JP3477168B2 - Optical disc having rewritable area and read-only area - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having an area in which recording or reproduction is possible (hereinafter, referred to as a rewritable area) and an area in which reproduction is possible only (hereinafter, referred to as a reproduction-only area).

[0002]

2. Description of the Related Art When a rewritable area and a read-only area are mixed on an optical disc, how to set a boundary between the rewritable area and the read-only area becomes a problem.

[0003]

At the boundary between the rewritable area and the read-only area, if the two areas are too close, data confusion will occur, while if the two areas are separated, the use efficiency of the optical disc will decrease.

[0004] The present invention solves the above-mentioned problem, determines an arrangement condition at the boundary between a rewritable area and a read-only area, prevents confusion between data in both areas, and makes both areas substantially adjacent to each other. It is an object of the present invention to provide a new optical disk which is arranged at a predetermined distance or through a land having a constant width and does not cause a reduction in the use efficiency of the optical disk.

[0005]

The invention to achieve the above object is as follows.

The optical disc of the present invention has a rewritable area having a single spirally formed recording track having a pitch Pa, wherein lands and grooves are alternately connected on a switching line assumed on a predetermined radius. Pitch Pb
And a read-only area in which information is recorded in advance by a series of marks formed on a single spirally formed recording track, and the switching between the rewritable area and the read-only area is generally performed using the radius An optical disc characterized by being performed along the switching line assumed above, thereby achieving the above object.

In the above-mentioned optical disk, the rewritable area has a plurality of recording sectors, and each recording sector has a header area pre-formatted with marks representing address information and a data recording area for recording data. together with and, the header area, (the K a positive integer) 2K number has a physical address area PID _i, and each physical address area PID _i includes an address area Pid for storing at least the sector address information , the physical address area PID _1, · · PID _k is positioned displaced in a first radial about Pa / 2 only disc from the groove recording track, the physical address area PID _k + 1, ·· PID _2k groove Only about Pa / 2 from the recording track
May be shifted in the radial direction.

In the above-mentioned optical disk, the above Pa and Pb may be substantially equal.

The invention described in the present specification is as follows.
At least: Both grooves and lands between the grooves are formed in a circle on the disk substrate, and the recording tracks of the grooves corresponding to one rotation of the disk and the recording tracks of the lands corresponding to one rotation of the disk are defined by a predetermined number. One recording spiral is formed by being alternately connected on a switching line assumed on the radius, and the track pitch Pa of the recording track is λ / N
A smaller than A, including a phase change recording film in which a local reflectance change occurs by irradiating a laser beam of a predetermined wavelength λ collected by a lens of a predetermined numerical aperture NA,
A rewritable area in which a first information data recording area in which information is recorded is arranged based on edge positions at both front and rear ends of a recording mark generated by the local reflectance change, and a pit row having a concave and convex shape on the optical disc in advance. By forming and arranging, a spiral recording track having a track pitch Pb substantially equal to the track pitch Pa of the recording track is formed, and a reproduction-only recording in which a second information data recording area in which information data is recorded in advance is arranged. The rewritable area has a plurality of recording sectors, each recording sector having a first header area pre-formatted with embossed pits representing address information, and a second recording area for recording data. 1 information data area, and the first header area has at least an address area P for storing sector address information. Physical address area PID, including the d
And the physical address area PID is repeated 2K times (K is a positive integer), and the 2K physical address area PID
ID is the following order _{PID 1, ... PID K, PID} K + 1, ..., P
When represented by ID _2K , the first half PID ₁ , ... P
ID _K, but about from the track of the groove recording sector Pa / 2
Is in the first radial direction of the disk, and the latter half P
ID _{K + 1} ,..., PID _2K are shifted from the track of the groove recording sector by about Pa / 2 in the second radial direction of the disk, and the rewritable area has a spiral pattern of one round at the top end. A portion of the physical address area PID which has a starting track land which is constituted and an end track land which is constituted by a spiral pattern at the end end, thereby being shifted from the track of the rewritable area by about Pa / 2. Is an optical disk characterized by entering into a start track land and an end track land.

