JP2009015911A - Information storage medium, and information recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information storage medium having a shape and a dimension of a pre-groove and those of a land prepit, with which a track deviation detection signal and a land prepit detection signal are obtained for recording light and simultaneously influence of the pre-groove and the prepit on regenerated light is reduced. <P>SOLUTION: The information storage medium is equipped with: a recording film which comprises a recording layer with a recording sensitivity to light of a wavelength shorter than 650±5 nm and a light reflection layer, and which has a light reflectance regenerated with light of 650±5 nm wavelength; the pre-groove which comprises a recessed part with a projecting and recessing shape arranged on a boundary between the recording layer and the light reflection layer and on which a recording mark is formed with the light of the short wavelength; and a land which comprises a protruding part with the projecting and recessing shape, which is interposed between the adjacent pre-grooves and in which intensity of reflected light in the irradiated region is made to be higher than that of the recording film in the region with no recording mark formed thereon on the pre-groove by irradiating the recording layer on the pre-groove with the light of the short wavelength. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information storage medium and an information reproduction method.

  It has been a long time since an information storage medium capable of recording and reproducing information using a laser beam, that is, an optical disk, has been put into practical use. For example, a standard image quality video can be recorded for several hours on a DVD standard optical disc having a diameter of 12 cm. On a read-only optical disc, video software and content can be recorded in a short time by pressing or molding. Note that a land pre-pit and a groove track (pre-groove) are formed on an optical disc of a type in which information can be written (added) or erased (rewritten).

In Patent Document 1, when a new recording mark is recorded on an information storage medium in which pregrooves and land prepits are present, a) reproduction reliability from address information recorded in the land prepits is ensured. Therefore, it is shown that a large detection signal can be obtained from the land pre-pit, and b) that a large track deviation detection signal can be obtained from the pre-groove in order to ensure high tracking stability during recording mark formation. .
JP 2001-266362 A

  In DVD-R discs and DVD-RW discs currently on the market, address information is recorded in advance by land pre-pits, and a recording mark is formed on the wobbled pre-groove.

In the example shown in Patent Document 1, the wavelength of the recording laser beam for the recording mark and the wavelength of the laser beam for reproducing information from the recording mark are the same.
1. Since the crosstalk signal from the land pre-pit is mixed in the reproduction signal from the recording mark, the reproduction signal characteristic from the recording mark is deteriorated, and the reproduction reliability from the recording mark is greatly lowered.
2. Due to the influence of the diffracted light from the pre-groove, the track shift detection characteristic by the DPD (DIFFERENTIAL PHASE DETECT) method is deteriorated, and the track shift detection stability from the recording mark is lowered.
3. Since the DC level from the pre-groove is reduced during reproduction, the reproduction signal amplitude from the recording mark is lowered, and the reproduction reliability from the recording mark is greatly reduced.
There's a problem.

  An object of the present invention is to obtain a track deviation detection signal and a land pre-pit detection signal for recording light, and at the same time, a pre-groove shape and size capable of reducing the influence of pre-groove and pre-pit on reproduction light, and An information storage medium having a land pre-pit shape and size, a method of recording information on the recording medium, and a method of reproducing information from the recording medium.

  An information storage medium according to an example of the present invention includes a recording layer having a recording sensitivity with respect to light having a wavelength shorter than 650 ± 5 nm, and a light reflection layer, and can reproduce light with light of 650 ± 5 nm. And a recording groove formed with a light having a wavelength shorter than 650 ± 5 nm, and a pre-groove formed of a concave and convex portion provided at the interface between the recording layer and the light reflecting layer. And irradiating the recording layer on the upper pregroove with light having a wavelength shorter than 650 ± 5 nm. And a land whose reflection intensity is higher than the reflected light intensity of the recording film in the area where the recording mark on the pregroove is not formed.

  In the information storage medium of the present invention, the recording light for forming the recording mark and the reproducing light for reproducing the recording mark can be light having different wavelengths, and the recording process and the reproducing process can be processed stably.

  In addition, the information storage medium of the present invention can obtain a track deviation detection signal and a land pre-pit detection signal with respect to the recording light, and at the same time, a pre-groove shape that hardly causes the pre-groove and the pre-pit to the reproduction light. In addition, the recording process and the reproducing process are further stabilized.

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

  FIG. 1 shows a cross-sectional structure of a current recordable information storage medium (current DVD-R disc). FIG. 2 is a schematic diagram for explaining the structure of land pre-pits of the write-once information storage medium shown in FIG.

  In the current DVD-R disc, the recording layer 103 is often formed on the transparent substrate 101 by spin coating of an organic dye material. Since the organic dye-based material has a low reflectance, it is difficult to obtain a sufficient reflected light intensity with the single recording layer 103. Therefore, in the current DVD-R disc, a light reflecting layer 102 made of an inorganic material such as Al or Au (which is often a metal) is formed adjacent to the recording layer 103 in order to increase the light reflectance. The surface of the light reflecting layer 102 has a step dc reflecting the uneven shape of the pregroove 107 and the land prepit 108 on the recording layer 103 side.

  Also in the current rewritable information storage medium (current DVD-RW disc), the transparent substrate 101 has a structure similar to the DVD-R disc shown in FIG. . However, the recording layer 103 is made of a phase change recording material and is different from the current DVD-R disc in that a recording mark is formed by the phase change of the recording layer.

  Therefore, in the DVD-R disc and the DVD-RW disc, not only the material of the recording layer 103 is different, but also the inside of the recording layer 103 includes a plurality of layers having different materials (an upper protective layer and a lower protective layer sandwiching the recording layer). , A laminated structure of an underlayer or the like.

  The fine structure in the information storage medium in the present embodiment is shown in FIGS. In FIG. 3, the land pre-pit 108 shown in FIG. 4 is not shown.

  As a material for the recording layer 103 in the write-once information storage medium in the present embodiment, an organic dye-based material described later is used. Further, an optical recording layer 102 made of an inorganic material such as Ag or an Ag alloy is formed adjacent to the recording layer 103. In the information storage medium shown in FIG. 3, an uneven shape exists at the interface on the opposite side of the light reflecting layer 102 as in FIG. 1. However, since the thickness of the light reflecting layer 102 is sufficiently thick, a drawing cut at the center of the light reflecting layer 102 is shown, and the description of the uneven shape at the interface on the opposite side is omitted.

  At the interface between the recording layer 103 and the light reflecting layer 102, a concavo-convex shape having a level difference Hr is generated in the pregroove 107 and the land prepit 108.

  As shown in FIG. 1, an uneven shape is present at the interface on the opposite side of the light reflecting layer 102, but FIG. 2 shows a drawing cut at the center of the light reflecting layer 102 because the light reflecting layer 102 is sufficiently thick.

  In the following description, an example in which an organic dye-based material is used as the recording layer 103 in the write-once information storage medium in this example will be described. However, the present invention is not limited thereto, and an inorganic substance is used as the material of the recording layer 103. May be.

