JP2002117550A - Optical information recording medium, and its method and device for recording/reproducing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium capable of facilitating sure information recording/reproducing even when a capacity is enlarged, and its method and device for recording/reproducing. SOLUTION: In an information track including groove and land tracks alternately formed in the radial direction of a disk, an information recording area and an address area are disposed in the tracking direction of a laser beam. A step plotting adjacent grove and land tracks is subjected to wobbling in the tracking reaction so as to have a constant special frequency within a range where both ends are plotted alternately in the radial direction and by the address area. In the address area, a prepit address recording information regarding a position on a recording medium is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical information recording medium for recording and reproducing information by irradiating a laser beam, and further relates to a recording and reproducing method and a recording and reproducing apparatus for this medium.

[0002]

2. Description of the Related Art An optical information recording medium has attracted attention as a large-capacity and high-density memory, and a rewritable so-called erasable medium is currently being developed. One of the erasable optical information recording media is to form a recording layer using a material that changes phase between an amorphous state and a crystalline state on a substrate, and record and record information by irradiating the recording layer with a laser beam. It is to be erased.

As a phase change material used for the recording layer, an alloy film containing Ge, Sb, Te, In or the like as a main component, for example, a GeSbTe alloy is known. Information is recorded by forming a recording mark by partially amorphizing the recording layer. Usually, information is often erased by crystallization of recording marks. Amorphization is performed by heating the recording layer above its melting point and then cooling it. Crystallization is performed by heating the recording layer to a temperature equal to or higher than the crystallization temperature and equal to or lower than the melting point. There is a difference in the reflectance and the transmittance of the irradiated laser light between the area where the recording mark is formed and the other area.

In general, a spiral or concentric guide groove (groove) for tracking a laser beam during recording and reproduction is provided on a substrate in advance. The area between the grooves is called a land. Recordable CD (C
In a DR) or a mini disc (MD), one of a groove and a land is used as an information track for recording information, and the other is used as a guard band for separating adjacent information tracks.

[0005] Recently, the amount of information to be handled has increased with the improvement in the processing capability of various information devices. Therefore, a recording medium having a larger capacity is required. As a means for increasing the capacity, in DVD-RAMs and the like, a method of increasing the track density by recording information in both the groove and the land is adopted (land & land).
Groove recording method).

By the way, in DVD-RAM, ZCLV
(Zoned Constant Linear Velocity) format is adopted. In this format structure, an information track has an information recording area (sector) divided into a large number by addresses indicating positions on the medium. In addition, the information recording area has several areas (Zo
ne), the number of sectors in one round is increased step by step in each zone from the inner circumference to the outer circumference, and the number of revolutions during use is increased. The recording / reproducing of information is performed with the linear velocity of the data and the time length of the sector being substantially constant.

On the other hand, in the case of a CD-R or MD, information is recorded and reproduced at a constant linear velocity over the entire recording area.
The LV (Constant Linear Velocity) method is used. This method has the advantage that the maximum recording density can be realized over the entire recording area, and the thermal conditions during recording become constant, so that the design of the recording layer is facilitated.

In the CLV system, it is necessary to frequently change the rotation speed during random access. For this purpose, the grooves meander in the radial direction at a constant spatial frequency (wobble)
In addition, there has been proposed a method of controlling a rotary motor of a recording / reproducing apparatus based on a signal obtained from the wobble when recording / reproducing information. However, since the length of the groove for one round differs depending on the position in the radial direction, a phase difference occurs between wobbles of adjacent grooves. Therefore, when an attempt is made to apply the land & groove recording method to the CLV method, a good circuit control signal cannot be obtained in the land because signals from wobbles having different phases are combined.

In order to solve this problem, Japanese Patent Laid-Open Publication No. Hei 6-3
No. 38066 proposes a recording medium in which only one edge of a groove is wobbled. In this recording medium, address information is recorded as a frequency-modulated signal using the rotation control signal as a carrier frequency.

[0010]

However, if the interval between information tracks (track pitch) is reduced to further increase the density, the fluctuation rate of the information track width increases while maintaining the amplitude of the wobble. For this reason, at the time of information reproduction, the signal amplitude fluctuates and the signal quality deteriorates. On the other hand, when the amplitude of the wobble is also reduced, the intensity of the signal obtained from the wobble is reduced accordingly, making it difficult to detect the address information.

As another means for increasing the density of information recording, a multilayer recording medium including two or more recording layers has been proposed. In many multilayer recording media, it is necessary to record and reproduce information with a laser beam that has passed through another recording layer. In some cases, it may be necessary to record information over a plurality of recording layers or to reproduce information from the plurality of recording layers continuously.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical information recording medium which can easily record and reproduce information reliably even when the capacity is increased. Specifically, an object of the present invention is, firstly, to provide an optical information recording medium in which address information can be easily detected while using a CLV method together with a land & groove recording method. Secondly, the present invention provides an optical information recording medium including two or more recording layers, and capable of recording and reproducing information stably even when recording and reproducing information with a laser beam passing through another recording layer. The purpose is to provide. A third object of the present invention is to provide an optical information recording medium capable of efficiently and reliably recording and reproducing information even when recording and reproducing information continuously over a plurality of recording layers.

[0013]

The first optical information recording medium of the present invention is an optical information recording medium in which a recording layer for recording, reproducing or erasing information by irradiating a laser beam is disposed on a disk-shaped transparent substrate. An information recording medium, wherein the recording layer has information tracks including groove tracks and land tracks alternately provided in a radial direction of the disk, and the information tracks are arranged along a tracking direction of the laser light. The information recording area and an address area interposed between the information recording areas. In the information recording area, every other step defining the adjacent groove track and the land track is provided every other step in the radial direction. And wobbled along the tracking direction so as to have a constant spatial frequency within a range defined at both ends by the address area. In which, in the address region, characterized in that the pre-pit address information is recorded on the position on the recording medium is formed.

If the first recording medium of the present invention is used, the address information can be reliably detected even if the CLV method is used together with the land & groove method, so that stable information recording and reproduction can be performed.

The present invention also provides a method for recording and reproducing information on the first optical information recording medium. This method is a recording / reproducing method for an optical information recording medium for recording, reproducing or erasing information on the first optical information recording medium using a laser beam, wherein the method uses a rotation control signal obtained from a wobbled step. While controlling the rotation speed of the recording medium, information is recorded, reproduced or erased at a constant linear velocity in any information recording area.

One embodiment of the second optical information recording medium of the present invention is an optical information recording medium in which n recording layers (where n is an integer of 2 or more) are arranged, wherein the recording layer is an information recording medium. A track on the recording medium, wherein the information track includes an information recording area arranged along a tracking direction of the laser beam and an address area interposed between the information recording areas. Is formed, and at least in the recording layers from the first layer to the (n-1) th layer counted from the transparent substrate side, the address areas are adjacent in the radial direction of the disk. For any pair of address areas that
It is characterized by being arranged so as not to be arranged on a straight line passing through the center of the disk.