According to the first aspect, in the optical disk, the boundary between the rewritable area and the read-only area always has the start track land or the end track land existing in contact with the boundary line above the rewritable area. The surface level of the land is the same as the level of the reproduction-only area at the boundary. As a result, the boundary between the rewritable area and the read-only area never touches the groove. The recording mark of the groove in the rewritable area is not mistakenly mixed with the embossed mark of the reproduction-only area.

The portion of the physical address area PID having a deviation of about Pa / 2 from the track in the rewritable area enters the start track land or the end track land. As a result, the shifted portion does not enter the read-only area. Therefore, the physical address area
There is no crosstalk between PID data and embossed marks in the read-only area.

A second aspect of the present invention is the optical disc according to the first aspect, further including an additional land having a predetermined width, located between the starting track land and the adjacent read-only area. With the end track land,
An optical disc characterized by including another additional land having a predetermined width and located between an adjacent read-only area.

According to the second aspect, it is possible to prevent crosstalk between the rewritable area and the read-only area by inserting an additional land. Further, since the additional land is provided, it is unnecessary to adjust the arrangement between the tracks in the rewritable area and the read-only area. Further, by detecting the additional land, it is possible to distinguish between the rewritable area and the reproduction-only area.

A third invention is an optical disc based on the first invention, wherein the rewritable area and the read-only area are at least a lead-in area at the center of the optical disc.
The optical disk is formed in an area, and the read-only area is used as a control data zone in which control data is previously written.

According to the third aspect, the rewritable area and the read-only area are provided in the lead-in area at the center of the optical disk. As a result, it is possible to add control data to the read-only area used as the control data zone so that no data is written to the start track and end track.

A fourth aspect of the present invention is the optical disc according to the third aspect, wherein the control data includes data for prohibiting recording of data on the start track land and the end track land. An optical disk.

According to the fourth aspect, the data read from the read-only area is not confused with the data read from the rewritable area. The reason is that no data is described in the start track or the end track land.

According to a fifth aspect of the present invention, there is provided the optical disk according to the first aspect, wherein the switching between the read-only area and the rewritable area is performed substantially along a switching line.

According to the fifth aspect, the leading ends of the tracks in the read-only area and the rewritable area are arranged along the switching lines. As a result, it is possible to easily seek the track and control the track. Further, it is possible to easily find where the switching between the reproduction-only area and the rewritable area is.

A sixth invention is an optical disc based on the first invention, wherein the wavelength of the laser beam is 650 nm,
The lens numerical aperture NA is 0.6, and the track pitch Pa
And track pitch Pb are both 0.74 μm,
This optical disc employs a modulation method of modulating 8 information bits into 16 channel bits, the shortest recording mark length is 3 channel bits, and the longest recording mark length is 11 channel bits.

According to the sixth aspect, it is possible to efficiently and compactly create a data format without wasting disk space.

The optical disk of the seventh invention has the following configuration.

Both grooves and lands between the grooves are formed circumferentially on the disk substrate, and recording tracks of the grooves corresponding to one rotation of the disk and recording tracks of the lands corresponding to one rotation of the disk Are alternately connected on a switching line supposed on a predetermined radius to form one recording spiral. The track pitch Pa of the recording track is set to a value smaller than λ / NA, and a predetermined numerical aperture is set. A phase change recording film in which a local reflectance change is generated by irradiating a laser beam of a predetermined wavelength λ collected by an NA lens, edges of front and rear ends of a recording mark generated by the local reflectance change A rewritable area in which a first information data recording area in which information is recorded according to a position is formed, and an uneven pit row is formed in advance on the optical disc. By arrangement, a spiral recording track having a track pitch Pb substantially equal to the track pitch Pa of the recording track is formed, and a read-only area in which a second information data recording area for pre-recording information data is arranged. And the rewritable area includes:
A plurality of recording sectors, each recording sector having a first header area pre-formatted with embossed pits representing address information, and a first information data area for recording data; The first header area is
Address area Pi for storing at least sector address information
d, the physical address area PID is repeated 2K times (K is a positive integer), and the 2K physical address area PID is changed to the next order PI
_{D 1, ... PID K, PID} K + 1, ..., when represented by PID _2K are beginning half PID _1, ... PID _K, but the tracks from about Pa / 2 displacement of the groove recording sector of the disk 1 in the radial direction, the latter half PID _{K + 1} ,..., PI
D _2K is about Pa / 2 from the track of the groove recording sector.
An optical disc, wherein the rewritable area is located close to the read-only area via a land having a width substantially equal to a plurality of track widths. It is.