  As an example of using an inorganic material as the material of the recording layer 103, a phase change type recording material such as a chalcogenide type (which forms the recording mark 105 using the phase change) may be used, or a direct material such as Te-C may be used. A type in which the recording mark 105 is formed by opening a hole, or a plurality of different types of inorganic layers may be laminated, and a mixture or a compound may be formed in the recording mark 105 by diffusion by heat.

  In the case of the information storage medium in the present embodiment having the cross-sectional structure shown in FIG. 3, the track deviation detection signal using the Push-Pull method and the detection signal from the land prepit 108 are recorded on the recording layer having the step Hr. It is obtained by diffraction / interference of the light reflected at the interface between the light reflecting layer 103 and the light reflecting layer 102.

  Next, the basic principle of the present invention will be described.

  Embodiments of the present invention provide an information storage medium that assures good recording characteristics and reproducing characteristics for recording light and reproducing light with different wavelengths as the recording / reproducing apparatus using different recording wavelengths. There is a big feature in doing.

  In addition, a track deviation detection signal and a land pre-pit detection signal can be obtained for the recording light, and at the same time, the pre-groove shape and dimensions and the land pre-prevention so that the reproduction light is hardly affected by the pre-groove or pre-pit. There are following features in setting the pit shape and dimensions.

  Current DVD-R discs and DVD-RW discs are premised on a reproduction light wavelength of 650 ± 5 nm.

  In the information storage medium in the present embodiment, reproduction is possible with light having a wavelength of 650 ± 5 nm in order to ensure reproduction compatibility with the current DVD-R disc or DVD-RW disc.

  A pre-groove size and a pre-groove size so that a track deviation detection signal and a land pre-pit detection signal are obtained with respect to the recording light, and at the same time, the reproduction light (650 ± 5 nm light) hardly affects the pre-groove or the pre-pit The relationship between the land pre-pit size and the wavelength of the recording light will be described with reference to FIG.

  As described above, the track deviation detection signal using the Push-Pull method and the detection signal from the land pre-pit 108 are diffracted by the light reflected by the interface between the recording layer 103 and the light reflection layer 102 (see FIG. 3). / Obtained by interference.

  A case will be described in which incident light 114 having a different wavelength is applied to both the pre-groove 107 or the land pre-pit 108 and the land 109 having a step amount of Hr.

FIG. 5A shows the case where the reproduction light having a wavelength of 650 nm is irradiated. The phase difference that the reflected light 115 reflected perpendicularly to the pregroove 107 or the land prepit 108 and the land 109 is received by the step Hr. , Ε ₆₅₀ .

FIG. 5B shows a case where recording light having a wavelength λW different from the reproduction light is irradiated. The phase difference received by the reflected light 115 by the recording light by the step Hr is assumed to be _ελW .

Further, when the step amounts HR are equal, the relationship of ε ₆₅₀ <ε _λW is established at λW <650 nm.

When ε ₆₅₀ <π and ε _λW <π, the larger the phase difference ε, the larger the amount of interference between the reflected lights 115, and a large track deviation detection signal and land pre-pit detection signal are obtained.

  On the other hand, the smaller the phase difference ε, the smaller the interference between the reflected lights 115, and the adverse effect from the pregroove or prepit (the crosstalk signal from the land prepit or the DC from the pregroove as shown in the problem of the prior art). Reproduction signal characteristic deterioration from recording mark due to level drop) is difficult to occur (reproduction signal characteristic deterioration is small).

  Therefore, in this embodiment, the recording light wavelength ΔW is shortened (λW <650 nm) with respect to the reproduction light wavelength (650 ± 5 nm), and a track deviation detection signal and a land prepit detection signal are obtained with respect to the recording light. At the same time, the main feature is that the reproduction light has almost no influence from the pregroove or prepit.

  The wavelength λW used for the recording light can take any value as long as it is shorter than 650 nm.

  However, since a 405 nm semiconductor laser light source is used in HD DVD and BD (Blu-ray), a recording optical head can be produced at low cost by using a 405 nm light source.

  Next, an optical head mounted in the recording apparatus will be described.

  A condensing spot condensed on the recording layer 103 traces (tracks) on the pre-groove 107 of FIG.

  Therefore, when the condensing spot size is not extremely small, that is, when the condensing spot size has a certain size or more, the larger the ratio of the distance Llc from the center of the pregroove 107 to the center of the land prepit 108 to the condensing spot size is. A large detection signal from the land pre-pit 108 can be obtained.

  Further, the numerical aperture NA (Numerical Aperture) of the objective lens used in the reproducing optical head on the current DVD-R disc or DVD-RW disc is defined as 0.60 ± 0.01.

  It is known that the size of the condensed spot condensed on the recording layer 103 is proportional to λ / NA, where λ is the wavelength of light.

  Therefore, in this embodiment, the objective lens NA value in the optical head mounted in the recording apparatus is made larger than that in the current reproducing optical head, thereby reducing the size of the condensing spot to be condensed on the recording layer 103, thereby reducing the land. Increase the pre-pit detection signal.

  The objective lens NA value in the optical head mounted in the recording apparatus is required to be larger than 0.6 that is the objective lens NA value of the reproducing optical head, but is preferably 0.65 or more.

  Furthermore, a larger land pre-pit detection signal can be obtained by setting NA = 0.70 or more or NA = 0.83 or more.

  In the above description, the recording apparatus and the reproduction apparatus are distinguished from each other for ease of explanation. However, in the present embodiment, the recording optical head and the reproduction optical head may be prepared in the same apparatus without being limited thereto. The same optical head in the same apparatus may have a 405 nm light source for recording, a recording objective lens of NA 0.65, a 650 nm light source for reproduction, and a reproduction objective lens of NA 0.60.

  Further, the present invention is not limited thereto, and only an objective lens with NA 0.65 may be used, and an aperture (shutter for limiting aperture) may be disposed in the light transmission system so that the NA is 0.60 during reproduction.

  In this embodiment, the reproducing optical head in the reproducing apparatus is adapted to the current DVD player (to ensure compatibility), and the light source of the recording optical head in the recording apparatus is replaced with a wavelength of 650 nm and NA 0.60. The wavelength is shorter than 650 nm (desirably 405 nm), and the NA value of the objective lens used for the recording optical head is set larger than 0.60 (preferably NA 0.65 or more), so that the recording is performed more than when reproducing. The amount of track deviation detection signal and the land pre-pit detection signal are increased at the time (by push-pull).

  Thus, by relatively increasing the track deviation detection signal amount and the land pre-pit detection signal amount during recording, the influence of the land pre-pit detection signal during reproduction is reduced and the track deviation detection signal amount during reproduction is reduced. It is possible to prevent the DC level from being lowered from the pregroove 107, and to prevent the reliability of the reproduction characteristics from the recording mark during reproduction from being lowered.