According to another aspect of the second optical information recording medium of the present invention, an n-layer recording layer for recording, reproducing, or erasing information by irradiating a laser beam on a disk-shaped transparent substrate is provided. n is an integer of 2 or more), wherein the recording layer has information tracks including groove tracks and land tracks alternately provided in the radial direction of the disk, and The track includes an information recording area arranged along the tracking direction of the laser beam and an address area interposed between the information recording areas, and a pre-recorded information on a position on the recording medium is recorded in the address area. A pit address is formed, a pair of information tracks radially adjacent to the disk have a common address area in which a common pre-pit address is formed,
At least from the first layer to the (n
-1) In the recording layers up to the layer, the common address area is
The pair of common address areas adjacent in the radial direction are arranged so as not to be arranged on a straight line passing through the center of the disk.

The use of the second recording medium of the present invention makes it possible to record and reproduce information stably even when recording and reproducing information with a laser beam passing through another recording layer. In this medium, even if the transmittance of the laser light differs between the information recording area and the address area, the influence on the transmitted laser light is reduced because the address area is dispersed without being blocked. The difference in the transmittance of the laser beam typically occurs due to the formation of a recording mark in the information recording area.

The present invention also provides an information recording / reproducing method and a recording / reproducing apparatus suitable for the second optical information recording medium. In this method and apparatus, a recording layer for recording, reproducing, or erasing information by irradiating a laser beam is disposed on a disc-shaped transparent substrate, the recording layer has an information track, and the information track is a laser beam. A pre-pit address in which information about a position on the recording medium is formed in the address area, comprising an information recording area arranged along the light tracking direction and an address area interposed between the information recording areas. And the address area is:
The present invention is applied to an optical information recording medium which is arranged so that any pair of address areas adjacent in the radial direction of the disk are not arranged on a straight line passing through the center of the disk.

Instead of this recording medium, a recording layer for recording, reproducing or erasing information by irradiating a laser beam is arranged on a disk-shaped transparent substrate, and the recording layers are alternately arranged in the radial direction of the disk. It has an information track including a provided groove track and a land track, and the information track is formed from an information recording area arranged along the laser light tracking direction and an address area interposed between the information recording areas. A pre-pit address in which position information on the recording medium is recorded in the address area;
A pair of information tracks adjacent in the radial direction of the disk have a common address area in which a common pre-pit address is formed, and the common address area is any of the pair of common address areas adjacent in the radial direction. Alternatively, an optical information recording medium arranged so as not to be arranged on a straight line passing through the center of the disk may be used.

The recording / reproducing method is a recording / reproducing method for an optical information recording medium for recording, reproducing or erasing information on the optical information recording medium using a laser beam, and irradiating the recording medium with the laser beam. The reflected light obtained is detected by a photodetector provided with two light receiving portions divided in a direction corresponding to the tracking direction of the laser light, and a sum signal of electric signals output from the two light receiving portions and Generating a difference signal, generating a corrected sum signal in which the amplitude variation of the sum signal is corrected using the difference signal, and reproducing the information by generating data information from the corrected sum signal. .

Further, the recording / reproducing apparatus is a recording / reproducing apparatus for an optical information recording medium for recording, reproducing or erasing information on the optical information recording medium using a laser beam, wherein the laser beam is transmitted to the recording medium. An optical head that outputs a reproduction signal of the information from reflected light obtained by irradiation, and a photodetector that has two light receiving units divided in a direction corresponding to a tracking direction of the laser light on the optical head. A summing amplifier for generating a sum signal of the electric signals output from the two light receiving units; a differential amplifier for generating a difference signal between the electric signals output from the two light receiving units; A waveform correction circuit that generates a corrected sum signal in which the amplitude fluctuation of the sum signal is corrected using a signal, and a data demodulation circuit that reproduces the information by generating data information from the corrected sum signal , Characterized by having a.

The recording / reproducing method and the recording / reproducing apparatus are:
Regardless of the number of recording layers, as in the second recording medium, the address area or the common address area passes through the center of the disk for any pair of (common) address areas adjacent in the radial direction of the disk. This is effective for optical information recording media arranged so as not to be arranged on a straight line.

The third optical information recording medium of the present invention comprises an n-layer recording layer (where n is 2 or more) for recording, reproducing or erasing information by irradiating a laser beam on a disk-shaped transparent substrate. An optical information recording medium on which a first information track for guiding a laser beam from the inner circumference of the disc to the outer circumference of the disc by rotation of the disc in a predetermined direction; A second recording layer having a second information track for guiding the laser beam from the outer circumference of the disk to the inner circumference of the disk by rotating in a predetermined direction.

The present invention also provides a method for recording and reproducing information on the third optical information recording medium. In this method, information is recorded on the third optical information recording medium using a laser beam,
A method for recording / reproducing an optical information recording medium to be reproduced / erased, wherein a first information layer and a second information track are provided in one of a first recording layer and a second recording layer. When the recording, reproduction or erasure of information on any one of the selected information tracks is completed at one end selected from the inner peripheral end and the outer peripheral end of the one information track,
In the other recording layer, recording, reproducing or erasing of information is continuously performed from the one end of the other track.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical information recording medium according to the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, an optical information recording medium according to the present embodiment has a thickness formed of polycarbonate or the like having a circular center hole for mounting in a recording / reproducing apparatus at the center. A recording layer (not shown) is provided on a transparent substrate 1 having a thickness of, for example, 0.6 mm. The recording layer is made of, for example, a GeSbTe alloy that is a phase change recording material. A recording layer made of such a phase change recording material is often used after being initialized (crystallized) in advance.
The recording mark is formed on the recording layer by being locally amorphized by the irradiation of the laser beam. On the substrate 1, a spiral information track 2 for tracking laser light at the time of recording and reproduction and recording information is provided in advance. This information track 2 is composed of grooves 3 and lands 4 alternately formed in the radial direction of the disk in order to support the land & groove recording method.

As shown in FIG. 2, information track 2 includes
The laser beam 8 is focused by the objective lens 7 of the recording / reproducing apparatus. The laser beam 8 is irradiated from below the drawing, that is, through the substrate.

The information track 2 has a double spiral structure in which the groove 3 and the land 4 form independent spirals, as shown in FIG. The information track 2 is configured such that information recording areas 5 and address areas 6 are alternately arranged in the circumferential direction of the disk (tracking direction of laser light). In other words, the information track 2 has a sector format structure divided into a number of areas by the address area 6.

For example, information is recorded and reproduced on the optical information recording medium by irradiating a laser beam having a wavelength of about 400 nm focused by an objective lens having an NA of about 0.65. The groove 3 is formed on the substrate 1 and has a depth of about 40 nm and a width of about 0.35 μm, for example.
The land 4 is, for example, a protrusion having a width of about 0.35 μm left between the grooves.