The optical disk of the eighth invention has the following configuration.

[0025] Both grooves and lands between the grooves are formed circumferentially on the disk substrate, and recording tracks of the grooves corresponding to one rotation of the disk and recording tracks of the lands corresponding to one rotation of the disk. Are alternately connected on a switching line supposed on a predetermined radius to form one recording spiral. The track pitch Pa of the recording track is set to a value smaller than λ / NA, and a predetermined numerical aperture is set. A phase change recording film in which a local reflectance change is generated by irradiating a laser beam of a predetermined wavelength λ collected by an NA lens, edges of front and rear ends of a recording mark generated by the local reflectance change A rewritable area in which a first information data recording area in which information is recorded according to a position is formed, and an uneven pit row is formed in advance on the optical disc. By arrangement, a spiral recording track having a track pitch Pb substantially equal to the track pitch Pa of the recording track is formed, and a read-only area in which a second information data recording area for pre-recording information data is arranged. And the rewritable area,
An optical disc, wherein switching between the read-only areas is substantially along a switching line.

A ninth invention is the optical disc according to the eighth invention, wherein the groove pitch of the rewritable area is twice the pitch of the embossed mark of the read-only area. It is.

According to the ninth aspect, data can be recorded in the rewritable area at the same density as the recording density used in the read-only area.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The invention can be more completely understood with the following detailed description and the accompanying drawings.

(First Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a plan view of an optical disc 1 according to the present invention. The optical disc 1 includes a rewritable area (recordable or reproducible area) 2, a read-only area (reproducible area) 3, a rewritable area 4, a read-only area 6, and a rewritable area 7 from the inside. .

The inner areas 2, 3, and 4 are lead-in areas.
An area 5 is formed, and rewritable areas 2 and 4 are areas for inspecting recording characteristics of the optical disk, and a read-only area 3 is an area in which characteristics and format of the optical disk 1 are recorded in advance.

A read-only area 6 and a rewritable area 7 outside the lead-in area 5 constitute a data area 8 in which audio data and video data are recorded.

The arrangement of the rewritable area and the read-only area provided on the optical disk 1 shown in FIG. 1 is merely an example. The optical disc 1 is provided with a spiral track from the inside to the outside. Data is recorded and reproduced along the track in the rewritable area, while data is reproduced along the track in the read-only area. You. In a preferred embodiment, the track pitch is 0.74 μm.

FIG. 2 is a diagram showing the details of the rewritable area 2 and the read-only area 3 formed on the substrate 10 having the refractive index n and the boundary thereof. The rewritable area 2 includes a land 11 existing at the same level as the reference surface of the disk and extending along the track, and a groove 12 recessed from the reference surface by a predetermined amount Dp and extending along the track. In a preferred embodiment, the predetermined amount Dp is 0.07 μm
It is. The land 11 and the groove 1 adjacent to the land 11
The pitch Pa of 2, that is, the distance between the center line of the land 11 and the center line of the groove 12 is 0.74 μm. Therefore, the pitch of the land 11 itself (or the groove 12 itself) is twice the track pitch, that is, 1.48 μm.

A phase change recording film 16 is provided on the surface of the land 11 or the groove 12 and emitted from a light source 17.
By locally irradiating the laser beam sent from the lens 18 having a predetermined numerical aperture NA, the irradiated portion undergoes a physical change, for example, a local change in reflectivity, and binary recording is performed. It becomes possible. This irradiated portion is indicated by a recording mark 13. The recorded mark can be rewritten by re-irradiating the laser beam whose intensity has been adjusted.

