.

FIG. 7 is a cross-sectional view of an optical disc for explaining the structure of a DVD-18.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Recording area, 3 ... Eccentricity determination area, 11 ... Eccentricity determination track, 12 ... Moire fringe, 21 ...
First transparent substrate, 22, 31, 43, 52, 55... Reflective film, 23... Second transparent substrate, 41.
... Transparent adhesive layer, 51,54 ... Semi-transparent film, 56,57 ... Transparent resin layer.

Claims (4)

[Claims] 1. A disc-shaped optical information recording medium having first and second information recording layers each having an information recording area and reproducing the first and second information recording layers from one side. Moire fringes due to eccentricity between the first information recording layer and the second information recording layer are respectively formed in a region other than the information recording region in the layer and in a region other than the information recording region in the second information recording layer. A disk-shaped optical information recording medium, characterized in that a pattern in which pits occur is formed. 2. A disc-shaped optical information recording medium having first and second information recording layers each having an information recording area and reproducing the first and second information recording layers from one side. In an area excluding the information recording area in the layer and an area excluding the information recording area in the second information recording layer, a row of a plurality of eccentricity determination tracks concentrically or a plurality of eccentricity determination tracks in a spiral shape are provided. A disc-shaped optical information recording medium having at least one row. 3. The eccentricity determination track row is concentric, and each eccentricity determination track is formed of a plurality of concentric or spiral tracks for recording information. The disk-shaped optical information recording medium according to claim 2. 4. An eccentricity determination track comprising:
5. An array according to claim 3, comprising a row of second eccentricity determination tracks, wherein an interval between rows of the first eccentricity determination track is different from an interval between rows of the second eccentricity determination track. Disc-shaped optical information recording medium.