  Therefore, this embodiment has a technical feature in that the shape and size of the pregroove 107 and the shape and size range of the land prepit 108 are defined by utilizing the difference in wavelength between the recording light and the reproduction light.

  As described with reference to FIG. 3, the land pre-pit detection signal amount and the track deviation detection signal amount are determined by light reflected at the interface between the recording layer 103 and the light reflection layer 102 (in this case, reproduction light). .

When the refractive index in the recording layer 103 in the reproduction light of 650 ± 5 nm is N ₆₅₀ , the pregroove depth (step) Hr equal to the land prepit depth (step) is 650 / (8 · N ₆₅₀ ). In the case of nm, the land pre-pit detection signal and the track deviation detection signal are detected most greatly.

Therefore, as conditions that are not affected by the reproduction, the pregroove depth (step) and the land prepit depth (step) HR are set to 650 / (16 · N ₆₅₀ ) nm or less, which is half of that. To do.

In addition, it is desirable to set it to 650 / (32 · N ₆₅₀ ) nm or less, which is half of that under conditions that are not affected more.

  The pregroove depth (step) HR at the interface between the recording layer 103 and the light reflecting layer 102 will be examined in more detail.

  The reflected light 115 shown in FIGS. 5A and 5B is detected by the two-divided detectors arranged in the radial direction of the information storage medium after passing through the objective lens.

  The amount of signal detected by each detection cell in the photodetector is represented by I1 and I2.

In the current DVD-R standard, as the range of this track deviation detection signal,
0.22 <| I1−I2 | AC / | I1 + I2 | DC <0.44 (1)
It stipulates.

Therefore, as a condition for reducing the influence of the track deviation detection signal at the time of reproduction and preventing the DC level drop from the pregroove 107, in this embodiment, as the detection signal characteristic range at the time of reproduction,
| I1−I2 | AC / | I1 + I2 | DC <0.22 (2)
And

The above equation (2) is the minimum condition. In consideration of the margin, the condition that the influence of the track deviation detection signal at the time of reproduction can be further reduced and the DC level drop from the pregroove 107 can be prevented is as follows. The condition was narrowed in half
| I1−I2 | AC / | I1 + I2 | DC <0.11 (3)
Is desirable.

In the current DVD-R standard, the range of the land pre-pit detection signal is 0.18 <| I1-I2 | OP / | I1 + I2 | DC <0.28 (4)
As a condition for reducing the influence of crosstalk from the land pre-pits during reproduction, in this embodiment, the detection signal characteristic range during reproduction is expressed as | I1−I2 | OP / | I1 + I2 | DC <0.18 (5)
And

  In the above formula, the direct current component for I1 + I2 which is the sum of signals obtained by two detection cells when the focused spot crosses the pregroove 107 and the land 109 a plurality of times is defined as | I1 + I2 | DC, The difference amplitude (AC component) of the signal obtained in the detection cell is defined as | I1-I2 | AC.

  A simulation was performed on the depth (step) HR of the pregroove at the interface between the recording layer 103 and the light reflecting layer 102 to satisfy the above expression (2).

  As a simulation condition, the track pitch Ptc (see FIG. 1) was fixed to 0.74 μm as in the current DVD-R.

  The pregroove cross-sectional shape at the interface between the recording layer 103 and the light reflecting layer 102 is assumed to be trapezoidal as in FIG. 1, and the inclination angle of the left and right slopes of the pregroove 107 is 50 degrees (90 for a vertical wall surface). The width at the center of the slope is defined as the land width and groove width.

  FIG. 6 shows a simulation result showing a relationship between the pre-groove depth Hr and the push-pull signal amplitude when the reproduction light having a wavelength of 650 nm is collected by an objective lens having NA of 0.60. In FIG. 6, curve A is an example in which the groove depth is 10 nm, curve B is an example in which the groove depth is 20 nm, curve C is an example in which the groove depth is 30 nm, and curve D is the groove depth. An example where the depth is 40 nm, a curve E shows an example where the groove depth is 50 nm, a curve F shows an example where the groove depth is 60 nm, and a curve G shows an example where the groove depth is 70 nm. Yes.

The value on the vertical axis in FIG. 6 is shown in equation (1).
| I1-I2 | AC / | I1 + I2 | DC (6)
Represents.

In FIG. 6, the value of equation (6) is calculated when the parameter is the pre-groove depth Hr and the ratio of the land width to the groove width at the center of the trapezoidal slope is changed. The A / W value (A: diameter of the objective lens, W: diameter of the E- ² width with respect to the central intensity in the incident light intensity distribution) indicating the beam filling rate of incident light incident on the objective lens is 0. 0 in the circumferential direction. 3058 and 0.1513 in the radial direction.

  FIG. 7 shows a simulation result when recording light having a wavelength of 405 nm is collected by an objective lens with NA of 0.65 under the same conditions. In FIG. 7, a to g of each curve indicate the groove depth, and each corresponds to a capital letter in FIG. 6.

  In the example shown in FIG. 7, the A / W value is 0.3331 in the circumferential direction and 0.3331 in the radial direction.

  It can be seen that a much larger Push-Pull signal amplitude is obtained in FIG. 7 than in FIG.

  FIG. 8 shows the calculation result of FIG. 6 and the calculation result of FIG. 7 with the horizontal axis as the groove depth.

  The range of the above formula (1) is the “PUSH-PULL signal amplitude range condition defined by the DVD-R standard” indicated by the area “H” in FIG.

  It can be seen that the pregroove depth (step) HR at the interface between the recording layer 103 and the light reflecting layer 102 should be 20 nm or less as a condition that satisfies the above expression (2).

  It can also be seen from FIG. 8 that even under this condition, a sufficiently large Push-Pull signal amplitude can be obtained with recording light having a wavelength of 405 nm that has passed through an objective lens with NA of 0.65.

  From FIG. 8, as a condition for satisfying the above expression (3), the depth (step) Hr of the pregroove at the interface between the recording layer 103 and the light reflecting layer 102 should be 10 nm or less. Recognize.

When the recording light of 405 nm is irradiated with NA 0.65, the pregroove depth (step) Hr is
60 nm ≦ Hr ≦ 100 nm (7)
8 shows that the condition of the expression (1) is satisfied.

  Therefore, in this embodiment, the range of the depth (step) of the pregroove is set within the range of the expression (7).

  The description of the present embodiment relating to the recording layer 103 having the structure shown in FIG. 3 and capable of recording with recording light having a wavelength of 405 nm and capable of obtaining a sufficiently large reproduction signal amplitude from the recording mark 105 with reproduction light having a wavelength of 650 nm. Do.

On the current DVD-ROM disc standard for playback only,
When the reflectance at 650 nm reproducing light is circularly polarized,
45-85% in a single layer,
When the reflectance at 650 nm reproduction light is incident on non-circularly polarized light (linearly polarized light),
60-85% in a single layer,
It stipulates that it falls within the range of.