In a preferred embodiment of the present invention, the wavelength λ of the laser beam is 650 nm, and the numerical aperture NA of the lens 18 is 0.6. The optical disk substrate 10
Has a refractive index n of about 1.5. Note that the pitch Pa is λ
The value is smaller than / NA.

In the track in the rewritable area, lands and grooves are alternately arranged as described above. This is to enable laser beam tracking.

In FIG. 2, the read-only area 3 has a plurality of embossed marks 15, such as pits, arranged along tracks on a land surface 14 which is at the same level as the reference surface of the disk. Since the embossed mark 15 is formed in advance, the user of the optical disc cannot erase or rewrite the embossed mark 15. The pitch Pb of the embossed marks 15 arranged adjacent to each other is 0.74 μm.

The last track of the rewritable area 2 adjacent to the reproduction-only area 3 (referred to as an end track)
Is always composed of lands 11 as shown in FIG. 2, and such lands are handled as end track lands 11a. Recording of all data is prohibited on the land 11a which is the end track. This prohibition is recorded in advance in the format of the disc version protocol described above. The disc version is recorded in the read-only area 3 of the lead-in area 5. As shown in FIG. 4, the first track (referred to as a start track 11s) of the rewritable area 2 adjacent to the read-only area 3 is also formed of a land, and any recording is prohibited as in the case of the end track. You.

In other words, in the rewritable area of the optical disk according to the present invention, grooves and lands are alternately arranged on each circumference of the disk, and rewritable tracks always start with the groove and end with the groove. Further, the first track land 11s is located outside the first rewritable groove of the rewritable area, that is, on the inner peripheral side. The end track land 11a is outside the rewritable groove at the end of the rewritable area, that is, on the outer peripheral side. Data recording is prohibited on the first track land 11s and the last track land 11a. The first track land 11s and the last track land 11a are the first half 24 of the first header and the next header 24 deviated from the groove track of the reproduction-only area adjacent to the first track land 11s and the last track land 11a by half a track. The header first half 25 is stored.

FIG. 3 is an enlarged plan view of the rewritable area 2 and the read-only area 3 as viewed from above, and one spiral track extends from the inside to the outside. Rewriteable area 2
As described above, lands 11 and grooves 12 are alternately arranged as described above. More specifically, the land 11 exists once around the predetermined switching line 26 as a starting point, returns to the switching line 26 again, and subsequently, the groove 12 similarly exists around the same. Further, the land 11 is present once. The switching line 26 is an imaginary line extending in the radial direction from the center of the optical disc 1, and has a configuration in which the land 11 and the groove 12 are switched on this line. Further, switching between the land 11 which is the end track and the next reproduction-only area 3 is also performed by this switching line 26. That is, the switching point between the rewritable area and the reproduction-only area is always performed on the switching line 26. Further, as described above, a series of emboss marks 15 are formed on the spiral track in the read-only area 3.

The leading ends of the tracks in the rewritable area and the reproduction-only area are arranged along the switching line 26. As a result, it becomes easy to search for and manage tracks. Further, the location of the switching line 26 between the rewritable area and the reproduction-only area can be easily found.

FIG. 4 is an enlarged plan view of the rewritable area 2, the reproduction-only area 3, and the rewritable area 4 near the switching line 26. The track is divided into N (N is a positive integer, for example, 17) sectors 23 per round with the switching line 26 at the top. In the rewritable area 2, each sector 23 has a header area 21 at the head thereof, and an information data recording area 22 following the header area 21 via a mirror area.
As will be described later, the read-only area 3 also has a header area 3
1 and an information data recording area 32. In particular, the header area 21 and the information data recording area 2 in the rewritable area 2
2 is referred to as a first header area and a first information data recording area, while the header area 31 and the information data recording area 32 in the read-only area 3 are referred to as a second header area.
It is referred to as a second information data recording area.

