JP2001216640A - Reading device of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording device of an optical disk having the satisfied using efficiency for the area on the disk surface. SOLUTION: The reading device of the optical disk P1 that a track WT1 constituted of groove parts and land parts and records user's data and the sub-information is stored in the track WT1 by using the combination of a wobble part and non-wobble part, both of which are provided on the track WT1, a head 31 for detecting a wobble signal from the wobble part and non-wobble part of the track WT1, and a discrimination means 34 for discriminating from a phase of the wobble signal whether this wobble signal is a signal obtained from the land part, or a signal obtained from the groove part are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the physical format of a rewritable optical disk using a phase change medium or a magneto-optical (MO) medium, or a write-once (write-once) optical disk using a dye-based medium. In particular, the present invention relates to a device for detecting a physical format suitable for handling a large amount of data such as image data and audio data.

[0002]

2. Description of the Related Art DVDs (digital video disks), MO disks, and CDs (compact disks) have been commercialized as large-capacity storage media used in computers. Also, with the spread of computers, users often edit data stored in a storage medium, and the need for a storage medium on which data can be changed or additionally recorded has been increased.

A rewritable storage medium on which a user can change data many times is a DVD-RAM (randomly readable and writable memory) using a phase change medium, an MO disk using an MO medium, CD-RW (Re
Writable). A write-once (write-once) storage medium on which a user can write data only once is a CD-R using a dye-based medium. In these storage media, addresses for recognizing the positions where the data are written on these storage media are stored in advance.

On the DVD-RAM or MO disk, an ID section (Identification section) for indicating an address is provided separately from a section in which user data is stored. The ID part is arranged as a pre-pit for each frame which is the minimum unit for recording data.

[0005] For address management in the above-mentioned CD-RW and CD-R, a wobble addressing method based on FM modulation (frequency modulation) is used. Here, wobble means meandering, and indicates a structure in which tracks on the disk meander in the radial direction of the disk. That is, in a CD-RW or CD-R, an address is stored by changing the frequency of a wobble (meandering) of a track. Therefore, CD-RW and C
In the DR, user data and addresses are superimposed and stored along the track.

[0006]

However, these prior arts have the following problems. That is, the above D
Since the VD-RAM and the MO disk need to be provided with an ID section separately from the area where the user data is stored, there is a problem that the area use efficiency of the disk surface is deteriorated and it is not suitable for increasing the capacity.

[0007] Further, since the structure of the disk surface is different between the area where the user data is stored and the ID portion, manufacturing such a disk requires a complicated manufacturing process and makes it difficult to manufacture the disk. There is a problem. Particularly, in the DVD-RAM, since the ID portions are arranged in a staggered manner, the manufacturing process is further complicated.

In the above-mentioned CD-RW and CD-R,
Since the address corresponds to the frequency of the wobble, the disk reader needs to read a signal (wobble) of a different frequency in order to read the address,
There is a problem that the configuration of the reading device is complicated.

Further, since the frequency of the wobble of the track is changed in accordance with the address value, the length of the track required for expressing the address differs for each address value, and data write control becomes complicated. Problem.

Further, the above-mentioned method of making the address correspond to the frequency of the wobble is a method of storing the address by FM-modulating the wobble.
There is a problem that the / N (Carrier to Noise) ratio is large.

In the above-mentioned system in which the address is made to correspond to the wobble frequency, the wobble frequency is not constant, so that the pitch between adjacent wobble tracks is not constant. There is a problem that it cannot cope with a method of recording information on both lands and grooves.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has an advantage in that the area of the disk surface can be used efficiently, the disk can be easily manufactured, the configuration of the disk reading device is simple, and the disk can be easily read. An object of the present invention is to provide an optical disk reading apparatus which can easily control data writing, has a small required C / N ratio, and can cope with land & groove recording.

[0013]

According to a first aspect of the present invention, there is provided an optical disk drive comprising: a groove portion serving as a bottom portion of a track groove provided on a surface of an optical disk; and a land portion serving as another portion. It has a track for recording data, and this track is provided with a wobble portion meandering in the radial direction of the optical disc and a non-wobble portion that does not meander, and the wobble portion and the non-wobble portion are provided. A rewritable optical disk such as a phase-change medium or a magneto-optical medium, or a write-once optical disk such as a dye-based medium, in which sub-information, which is data other than the user data, is stored in the track. hand,
A head for detecting a wobble signal from the wobble portion and the non-wobble portion of the track; and a phase of the wobble signal detected by the head, the wobble signal is a signal obtained from a land portion of the track, or a groove of the track. A discrimination means for discriminating whether the signal is obtained from a unit.