  Therefore, the recording film is designed so that the reflectance with respect to the reproduction light of 650 nm falls within the range of 35 to 85% (18 to 30% in the case of a multilayer) also for the information storage medium of this embodiment.

  Specifically, the present embodiment is characterized in that AgBi is used as the material of the light reflecting layer 102 shown in FIG. 3 in order to obtain the large light reflectance.

  The present invention is not limited to this, and a silver alloy or silver alone may be used as the material of the light reflecting layer 102.

Further, regarding the modulation degree of the reproduction signal from the recording mark 105 on the current DVD-ROM disc standard,
The value I _14H when the reproduction signal is the largest when viewed from “0 level”,
For the value I _14L where the reproduction signal is the smallest,
(I _14H −I _14L ) / I _14H ≧ 0.60 (8)
It is prescribed to satisfy. The present embodiment is devised to satisfy the following.

(I _14H −I _14L ) / I _14H ≧ 0.60 (8)
FIG. 9 shows the light absorption spectrum of the organic dye recording material used in the recording layer 103 in this example. In FIG. 9, curve I represents the absorption (absorbance) of the organic dye material before recording, and curve J (dotted line) represents the absorption (absorbance) of the organic dye material after recording.

  The present embodiment is greatly characterized in that an organic recording material recorded with 405 nm recording light and an organic recording material whose light reflection amount is changed by 650 nm reproduction light at the recording mark 105 are mixed (combined).

  The organic recording material used in this example and recorded with 405 nm recording light is reflected from the non-recorded portion in the recorded portion (record mark) shown in Japanese Patent Application Laid-Open No. 2006-205683 by the applicant. An L → H type recording material is used which increases the rate.

As described in Japanese Patent Application Laid-Open No. 2006-205683, the value of the maximum absorption wavelength λ _{max write} of an organic recording material recorded with 405 nm recording light is set to a value larger than the recording light wavelength of 405 nm. Thus, it is characterized by preventing deterioration during reproduction and ensuring long-term storage stability.

  As shown in FIG. 9, the recording material used in this example has a lower absorbance after recording with respect to light having a wavelength of 405 nm than before recording.

  The light of 405 nm is incident from the transparent substrate 101 side in FIG. 3, passes through the recording layer 103, is reflected by the light reflecting layer 102, and returns again through the recording layer 103.

  In the middle of the optical path, light absorption in the recording mark 105 decreases, and the amount of reflected light that is returned increases from the other part (the amount of reflected light is L: Low) (the amount of reflected light is H: High).

  At this time, holes are not opened in the recording mark 105, but as described in Japanese Patent Application Laid-Open No. 2006-205683, a change in the molecular orbital structure causes a change in the electron orbital in the molecule. The characteristics have changed.

  A specific organic recording material in this example is an azo Co complex anion (a kind of azo metal complex) using Co (cobalt) as a central metal, and an azo dye that is not a metal complex for high sensitivity. The hemicyanine cation was combined with the 10% added material.

  In the present embodiment, the material is not limited thereto, and a material in which a monomethine cyanine cation is combined with a material in which 10% of an azo dye is added to an azo Co complex anion may be used.

  As another application example, a styryl cation may be combined with a material in which 10% of an azo dye is added to an azo Co complex anion. In addition, an azo Cu complex alone or a central metal using copper Cu as a central metal. Alternatively, an azo Ni complex alone using nickel Ni may be used.

  The material described in Japanese Patent Application Laid-Open No. 2006-289878 by the present applicant may be used as an organic recording material whose light reflection amount is changed by 650 nm reproduction light.

  Further, in this embodiment, the recording / reproducing characteristics can be improved by adjusting the temperature change temperature or decomposition temperature at the molecular level of the organic recording material whose light reflection amount is changed by 650 nm reproducing light to the organic recording material recorded by 405 nm recording light. It is characterized by having been stabilized.

  When the recording mark 105 is formed, the temperature of the organic recording material recorded with the 405 nm recording light rises to cause a molecular arrangement change or a minute molecular structure change. In response to this temperature rise, the light reflection amount is reduced by the 650 nm reproducing light. The principle that the light reflection amount in the recording mark 105 is changed even with respect to 650 nm reproduction light by causing a molecular arrangement change or a minute molecular structure change in the changing organic recording material.

  Specifically, since the decomposition temperature of the organic recording material recorded with the 405 nm recording light described above is 230 to 250 degrees Celsius, the organic recording material in which the amount of light reflection is changed by the 650 nm reproducing light is also adapted thereto.

  Specifically, in this embodiment, an azo Co complex anion is combined with a pentamethine cyanine cation as an organic recording material in which the amount of light reflection is changed by 650 nm reproduction light.

  In addition, the azo Cu complex alone may be used.

  When the recording material described above is used, an L → H type recording material is obtained in which the absorbance decreases after recording as compared to before recording even for light having a wavelength of 650 nm.

Further, as shown in FIG. 9, by setting the value of the maximum absorption wavelength λ _{max read} of the organic recording material whose light reflection amount is changed by 650 nm reproduction light to a longer wavelength side than 650 nm which is the reproduction light wavelength, L → H It is characterized in that the reproduction signal amplitude from the recording mark 105 is increased in the shape recording characteristics.

  The current DVD-ROM is an H → L type medium in which the amount of light reflection is reduced at the recording pit portion. When only the focus servo follows, the beam spot crosses the radial direction of the information storage medium. Already commercially available information recording / reproducing apparatuses detect changes in the amount of reflected light that occur when crossing radial pits and mirrors, and generate track movement detection signals. When the reflectance on the land is low, the track movement detection signal cannot be generated and the PUH cannot be moved.

  Therefore, before or after forming the recording mark on the information storage medium shown in FIG. 3, the recording layer on the land is irradiated with recording light to perform recording on the recording layer on the land. By increasing the reflectance of the portion, a pseudo DVD-ROM disk is obtained.

  By doing so, it is possible to reproduce the DVD recorder that is already on the market without imposing a load. In this embodiment, recording processing on the land 109 is performed as such pre-record processing or finalization processing. However, the present invention is not limited thereto, and recording may be performed on the recording layer 103 on the land 109 as part of the characteristic inspection before shipment in the factory immediately after the information storage medium is created.

  Hereinafter, a recording method in the case of pre-record processing of the recording layer 103 in the land portion will be described. The information storage medium is placed on the information recording apparatus, the information storage medium is rotated, focus and tracking servo are applied to the land portion with 405 nm light, and the light spot follows the land portion. When the pickup head (PUH) comes to the recording start point, 405 nm light emitted from the PUH to the information storage medium is set to a recordable power. The PUH continuously moves while recording on the land portion from the inner periphery to the outer periphery of the information storage medium. When the PUH reaches the recording end point, the recording ends. When recording on the land portion, it is possible to record on the land by recording not only with continuous light but also with laser light whose intensity changes at a single frequency with a period shorter than the shortest mark to be recorded.