Further, the first header area 21 is divided into a first half part 24 and a second half part 25 of the header. The header first half 24 is located on the one side from the center line of the groove 12 by about a half track pitch, which is shifted by 0.37 μm in the above-described example, while the header second half 25 is positioned by the groove 12.
Is located at a position shifted from the center line by approximately a half pitch of the track to the other side, in the example described above, by 0.37 μm. The details of the first header area 21 will be further described.

As shown in FIG. 5, the first half 24 of the header is composed of a first area PID1 and a second area PI which are continuously arranged.
D2, and the second half part 25 of the header is composed of a third area PID3 and a fourth area PID4 arranged continuously. In each of the first to fourth areas, the first to fourth identification codes are recorded, and the addresses of the sectors are also recorded. The address in this embodiment is modulated by a modulation method with a limited run length.

FIG. 6 shows a specific data structure of the first header area 21 in the rewritable area. First, the signal format of the first header area 21 will be described. The first area PID1 includes a single frequency pattern area VFO1 for obtaining a synchronous clock generation and detection timing at the time of reproduction, an address mark area AM for recognizing byte synchronization at the time of header reproduction and start of the detection timing, It is composed of an address area Pid1 for holding address information of a sector, an address error detection area IED1 for holding a code for detecting an error in the address area, and a postamble area PA for completing modulation.

Similarly, the second area PID2 includes a single frequency pattern area VFO2 and an address mark area AM0.
, Address area Pid2, and address error detection area I
ED2 and a postamble area PA.

Similarly, the third area PID3 includes a single frequency pattern area VFO1 and an address mark area AM
, The address area Pid3, and the address error detection area I
It is made up of ED3 and postamble area PA.

Further, the fourth area PID4 includes a single frequency pattern area VFO2, an address mark area AM,
Address area Pid4 and address error detection area IED
4 and a postamble area PA.

The modulation method is a method in which 8 information bits are modulated at a ratio of 16 channel bits, the shortest recording mark length channel bit is 3 bits, and the longest recording mark length channel bit is 11 bits.

Each of the single frequency pattern areas VFO1 is an area in which a specific pattern, for example, a repeated pattern of (00010001) is recorded.
Is used for synchronizing the reproduction clock generated from the oscillation circuit (in the PLL circuit 152 shown in FIG. 8) in the reproduction circuit during the period of. Area VFO1
Is a length that can include a sufficient number of edges of the recording marks for synchronization pull-in, and is preferably 36 bytes in the present invention.

The same specific pattern is repeatedly recorded in each of the single-frequency pattern areas VFO2, and the VFO2 has a length enough to include a sufficient number of recording mark edges for resynchronization of the reproduction clock in the VFO2. In the present invention, it is preferably 8 bytes.

Each of the address mark areas AM has a length that can include a channel bit pattern of a recording mark length that does not appear in the modulation bit string, and is longer than the longest recording mark length of the modulation method. In this embodiment, 3 bytes are preferred.

Address areas Pid1, Pid2, Pid
Each of 3 and Pid4 is an address for identifying a recording sector, and is preferably 4 bytes in the present invention.

Address error detection areas IED1, IED
2, IED3 and IED4 each have an address area P
The length is such that the reproduction error of id can be detected at a known maximum error rate, and is preferably 2 bytes in the present invention.

The postamble PA area has a length equal to or longer than the length required for the modulation method and a length that can terminate the recording mark. The postamble area PA is preferably one byte in the present invention.

Further, as shown in FIG. 6, a mirror area 121 follows the first header area 21. Mirror area 12
Numeral 1 exists on a plane portion where the groove and the emboss mark are not formed, and corrects, for example, tracking deviation. The detailed format of the first information data recording area 22 following the mirror area 121 will be described below.

The first information data recording area 22 includes a gap area 122, a first guard data area, a single frequency pattern (VFO3) area 124, a pre-synchronization area, a data area 125, a postamble area, and a guard data. An area 126 and a buffer area 128 are included. The gap area 122, the first guard data area, the single frequency pattern (VFO3) area 124, and the pre-synchronization area collectively form a first buffer area, while the second guard data area 126 and the buffer The regions 128 together form a second buffer region.