According to a second aspect of the present invention, the meandering phases of the wobble portions of adjacent tracks provided on the surface of the optical disk coincide with each other. Reading device.

According to a third aspect of the present invention, the discriminating means determines that the wobble signal is based on a phase of the wobble signal detected by the head from a boundary point between the wobble portion and the non-wobble portion of the track. 2. The optical disk reading device according to claim 1, wherein it is determined whether the signal is obtained from a land portion or a signal obtained from a groove portion of the track.

According to a fourth aspect of the present invention, the head includes:
The optical disc has two light receiving sections arranged along the radial direction of the optical disc, and the discriminating means detects the phase of the wobble signal from the difference between the outputs of the two light receiving sections, and the wobble signal is used as the land of the track. 4. The optical disk reading apparatus according to claim 1, wherein the apparatus determines whether the signal is obtained from a groove portion or a signal obtained from a groove portion of the track.

According to a fifth aspect of the present invention, the sub-information comprises:
5. The optical disk reading apparatus according to claim 1, wherein the address is an address in the track.

The invention according to claim 6, wherein the track is divided into a plurality of zones in a radial direction of the optical disk, wherein the track is divided into a plurality of zones. It is.

[0019] In the invention according to claim 7, the sub-information is:
7. The optical disk reading device according to claim 6, wherein the zone address is the zone address of the zone.

The invention according to claim 8 is characterized in that the meandering phases of the wobble portions of adjacent tracks in the zone coincide with each other.
2. An optical disk reading device according to item 1.

According to a ninth aspect of the present invention, the length of the wobble portion and the non-wobble portion is an integral multiple of one cycle of meandering in the wobble portion.
9. An optical disk reading device according to any one of claims 1 to 8.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a configuration of an optical disk P1 used for an optical disk reading apparatus according to the present invention. On the surface of the optical disk P1, a wobble track WT1 is provided.
The sub-information is recorded in advance along the line 1. User data is superimposed and stored on the wobble track WT1 on which the sub information is recorded.

Here, the sub information is information other than the user data, and a typical example thereof is an address. In addition, various pieces of parameter information related to the disc are also included in the sub-information.

The optical disk P1 shown in the figure is, for example, a rewritable optical disk such as a DVD-RAM using a phase change medium, a CD-RW, and an MO disk using an MO medium.
Alternatively, it is a write-once optical disk such as a CD-R using a dye medium.

As described above, the wobble track WT1 is provided on the surface of the optical disk P1, as shown in FIG. 1, and user data is recorded along the wobble track WT1. Here, the wobble means a meandering, and indicates a structure in which the track is meandering in the radial direction of the optical disc P1.
However, as shown in FIG. 1, the wobble track WT1 has a wobble portion AWT which is wobbled (meandering).
And a non-wobbled portion NWT that has not been wobbled. These wobble part AWT and non-wobble part NWT
Wobble truck WT1
Stores the sub information.

FIG. 2 is an enlarged view showing the detailed structure of the wobble track WT1 on the optical disk P1.
A meandering track groove T is provided on the surface of the optical disk P1, and the bottom of the track groove T is called a groove G, and a portion sandwiched between adjacent track grooves T is called a land L. The undulation (meandering) of the track groove T is called a wobble.

When recording user data on the optical disk P1 using the land & groove recording method,
Recording marks P are formed on both the land L and the groove G. That is, the track of the optical disk P1 is the land L
And a groove G. In order to read recorded data, light H is incident from the bottom surface of the optical disc P1.

The wobble of the track groove T is used to represent sub-information of user data recorded on the optical disc P1. The sub information is, for example, information indicating a position of user data recorded along the track groove T, that is, an address. Therefore, the optical disk P1
In the above, the user data and the sub-information are superimposed and stored along the track groove T.

