JPH05182203A - Optical recording medium disk - Google Patents

Optical recording medium disk

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Publication number
JPH05182203A
JPH05182203A JP4018579A JP1857992A JPH05182203A JP H05182203 A JPH05182203 A JP H05182203A JP 4018579 A JP4018579 A JP 4018579A JP 1857992 A JP1857992 A JP 1857992A JP H05182203 A JPH05182203 A JP H05182203A
Authority
JP
Japan
Prior art keywords
optical disc
recording
pit
disc
optical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP4018579A
Other languages
Japanese (ja)
Inventor
Makoto Itonaga
誠 糸長
Original Assignee
Victor Co Of Japan Ltd
日本ビクター株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Victor Co Of Japan Ltd, 日本ビクター株式会社 filed Critical Victor Co Of Japan Ltd
Priority to JP4018579A priority Critical patent/JPH05182203A/en
Publication of JPH05182203A publication Critical patent/JPH05182203A/en
Granted legal-status Critical Current

Links

Abstract

PURPOSE:To obtain an optical disk capable of high density recording. CONSTITUTION:By arranging a recording track 1 formed in the alignment of a pit having a first pit width and the recording track 2 formed in the alignment of the pit having a second pit width different from the first pit width successively and alternately in the radial direction of the disk at a prescribed interval, the period of the periodic structure of the optical disk is made twice as many as the track pitch, or by arranging a guide groove having a first groove width and the guide groove having a second groove width different from the first groove width successively and alternately in the radial direction of the disk in a prescribed interval, the period of the periodic structure of the optical disk is made twice as many as the track pitch. Then the optical disk capable of high density recording as compared to a conventional optical disk is provided easily since a 1st-order diffracted light beam generated by the periodic structure of the optical disk by a light beam irradiating the optical disk is made incident on the pupil of a condenser lens even when the track pitch is narrowed up to the track pitch nearly 1/2 of the track pitch corresponding to a resolution limit.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an optical recording medium disk.

[0002]

2. Description of the Related Art The reproduction of recorded information recorded on the signal surface of an optical recording medium disc (hereinafter, also referred to as an optical disc) is performed by reproducing light condensed (focused) by a condenser lens. The optical recording medium disc is set with the beam waist portion located on the signal surface of the optical recording medium disc, that is, the signal surface of the optical recording medium disc is located on the focusing surface of the condenser lens. By projecting a spot of reproducing light having a diameter having a predetermined relationship with the width of the pits or the width of the bits of the recording information string (for example, the array of pits or the array of bits) formed on the signal surface of This is performed by photoelectrically converting the read light generated in the spot of the reproduced light.

By the way, if the recording mark interval (track pitch) is reduced in order to increase the recording density of the optical disk, it may happen that the tracking error signal cannot be obtained due to the resolution limit of the optical system. There is a limit to increase the recording density of an optical disc by reducing the distance. As is well known, the resolution of the optical system depends on the wavelength λ of the reproduction light and the numerical aperture NA of the condensing lens (objective lens), and the dimension d that becomes the resolution limit is expressed by the following equation (1) d = λ / NA / 2 ... (1) Here, the optical system used in the reproducing system of an optical disc known as a compact disc will be described as an example. In the live system of the compact disc, since the wavelength λ of the reproduction light is 780 nm and the numerical aperture NA of the objective lens is 0.45, the dimension d due to the resolution limit obtained by the equation (1) is 0.87 micron.
Therefore, in the reproducing system of the compact disc, tracking information cannot be detected when the optical disc recorded with the track pitch of 0.87 micron or less, which is the resolution limit thereof, is reproduced. For this reason, it is well known that in a compact disc, a tracking pitch of 1.6 μm, which is close to twice the resolution limit described above, is employed to enable stable detection of tracking information.