The gap area 122 is an area to which no signal is assigned, and is provided for adjusting the laser power.

First and second guard data area number 1
Reference numeral 26 is provided at the start and end of the recording data in order to compensate for the deterioration of the recording medium when repeated recording and reproduction are performed.

Further, the recording medium has a property that if the same data is repeatedly recorded in the same place, the deterioration proceeds.
To compensate for this, the length of the guard data area before and after the data area is adjusted, and the recording position of the data area is moved. By adjusting the length of the guard data area,
The total length of the first guard data area and the second guard data area is constant.

Single frequency pattern (VFO3) area 12
Reference numeral 4 denotes an area for recording a specific pattern, for example, a repetition pattern in which a specific pulse width of a modulation code is continuous, in order to set an oscillation frequency of an oscillation circuit (in the PLL 152 in FIG. 8) in the reproduction circuit. .

The pre-sync area is a synchronization signal for detecting the head of the data area, and records a code pattern having a large autocorrelation.

The data area 125 is an area for recording data that the user wants to store, including an error correction code and the like. This data is erasable and rewritable.

The postamble area has a length equal to or longer than the length required by the modulation method, and has a length that can terminate the recording mark. The postamble area is preferably 1 byte in the present invention.

The buffer area 128 is an area in which nothing is recorded, and is provided to absorb a timing shift that occurs as a result of the rotational jitter of the optical disc 1. Therefore, the end 123b of the recording data can be prevented from overlapping the next header area.

In a preferred embodiment of the present invention,
The mirror area 121 has 2 bytes, and the gap area 122 has 1 byte.
0 byte, single frequency pattern (VFO3) area 124
Is set to 35 bytes, the pre-synchronization area is set to 3 bytes, the data area 125 is set to 2418 bytes, the postamble area is set to 1 byte, and the buffer area 128 is set to 40 bytes. The first guard data area is 19 ± 4 bytes,
The second guard data area is 41 ± 4 bytes, and the total length of both guard data areas is fixed at 60 bytes.

It should be noted that, in the present embodiment, the length of the first and second guard data areas is expanded or contracted to move the position of the data area, but the present invention is not limited to this. For example, the same effect can be obtained even if the length of the gap region and the length of the buffer region are similarly expanded and contracted.

FIG. 7 shows the signal format of the header area 31 (described above as the second header area) in the read-only area. This second header area 31
Is a data sequence that has the same data arrangement and the same data capacity as the header area 21 and is modulated by the same modulation code.

The 2-header area 31 is followed by a 2-byte mirror area 130, followed by a second information data recording area 32. Hereinafter, a detailed format of the second information data recording area 32 will be described.

In the data area 131, information data is recorded in advance by embossed pit strings. Therefore, this data area 131 can be reproduced only.

The postamble area PA has a length equal to or longer than the length required for the modulation method and a length that can terminate the recording mark. The postamble area PA is preferably one byte.

In the second information data recording area 32, embossed pit rows are all recorded in advance at the time of manufacturing a disc. In contrast to this, the first information data recording area 22 where the user repeatedly records with the recording mark
It is. Therefore, the recording state of the second information data recording area 32 is more stable than the recording state of the first information data recording area 22. Therefore, in the second information data recording area 32, the gap area 122,
The guard data area 126 and the buffer area 128 are not required.

Therefore, the second information data recording area 32 is set to the same length as the first information data recording area 22, and
In order to make the data area 131 the same length as the data area 125, in the second information data recording area 32, the first dummy data is inserted into a portion corresponding to the first buffer area, and the second dummy data is stored in the second buffer area. Second in the corresponding part
Of dummy data.

In the data format shown in FIG. 7,
As a first dummy area, a first pad area of 28 bytes and a postamble area of 1 byte are added.
These two areas are the first information data recording area 2
2 corresponds to the gap area and the first guard data area. Further, as described above, the length of the guard data area can be adjusted, and the position of the first dummy area is aligned with the center of the length of the variable guard data area range. The postamble area has a length (1 byte) equal to or longer than the length required for the modulation method, and records a pattern that can complete a recording code and a recording mark. In addition, the same pattern recorded in the VFO area (35 bytes) of the single wavelength pattern and the pre-sync area (3 bytes) included in the first guard area is the same as the V of the single wavelength pattern in the first dummy area.
It is recorded in the FO area (35 bytes) and the pre-sync area (3 bytes).