FIG. 3 shows that the sub information is stored in the wobble of the track groove T, that is, based on the sub information data,
FIG. 11 is a diagram showing a procedure for forming a wobble track WT1 on the optical disc P1. First, the sub-information data 1 is converted into the converted sub-information data 3 by the conversion table 2.
Further, the converted sub-information data 3 is MAM-modulated,
Based on the MAM-modulated waveform data, the track groove T
A wobble is formed. Here, the MAM modulation means an improved AM modulation that has been improved so that it can be applied to an optical disc.

FIG. 4 shows an example of the conversion table 2. As described above, the conversion table 2 receives the sub information data 1 and outputs the converted sub information data 3. Both the sub information data 1 and the converted sub information data 3 are "0".
And "1".

According to the conversion table shown in FIG. 4, arbitrary 2-bit sub-information data is converted into 4-bit conversion sub-information data. In any case, the converted conversion sub-information data includes the same number of “0” and “1”. That is, 4
Two bits of the converted sub-information data are "0" and the remaining two bits are "1".

FIG. 5 shows an example of the MAM modulation. That is, by the MAM modulation, “0” included in the converted sub-information data is converted into a waveform shown in FIG.
"1" included in the converted sub-information data is converted into a waveform shown in FIG.

FIG. 5 corresponding to the conversion sub-information data "0"
The waveform shown in (a) is composed of a wobble period A0 having a meandering period of 10 periods and a non-wobble period B0 not meandering. The length of the non-wobble period B0 is set to the meandering length of two cycles in the wobble period A0. The meandering period T in the wobble period A0
d is always constant.

FIG. 5 corresponding to the conversion sub information data "1"
The waveform shown in (b) is composed of a wobble period A1 having a meandering period of 14 periods and a non-wobble period B1 not meandering. The length of the non-wobble period B1 is set to the meandering length of two cycles in the wobble period A1. The meandering cycle in the wobble period A1 is always constant, and the conversion sub-information data "
It is equal to the meandering period Td in the wobble period A0 included in the waveform corresponding to “0”.
The length of the non-wobble period B1 included in the waveform corresponding to "1" is equal to the length of the non-wobble period B0 included in the waveform corresponding to the converted sub-information data "0".

Therefore, if the lengths of A0, B0, A1, and B1 are expressed in units of a common meandering period Td, (A0, B0) = (10, 2) (A1, B1) = (14, 2)

A wobble track WT1 is formed by forming a wobble portion AWT and a non-wobble portion NWT in the track groove T of the optical disk P1 based on the waveform generated by the MAM modulation.

The above settings, for example, the lengths of the wobble periods A0 and A1 are not limited to 10 or 14 periods.
Can be set arbitrarily.

The above MAM modulation method is a digital modulation type of OAM (On Off Keyin) of AM modulation (amplitude modulation).
This is an improved AM modulation method that utilizes g) and is modified so that it can be applied to the physical format of an optical disk. A modulation signal by this modulation method is DC-free, and is extremely practical.

Further, in this MAM modulation system, "0" and "1" are represented by the presence or absence of a wobble (meander). That is, "0" and "1" are distinguished by the length of the section where the wobble continues, so that it is not necessary to change the wobble frequency as in the conventional FM modulation method.

Further, in the conventional FM modulation system, a large C / N (Carrier) is used to detect the wobble frequency.
to Noise (carrier to noise) ratio was required, but MA
When the M modulation method is used, it is only necessary to detect the presence or absence of a wobble, so that a large C / N ratio unlike the related art is not required.

In the MAM modulation system described above, "
The length of the non-wobble period B0 included in “0” is equal to the length of the non-wobble period B1 included in “1.” That is, B0 = B1 = two periods of wobble. It is not necessary to change the non-wobble period depending on whether the value of the information is “0” or “1”.
Since only the wobble period needs to be changed, the optical disk can be realized more easily.

The length of the non-wobble periods B0 and B1 can be set to one or two periods of the wobble in consideration of the influence on the PLL circuit that synchronizes with the wobble in order to read the wobble. Is appropriate.

However, each of the above set values may be determined according to the system to which the present invention is applied, and the present invention is not limited to the above set values.

When the above conversion table and MAM modulation are used, all the converted sub-information data has the same length on the track. That is, the conversion sub information data “0” and “
The length of the waveform "1" is different, and therefore the length on the track is also different. However, the converted sub-information data always has a set of 4 bits, and "0" and "1". , The length on a 4-bit track is
The conversion sub-information data of any value is equal. Therefore, the length of the sub information on the track can be made uniform,
Data write control is simplified.