One of two edges (steps) formed along both ends of the groove 3 is wobbled at a constant spatial frequency (in other words, constant along the tracking direction of the laser beam). Is wobbled in a cycle). On the other hand, the other edge is not wobbled. The spatial frequency is set to be constant at least in the same information recording area 5. In this state, only one wobble of two adjacent grooves in the land 4 is detected. Therefore, even if a phase shift occurs between adjacent wobbles, adverse effects on signals from wobbles used for rotation control are reduced.

In this recording medium, the address area 6 is constituted by embossed pits formed on the groove 3 and the land 4. Therefore, even if the track pitch is reduced, it is possible to detect the address information with a sufficiently large signal intensity as compared with a medium to which the address information is added by frequency-modulating the wobble.

As described above, in the optical information recording medium, a signal from a stable wobble can be detected in a land as in the case of a groove, so that stable rotation control can be performed and address information can be reliably detected. This effect is particularly remarkable when the track pitch (FIG. 2P) is small, for example, 0.4 μm or less.

The address area 6 is used for equalizing the capacity of each sector when recording and reproducing by the CLV method.
It is preferable to arrange them so that the circumferential intervals along the information tracks are substantially constant (in other words, the circumferential lengths of the information recording areas are substantially uniform).

By the way, as shown in FIG. 1, in a recording medium having a double spiral structure, particularly when recording moving image information for a long time, after recording on one of the land track and the groove track, the other track is used. Is advantageous because the access operation during recording and reproduction is not required. However, when the track pitch is small, depending on the optical system of the recording apparatus and the recording conditions, the recording mark of the previously recorded information track is reduced due to thermal energy propagating from the information track to be recorded later, and the signal quality is deteriorated. Erasure (cross erase) may occur.

When adjacent erasure is anticipated, the land track and the groove track are compared, and the information track is first preceded by a track having a large signal amplitude due to the relationship between the optical properties of the recording layer and the groove shape of the information track. Should be recorded. According to this preferred example, even if the signal quality is deteriorated due to adjacent erasure, the signal intensity of the previously recorded information track can be set to a level sufficient for demodulation, so that a reproduction error can be suppressed. By making the width of the track to be recorded first wider than the width of the track to be recorded later, a decrease in signal quality due to adjacent erasure may be suppressed.

In the recording medium, the information track has a double spiral structure. However, the present invention is not limited to this. For example, the information track may have a single spiral structure in which a land and a groove are switched every one turn to form a spiral. Is also good. In the switching portion between the land 9 and the groove 10 in this structure, the address area 6 may be arranged as shown in FIG. Such a single spiral structure has an advantage that continuous recording and reproduction of information over the entire recording area of the medium is facilitated while using the CLV method together with the land & groove recording method.

When the edge of the groove is wobbled, the groove width and the land width fluctuate, and this fluctuation may affect the reproduced signal. If it is necessary to eliminate this effect, the wobbling frequency should be within the control band of the data demodulation circuit of the recording / reproducing apparatus used for the recording medium. If the information is corrected by the data demodulation circuit according to the wobbling frequency, the data recorded on the recording medium can be demodulated more reliably.

In the above description, the thickness of the transparent substrate is set to about 0.6 mm, and the width of the groove track is set to about 0.6 mm, assuming the use of an apparatus provided with an objective lens having an NA of about 0.65 and a laser light source having a wavelength of about 400 nm. Although exemplified as 0.35 μm,
Naturally, each numerical value is not intended to be limited to this. For example, N
When it is assumed that an apparatus having an objective lens of about 0.85 and a laser having a wavelength of about 400 nm is used, for example, the thickness of the transparent substrate is about 0.1 mm, and the width of the groove track is about 0.3 μm. I just need. The depth of the groove track and the like may be appropriately adjusted.

As shown in FIGS. 1 and 4, the address area may be arranged in the radial direction of the disk so as not to coincide with a straight line (a straight line including a diameter portion) 12 passing through the center of the disk. preferable. More specifically, in these media, the address areas adjacent to each other along the radial direction of the disk are arranged so as not to be on the straight line. When the address areas are arranged in a dispersed manner in this manner, there is a case where information is recorded / reproduced on / from another recording layer by a laser beam transmitted through a recording layer in which the transmittance of the laser light differs between the address area and the information recording area. However, stable recording and reproduction of information can be performed. This will be described in a second embodiment below.

(Second Embodiment) As shown in FIG. 5, the optical information recording medium of the present embodiment has two recording layers 14, 1
6 having a single-sided two-layer structure, and irradiating a laser beam 19 from the substrate 13 side to the first recording layer 14 or the second recording layer
The information is recorded, reproduced, or erased on both recording layers by focusing on. The recording layers 14 and 16 are separated from each other by a separation layer 15.
4, 15 and 16 are sandwiched between the substrate 13 and the protection plate 18.

At least in the first recording layer 14, as shown in FIGS. 1 and 4, adjacent address areas along the radial direction of the disk are arranged so as not to be on a straight line passing through the center of the disk. Have been. With this arrangement, the angular position of the address area viewed from the center of the disk does not match between adjacent information tracks. For this reason, Z
Address regions are not arranged at the same angular position in the same Zone as in the case where the CLV method is adopted.

By arranging the address areas so as not to form blocks, the transmittance of the laser light is different between the address area and the information recording area, typically, by the formation of a recording mark, the transmittance of the laser light is reduced. Even if the first recording layer 14 is formed of a changing material, local changes in the amount of laser light transmitted through the recording layer can be suppressed. Therefore, an effect is obtained that the local influence on the reproduction signal level from the second recording layer 16 is reduced.

For example, when the first recording layer 14 is made of a material whose transmittance is reduced by recording information, the transmittance of the laser beam in the address area is higher than that in the information recording area where the recording mark is formed. When the first recording layer 14 is made of a material whose transmittance increases by recording information,
Conversely, the transmittance of the laser beam in the address area decreases. However, if the address area is not concentrated in the area where the laser light is transmitted through the first recording layer 14, this influence hardly causes a problem.

The effect obtained by dispersing the address areas becomes more remarkable in an optical information recording medium as shown in FIG. 6 having a total of n ′ recording layers (n ′ ≧ 3). When information is recorded / reproduced on the n′-th recording layer 17, at least in the (n−1) recording layers on the laser beam incident side of this layer, the address area is shown in FIGS. The arrangement may be non-linear as shown. In the recording medium shown in FIG. 6, as in the recording medium shown in FIG. 5, a separation layer 15 is arranged between each recording layer, and the entire substrate is protected by a substrate 13 and a protective layer 18 from both sides. are doing. However, it is not necessary to form a separation layer between each recording layer.

Here, as in the first embodiment, a sector format structure in which an information track is divided into a large number by an address area is preferably used for each recording layer. The address area is used for recording and reproduction by the CLV method. It is preferable to arrange the circumferential intervals substantially constant so that the capacities of the sectors are equal. Also here,
The substrate 13 has the same configuration as the substrate 1 in the first embodiment.
In the information recording area, only one edge of the groove is wobbled at a constant spatial frequency, and a pre-pit address is preferably arranged in the address area.