Next, after the postamble area PA of the data area 131, the second data recording area 32 has the second
To create a dummy area, a second pad area of 80 bytes and a postamble of 1 byte are added. These two areas correspond to a second guard data area and a buffer area in the first information data recording area 22. Similarly to the first dummy area, the position of the second dummy area is aligned with the center of the length of the corresponding variable guard data area range. The postamble area has a length (1 byte) that is equal to or longer than the length required by the modulation method, and records a recording code and a pattern that can terminate a recording mark.

A predetermined specific pattern is recorded in the first pad area and the second pad area. As this pattern, for example, there is a single frequency pattern in which inversion is repeated at a constant cycle similar to the VFO area, a pattern based on predetermined data, and the like.

Returning to FIG. 4, it is assumed that the read spot of the laser beam is traveling on the land track along arrow A1. When the disk has made almost one round, it proceeds toward the arrow A2 and eventually reaches the switching line 26. Next, if it crosses the switching line 26, it advances on the groove track along the arrow B1. After making substantially one round, the vehicle travels toward the arrow B2 and reaches the switching line 26 again. Thus, in the rewritable area 2, the land track and the groove track are alternately switched for each round. And rewritable area 2
Is configured such that the land 11 always comes. When the land 11 which is the end track ends, the area is switched to the reproduction-only area 3 on the switching line 26. Further, the end track of the rewritable area 2 is set so that no recording mark is attached.

Similarly, when switching from the read-only area 3 to the rewritable area 4, the land 11 is provided at the start track of the rewritable area 4, and data writing to this land 11 is set to be prohibited at all. ing.

FIG. 8 is a simple block diagram of a reproduction signal processing circuit for reproducing an optical disk having any of the signal formats shown in FIGS. 6 and 7. 8, a track 139 is a track of the groove 12 or the land 11 on the optical disc 1. Reference numeral 140 denotes a split photodetector which receives reflected light from a track and converts reflected light from uneven pits in a reproduction-only area or recording marks in a rewritable area into a reproduction signal. Then, the sum signal of the split photodetector 140 is output by the operational amplifier 141, and the difference signal is output by the operational amplifier 14.
Output with 2. The selection switch 143 switches between the sum signal and the difference signal and inputs the signal to the binarization circuit 144.

The difference signal output is detected by the envelope detector 145. When the difference signal output exceeds a predetermined threshold value,
The switch 143 is switched to the difference signal output side. In the signal format shown in FIG. 4, since the difference signal output becomes equal to or larger than the predetermined threshold value only in the first header area 21 of the rewritable area, the switch is switched to the difference signal output side. First
Switch 143 when the header area 21 is reproduced.
Outputs only the difference signal. In the first information data recording area 22 of the rewritable area and the entire area of the reproduction-only area,
Since the difference signal output is equal to or less than the predetermined threshold value, the switch 143 outputs a sum signal during reproduction from these areas.

The digitizing circuit 144 operates according to the threshold value set for each of the sum signal and the difference signal, and digitizes the reproduced signal. The PLL 152 extracts a reproduction clock from the digitized signal and inputs the clock to a PID reproducer 153 that reproduces each header area. The timing signal generator 154 outputs a gate signal for reading user data.
Demodulated to quantified data.

(Second Embodiment) FIGS. 9 and 10 show an optical disk having a rewritable area and a read-only area according to a second embodiment of the present invention. The difference between the optical disc of the first embodiment and the optical disc of the second embodiment is as follows.
End track land 11a and start track land 1
The point is that additional lands 11b and 11c are provided near 1s to change the format of data in the read-only area.

First, additional lands will be described below. Any kind of recorded data can be stored in additional lands 11b and 11
Recording to c is prohibited. This recording ban,
This is completed by writing information describing that recording in the read-only area 3 of the lead-in area 5 is prohibited.