By the way, when reading recorded information from an optical disc on which high density recording is performed, the recorded information in the recording trace (track) can be read even by using a light spot having a diameter larger than the track pitch. As a means for doing so, the recording information is read from the recording traces on both sides of the recording trace from which the recording information is read out, and the recording information read from the three recording traces is calculated, so that the light having a large diameter can be detected. A proposal to obtain recorded information in a state without crosstalk even using spots is also disclosed in JP-A-57-58248, but the technical means described in the above-mentioned publication performs tracking control correctly. It is effective only in the state where the tracking information is not available, and cannot be applied when the tracking information cannot be obtained correctly. It is how. That is, when trying to increase the density of the optical disc by narrowing the track pitch as described above, the tracking information is limited because the wavelength of the reproduction light and the performance of the condenser lens used are limited. Is insufficient, and the tracking control operation becomes unstable.

As a technique for overcoming the above-mentioned restrictions in the prior art, a track formed by an array of pits having a first pit depth and a second pit depth different from the first pit depth described above. A paper has been published on an optical disk in which tracks formed by an array of pits having a pit depth of 100 are alternately provided at predetermined intervals in the radial direction of a disk (see “A
PPLIED OPTICS "VOL.22, NO.14 /
15july 1983, pages 2196 to 2201,
J. Braat, "Optically read d"
isks with increased information
ation density ”). Since the optical discs published by the articles described in the above publications can be regarded as a structure having two tracks as one period in the radial direction, a tracking error signal with two tracks as a period can be detected by a so-called push-pull method. It is also possible to reduce the track pitch of the tracks by the pit row to half.

[0006]

However, since the optical disk described in the above-mentioned publication has pits having pits of different depths alternately provided in the radial direction of the disk, It is unsuitable as an optical disc adopting the pit edge recording method suitable for high density recording.
That is, in an optical disc having a pit array in which all pits have the same depth, a photoresist layer having a film thickness corresponding to the depth of the pits is used, and the photoresist layer in the pit portion is formed. It is easy to manufacture an optical disk in which all the pits have the same depth by performing exposure and development for forming pits so that the pits are in the removed state. In the optical disc having pits of two kinds of depths, such as the optical disc described above, a photoresist layer having a film thickness corresponding to the depth of the deeper pits is used, and the pits of the deeper pits are formed. It is easy to perform exposure and development for forming pits so that the photoresist layer is punched out and to make the pits with the deepest depth the same depth. Since it is necessary to form a pit with a shallow depth in a state where the photoresist layer up to the middle of the thickness of the photoresist layer is removed, it is possible to obtain a constant irrespective of the pit length. It is difficult to satisfactorily form a pit having a shallow depth.

As described above, when forming a pit having a depth up to the middle of the thickness of the photoresist layer, a pit having a constant depth can be favorably formed regardless of the length of the pit. The reason is that the exposure amount for forming pits during recording of short pits decreases due to the limitation of the spatial frequency characteristics of the optical system, so that the pits formed through the exposure process and the development process are This is because the size and depth of the pit to be recorded are smaller and shallower. Then, depending on the length of the pit to be recorded, the length of the formed pit changes, or the depth of the pit changes, which causes a large change from the original reproduction modulation degree. Since it is more difficult to reproduce a signal from a short pit, which has been difficult, an optical disc obtained by forming a pit having a depth up to the middle of the thickness of the photoresist layer is similar to a CD signal. This means that it is completely unsuitable for the pit edge recording method suitable for high density recording.

In order to solve the above-mentioned problem that occurs when forming pits having a depth up to the middle of the thickness of the photoresist layer, for example, the exposure amount (light amount × light amount ×
It is also possible to control the time) to make the pit depth constant, but since the characteristics of the exposure and development process are essentially non-linear processes, practical management of the pit depth and length is required. It is almost impossible to achieve, even if
Even if that could be achieved, the pits with a depth up to the middle of the thickness of the photoresist layer were inferior in resolution to the pits formed by stamping the photoresist layer, and during the development process. Noise increases due to the roughness of the surface of the photoresist layer that corresponds to the bottom surface of the pits.Therefore, a glass surface is used for the area that corresponds to the bottom surface of the pits, and the same recording as a pit formed by punching the photoresist layer is performed. It is difficult to keep the density. Therefore, it is very difficult to provide an optical disc having good reproduction characteristics with the optical discs disclosed in the above-mentioned publications. The present invention has been made for the purpose of easily providing an optical disk which can obtain good tracking information even when the track pitch is narrowed to increase the density of the optical disk and which shows good reproduction characteristics. Is.