Further, in the multilayer recording medium as shown in FIGS. 5 and 6, it is preferable to form a recording layer in which the spiral direction of the information track is reversed when viewed from a predetermined direction. This is because so-called seamless recording and seamless reproduction can be performed. This will be described in a third embodiment below.

(Third Embodiment) In the optical information recording medium of the present embodiment, as shown in FIG. 7, the first recording layer 14 and the second recording layer 16 Since the spiral direction of the information track is opposite,
By alternately using one recording layer, seamless recording and seamless reproduction using the maximum capacity of the recording medium can be performed.

For example, in FIG. 7, recording (or reproduction) of information may be performed according to the following procedure. First, the laser beam 19 is focused on the second recording layer 16 and information is recorded from the inner peripheral end A of the second groove 22 toward the outer periphery. To the outer peripheral end C of the first groove 20 of the first recording layer 14. Further, information is recorded on the first groove 20 toward the inner periphery, and when the inner periphery D is reached, the laser beam is again focused on the inner periphery E of the second land 23 of the second recording layer 16. Match. Subsequently, recording is performed on the second land 23 toward the outer periphery, and when the outer peripheral end F is reached, the laser beam 19 is again focused on the outer peripheral end G of the first land 21 of the first recording layer 14. Then, recording is performed on the first land 21 toward the inner peripheral end H. Here, the outer edge (inner edge) means the outer edge (inner edge) of the area to be used for recording information.

As described above, when recording and reproduction of information are continuously performed while changing recording layers appropriately at the end of the information track,
While the entire information recording area of the medium is used, it is not necessary to move the optical head for switching information tracks. Therefore, seamless recording and seamless reproduction can be performed while maximizing the capacity of the recording medium.

In the recording medium shown in FIG.
In order to reverse the spiral direction of the information track in 4 and 16, for example, the spiral direction of the groove formed on the substrate 13 and the protection plate 18 may be reversed. In this case, the recording layers 14 and 16 are formed on the substrate 13 and the protection plate 18, respectively, and the substrate and the protection plate are bonded with the two recording layers inside using a UV-curable resin serving as a separation layer. When combined, a recording medium as shown is obtained. The thickness of the separation layer may be, for example, about 40 μm. However, the present invention is not limited to this, and a groove whose spiral direction is opposite to that of the transparent substrate may be formed in the separation layer 15. In this case, for example, the first recording layer 14 and the separation layer 15 are laminated in this order on the substrate 13, an information track is formed on the separation layer 15 by a 2P method or the like, and the second recording layer 16 is formed thereon. After the formation, the protection plate 18 may be provided.

In a recording medium having three or more recording layers as shown in FIG. 6, at least one recording layer having information tracks having first and second spiral directions opposite to each other is provided. By arranging layers one by one, seamless recording (reproduction) at the same level as described above can be performed. When the number of recording layers is three or more, the number of recording layers (group) having the first spiral direction is equal to the number of recording layers (group) having the second spiral direction. If the number difference is set to 1, seamless recording (reproduction) using the maximum capacity of the recording medium is possible.

The order of recording information on the recording layer is not particularly limited. For example, in the case of a recording medium having a two-layer structure, the first recording layer has a property of increasing the transmittance of laser light by recording information. In this case, it is preferable to start recording information from the first recording layer. Conversely, when the first recording layer has a property that the transmittance is reduced by recording information, it is preferable to record information from the second recording layer.

Here, as in the first embodiment, it is preferable to adopt a sector format structure in which information tracks are divided into a large number by address areas for each recording layer, and the address areas are used when recording and reproducing by the CLV method. It is preferable to arrange the circumferential intervals substantially constant so that the capacities of the sectors are equal. Also here,
The substrate 13 has the same configuration as the substrate 1 in the first embodiment.
In the information recording area, only one edge of the groove is wobbled at a constant spatial frequency, and a pre-pit address is preferably arranged in the address area.

(Fourth Embodiment) This embodiment shows a modification of the pre-pit address in the address area shown in each of the above embodiments. The optical information recording medium of the present embodiment shown in FIG. 8 has a recording layer (not shown) on the substrate 1 on which the grooves 3 and the lands 4 are formed, similarly to the recording medium of the first embodiment shown in FIG. Is provided. The recording layer formed on the surface of the groove and the land has an information track 2 on which a sector in which information recording areas 75 and address areas 76 are alternately arranged along the radial direction of the disk. It has a format structure.

Also in this optical information recording medium, as shown in FIG. 9, in the information recording area 75, only one edge of the groove 3 is wobbled at a constant spatial frequency. Since the other edge is not wobbled, the wobbled edges are arranged every other in the radial direction of the disk. In the address area 76, a pre-pit address 71 including a group of emboss pits is formed. Thus, even in the medium of the present embodiment, the CLV
In spite of using the method, the signal from the wobble can be stably detected in both the land and the groove, so that stable rotation control can be performed. At the same time, the address information can be reliably detected. In this case as well, the address areas 76 may be arranged at substantially constant circumferential intervals along the information tracks so that the capacity of each sector becomes equal when recording and reproducing by the CLV method.

As shown in FIG. 9, in this embodiment, the pre-pit address 71 is provided on an extension of the edge of the groove 3, and the land 4 and the groove 3 adjacent to each other via this edge are connected to the pre-pit address 71. The pit address 71 is shared. The pre-pit addresses 71 are arranged at intervals equal to the track pitch in the radial direction. Address area 76 in which a common pre-pit address is formed
Is a common address area for a pair of information tracks radially adjacent to the disk.

As described above, the common pre-pit address 71
Is formed so as to straddle the boundary between a pair of information tracks, the pre-pits can be made larger than in the case where a pre-pit address is provided for each information track. Further, as illustrated, it is preferable that a pair of information tracks having a common address area share a wobbled step in the information recording area. In this way, wobbles can be formed continuously without breaks in the information recording areas of the groove track and the land track.

When a common pre-pit address is formed for a pair of groove track and land track as in this embodiment, at least one of the two tracks in the common address area 76 as shown in FIG. , Groove / land identification pits 72 are preferably formed. The illustrated groove / land identification pit 72 is detected only when recording / reproducing is performed on the groove track 3, so that the identification of both tracks is ensured. Here, the pits 72 are provided only on the groove track 3, but the identification pits may be formed only on the land track 4 or on both tracks. Further, as shown in FIG. 10, it is preferable that the groove / land identification pit 72 is formed so as to extend over the center line extending in the circumferential direction of the track to be identified.

(Fifth Embodiment) In this embodiment, a modification of the groove track and the land track in each of the above embodiments will be described. The optical information recording medium of the present embodiment can be applied to a recording medium in which address areas adjacent in the radial direction of a disk are not arranged on a straight line passing through the center of the disk.