  Next, actual content information is recorded in the information storage medium. Content data is previously stored in a hard disk or the like. This is recorded in the groove portion. The information storage medium is placed on the information recording device, the information storage medium is rotated, the light is focused on the groove portion by 405 nm light, and the light spot is followed by the tracking servo. When the PUH comes to the recording start point, the light of 405 nm is emitted to a recordable power, and at the same time, the data is output from the information storage medium storing the content data such as a hard disk and synchronized with this. It emits light of 405 nm and records data such as content information on the information storage medium. The PUH moves continuously while recording data from the inner periphery to the outer periphery. When the PUH reaches the recording end point, the recording ends.

  FIG. 10 shows an information storage medium in which the recording on the land portion and the recording of the content have been completed. As shown in FIG. 10, the recording mark 105 is formed on the recording layer on the pregroove and the recording layer 103A on the land 109 is recorded. The reflectance of the recording layer 103A is higher than the reflectance of the region where the recording mark 105 on the pregroove 107 is not formed.

  In addition, the present embodiment can record not only continuous light of a land portion or a single frequency but also images of characters, symbols, photographs, and the like. Image recording data such as photographs is prepared in advance. The image recording data is developed so that the image data is exposed when the recording surface is visually observed after recording on the land 109 using the image recording data.

  When recording processing is performed on the land 109 using image recording data, the information storage medium is placed on the information recording apparatus, the information storage medium is rotated, and the land and the tracking servo are caused to follow with the light of 405 nm. When PUH comes to the recording start point, 405 nm light is emitted to a recordable power, and at the same time, 405 nm light is emitted in synchronization with the image recording data, and an image such as an image is recorded on the information storage medium. The The PUH moves continuously while recording data from the inner periphery to the outer periphery. When the PUH reaches the recording end point, the recording ends. Data such as photographs emerges on the recording surface of the information storage medium. The data to be recorded can be not only digital but also analog data for power modulation.

  In this embodiment, the thickness Dg of the recording layer 103 in the pregroove 107 is optimized in order to exhibit the above effect.

  As a result of experiment under different conditions, it was found that the thickness Dg of the recording layer 103 in the pregroove 107 is 60 nm, and the detection signal amplitude from the recording mark 105 can be maximized, and the range of 30 to 90 nm is appropriate.

  This embodiment is technically characterized in that the shape and size of the pregroove 107 and land prepit 108 are optimized in accordance with the recording layer 103 material.

  In this embodiment, since the recording layer 103 is formed by spinner coating, the thickness Dl of the recording layer 103 in the land 109 is smaller than the thickness Dg of the recording layer 103 in the pregroove 107 as shown in FIG. ing.

  Therefore, the depth (step) Hg of the pregroove 107 on the transparent substrate 101 for satisfying both the condition of the expression (7) and the above-described range of Dg is set in the range of 20 to 33 nm.

  According to the experimental results, it is found that if the depth (step) Hg of the pregroove 107 on the transparent substrate 101 is 15 nm or less, the thickness Dg of the recording layer 103 cannot be increased, and the reproduction signal amplitude from the recording mark 105 is reduced. It was.

  Further, as pointed out in the problems of the prior art, there has been a problem that when the DC level from the pre-groove 107 at the time of reproduction decreases, the reproduction signal amplitude from the recording mark decreases.

In order to solve the above problem, in this embodiment, the width W _{GC of the} pregroove 107 is set to 250 to 380.

  Although not shown in the present embodiment, the pre-groove 107 is wobbled to facilitate rotation synchronization and signal synchronization.

  If the wobble amplitude value is too large, the reproduction signal characteristic from the recording mark 105 is adversely affected.

  In this embodiment, the wobble amplitude is set to 15 nmp-p or less (5 nmp-p is most suitable), and the reproduction signal characteristic from the recording mark 105 is kept good (reproduction signal characteristic is stabilized).

  In addition, as pointed out in the problems of the prior art, mixing of the crosstalk signal from the land pre-pit 108 adversely affects the reproduction signal characteristics from the recording mark 105.

  Therefore, in this embodiment, technical contrivance is made with respect to the shape and size of the land pre-pit 108 in order to reduce the crosstalk signal mixture from the land pre-pit 108.

  As shown in FIGS. 1 and 2, in the current DVD disc, the land pre-pits 108 are formed in an uneven pit shape.

  In this case, the influence of crosstalk was large because of a large signal change (including shaking back) at the pit boundary.

  On the other hand, in this embodiment, as shown in FIG. 4, a part of the pregroove 107 is meandered to form land prepits 108.

  As a result, it is possible to appropriately control the amount of signal change before and after the land pre-pit 108 and to keep the reproduction signal characteristic from the recording mark 105 good.

In the present embodiment has a serpentine length L _PC of the pre-groove 107 in the land pre-pit 108 400 nm, the meandering amplitude W _PC to 300 nm.

  The information storage medium in the present invention is used for network distribution of video information as shown in FIG.

  The encrypted specific information 45 (video content 11) transferred from the production company (content provider) 54 of the specific information via the network is an information (copy) recording device 55 in the retail store (service anchor) 5. In the information storage medium 10 using 405 nm recording light.

  From the information storage medium 10 recorded in this manner, the end user 6 reproduces the video content 11 using reproduction light of 650 nm.

  In the present invention, the following two methods are assumed as a method of using the information storage medium.

  In one method, as shown in FIG. 11, the encrypted specific information 45 (video content 11) is distributed over the network to the retail store 5 and recorded in the information storage medium 10 in the retail store 5 by MOD ( Manufacturing On Demand).

  The other method is a method of directly distributing to the end user 6 over the network and recording on the information storage medium 10 using a 405 nm recording light in a recording apparatus owned by the end user 6, and is an EST (Electric Sell Through). Call it.

  FIG. 12 shows a macro structure in the information storage medium of the present embodiment.

  The track pitch and the linear density of the system lead-in area SYLDI are both larger (approximately twice each) than the data lead-in area DTLDI.

  In this embodiment, both the system lead-in area SYLDI and the data lead-in area DTLDI record information by forming a recording mark 105 with 405 nm recording light after forming the information storage medium.

  In the system lead-in area SYLDI, as shown in FIG. 13, the control data zone CDZ can be recorded, and the byte position in the physical format information PFI in the area is from 32 bytes to 127 bytes. Identification information 262 for the invention medium can be recorded.

  Further, the type and version specific information 263 of each standard document and the information content 264 that can be set for each revision can be recorded, and the information content 264 that can be set for each revision can be recorded using 405 nm recording light. Recording conditions (write strategy) for recording in the medium 10 can be recorded.

  As shown in FIG. 11, the information storage medium 10 in a blank state 20 is sold from the information storage medium manufacturer 9.