[0009]

According to the present invention, there are provided a recording trace formed by an array of pits having a first pit width and a pit having a second pit width different from the above-mentioned first pit width. An optical disc in which recording marks formed by an array are sequentially and alternately provided at predetermined intervals in the radial direction of the disk, a guide groove having a first groove width, and the first groove width described above. Provides an optical disc in which guide grooves having different second groove widths are sequentially and alternately formed at predetermined intervals in the radial direction of the disk.

[0010]

A recording mark formed by an array of pits having a first pit width, and a recording mark formed by an array of pits having a second pit width different from the first pit width described above. Are alternately arranged in the radial direction of the disc at a predetermined interval, so that the period of the periodic structure of the optical disc is doubled the track pitch, or a guide groove having a first groove width. By arranging a guide groove having a guide groove having a second groove width different from the first groove width and the guide grooves having a guide groove having a second groove width alternately in the radial direction of the disc at a predetermined interval, the period of the periodic structure of the optical disc is reduced. Since the track pitch is doubled, even if the track pitch is narrowed to a track pitch close to 1/2 of the track pitch corresponding to the resolution limit, the light irradiated onto the optical disc does not Since first-order diffracted light generated by the periodic structure of the optical disc described above is incident on the pupil of the condenser lens Te, it is possible to obtain a satisfactory tracking error signal from any high density recording optical disc as compared with the conventional optical disk.

[0011]

The concrete contents of the optical recording medium disk of the present invention will be described in detail below with reference to the accompanying drawings. 1 and 8 are plan views of a schematic configuration of an optical recording medium disc of the present invention, FIG. 2 is an enlarged plan view of a part of the optical recording medium disc shown in FIG. 1, and FIG. 3 is A-A in FIG. 4 is an enlarged cross-sectional view at the line position, FIG. 4 is a view showing a tracking error signal generated by the optical recording medium disc shown in FIG. 1, and FIGS. 5 to 7 are 0-order diffracted light incident on the pupil of the condenser lens and ± 1. FIG. 9 is a diagram showing a second diffracted light, FIG. 9 is an enlarged cross-sectional view of a part of the optical recording medium disc shown in FIG. 8, and FIG. 10 is a diagram showing a tracking error signal generated by the optical recording medium disc shown in FIG. is there. In FIG. 1, which shows a schematic structure of an optical recording medium disc (optical disk) of the present invention, D is the whole code of the optical disk, and in FIG. 1, a spiral line 1 shown by a solid line and a spiral line shown by a dotted line are shown. 2 is a recording mark (track)
1 and 2 are shown. The optical disc D shown in FIG. 1 is an example of a structure in which the recording trace 1 and the recording trace 2 are formed in separate spiral shapes. The trace 1 and the record trace 2 may be formed concentrically, or one spiral shape in which the record trace 1 and the record trace 2 are sequentially and alternately switched at a specific radial position of the disk. It may be formed as a thing.

A recording trace 1 shown by a spiral line in FIG. 1 is a recording trace formed by an array of pits Pt1, Pt1 ... According to information to be recorded / reproduced. , Each of the pits Pt1, Pt1 ... Has a pit width of W1 as shown in FIG.
The recording trace 2 shown by the spiral line in the figure is
Pits Pt2, P according to the information to be recorded and reproduced
Each of the pits Pt2, Pt2 ... Has a pit width W2 having a relationship of W1 <W2 with respect to the pit width W1 of the pit Pt1. There is. The above-mentioned recording traces 1 and 2 are arranged alternately in the radial direction of the disk at a constant recording trace interval (track pitch) Tp, as shown in FIG. Then, as described above, the pit widths are W1 and W, respectively.
By the arrangement of the pits P1 and P2, which are different from each other as shown in FIG. 2, the recording traces 1 and the recording traces 2 formed respectively have a constant recording trace interval Tp in the radial direction of the disk.
Since the discs are arranged alternately in sequence, the period of the unevenness of the disc (the period of the periodic structure of the disc) Pe is equal to the recording mark interval Tp.
2 times, that is, Pe = 2Tp.