In the recording medium in which the address area is arranged as described above, the information recording area is adjacent to at least a part of the address area. For this reason, as shown in FIG. 11, the recording mark 77 formed on the land track 4 has a smaller diameter in the portion (region A) adjacent to the address region 76 than in the other information recording region 75 (region B). It is formed to expand in the direction. Such partial enlargement of the recording mark causes distortion of the reproduced signal. As shown in FIG. 11, such irregularity of the recording marks becomes remarkable when a pair of adjacent information tracks share the pre-pit address 71.

Accordingly, in the present embodiment, as shown in FIG. 12, a recording mark shaping groove 68 is provided in the address area. The address area 66 is formed by the shaping groove 68.
Has a step at the boundary between two information recording areas 65 adjacent to each other along the radial direction of the disk, the step defining both the groove 63 and the land 64. Therefore, the recording mark 67 is formed without enlargement even in a portion adjacent to the address area, and distortion of a reproduction signal is suppressed.

As shown in FIG. 12, the recording mark shaping groove 68 may be formed by extending an edge that is not wobbled from the information recording area to the address area 66. As illustrated, the shaping groove 68 and the pre-pit address 61 may be formed so as to be continuous.

(Sixth Embodiment) In the present embodiment, an embodiment will be described in which the optical information recording medium of each of the above embodiments is further provided with a servo condition correction track. In the optical information recording medium of this embodiment, as shown in FIG.
Is used. It is preferable that the servo condition correcting tracks are arranged at regular intervals between the information tracks. The servo condition correcting pits provided on the servo condition correcting track 85 are centered at positions equidistant in the radial direction from the centers of the groove 83 and the land 84 (in FIG. 14, the d1 and d2 are made equal. ) It is good to arrange. Also, the servo condition correction pits 86 are preferably arranged in a staggered manner as shown in the figure.

More specifically, the servo condition is, for example, a tracking servo condition for correcting a deviation of a laser beam scanning a track from the center of a track during recording and reproduction, and a tilt servo condition for correcting a tilt of a laser beam applied to a medium. is there. For example, the tracking servo condition and the tilt servo condition are divided into directions corresponding to the circumferential direction of the recording medium (the tracking direction of the laser light) when the servo condition correction pits on the servo condition correction track are scanned by the laser light. It can be obtained using the difference signal between the electric signals output from the two light receiving units. A recording / reproducing apparatus having these two light receiving units will be described later.

The servo condition correction tracks are preferably provided for each radial position range to which the same servo condition can be applied. The shorter the interval and the greater the number, the higher the reliability of the servo condition. However, in order not to reduce the recording capacity of the medium, it is preferable to reduce the number as much as possible.

The servo condition correcting tracks may be provided, for example, at a rate of one set for every 5,000 information tracks.
When the interval between information tracks is 0.35 μm, 5000 information tracks correspond to a length of 1.75 mm along the radial direction. In the case of a general recording medium using a substrate having a thickness of about 0.6 mm, if the difference in the radial position is 5 mm or less, a shape change that greatly changes the optimum servo condition does not occur. Therefore, if the servo condition correction tracks are provided at the above-mentioned frequency and are prepared every 5 mm or less in the radial direction, it is sufficient to correct the servo conditions for each radial position.

In FIG. 14, one set of servo condition correction tracks is equivalent to three information tracks (corresponding to five information tracks when the preceding and following tracks are included). In this case, the area occupied by the servo condition correcting track is only 0.1% or less of the entire recording area, so that the recording capacity is not substantially reduced. In the present embodiment, an example has been described in which the servo condition correcting track is provided on both the groove and the land, but it may be provided on only one of the groove and the land. However, when the servo condition correcting track is provided on the groove and the land, the difference between the groove and the land is compensated, and the servo condition can be corrected more reliably.

In the drawings referred to in the description of the above embodiments, the shapes of the pre-pits and the pits for correcting the address servo condition are shown in a rectangular shape in plan view. As is often seen in
The corners of the pits may be rounded.

(Seventh Embodiment) In this embodiment, an example of a method for manufacturing an optical information recording medium of each of the above-described embodiments, particularly a recording medium provided with a groove having an edge wobbled at a constant spatial frequency will be described. .

First, a stamper is manufactured according to the following procedure.
A photoresist is applied on a glass substrate, and a laser beam is applied to the photoresist to expose portions corresponding to the groove and prepit addresses. At this time, as shown in FIG. 15, in the portion corresponding to the groove 3, the two laser spots 78 and 79 are irradiated while moving the glass substrate spirally. Among these spots, one laser spot 78 is meandered in the radial direction of the glass substrate, and the other laser spot 79 is irradiated without meandering in the same radial direction. Meandering laser spot 78
Is meandering while maintaining a state of partially overlapping the other spot 79. In the case of forming the pre-pit address 71 in the illustrated form, in a portion corresponding to the pre-pit address, for example, only one laser spot 78 is used, this spot is displaced in the radial direction, and the boundary between the groove 3 and the land 4 is formed. What is necessary is just to irradiate the position corresponding to a line intermittently.

When forming a recording shaping groove, a stamper may be manufactured in substantially the same procedure as described above. In this case, as shown in FIG. 16, when the laser spot 78 is intermittently irradiated for forming the pre-pit address 61, the laser spot 79 may be irradiated continuously and in parallel.

Next, the photoresist exposed by the irradiation of the laser beam is developed, and a Ni layer is formed on the photoresist surface by, for example, sputtering and electroforming. The stamper is obtained by removing the Ni layer from the glass substrate and removing the photoresist. By using this stamper and, for example, injection molding a polycarbonate resin, a substrate having the groove 3 and the pre-pit address 71 as shown in the figure on one surface is obtained.
Further, a recording layer is provided on a surface of the substrate on which the groove 3 and the like are formed by a conventionally performed method (for example, sputtering), and further, a protective layer made of, for example, a UV resin is provided, so that optical information recording is performed. A medium is obtained. In this specification, the protective layer, the reflective layer, and the like which are appropriately provided on both surfaces of the recording layer are omitted, but these layers may be appropriately formed by sputtering or the like within a necessary range.

(Eighth Embodiment) In this embodiment, a recording / reproducing apparatus and a recording / reproducing method will be described.

FIG. 17 is a block diagram schematically showing the configuration of one embodiment of the recording / reproducing apparatus of the present invention. FIG. 18 shows the configuration of the optical head 43 of this recording / reproducing apparatus.

In the optical head 43 shown in FIG. 18, the laser light emitted from the semiconductor laser 53 is applied to a collimator lens 54, a beam splitter 55, and a １ ／ wavelength plate 5
6. The recording layer 5 of the recording medium 100 through the objective lens 57
The light is collected at 9. The focused laser light is focused on the recording layer 59 by adjusting the position of the objective lens 57 by the voice coil 58. The light reflected from the recording layer 59 passes through the objective lens 57 and the quarter-wave plate 56 again, is reflected by the beam splitter 55, enters the photodetector 50, and is converted into an electric signal. Photodetector 5
0 includes light receiving units 51 and 52 divided into two in a direction corresponding to the tracking direction of the recording medium 100.