In other words, the conversion table converts 2-bit sub-information data into 4-bit conversion sub-information data. In, the frequency of occurrence of “0” and “1” is 1: 1.

FIG. 6 shows an example of conversion from sub-information data to converted sub-information data. As shown in FIG. 6, if certain sub-information data is composed of 8 bits, the converted sub-information data obtained by converting this sub-information data using the conversion table has 16 bits, and 8 bits of the converted sub-information data are " 0 ", and the remaining 8 bits become" 1 ".

Specifically, in Example 1 shown in FIG. 6, 8-bit sub-information data (01111111) is converted into 16-bit converted sub-information data (11001010101010110) by the conversion table shown in FIG.
That is, the first two bits (01) of the sub information data are
The conversion table shown in FIG. 4 is converted into 4-bit conversion sub-information data (1100). Subsequent 2-bit sub-information data (11) is converted into 4-bit conversion sub-information data (1010). Is done.

When the entire length of the bit string of the converted sub information data is expressed in units of a wobble period Td, the total length = the length of “0” + the length of “1” = 8 bits × (10Td + 2Td) ) +8 bits × (14Td + 2Td) = 224Td.

In the example 2 shown in FIG. 6, the 8-bit sub information data (10000000) is converted into the 16-bit converted sub information data (00 00) by the conversion table shown in FIG.
11010101010101). That is, the leading two bits (10) of the sub-information data are converted into 4-bit conversion sub-information data (0011), and the subsequent two-bit sub-information data (00) is converted into four-bit conversion sub-information. It is converted into information data (0101).

If the total length of the bit string of the converted sub information data is expressed in units of a wobble period Td, the total length = the length of “0” + the length of “1” = 8 bits × (10Td + 2Td) ) +8 bits × (14Td + 2Td) = 224Td, which is the same length as in Example 1.

That is, the length on the track for expressing one piece of sub-information is always constant, which makes it very easy to put the optical disk into practical use.

Next, another example of an optical disk that can be used in the optical disk reader of the present invention will be described with reference to FIG. In the optical disk P2 shown in FIG. 7, the wobble track W provided on the surface of the optical disk P2
T2 is divided into a plurality of zones 21, 22,..., 2n.

The optical disc P2 has a ZCAV
(Zoned Constant Angular Velocity) or ZCLV
(Zoned Constant Linear Velocity) format.

In the optical disc P2, the zone addresses of the respective zones 21, 22,..., 2n are stored in the wobble track WT2 belonging to each zone as sub-information. That is, since the same zone address is stored in all wobble tracks in the same zone, the same zone address is also stored in adjacent tracks in the same zone. Therefore, the phases of the wobble of the adjacent wobble track WT2 are substantially the same.

With such a configuration, a constant track pitch can always be ensured even if a track has a wobble (meandering), so that the wobble method and the land & groove recording method can be used together. Also, in reading a wobble, detection can be performed without crosstalk from an adjacent track.

As described above, A0, B0, A1,
If all of B1 are set to an integral multiple of the wobble period Td, disc creation becomes extremely easy, and the PLL control system in the wobble reading device can be operated stably.

Next, an optical disk reader according to an embodiment of the present invention will be described. An optical disk used in the optical disk reader according to the present invention has a wobble track groove configuration using the above-described improved AM modulation method. The reading apparatus according to the present invention can detect whether the head of the reading apparatus is currently tracing the land (land L) or the groove (groove G) of the optical disc. This is convenient when data is read from an optical disk on which land and group recording has been performed.

FIG. 8 is a block diagram showing the configuration of the optical disk reading apparatus according to the present embodiment. Reference numeral P1 in this figure denotes an optical disk to be read by a reading device. A wobble track WT1 is provided on the surface of the optical disk P1, and recording marks are formed along the wobble track WT1.

At a position facing the lower surface of the optical disk P1, a head 31 of a reading device for reproducing a recording mark of the optical disk P1 is arranged. The head 31 can be moved in the radial direction of the optical disk P1 by a moving means (not shown). By this moving means, the position of the light spot projected on the wobble track WT1 of the optical disk P1 in the radial direction is moved by the light beam emitted from the head 31 with the rotation of the optical disk P1, and the wobble of the light spot is changed. -It is possible to scan the track WT1.