Therefore, the minimum period at which the tracking error signal can be generated by the push-pull method by the period of the unevenness of the disc (period of the periodic structure of the disc) Pe = 2Tp in the optical disc of the present invention shown in FIG. Is
Pe = 2Tp = λ / 2NA, that is, Tp = λ / 4NA
Becomes However, the minimum period in which the tracking error signal can be generated by the push-pull method is Tp = λ / 2NA, which corresponds to the period Tp of the irregularities of the disc (period of the periodic structure of the disc) Tp in the conventional optical disc. With this optical disc, an optical disc D having a recording trace interval that is half that of the conventional optical disc can be constructed. The pits P1 and P2 in the optical disc D of the present invention are
Since all the pits have the same depth, when manufacturing an optical disc, a photoresist layer having a film thickness corresponding to the depth of the pit is used so that the photoresist layer in the pit portion is punched out. It is easy to make an optical disc with all the pits having the same depth by performing exposure and development for forming pits, which occurs in the optical discs described in the publications already mentioned at this point. It is clear that there will be no problems.

Next, the principle of generation of the tracking error signal in the optical disc D of the present invention shown in FIG. 1 having the above construction will be described. In the optical disc D of the present invention, as described above, the period of the unevenness of the disc (the period of the periodic structure of the disc) Pe is 2 of the recording mark interval Tp such as Pe = 2Tp.
Since it is doubled, the tracking error signal St generated in the optical disc D of the present invention has a cycle of the unevenness (cycle of the periodic structure of the disk) Pe in the optical disk D as illustrated in FIG. And a sinusoidal function. Then, the tracking error signal St generated by the optical disc D of the present invention shown in FIG. 4 is obtained by reversing the polarity of the tracking servo for each rotation based on the specific radial position of the optical disc D. This indicates that good tracking control can be performed on any recording trace.

When an optical disc having a signal surface having a periodic uneven shape is irradiated with a light spot of a minute diameter condensed by a condenser lens, the signal surface has a periodic uneven shape (disc cycle). The structure) functions as a diffraction grating to generate diffracted light corresponding to the period (period of the periodic structure of the disk) Pe of the periodic unevenness on the signal surface. Then, the diffracted light reflected by the signal surface of the optical disc D returns to the condenser lens,
A tracking error signal is obtained by the interference of the diffracted lights that have passed through the pupil of the condenser lens. 5 to 7 show that the diffracted light reflected by the signal surface of the optical disc D returns to the condenser lens,
FIG. 8 is a diagram for explaining that a tracking error signal is obtained by interference between diffracted lights that have passed through the pupil of the condenser lens, and in FIGS. 5 to 7, reference numeral 3 denotes the pupil of the condenser lens, and Reference numeral 4 denotes the 0th-order diffracted light that has entered the pupil of the condenser lens, and 5 and 6 denote the ± 1st-order diffracted light. 3 shows ± 1st-order diffracted lights 5 and 6 outside the pupil.

Further, in FIG. 5 and FIG. 7, the hatched portion in the pupil 3 of the condenser lens is the zero-order diffracted light 4
And the ± first-order diffracted lights 5 and 6 overlap each other. Here, the distance X between the center Oa (center of the 0th-order diffracted light) of the condenser lens and the center Ob of the 1st-order diffracted light 6 is defined by the radius of the pupil of the condenser lens r and the aperture of the condenser lens. Number N
A, the wavelength of light is λ, and the recording mark interval is Tp. X = rλ / NA / Tp (2) By the way, the diffracted light of the lowest order among the diffracted lights is 1
Since the condition for generating the tracking error signal is that the first-order diffracted light passes through the pupil 3 of the condenser lens, the state of FIG. 6 where the first-order diffracted light does not pass through the pupil 3 of the condenser lens is solved. It is the image limit. Then, the resolution limit is shown by Xl = 2r (3) from FIG. In the above formula (3), the recording mark interval Tp = λ / 2 / NA on the optical disk
Since this is an optical disc having a periodic structure of, that is, a conventional optical disc, the first-order diffracted light goes out of the pupil 3 of the condensing lens in the state of Tp = λ / 2 / NA in the conventional optical disc. Therefore, in the above state, the tracking error signal cannot be obtained. It should be noted that Xl in the equation (3) represents the distance between the center Oa (center of the 0th-order diffracted light) of the pupil 3 of the condenser lens and the center Ob of the 1st-order diffracted light 6 in the case of the resolution limit.