The recording / reproducing apparatus shown in FIG. 17 is mounted in a center hole of a recording medium 100 and rotates a spindle motor 39, a controller 40, a modulator 41 for converting data to be recorded into a recording signal, and a recording signal. A laser drive circuit 42 for driving the semiconductor laser according to the above, the optical head 43 having the semiconductor laser, and a sum signal 44S of electric signals output from the light receiving units 51 and 52 of the photodetector 50 provided in the optical head 43 are output. Adder amplifier 44, difference signal 45S between electric signals output from light receiving units 51 and 52
, An address demodulation circuit 46 for demodulating address information from the sum signal 44S, and a corrected sum signal 4 in which the amplitude fluctuation of the sum signal 44S is corrected using the difference signal 45S.
A waveform correction circuit 47 for generating 7S, a data demodulation circuit 48 for demodulating data information recorded on the track from the correction sum signal 47S, and a laser beam scanning the track of the recording medium 100 appropriately based on the difference signal 45S. Control circuit 49 for controlling the optical head 43 as described above.

Here, the corrected sum signal 47S is the difference signal 45
It is generated by amplifying S by a constant coefficient and subtracting it from sum signal 44S. The generation of the corrected sum signal is particularly effective for demodulating data information from an information track including a partially enlarged recording mark, for example, as shown in FIG.

FIG. 19 is a waveform diagram schematically showing various signals obtained from the information track showing the recording mark 75 in FIG. 11 using the recording / reproducing apparatus.
19A shows a sum signal 44S, FIG. 19B shows a difference signal 45S,
FIG. 19C shows the corrected sum signal 47S. As shown in these figures, the width of the recording mark 75 in the portion A adjacent to the address area 76 is larger than that in the other portion B.
In the sum signal 44S, amplitude fluctuation occurs in both regions. Further, since the land width is widened, the difference signal 45S also fluctuates. However, in the adjacent area A of the address area, the enlarged width of the land and the enlarged width of the recording mark are substantially constant, and thus the fluctuation amounts of the sum signal 44S and the difference signal 45S are also substantially constant.
Therefore, by amplifying the difference signal 45S by a constant coefficient and subtracting it from the sum signal 44S, it is possible to generate a corrected sum signal 47S without amplitude fluctuation. The corrected sum signal enables reliable demodulation of the recorded information.
The corrected sum signal may be generated by, for example, generating a gate signal from a change in the difference signal, and partially amplifying the sum signal according to the gate signal.

As described above, it is preferable that the control band of the data demodulation circuit 48 includes the wobbling frequency of the information track of the optical information recording medium for recording and reproducing information in the recording and reproducing device. This is because, when information is reproduced, even if the reproduction signal fluctuates due to the fluctuation of the width of the groove and land according to the wobbling, the data can be reliably demodulated.

[0081]

As described above, according to the present invention,
Even if the capacity is increased, it is possible to obtain an optical information recording medium that can easily record and reproduce information reliably. In particular, according to the first optical information recording medium of the present invention, it is easy to detect the address information while using the CLV method together with the land & groove recording method. Further, according to the second optical information recording medium, even when information is recorded / reproduced by a laser beam having two or more recording layers and passing through another recording layer, the address area is dispersed without being blocked. Therefore, stable recording and reproduction of information can be performed. Further, according to the third optical information recording medium, even when information is continuously recorded and reproduced over a plurality of recording layers, the information tracks whose spiral directions are reversed are used efficiently and efficiently. Information can be recorded and reproduced reliably.

The present invention also provides an information recording / reproducing method and a recording / reproducing apparatus suitable for the above-mentioned optical information recording medium. In particular, as in the second optical information recording medium, any pair of (common) address areas adjacent in the radial direction of the disk are arranged so that they are not arranged on a straight line passing through the center of the disk. Even when a medium is used, it is possible to reliably reproduce information while correcting partial enlargement of a recording mark.

[Brief description of the drawings]

FIG. 1 is a plan view of one embodiment of the optical information recording medium of the present invention.

FIG. 2 is a partial perspective view showing an enlarged surface of the recording medium shown in FIG. 1;

FIG. 3 is a perspective view showing an example of a spiral of an information track in the optical information recording medium of the present invention.

FIG. 4 is a plan view showing a switching portion of an information track of the recording medium shown in FIG. 3;

FIG. 5 is a sectional view of another embodiment of the optical information recording medium of the present invention.

FIG. 6 is a cross-sectional view of another embodiment of the optical information recording medium of the present invention.

FIG. 7 is a diagram showing still another embodiment of the optical information recording medium of the present invention, together with a scanning order of laser light.

FIG. 8 is a plan view showing still another embodiment of the optical information recording medium of the present invention.

9 is an enlarged partial perspective view showing an example of the surface of the recording medium shown in FIG. 8;

10 is a partial perspective view showing another example of the surface of the recording medium shown in FIG. 8 in an enlarged manner.

FIG. 11 is a partial plan view showing an example of the arrangement of an information recording area and an address area in the optical information recording medium of the present invention, together with recording marks formed in the information recording area.

FIG. 12 is a partial plan view showing another example of the arrangement of the information recording area and the address area in the optical information recording medium of the present invention, together with recording marks formed in the information recording area.

FIG. 13 is a plan view of an optical information recording medium showing an example of the arrangement of servo condition correction tracks.

FIG. 14 is an enlarged partial plan view showing an example of the surface of the recording medium shown in FIG.

FIG. 15 is a partial plan view showing an example of a stamper manufacturing step in the method for manufacturing an optical information recording medium of the present invention.

FIG. 16 is a partial plan view showing another example of the stamper manufacturing step in the method for manufacturing an optical information recording medium of the present invention.

FIG. 17 is a configuration diagram showing an example of a recording / reproducing apparatus for an optical information recording medium according to the present invention.

18 is a cross-sectional view illustrating a configuration of an optical head of the recording / reproducing device illustrated in FIG.

19A and 19B are diagrams for explaining an example of a recording / reproducing method using the recording / reproducing device shown in FIG. 17, where FIG.
Shows an example of a sum signal of the electric signals obtained from the two light receiving units,
(B) shows an example of a difference signal of the electric signal, and (c) shows an example of a sum signal (corrected sum signal) corrected using the difference signal.