The head 31 includes a laser diode 37 for emitting a laser beam, a collimator lens 38 for converting the laser beam emitted from the laser diode 37 into a parallel beam, a beam splitter 39, and a parallel beam on the wobble track WT1 of the optical disk P1. And an objective lens 32 for converging the reflected light from the wobble track WT1 and turning the reflected light from the wobble track WT1 into parallel light again, and a two-division surface light receiving type photodiode 33 for receiving the reflected light converted into parallel light. I have.

The laser light emitted from the laser diode 37 is converted into parallel light by a collimator lens 38, reflected by a beam splitter 39, and condensed by an objective lens 32 to form a light beam. A light spot is projected on the track WT1. The reflected light whose intensity has been modulated by the recording mark provided along the wobble track WT1 is returned to the beam splitter 39 via the objective lens 32 again, transmitted through the beam splitter 39, and split into two-part light receiving photo The light is received by the diode 33. The two-divided surface light receiving photodiode 33 outputs a reproduction signal corresponding to the received light, that is, the light whose intensity is modulated by the recording mark.

The two-divided surface light receiving type photodiode 33
On the upper side, two light receiving surfaces 33a and 33b are arranged along the radial direction of the optical disk P1. Two light receiving surfaces 33a of the two-division surface light receiving type photodiode 33
The outputs from and 33b are input to the determination means 34. The discriminating means includes a differential amplifier and a discriminating unit. The output from the light receiving surface 33a is input to the non-inverting input terminal 35a of the differential amplifier 35, and the output from the light receiving surface 33b is input to the inverting input terminal 35b of the differential amplifier 35. The tracking error signal output from the differential amplifier 35 is input to the determination unit 36.

As a method for detecting a wobble signal, a push-pull method, which is well known as a track signal detection method, is used. Here, the principle of the push-pull method will be described with reference to FIG. The push-pull method is also called the far-field method, and the optical disk P1
The light reflected and diffracted by the upper groove G is split into two split surface light receiving photodiodes 33 having two light receiving surfaces symmetrically arranged with respect to tracks along the radial direction of the disk.
In this method, a tracking error is detected by extracting the difference between the outputs from the two light receiving surfaces 33a and 33b. That is, as shown in FIG. 9A, when the center of the spot and the center of the groove G (or the center of the spot and the land L) coincide with each other, a reflected and diffracted light distribution symmetrical on the left and right sides of the track can be obtained. As shown in FIG. 9B, when the center of the spot and the groove G (or the center of the spot and the land L) are displaced from each other, the two light receiving surfaces 33a and The distribution of the reflected light incident on 33b is not symmetric.

For this reason, if the spot is moved in the direction crossing the track, the difference between the outputs from the two light receiving surfaces 33a and 33b of the two-division surface light receiving type photodiode 33, that is, the tracking error signal is obtained as shown in FIG. An S-shaped curve as shown in FIG.

This operation will be described in more detail with reference to FIG. Track size TP
With a small size, the groove G looks like a diffraction grating. That is, the phases of the light overlap in the direction satisfying Psin θ = Nλ (where N is an integer), and the light intensity increases. That is, in the region where the 0th-order and the 1st-order diffracted light overlap, the intensity distribution of the spot changes due to the interference effect due to the track shift. 33, and the differential amplifier 35 calculates the difference between the output from the light receiving surface 33a and the output from the light receiving surface 33b.
A tracking error signal can be obtained. In addition,
The intensity pattern on the two-division surface light receiving photodiode 33 is determined by the NA of the objective lens 32 of the head, the track pitch TP, and the wavelength of light applied to the optical disk.

As shown in FIG. 12, the tracking error signal changes the depth of the groove G to λ / 8n (where n is
(Refractive index of the substrate of the optical disc). Assuming that the depth of the groove G is λ / 4n, the phase difference between the light reflected and diffracted at each of the land L and the groove G is π. If there is no groove G, the two light receiving surfaces 33 of the two-part split surface light receiving type photodiode 33
Since the same light amount returns to a and 33b, the difference signal becomes 0.

FIG. 13 shows a wobble signal, which is a push-pull signal obtained by applying a spot to a track groove formed on an optical disk by the improved AM modulation method. 13A shows a wobble signal obtained from the groove G, and FIG. 13B shows a wobble signal obtained from the land L. As can be seen from this waveform, the phase of the waveform differs between the wobble signal obtained from the land L and the wobble signal obtained from the group G. By detecting this phase difference, the determination means 34 determines whether the head 31 is currently tracing the land L or the groove G.