However, in the optical disc D of the present invention, the period of the irregularities of the disc (the period of the periodic structure of the disc) Pe is
Since the recording mark interval Tp is twice as Pe = 2Tp, the positions on the pupil 3 of the first-order diffracted lights 5 and 6 are shown in FIG. As described above, since the position is half that in the case of the conventional optical disc, the pupil 3 of the condenser lens in this state is
The distance X between the center Oa (center of the 0th-order diffracted light) and the center Ob of the first-order diffracted light 6 is represented by X = r.
Therefore, in the optical disc of the present invention, even when the conventional optical disc reaches the resolution limit, the 0th-order diffracted lights 4 ± 1st-order diffracted lights 5 and 6 are generated in the pupil 3 of the condenser lens as shown in FIG. It is in a state of overlapping. Therefore, in the optical disc D of the present invention, the minimum period in which the conventional optical disc can generate the tracking error signal by the push-pull method is Tp = λ / 2NA due to the period (period of the periodic structure of the disc) Tp of the irregularities of the disc. In comparison with the above, the minimum cycle in which the tracking error signal can be generated by the push-pull method is Pe = 2Tp = λ / 2NA, that is, Tp = λ
Since it becomes / 4NA, it is possible to configure the optical disc D having a recording trace interval which is half that of the conventional optical disc. As described above, in the optical disc D of the present invention, even if the recording trace interval is half that of the conventional optical disc, the tracking control operation can be satisfactorily performed. As described in Japanese Patent Laid-Open No. 58248, the record information is read from the record marks on both sides of the record mark from which the record information is read.
A correct information signal can be reproduced by calculating the recording information read from one recording trace.

Next, the optical disc D of the present invention illustrated in FIG. 8 will be described. In FIG. 8 showing a schematic structure of the optical disc of the present invention, the spiral line G1 shown by a solid line and the spiral line G2 shown by a dotted line in FIG.
(Tracking guide grooves) G1 and G2 are shown.
The optical disc D shown in FIG. 8 shows an example of a structure in which the guide groove G1 and the guide groove G2 are formed as separate spirals. The above-mentioned guide groove G1 and guide groove G2 may be concentrically formed, or guide groove G1 and guide groove G2.
And may be formed as one spiral shape as a state in which they are sequentially and alternately switched at a specific radial position on the disk.

The guide groove G1 shown by the spiral line shown in FIG. 8 has a width W1 as shown in FIG. 9, and the spiral groove shown by the dotted line. The guide groove G2 indicated by the line has a guide groove width W2 having a relationship of W1 <W2 with respect to the guide groove width W1. The optical disc D shown in FIG. 8 is an optical disc capable of recording and reproducing information, and on the surface on which the guide grooves G1 and G2 shown in FIG. 8 are formed, Although not shown, a recording / reproducing recording layer, for example, a recording layer for magneto-optical recording, a recording layer for phase change recording, or the like is provided. The above-mentioned guide groove G1 and guide groove G2 are shown in FIG.
As shown in FIG. 10, the recording tracks are arranged at regular intervals (track pitch) Tp alternately in the radial direction of the disk. As described above, the guide grooves G1 and G2 whose guide grooves have different widths W1 and W2, respectively, are arranged alternately in the radial direction of the disk at a constant recording mark interval Tp. The unevenness of the disk
(Cycle of the periodic structure of the disk) Pe is 2 of the recording mark interval Tp.
Double, that is, Pe = 2Tp.