[Explanation of symbols]

 1,13,81 (transparent) substrate 2,82 Information track 3,63 Groove 4,64 Land 5,65,75 Information recording area 6,66,76 Address area 8,19 Laser beam 12 Straight line passing through the center of disk 14 1st recording layer 15 separation layer 16 2nd recording layer 18 protective layer 20 1st groove 21 1st land 22 2nd groove 23 2nd land 39 spindle motor 40 controller 41 modulator 42 laser drive circuit 43 optical head 44 addition amplifier 45 Differential amplifier 46 Address demodulation circuit 47 Waveform correction circuit 48 Data demodulation circuit 49 Tracking control circuit 50 Photodetector 53 Semiconductor laser 54 Collimator lens 55 Beam splitter 56 Quarter-wave plate 57 Objective lens 58 Voice coil 59 Recording layer 67, 77 Record mark 68 Record mark Groove 71 Prepit address 72 Groove land identification pit 78, 79 Laser spot 86 Servo condition correction pit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/24 565 G11B 7/24 565F 20/12 20/12 (72) Inventor Kenji Narumi Kadoma City, Osaka 1006 Oaza Kadoma Matsushita Electric Industrial Co., Ltd. F-term (reference) AA14 BA01 BB08 BC08 BC09 BC12 BC13 BD02 CA13 CD03 CD04 CD07 CD08

Claims (37)