  In this embodiment, when used as MOD, information in the system lead-in SYLDI shown in FIG. 13 (including physical format information PFI in the control data zone CDZ) is stored in the information storage medium 10 in the blank state 20. Sold in an unrecorded state.

  In this method, the information storage medium manufacturing company 9 does not incur the cost of recording the information in the system lead-in SYLDI (including the physical format information PFI in the control data zone CDZ) in the information storage medium 10. 5, the information storage medium 10 in the blank state 20 can be sold at a low cost.

  In the case of this MOD, a recording condition (write strategy) when recording using 405 nm recording light is recorded in advance in the land pre-pit 108.

  In the case of MOD, since the information (duplicate) recording device 55 having excellent reproduction performance for information recorded in advance in the land pre-pit 108 is used, the information reproduction stability from the land pre-pit 108 is ensured. .

  In contrast, when used in EST, the information reproduction stability from the land pre-pit 108 of the recording device owned by the end user 6 cannot be guaranteed.

  Therefore, in the present embodiment, the control data zone CDZ including the physical format information PFI in which the recording condition (write strategy) for recording using the 405 nm recording light is recorded as the information storage medium 10 in the blank state 20 is included. System lead-in area SYLDI) information is recorded and sold.

  Since the reproduction reliability from the information (record mark 105) recorded using the 405 nm recording light is high, according to this embodiment, the acquisition reliability of the recording condition (write strategy) information when used in EST is greatly increased. improves.

  FIG. 14 shows the detailed information contents in the physical format information PFI shown in FIG.

  The information storage medium of the present invention is premised on that it can be reproduced by a current DVD player.

  Therefore, the physical format information PFI is the current reproduction-only DVD-ROM disc, the current write-once DVD-R disc, or the information storage medium of the present invention so that the recording device or the reproduction device can operate stably. The feature of this embodiment lies in having such identification information.

  In the embodiment shown in FIG. 14, the page descriptor PGD is arranged at the 34th byte position in the recording area of the identification information 262 for the medium of the present invention.

This page descriptor PGD is
At 00H, it indicates the current read-only DVD-ROM disc or the current write-once DVD-R disc,
At 10H, it is used as MOD in the information storage medium of the present invention,
At 11H, it is used as an EST in the information storage medium of the present invention
It shows that.

  As a result, disc discrimination between the recording apparatus and the reproducing apparatus can be performed quickly and easily, and the simplification and stabilization of the recording / reproducing process can be guaranteed.

  As shown in FIG. 14, the recording condition (write strategy) when recording using the 405 nm recording light can be recorded after the byte position 512 in the area of the information content 264 that can be set uniquely for each revision.

  In the current write-once DVD-R disc, recording conditions (write strategy) when recording with 650 nm wavelength light can be recorded in this area, so that different recording conditions (write strategy) for each type of information storage medium. ) Can be recorded in the same area, and it is possible to effectively use the area in the physical format information PFI.

  FIG. 15 shows the information contents in the location information of the data area DTA shown in FIG.

  The information storage medium of the present embodiment also records common information as “in the write-once information storage medium” in the same manner as the current DVD-R disc.

  As another method of the present invention, the physical format information PFI has identification information as to whether it is the current reproduction-only DVD-ROM disc, the current write-once DVD-R disc, or the information storage medium of the present invention. In the embodiment, not only in FIG. 15, but using the “standard type information and version number information” shown in the 0th byte at the byte position in FIG. 14 (changing the version number with the current value), the identification information is changed. It may be provided with identification information indicating whether MOD is used or EST is used.

  As another embodiment, a specific value is set in the revision number information, revision number table, class status information, or extended (part) version information shown in the 17th to 27th bytes at the byte position in FIG. Thus, the information storage medium of the present invention may be used and identification information indicating whether MOD is used or EST is used.

  The information contents recorded on the current DVD-VIDEO disc and the creation location will be described with reference to FIG.

  In the current DVD-VIDEO disc, encryption processing using the CSS method is performed as a function for preventing unauthorized copying of video information.

  The video content 11 created by the content production company (studio) 1 is distributed to the disk duplication company (replicator) 4 using a tape as a medium or by network transfer.

  In order to prevent unauthorized copying of the video content 11, the distributed video content 11 itself is not recorded in the DVD video disc 3, but an encrypted video obtained by encrypting the video content 11 with the title key 12. Content 14 is recorded in the DVD video disk 3.

  This encryption processing is performed in the video content encryptor 22 existing in the disc duplication company (replicator) 4, and the title key 12 used for encryption is also present in the disc duplication company (replicator) 4. Issued within the key generation unit 21.

  Further, the disk replicating company (replicator) 4 obtains the disk key information 15 and the encrypted disk key group 16 information from the CSS entity 2 which is the encryption key issuing company for a fee (paying the key price 17). The information of the converted disc key group 16 is recorded in the DVD video disc 3.

  Further, the title key 12 is encrypted using the information of the disc key 15 received from the CSS entity 2, and the encrypted title key 13 is also recorded in the DVD video disc 3.

  In the current DVD-VIDEO disc, the encrypted disk key group 16 is recorded in the lead-in area (in the control data zone CDZ shown in FIG. 13A in the system lead-in area SYLDI in FIG. 12). Information related to the encrypted title key 13 is distributed and recorded in specific locations in a physical sector, which is a basic recording unit of the DVD video disc 3.

  Each time the DVD duplication company (replicator) 4 manufactures the DVD video disk 3, it pays the DVD license company 19 a DVD license fee 19 and obtains a DVD video disk manufacturing license right 18.

  The end user 6 purchases the DVD video disc 3 on which the disc key group 16 thus encrypted, the encrypted title key 13 and the encrypted video content 14 are recorded at a purchase price 35.

  Although not shown in the DVD player, which is a playback device owned by the end user 6, the disc key is decrypted using the master key and generated (decrypted) using the decrypted disc key. The video content 14 encrypted using the title key 12 is returned to the non-encrypted video content 11 and reproduced and displayed.

In the current DVD video disc 3, the encrypted disc key group 16, the encrypted title key 13, and the encrypted video content 14 are recorded as pits having a fine uneven shape. In the embodiment, encrypted specific information 45 (encrypted information which is recorded in the information storage medium 10 in the form of a recording mark 105 formed by recording light having a wavelength λ _W and is related to the video content 11 is encrypted. The video content 14) and encryption related information related to the CSS system are distributed over the network.

  The DVD-R disc, which is the current write-once information storage medium, uses CPRM as an encryption method for preventing unauthorized copying, whereas the information storage medium 10 shown in this embodiment is shown in FIG. In addition, recording information related to CSS has a great feature as an information storage medium.

  That is, the information storage medium corresponding to the present embodiment after the information is recorded by the recording light with the wavelength λW is as if the recording mark 105 is formed instead of the pit having the uneven shape, as shown in FIG. The DVD player (reproducing device) recognizes it as if it was a created DVD-VIDEO disc and enables reproduction.