Therefore, the minimum period at which the tracking error signal can be generated by the push-pull method is Pe = 2Tp and the tracking is performed by the push-pull method. The minimum cycle in which the error signal can be generated is Pe =
Since 2Tp = λ / 2NA, that is, Tp = λ / 4NA, the optical disc D of the present invention shown in FIG. 8 has a half recording space as compared with the conventional optical disc.
Can be configured in the same manner as in the case of the optical disc described with reference to FIG. Further, since the guide grooves G1 and G2 in the optical disc D of the present invention shown in FIG. 8 are guide grooves having the same depth, the guide grooves are formed by using a photoresist layer having a film thickness corresponding to the depth of the guide grooves. It is easy to manufacture an optical disc by exposing and developing for forming guide grooves so that all the photoresist layers are punched out so that all the guide grooves have the same depth. ,
In this respect, it is obvious that the problems that occur in the optical discs described in the publications already mentioned do not occur.

The generation principle of the tracking error signal in the optical disc D of the present invention shown in FIG. 8 having the above-mentioned structure is the same as that of the optical disc described with reference to FIG. 1, and the optical disc shown in FIG. In D, the period of the unevenness of the disc (the period of the periodic structure of the disc) Pe is twice the recording mark interval Tp as Pe = 2Tp, so the tracking error signal generated in the optical disc D shown in FIG. As shown in FIG. 10, St is a sinusoidal function having a period of the unevenness (period of the periodic structure of the disk) Pe on the optical disc D as a period. The tracking error signal St shown in FIG. 10 generated by the optical disc D shown in FIG. 8 is calculated by reversing the polarity of the tracking servo for each rotation with reference to a specific radial position of the optical disc D. It is shown that the tracking control can be favorably performed also for the recording trace.

When an optical disc having a signal surface having a periodic uneven shape is irradiated with a light spot having a minute diameter condensed by a condenser lens, the periodic uneven shape of the signal surface serves as a diffraction grating. It functions to generate diffracted light corresponding to the above-mentioned periodical uneven shape of the signal surface (period of the periodic structure of the disk) Pe. Then, the diffracted light reflected by the signal surface of the optical disc D returns to the condensing lens, and a tracking error signal is obtained by the interference of the diffracted light passing through the pupil of the condensing lens. Also in the optical disc D of the present invention shown in FIG. 8, similar to the explanation of the optical disc of the present invention shown in FIG. 1 with reference to FIG. 5 to FIG. ) Pe is Pe
= 2Tp, which is twice the recording trace interval Tp, so that 1 in the condition where the conventional optical disc reaches the resolution limit.
As shown in FIG. 7, the position of the next-order diffracted lights 5 and 6 on the pupil 3 is half the position of the conventional optical disc, and the center of the pupil 3 of the condenser lens in this state. O
The distance X between a (the center of the 0th-order diffracted light) and the center Ob of the 1st-order diffracted light 6 is represented as X = r. Therefore, the optical disc of the present invention shown in FIG. Even in the limit state, as shown in FIG. 7, the 0th order diffracted light 4 ± 1st order diffracted lights 5 and 6 are overlapped in the pupil 3 of the condenser lens.

Therefore, also in the optical disc D of the present invention shown in FIG. 8, the conventional optical disc has a minimum period in which a tracking error signal can be generated by the push-pull method due to the period Tp of the irregularities of the disc (period of the periodic structure of the disc). Tp = λ
In comparison with the case of / 2NA, the minimum cycle in which the tracking error signal can be generated by the push-pull method is Pe = 2.
Since Tp = λ / 2NA, that is, Tp = λ / 4NA, it is possible to construct an optical disc D having a half recording space as compared with the conventional optical disc. That is, the present invention shown in FIG. This is the same as the optical disc D, and since the recording can be performed at half the recording mark interval of the conventional optical disc, the read operation of the recorded information is disclosed in Japanese Patent Laid-Open No. 57-582.
As described in Japanese Patent Publication No. 48, the correct information is obtained by reading the record information from the record marks on both sides of the record mark from which the record information is read and calculating the record information read from the three record marks. The signal can be reproduced.