[Claims] 1. An optical information recording medium in which a recording layer for recording, reproducing or erasing information by irradiating a laser beam is disposed on a disk-shaped transparent substrate, wherein the recording layer is arranged in a radial direction of the disk. And information tracks including groove tracks and land tracks alternately provided in the information track, wherein the information tracks are information recording areas arranged along the tracking direction of the laser beam and addresses interposed between the information recording areas. In the information recording area, a step defining the adjacent groove track and the land track is constant every other step in the radial direction and within a range defined at both ends by the address area. Wobbled along the tracking direction so as to have a spatial frequency of An optical information recording medium, wherein a pre-pit address in which information about the information is recorded is formed. 2. The optical information recording medium according to claim 1, wherein a pair of information tracks radially adjacent to the disk have a common address area in which a common pre-pit address is formed. 3. The optical information recording medium according to claim 2, wherein a common pre-pit address is arranged so as to straddle a boundary between a pair of information tracks. 4. The optical information recording medium according to claim 2, wherein a pair of information tracks sharing a common address area share a step wobbled in the information recording area. 5. At least one of a pair of information tracks sharing a common address area has groove / land identification pits in the common address area.
5. The optical information recording medium according to any one of items 1 to 4, 6. The optical information recording medium according to claim 1, further comprising a servo condition correcting track. 7. A servo condition correcting track is provided on a groove track and a land track.
An optical information recording medium according to claim 1. 8. The optical information recording medium according to claim 1, wherein the groove track and the land track have a double spiral structure in which independent spirals are formed. 9. The optical information recording medium according to claim 1, which has a single spiral structure in which a groove track and a land track are switched with each other to form one spiral. 10. An address area provided at a position where a groove track and a land track are mutually switched,
The optical information recording medium according to claim 9, wherein any pair of address areas adjacent in the radial direction of the disk are arranged so as not to be arranged on a straight line passing through the center of the disk. 11. The optical information recording device according to claim 1, wherein the address areas are arranged so as not to be arranged on a straight line passing through the center of the disk with respect to any pair of address areas adjacent in the radial direction of the disk. Medium. 12. A step which defines a groove track and a land track is formed at a boundary between the address area and two information recording areas adjacent to the address area along the radial direction of the disk. Item 12. The optical information recording medium according to Item 11. 13. The method according to claim 1, wherein the common address area is any pair of common address areas adjacent in the radial direction of the disk.
3. The optical information recording medium according to claim 2, wherein the optical information recording medium is arranged so as not to be arranged on a straight line passing through the center of the disk. 14. In a common address area, a pre-pit address is formed so as to straddle a boundary in a pair of information tracks, and two common addresses adjacent to the common address area along the radial direction of the disk are formed. 14. The optical information recording medium according to claim 13, wherein a step defining a groove track and a land track is formed at a boundary with the information recording area. 15. The optical information recording medium according to claim 1, wherein the recording layer includes a material that reversibly changes between a crystalline state and an amorphous state by irradiation with a laser beam. 16. The optical information recording medium according to claim 1, wherein at least two recording layers are arranged. 17. A first recording layer having a first information track for guiding a laser beam from the inner periphery of the disk to the outer periphery of the disk by rotating the disk in a predetermined direction, and the laser beam is rotated by the rotation in the predetermined direction to the outer periphery of the disk. The optical information recording medium according to claim 16, further comprising: a second recording layer having a second information track guided from the side to the inner peripheral side of the disk. 18. A method for recording / reproducing information on / from an optical information recording medium according to claim 1, wherein the information is recorded / reproduced / erased by using a laser beam. Recording, reproducing or erasing information at a constant linear velocity in any information recording area while controlling the rotation speed of the recording medium by the rotation control signal obtained from the optical recording medium. Playback method. 19. An optical information recording medium in which n recording layers (where n is an integer of 2 or more) for recording, reproducing, or erasing information by irradiating a laser beam are disposed on a disk-shaped transparent substrate. Wherein the recording layer has an information track, the information track comprises an information recording area disposed along a tracking direction of the laser light and an address area interposed between the information recording area, A pre-pit address in which information on a position on the recording medium is recorded is formed in an address area, and at least the first to (n-1) th recording layers counted from the transparent substrate side have the address area. Is arranged so that any pair of address areas radially adjacent to the disk are not arranged on a straight line passing through the center of the disk. recoding media. 20. The optical information recording medium according to claim 19, wherein the information tracks include groove tracks and land tracks provided alternately in a radial direction of the disk. 21. A step which defines a groove track and a land track is formed at a boundary between the address area and two information recording areas adjacent to the address area along the radial direction of the disk. 21. The optical information recording medium according to 19 or 20. 22. An optical information recording medium in which n recording layers (where n is an integer of 2 or more) for recording, reproducing or erasing information by irradiating a laser beam are disposed on a disk-shaped transparent substrate. Wherein the recording layer has information tracks including groove tracks and land tracks alternately provided in the radial direction of the disk, and the information tracks are information arranged along a tracking direction of the laser light. A pair of information tracks, each including a recording area and an address area interposed between the information recording areas, and a pre-pit address in which position information on the recording medium is recorded in the address area; Have a common address area in which a common pre-pit address is formed, and are counted from the first layer to the (n-
1) In the recording layers up to the layer, the common address areas are arranged so as not to be arranged on a straight line passing through the center of the disk with respect to any of the pair of common address areas adjacent in the radial direction. Optical information recording medium. 23. In a common address area, a pre-pit address is formed so as to straddle a boundary between a pair of information tracks, and a boundary between the common address area and two information recording areas radially adjacent to a disk is formed. 23. The optical information recording medium according to claim 22, wherein a step for defining a groove track and a land track is formed. 24. The recording layer according to any one of claims 19 to 23, wherein the recording layers from the first layer to the (n-1) th layer counted from the transparent substrate side change the transmittance of laser light by recording information. Optical information recording medium. 25. A first recording layer having a first information track for guiding a laser beam from the inner circumference of the disk to the outer circumference of the disk by rotating the disk in a predetermined direction; And a second recording layer having a second information track leading from the side to the inner periphery of the disk.
The optical information recording medium according to any one of the above. 26. A recording / reproducing method for an optical information recording medium for recording, reproducing or erasing information on an optical information recording medium by using a laser beam, wherein the optical information recording medium comprises: A recording layer for recording, reproducing or erasing information by irradiating laser light is arranged, the recording layer has an information track, and the information track has an information recording area arranged along a tracking direction of the laser light. An address area interposed between the information recording areas, and a pre-pit address in which information about a position on the recording medium is recorded in the address area;
The address areas are arranged so as not to be arranged on a straight line passing through the center of the disk for any pair of address areas adjacent in the radial direction of the disk, and are obtained by irradiating the recording medium with the laser beam. Reflected light,
Detected by a photodetector having two light receiving sections divided in a direction corresponding to the tracking direction of the laser light,
Generating a sum signal and a difference signal of the electrical signals output from the two light receiving units, generating a corrected sum signal in which the amplitude fluctuation of the sum signal is corrected using the difference signal, and generating data information from the corrected sum signal; And reproducing the information by generating an optical information recording medium. 27. The optical information recording medium according to claim 19, wherein:
3. The optical information recording medium according to claim 1,
7. The method for recording / reproducing an optical information recording medium according to item 6. 28. A recording / reproducing method for an optical information recording medium for recording, reproducing, or erasing information on an optical information recording medium by using a laser beam, wherein the optical information recording medium comprises: A recording layer for recording, reproducing or erasing information by irradiating a laser beam is arranged, and the recording layer has an information track including a groove track and a land track provided alternately in a radial direction of the disk, and The information track is composed of an information recording area arranged along the tracking direction of the laser beam and an address area interposed between the information recording areas, and a pre-pit recording position information on the recording medium in the address area. A pair of information tracks on which an address is formed and which are adjacent in the radial direction of the disk have a common address area in which a common pre-pit address is formed. The common address area is arranged so as not to be arranged on a straight line passing through the center of the disk for any pair of common address areas adjacent in the radial direction, and is obtained by irradiating the recording medium with the laser beam. Reflected light,
Detected by a photodetector having two light receiving portions divided in a direction corresponding to the tracking direction of the laser light,
Generating a sum signal and a difference signal of the electrical signals output from the two light receiving units, generating a corrected sum signal in which the amplitude fluctuation of the sum signal is corrected using the difference signal, and generating data information from the corrected sum signal; And reproducing the information by generating an optical information recording medium. 29. The recording / reproducing method for an optical information recording medium according to claim 28, wherein the optical information recording medium is the optical information recording medium according to claim 22 or 23. 30. A recording / reproducing apparatus for an optical information recording medium for recording, reproducing, or erasing information on an optical information recording medium by using a laser beam, wherein the optical information recording medium comprises: A recording layer for recording, reproducing or erasing information by irradiating laser light is arranged, the recording layer has an information track, and the information track has an information recording area arranged along a tracking direction of the laser light. An address area interposed between the information recording areas, and a pre-pit address in which information about a position on the recording medium is recorded in the address area;
The address areas are arranged so as not to be arranged on a straight line passing through the center of the disk for any pair of address areas adjacent in the radial direction of the disk, and are obtained by irradiating the recording medium with the laser beam. An optical head that outputs an electric signal from the reflected light, the optical head includes a photodetector having two light receiving units divided in a direction corresponding to a tracking direction of the laser light, An addition amplifier that generates a sum signal of the electric signals output from the light receiving units, a differential amplifier that generates a difference signal between the electric signals output from the two light receiving units, and a sum of the sum signals using the difference signal It has a waveform correction circuit for generating a corrected sum signal corrected for amplitude fluctuations, and a data demodulation circuit for reproducing data by generating data information from the corrected sum signal. Recording / playback device. 31. The optical information recording medium according to claim 19, wherein
4. The optical information recording medium according to claim 1,
0. A recording / reproducing apparatus for an optical information recording medium according to 0. 32. An optical information recording medium recording / reproducing apparatus for recording, reproducing, or erasing information on an optical information recording medium by using a laser beam, wherein the optical information recording medium comprises a disc-shaped transparent substrate, A recording layer for recording, reproducing or erasing information by irradiating a laser beam is arranged, and the recording layer has an information track including a groove track and a land track provided alternately in a radial direction of the disk, and The information track is composed of an information recording area arranged along the tracking direction of the laser beam and an address area interposed between the information recording areas, and a pre-pit recording position information on the recording medium in the address area. A pair of information tracks on which an address is formed and which are adjacent in the radial direction of the disk have a common address area in which a common pre-pit address is formed. The common address area is arranged so as not to be arranged on a straight line passing through the center of the disk for any pair of common address areas adjacent in the radial direction, and is obtained by irradiating the recording medium with the laser beam. An optical head that outputs an electric signal from the reflected light, the optical head includes a photodetector having two light receiving units divided in a direction corresponding to a tracking direction of the laser light, An addition amplifier that generates a sum signal of the electric signals output from the light receiving units, a differential amplifier that generates a difference signal between the electric signals output from the two light receiving units, and a sum of the sum signals using the difference signal It has a waveform correction circuit for generating a corrected sum signal corrected for amplitude fluctuations, and a data demodulation circuit for reproducing data by generating data information from the corrected sum signal. Recording / playback device. 33. The recording / reproducing apparatus for an optical information recording medium according to claim 32, wherein the optical information recording medium is the optical information recording medium according to claim 22 or 23. 34. The control band according to claim 30, wherein the control band of the data demodulation circuit includes a wobbling frequency of an information track of an optical information recording medium for recording, reproducing, or erasing information in the recording / reproducing apparatus. Recording and playback device. 35. An optical information recording medium in which n recording layers (where n is an integer of 2 or more) for recording, reproducing or erasing information by irradiating a laser beam are disposed on a disk-shaped transparent substrate. A first recording layer having a first information track that guides a laser beam from an inner peripheral side of the disk to an outer peripheral side of the disk by rotating the disk in a predetermined direction; Second from the side to the inner circumference of the disk
And a second recording layer having the information track of (1). 36. The optical information recording medium according to claim 35, wherein a difference between the number of the first recording layers and the number of the second recording layers is 0 or 1. 37. A recording / reproducing method for an optical information recording medium for recording, reproducing or erasing information on the optical information recording medium according to claim 35 or 36 using a laser beam, comprising: In one of the two recording layers, recording, reproducing, or erasing of information on one of the first information track and the second information track is performed on the one information track. When the recording is completed at one end selected from the inner peripheral end and the outer peripheral end, the recording, reproduction or erasure of information is continued from the one end of the other information track on the other recording layer. Recording / reproducing method for an optical information recording medium.