When the phases of the wobbles on adjacent tracks on the optical disk are formed so as to be substantially aligned, the wobble signal obtained from the land L and the group G
Has a phase difference of about 180 degrees from the wobble signal obtained from the above, which makes detection extremely easy. Moreover, since the phases of the wobble in the adjacent tracks are substantially aligned, the wobble signal can be detected without being adversely affected by crosstalk, so that it is possible to cope with a narrow track pitch.

As a method for detecting the phase difference, as shown in FIG. 14, the wobble period A0 or A1 is used.
, The phase of the wobble signal in the transition from the non-wobble period B0 or B1 or the transition from the non-wobble period B0 or B1 to the wobble period A0 or A1, that is, the polarity of the waveform immediately before or immediately after the transition may be detected. The configuration of the part 36 can be made extremely simple. That is, since the phase of the wobble signal from the land L differs from that of the wobble signal from the groove G by 180 degrees, the polarity of the waveform immediately before the transition from the wobble period to the non-wobble period is reversed, and The polarity of the waveform immediately after the transition to the wobble period is also reversed. The discrimination unit 36 detects these polarities, and from the detection result,
It is determined whether the wobble signal is obtained from the groove G or the land L.

By the way, the above-mentioned sub-information is specifically information other than user data, and a typical example thereof is address information. If address information is used as sub-information, it is not necessary to provide an area for storing address information separately from an area for storing user data, so that extremely high format efficiency can be realized.

Of course, in addition to the address information, it is also possible to use, for example, various parameter information relating to the disc as the sub-information.

The present invention can be applied to the optical disk P2 of the ZCAV or ZCLV format shown in FIG. In this case, since the optical disk P2 is divided into a plurality of zones in the radial direction, the above-described embodiment of the present invention may be applied to each zone.

If the zone address information in each zone is adopted as the sub information, the sub information of the track in each zone becomes the same, so that the phases of the wobble of the adjacent tracks in each zone are substantially aligned. Can be. With such a configuration, a constant track pitch can always be ensured in each zone. Therefore, whether the wobble signal from the land L or the wobble signal from the groove G is used, the modulation To
Detection can be performed without crosstalk from an adjacent track.

Further, by setting all of the wobble periods A0 and A1 and the non-wobble periods B0 and B1 so as to be integral multiples of the wobble period, it is possible to extremely easily manufacture a disk. A stable operation of the control system can be realized.

As described above, by using the present invention, it is possible to provide a physical format of an optical disk that is extremely suitable for increasing the capacity.

[0076]

According to the first aspect of the present invention, since it is possible to determine from the wobble signal whether the land portion is being traced or the groove portion is being traced, the discrimination area is botherged in the disk format. There is no need to provide a special format, and an extremely efficient format can be provided.

According to the second aspect of the present invention, the phase difference between the wobble signal from the land portion and the wobble signal from the groove portion is close to 180 degrees. Extremely accurate determination can be made in determining whether a trace is being made or a groove is being traced.

According to the third aspect of the present invention, since the phase of the wobble signal is detected at the switching point between the wobble period and the non-wobble period, the wobble signal from the land portion and the groove are detected. There is no need to compare the phase with the wobble signal from the unit, and the wobble signal from the land and the wobble signal from the groove can be reliably discriminated.

According to the fourth aspect of the present invention, since the wobble signal is configured to be detected by the push-pull method, the present invention can be realized with a very simple configuration.

According to the fifth aspect of the present invention, since the address information is stored in the track as the sub information,
It is not necessary to specially provide an area for storing address information in the disk format, and an extremely efficient format can be provided.

According to the invention described in claim 6, the present invention can be applied to ZCAV or ZCLV format.

According to the seventh aspect of the present invention, the present invention can be applied to a system in which zone address information is superimposed on a disk for each zone.

According to the eighth aspect of the present invention, since the track pitch in each zone can be always kept constant, a wobble signal can be detected without crosstalk from an adjacent track.

Further, according to the ninth aspect of the present invention, the manufacture of the disk becomes extremely easy. Further, when configuring the PLL control system based on the wobble signal, it is possible to stably maintain the PLL control system.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of an optical disk P1 to be loaded on a reading device of the present invention.