[0024]

As is apparent from the above detailed description, the optical disc of the present invention has the recording trace formed by the array of pits having the first pit width and the above-mentioned first pit width. Are sequentially arranged in the radial direction of the disk at predetermined intervals alternately with the recording traces formed by the array of pits having different second pit widths, so that the cycle of the periodic structure of the optical disk is the track pitch. Or a guide groove having a first groove width, and a guide groove having a guide groove having a second groove width different from the first groove width described above are arranged at predetermined intervals. By sequentially and alternately arranging the discs in the radial direction, the period of the periodic structure of the optical disk is doubled the track pitch. Even if the track pitch is narrowed to the maximum pitch, the first-order diffracted light generated by the above-mentioned periodic structure of the optical disk is incident on the pupil of the condensing lens due to the light irradiated on the optical disk. It is possible to easily provide optical discs that
Further, since a good tracking error signal can be obtained from an optical disc on which high density recording is performed as compared with the above-mentioned conventional optical disc, high density recording / reproducing operation can be performed favorably. Further, in the optical disc of one embodiment of the present invention, all the pits have the same depth, and in the other embodiments, all the guide grooves have the same depth, so that the optical disc can be easily manufactured. However, the problems that occur in the optical discs described in the above-mentioned publications do not occur.

[Brief description of drawings]

FIG. 1 is a plan view of a schematic configuration of an optical recording medium disc of the present invention.

FIG. 2 is an enlarged plan view of a part of the optical recording medium disc shown in FIG.

3 is an enlarged cross-sectional view taken along the line AA in FIG.

FIG. 4 is a diagram showing a tracking error signal generated by the optical recording medium disc shown in FIG. 1.

FIG. 5 is a diagram showing 0th-order diffracted light and ± 1st-order diffracted light incident on the pupil of the condenser lens.

FIG. 6 is a diagram showing 0th-order diffracted light and ± 1st-order diffracted light incident on the pupil of the condenser lens.

FIG. 7 is a diagram showing 0th-order diffracted light and ± 1st-order diffracted light incident on the pupil of the condenser lens.

FIG. 8 is a plan view of a schematic configuration of an optical recording medium disc of the present invention.

9 is an enlarged cross-sectional view of a part of the optical recording medium disc shown in FIG.

10 is a diagram showing a tracking error signal generated by the optical recording medium disc shown in FIG.

[Explanation of symbols]

 1, 2 ... recording marks, D ... optical disk, G1, G2 ... guide groove,

Claims (2)

[Claims]
1. A recording trace formed by an array of pits having a first pit width and a recording trace formed by an array of pits having a second pit width different from the first pit width described above. An optical recording medium disc in which traces are sequentially and alternately provided at predetermined intervals in the radial direction of the disc.
2. A guide groove having a first groove width and a guide groove having a second groove width different from the first groove width.
An optical recording medium disc formed by alternately forming the disc in a radial direction at predetermined intervals.
JP4018579A 1992-01-07 1992-01-07 Optical recording medium disk Granted JPH05182203A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4018579A JPH05182203A (en) 1992-01-07 1992-01-07 Optical recording medium disk

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4018579A JPH05182203A (en) 1992-01-07 1992-01-07 Optical recording medium disk

Publications (1)

Publication Number Publication Date
JPH05182203A true JPH05182203A (en) 1993-07-23

Family

ID=11975543

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4018579A Granted JPH05182203A (en) 1992-01-07 1992-01-07 Optical recording medium disk

Country Status (1)

Country Link
JP (1) JPH05182203A (en)