  Therefore, the information storage medium corresponding to the present embodiment after the information is recorded by the recording light having the wavelength λW is the encrypted disk key group 16 (system lead-in area SYLDI shown in FIG. 13) which is information related to the CSS. Recorded in the control data zone CDZ), the encrypted title key 13 and the encrypted video content 14 are recorded.

  Further, in order to make an existing DVD player (playback apparatus) recognize as if it is a read-only DVD-VIDEO disc, “reproduction-only medium (in the physical format information PFI in the control data zone CDZ shown in FIG. It is also a feature of this embodiment that it is clearly indicated as “DVD-ROM disc)”.

  As a result, it is possible to stably reproduce the information recorded in the information storage medium 10 shown in the embodiment of the present invention without imposing any burden on the DVD player (reproducing apparatus).

  Specifically, in this embodiment, the standard type is set to “0000B” in the “standard type information and version number information” recorded in the 0th byte at the byte position in FIG. Is specified.

  Even if the specification type is specified in this way, it is possible to identify the information storage medium of this embodiment or a genuine DVD-ROM disc by using the information of the page descriptor PGD shown in FIG.

  Further, in the present embodiment, the presence or absence of an emboss pit and an additional write area or a rewrite area is specified in the medium structure recorded at the second byte at the byte position in FIG. The value of B0 is set to “001”, and it is clearly shown to the DVD player (reproducing device) as if it has a structure with only embossed pits.

In the medium structure information,
In the case of B2 = 0B, it indicates that there is no rewritable user area in the corresponding information storage medium,
When B2 = 1B, this indicates that the corresponding information storage medium has a rewritable user area.

Also,
In the case of B1 = 0B, it indicates that there is no user area that can be additionally written in the corresponding information storage medium,
In the case of B1 = 1B, it indicates that the corresponding information storage medium has a user area that can be additionally written.

further,
In the case of B0 = 0B, the corresponding information storage medium does not have a user area where embossed pits are formed,
When B0 = 1B, the corresponding information storage medium has a user area in which embossed pits are formed.
Means that.

  As shown in FIG. 11, the information storage medium 10 used in the above-described MOD method includes a disk key group 16 encrypted by an information (copy) recording device 55 installed in the retail store 5 and an encrypted title key. 13. An encrypted video content 14 is recorded, and an information storage medium used for the EST method is a disc key group 16 encrypted by a recording device owned by the end user 6 and an encrypted title key 13 The encrypted video content 14 is recorded.

  In any case, in the present embodiment, CSS related information and information related to specific information such as video content 14 are distributed to the recording device via the network.

  In this way, the specific information such as the video content 14 is illegally copied during the distribution via the network, or various key information related to the CSS is stolen, so that the encrypted specific information recorded in the information storage medium 10 is stored. There is a high risk that the information 42 (encrypted video content 14) is illegally decrypted and illegally copied.

  In order to solve this problem, the present embodiment is characterized in that the encrypted information is distributed via the network for both the specific information such as the video content 14 and the various key information related to CSS. There is.

  As a result, even if information is leaked via the network, the leaked information is not encrypted (plain) information but is always encrypted information, so it cannot be reused and illegal copying is prevented. The effect is said.

  A detailed description of the features of the present embodiment will be given with reference to FIG.

  As described above, the information storage medium 10 used in the MOD method is recorded with the light having the recording wavelength λW (≠ 650 nm) in the information (copy) recording device 55 installed in the retail store 5.

  The information (duplicate) recording device 55 includes a communication key storage unit 52 and a master key storage unit 27.

  In FIG. 11, the two are described so as to be different from each other. However, the communication key storage unit 52 and the master key storage unit 27 may be combined in one memory.

  The retail store 5 pays the communication key price 49 to the production company (content provider) 54 of the specific information such as the video content 11 and purchases the communication key 44.

  This specific information production company (content provider) 54 uses this communication key to encrypt the specific information such as the video content 11, and the specific information 45 encrypted with the communication key is sent to the retail store 5 via the network. To deliver.

  Further, when the retail store 5 sells the information storage medium 10 in which the specific information is encrypted and sold to the end user 6, a copy permission fee 47 corresponding to the sales is paid to the production company (content provider) 54 of the specific information. .

  The specific information 45 encrypted with the communication key distributed from the production company (content provider) 54 of the specific information uses the information of the communication key 44 already distributed, and is decrypted once in the multi-function device 51 for the specific information. Is done.

  Immediately thereafter, the information is encrypted with the title key 12 and recorded in the information storage medium 10 in the form of the specific information 42 encrypted with the title key.

  In the current example shown in FIG. 16, the disk key 15 is transferred between the encryption key issuing company (CSS entity) 2 and the disk duplication company (replicator) 4, but this route has sufficient security measures. Is transferred under the specified environment. In comparison, the network route on the system shown in FIG. 11 has a weak security measure, and there is a risk that the disk key 15 leaks to the outside along this route.

  In contrast, in the embodiment shown in FIG. 11, the encrypted title key 13 is transferred to the retail store 5 via the network instead of the plain (non-encrypted) disk key 15.

  In order to make this possible, an agent company 8 is arranged between the encryption key issuing company (CSS entity) 2 and the retail store 5 in this embodiment.

  In the agent company 8, the title key generation unit 21 issues a title key 12 for each title.

  Next, a title key 13 encrypted using the disk key 15 transferred from the encryption key issuing company (CSS entity) 2 is generated in the title key encryptor 23 in an environment in which sufficient security measures are taken. Then, network distribution to the retail store 5 is performed.

  In the information (copy) recording device 55 in the retail store 5, the encrypted title key 13 distributed on the network is recorded in the information storage medium 10 as it is.

  The retail store 5 pays a key fee and a DVD license fee 33 to the agent company 8 according to the number of times the title key 13 recorded in the information storage medium 10 is recorded.

  The agent company 8 collectively pays the DVD license fee 33 collected thereby to the DVD license company 7.

  The DVD license company 7 gives the information storage medium manufacturing license 31 instead of collecting the DVD license fee 32 to the information storage medium manufacturing company 9 that manufactures the information storage medium 10 in the blank state 20.

  The agent company 8 shown in FIG. 11 receives the encrypted disk key group 16 together with the disk key 15 from the encryption key issuing company (CSS entity) 2 in the same manner as the disk replication company (replicator) 4 shown in FIG. The agent company 8 distributes the encrypted disk key group 16 to the retail store as it is.

  As described above, all of the information distributed to the retail store 5 over the network is “specific information 45 encrypted with a communication key”, “encrypted disc key group 16”, and “encrypted title key”. Since the information is encrypted, unauthorized copying can be prevented even if the information leaks in the middle of the network path.