FIG. 2 is an enlarged view showing a structure of a wobble track WT1 formed on a surface of an optical disc P1.

FIG. 3 is a diagram showing a procedure for storing sub-information in a wobble track.

FIG. 4 is a diagram illustrating an example of a conversion table of sub information data.

FIG. 5 is a diagram illustrating a waveform representing bits of converted sub-information modulated by the MAM modulation method.

FIG. 6 is a diagram illustrating an example of conversion from sub information data to converted sub information data.

FIG. 7 is a conceptual diagram showing a configuration of another optical disk P2 that can be used in the reading device of the present invention.

FIG. 8 is a block diagram illustrating a configuration of an optical disk reading device according to an embodiment of the present invention.

FIG. 9 is a diagram for explaining the principle of the push-pull method.

FIG. 10 is a diagram showing a waveform of a tracking error signal when a spot is moved in a direction crossing a track.

FIG. 11 is a diagram for explaining an operation when a spot is moved in a direction crossing a track.

FIG. 12 is a graph showing a relationship between a tracking error signal and a depth of a groove G;

FIG. 13 is a diagram showing a waveform of a wobble signal obtained by the optical disk reader according to the embodiment of the present invention.

FIG. 14 is a diagram for explaining a method of detecting a phase difference between a wobble signal obtained from a land L and a wobble signal obtained from a group G.

[Explanation of symbols]

P1, P2 Optical discs WT1, WT2 Wobble track (track) AWT Wobble section NWT Non-wobble section T Track groove L Land G Groove P Recording mark H Light 1 Sub-information data 2 Conversion table 3 Conversion sub-information data 21, 22, ..., 2n zone 31 head 32 objective lens 33 two-division surface light receiving type photodiode 33a, 33b light receiving surface 34 determining means 35 differential amplifier 35a non-inverting input terminal 35b inverting input terminal 36 determining part 37 laser diode 38 collimator lens 39 beam splitter

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) BB06 BB07 BC02 BC12 BC13 BF17 CA13 CD03

Claims (9)

[Claims] 1. A track for recording user data, comprising a groove as a bottom of a track groove provided on a surface of an optical disc and a land as another portion, the track having a groove. Is provided with a wobble portion meandering in the radial direction of the optical disc, and a non-wobble portion that does not meander.Using a combination of the wobble portion and the non-wobble portion, data other than the user data is used. An apparatus for reading a rewritable optical disk such as a phase change medium or a magneto-optical medium or a write-once optical disk such as a dye-based medium in which certain sub-information is stored in the track, wherein the wobble part and the non-wobble part of the track A head for detecting a signal, and a wobble signal based on the phase of the wobble signal detected by the head. Reading device of an optical disk, characterized in that it comprises a determination means for determining whether the signal obtained from the command unit, or whether the signal obtained from the groove portion of the track. 2. The optical disk reading apparatus according to claim 1, wherein the meandering phases of wobble portions of adjacent tracks provided on the surface of the optical disk coincide with each other. 3. The method according to claim 1, wherein the discriminating unit is configured to determine whether the wobble signal is obtained from a land portion of the track based on a phase of the wobble signal detected by the head from a boundary point between the wobble portion and the non-wobble portion of the track. 2. The optical disk reading apparatus according to claim 1, wherein whether the signal is a signal obtained from a groove portion of the track is determined. 4. The head has two light receiving units arranged along a radial direction of the optical disk, and the determining unit detects a phase of a wobble signal from a difference between outputs of the two light receiving units. 4. The optical disk according to claim 1, wherein the wobble signal is a signal obtained from a land portion of the track or a signal obtained from a groove portion of the track. Reader. 5. The optical disk reading apparatus according to claim 1, wherein the sub information is an address in the track. 6. The optical disk reading apparatus according to claim 1, wherein the track is divided into a plurality of zones in a radial direction of the optical disk. 7. The apparatus according to claim 6, wherein the sub information is a zone address of the zone. 8. The optical disk reading apparatus according to claim 6, wherein the meandering phases of the wobble portions of adjacent tracks in the zone coincide with each other. 9. The optical disk reading device according to claim 1, wherein the length of the wobble portion and the non-wobble portion is an integral multiple of one cycle of meandering in the wobble portion. .