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US6088306A (en) * 1998-02-13 2000-07-11 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for combined writing and reading operations
US6088309A (en) * 1998-02-13 2000-07-11 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for controlling vertical laser alignment
US6097677A (en) * 1998-02-13 2000-08-01 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for combined writing and reading operations
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US6108282A (en) * 1998-02-13 2000-08-22 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for multilayer laser source positioning
US6111830A (en) * 1998-02-13 2000-08-29 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for determining linear and/or angular velocity
US6118740A (en) * 1998-02-13 2000-09-12 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for writing closely spaced information tracks
US6128262A (en) * 1998-02-13 2000-10-03 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for customizing said media with timing information
US6222813B1 (en) 1998-02-13 2001-04-24 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for controlling vertical laser alignment
US6232045B1 (en) * 1998-02-13 2001-05-15 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for producing a recording blank
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WO2003034412A2 (en) * 2001-10-19 2003-04-24 Koninklijke Philips Electronics N.V. Optical record carrier and optical scanning device
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WO2008071653A1 (en) * 2006-12-14 2008-06-19 Thomson Licensing Optical storage medium comprising tracks with different width, and respective production method
EP1968050A3 (en) * 2007-03-08 2009-01-21 Thomson Licensing Optical storage medium and apparatus for reading of respective data
EP2287838A1 (en) 2009-07-23 2011-02-23 Thomson Licensing Optical storage medium comprising tracks with modified mark dimensions, and respective apparatus for reading of data
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US6300041B1 (en) * 1997-06-10 2001-10-09 Sony Corporation Optical recording medium and manufacturing method thereof
US6097677A (en) * 1998-02-13 2000-08-01 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for combined writing and reading operations
US6075764A (en) * 1998-02-13 2000-06-13 International Business Machines Corporation Laser-writable information recording medium with reference track for laser-writing information thereto using edge following
US6081489A (en) * 1998-02-13 2000-06-27 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for performing both read and write operations
US6081487A (en) * 1998-02-13 2000-06-27 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for controlling laser positioning
US6088306A (en) * 1998-02-13 2000-07-11 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for combined writing and reading operations
US6088309A (en) * 1998-02-13 2000-07-11 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for controlling vertical laser alignment
US6049512A (en) * 1998-02-13 2000-04-11 International Business Machines Corporation In a system for creating, reading and writing on rotatable information storage media, an apparatus for two-sided writing
US6097681A (en) * 1998-02-13 2000-08-01 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for determining angular position, θ
US6108282A (en) * 1998-02-13 2000-08-22 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for multilayer laser source positioning
US6111830A (en) * 1998-02-13 2000-08-29 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for determining linear and/or angular velocity
US6118740A (en) * 1998-02-13 2000-09-12 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for writing closely spaced information tracks
US6128262A (en) * 1998-02-13 2000-10-03 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for customizing said media with timing information
US6222813B1 (en) 1998-02-13 2001-04-24 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, an apparatus for controlling vertical laser alignment
US6232045B1 (en) * 1998-02-13 2001-05-15 International Business Machines Corporation System for creating, reading and writing on rotatable information storage media, a method for producing a recording blank
US6046970A (en) * 1998-02-13 2000-04-04 International Business Machines Corporation System for creating, reading and writing on rotatable storage media, an apparatus for determining laser aging characteristics
US6700862B2 (en) * 2000-10-03 2004-03-02 Matsushita Electric Industrial Co., Ltd. Optical disc and manufacturing method for the same
US6842420B2 (en) 2000-10-03 2005-01-11 Matsushita Electric Industrial Co., Ltd. Optical disc having plural grooves of different depths
US7068590B2 (en) 2000-10-03 2006-06-27 Matsushita Electric Industrial Co., Ltd. Optical disc and manufacturing method for the same
US7020051B2 (en) 2000-12-08 2006-03-28 Samsung Electronics Co., Ltd. Optical pickup capable of detecting and/or compensating for spherical aberration
WO2003034412A2 (en) * 2001-10-19 2003-04-24 Koninklijke Philips Electronics N.V. Optical record carrier and optical scanning device
WO2003034412A3 (en) * 2001-10-19 2003-08-28 Koninkl Philips Electronics Nv Optical record carrier and optical scanning device
WO2008071653A1 (en) * 2006-12-14 2008-06-19 Thomson Licensing Optical storage medium comprising tracks with different width, and respective production method
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