  Although FIG. 11 describes the information storage medium 10 used in the MOD method, the present invention is not limited to this and can be applied to the information storage medium 10 used in the EST method.

  In the case of EST, the distribution destination via the network is the end user 6. Even in this case, for the end user 6, “specific information 45 encrypted with a communication key” and “encrypted disk key group” Since all encrypted information such as “16” and “encrypted title key” is distributed, unauthorized copying can be prevented.

  Further, in both cases of MOD and EST, information related to CSS distributed on the network is recorded in the information storage medium 10 as “encrypted disc key group 16” and “encrypted title key”. Therefore, the pre-recording process in the information (duplication) recording device 55 is greatly simplified, and the price of the information (duplication) recording device 55 can be reduced and the processing reliability can be improved.

  Further, in the disk key complex 28 in the information (duplicate) recording device 55, the master key 40 transferred from the master key storage unit 27 is used, and the encrypted disk key group 16 distributed over the network from the agent company 8 is used. Decryption of.

  Using the disc key 15 obtained here, the title key composite unit 29 generates the title key 12 by decrypting the encrypted title key 13 distributed from the agent company 8 over the network. Using the title key 12, the specific information 43 is encrypted in the encoder 41 for the specific information and recorded in the information storage medium 10.

  Another embodiment (application example) of the present invention is shown in FIG.

  Also in FIG. 17, the CSS-related information distributed over the network to the information (duplication) recording device 60 is an encrypted information storage medium called “encrypted disc key group 16” and “encrypted title key”. The fact that the information is recorded in 10 corresponds to the embodiment shown in FIG.

  However, the application example of FIG. 17 differs in that the normal DVD-VIDEO disc 3 is delivered 36 instead of the video content 11 being delivered over the network.

  In the embodiment shown in FIG. 17, the encrypted video content 14 recorded in the DVD-VIDEO disc 3 is decrypted (decrypted) inside the information (duplicate) recording device 60 and after the decryption. The video content 14 is encrypted again and recorded in the information storage medium 10 of the present invention.

  As described above, according to the information storage medium of the present invention, the use wavelength is changed between the recording light and the reproduction light with respect to the recording mark, and the track deviation detection signal and the land prepit detection signal are obtained with respect to the recording light. At the same time, by setting the pregroove shape and dimensions and the land prepit shape and dimensions so that there is almost no influence from the pregroove or prepit on the reproduction light, the recording process and the reproduction process are further stabilized. Can be planned.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

Schematic explaining an example of the structure of a write-once information storage medium. Schematic explaining the structure of the land prepit of the recordable information storage medium shown in FIG. Schematic explaining an example of a cross-sectional structure of an information storage medium different from the write-once information storage medium shown in FIG. Schematic explaining the structure of the land pre-pit of the write-once information storage medium shown in FIG. Schematic explaining the basic principle used in the embodiment of the present invention. The graph explaining the relationship between a groove depth and a Push-Pull signal amplitude at the time of condensing the light of wavelength 650nm with the objective lens of NA = 0.6. The graph explaining the relationship between a groove depth and a Push-Pull signal amplitude at the time of condensing the light of wavelength 405nm with the objective lens of NA = 0.65. The condition that the Push-Pull signal amplitude can be reduced when the light of wavelength 650 nm is condensed by the objective lens with NA = 0.6, and the Push-Pull signal amplitude can be increased when the light of wavelength 405 nm is condensed. Graph showing pregroove depth range to be satisfied (Push-Pull when light of wavelength 405 nm is condensed by an objective lens of different NA in a state where Push-Pull signal amplitude by light of wavelength 650 nm is set to a predetermined magnitude) Graph illustrating the relationship between Pull signal amplitude and groove depth). The graph which shows an example of the light absorption spectrum characteristic of a L-> H type organic dye recording material. Sectional drawing which shows the information storage medium which recording to the land part and recording of the content were complete | finished. The schematic diagram explaining an example of the picture information distribution system achieved by using the information storage medium of the present invention. Schematic explaining the structure of the recording area of the recordable information storage medium of FIG. Schematic explaining the data structure of the recording area of the recordable information storage medium of FIG. Schematic explaining the physical format information and R physical format information of the data structure shown in FIG. FIG. 15 is a schematic diagram for explaining physical format information and R physical format information in a data area DTA having the data structure shown in FIG. 14. Schematic explaining the current video information distribution system. The schematic diagram explaining an example of the picture information distribution system achieved by using the information storage medium of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Transparent substrate, 102 ... Light reflection layer, 103 ... Recording layer, 105 ... Recording mark, 107 ... Pregroove, 108 ... Land prepit, 109 ... Land

Claims (7)

A recording layer having a recording sensitivity with respect to light having a wavelength shorter than 650 ± 5 nm, and a light reflecting layer, and having a light reflectance that can be reproduced with light of 650 ± 5 nm;
A pre-groove composed of concave and convex portions provided at the interface between the recording layer and the light reflecting layer, wherein a recording mark is formed by light having a wavelength shorter than 650 ± 5 nm,
Reflecting the irradiated area by irradiating light having a wavelength shorter than 650 ± 5 nm to the recording layer on the upper pre-groove, which is composed of the concavo-convex convex portions and is sandwiched between the adjacent pre-grooves. An information storage medium comprising: a land having an intensity higher than a reflected light intensity of the recording film in an area where no recording mark is formed on the pregroove.   2. The information storage medium according to claim 1, wherein the light having a wavelength shorter than 650 ± 5 nm on the recording layer on the land is continuous light or light whose intensity changes at a single frequency. A recording layer having a recording sensitivity with respect to light having a wavelength shorter than 650 ± 5 nm, and a recording film having a light reflectance composed of a light reflecting layer and reproducible with light of 650 ± 5 nm;
A pre-groove composed of concave and convex portions provided at the interface between the recording layer and the light reflecting layer, wherein a recording mark is formed by light having a wavelength shorter than 650 ± 5 nm,
An information storage medium comprising: a land having a concavo-convex shape, sandwiched between adjacent pregrooves, and having a land having an intensity higher than the reflected light intensity of a recording film on the upper pregroove.   A recording mark on the pregroove having a reflection intensity of an irradiation region is formed by irradiating the recording layer on the land of the information storage medium according to claim 1 with light having a wavelength shorter than 650 ± 5 nm. An information recording apparatus, wherein the intensity of reflected light is higher than the reflected light intensity of the recording film in an unoccupied area.   5. The information recording apparatus according to claim 4, wherein the light having a wavelength shorter than 650 ± 5 nm in the recording layer on the land is continuous light or light whose intensity changes at a single frequency.   6. The information recording apparatus according to claim 5, wherein the single frequency corresponds to a period shorter than the shortest mark 1/2 recorded on the information storage medium.   The image data is recorded on the land portion by controlling the intensity according to the irradiation position of the light and prepared image data when the recording layer on the land is irradiated with light. Item 4. The information recording apparatus according to Item 4.

Images