In the example shown in FIG. 9, the width Pc of the additional lands 11b and 11c is 3.26 m as an example. However, the width Pc is not so limited, and can be appropriately selected. According to a preferred embodiment of the present invention, the width Pc is 0.68-
5.42 m (including the figures at both ends) Further, the end track land 11a and the additional land 11b are both referred to as a "joining zone". Similarly, the start track land 11s and the additional land 11c are both referred to as a "coupling zone". The coupling zone is a mirror area with high reflection.

The installation of the additional lands 11b and 11c simplifies the adjustment of the cutting machine during the manufacture of the disc. Generally, the cutting machine uses a first laser to create grooves and addresses in the rewritable area and a second laser to create embossed marks in the read-only area during the cutting operation. If the additional lands 11b and 11c are not installed as in FIGS. 2 and 4, it is necessary to switch from the first laser to the second laser during one rotation of the end track land 11a, and It is necessary to accurately maintain the arrangement of tracks in the rewritable area using the laser and the arrangement of tracks in the read-only area using the second laser. Therefore, a high degree of accuracy is required for positioning the beam spots of the first and second lasers. However, this adjustment is difficult. On the other hand, the installation of the additional land according to the present invention gives an additional time to switch from the first laser to the second laser, the arrangement of the tracks in the rewritable area using the first laser and the reproduction only using the second laser. It is unnecessary to keep the track arrangement of the area accurate. Furthermore, since movement between the rewritable area and the reproduction-only area can be performed by a seek operation during reproduction, it is not necessary to maintain an accurate track arrangement in the rewritable area and the reproduction-only area. That is, no tracking management is required for the combined zone.

It should be further noted that the additional land 11
The width of b and 11c is about ten times as large as the track pitch, and the entire surfaces of the additional lands 11b and 11c are mirror surfaces. Therefore, the detection of the additional land becomes easy during the seek operation. Since the additional land is located between each rewritable area and the reproduction-only area, there is a switch between the rewritable area and the reproduction-only area every time the optical head passes over the additional land. Therefore, if the initially accessed area located on the inner periphery of the disc is a rewritable area, when an additional land is detected, it is easy to determine whether the optical head is currently located in the rewritable area or the read-only area. Can be detected.

The detection signal corresponding to the additional land can be used as a tracking switching signal. The reason is that push-pull tracking control is used in the rewritable area, and phase difference tracking control is used in the read-only area.

It should be further noted that by providing an additional land, crosstalk between the rewritable area 2 and the read-only area 3 can be avoided.

The data format of the read-only area is described below.

As shown in FIG. 10, there are M sectors 23 ′ in the read-only area 3 and N sectors 23 in the rewritable area 2. M is greater than N, and the difference between M and N depends on the radial distance from the center of the disk.

FIG. 11 is a schematic diagram showing the format of the sector 23 'of the read-only area 3 shown in FIG.

Each of the sectors 23 'includes 2418 bytes, and has the same format as the data area 23 of the sector 23 in the read-only area of the first embodiment. 24
Of the 18 bytes, 2048 bytes are user data, and the rest are error correction codes. Further, each sector has many frames. Each frame is 91 bytes long and has a 2-byte synchronization code added. One sector includes 26 frames. A 4-byte address code (ID) representing the logical address of the sector is assigned to the first frame of the sector. Following the address code (ID), a 2-byte address code (ID)
There is an error detection code (IED) followed by a 6-byte spare zone (RSV) that records various information of the sector.

The sector of the read-only area of the second embodiment shown in FIG. 11 is different from the sector of the read-only area of the first embodiment shown in FIG. And removal of the second dummy area, simplification of the structure of the header area 31, and retention of the same format of the data area. Obviously, the user data area of the read-only area of the optical disk shown in FIG. 11 is larger than that of the optical disk shown in FIG. Further, FIG.
The format of the data area 131 'of the read-only area shown in FIG. 1 is the same as that of the data area 125 of the rewritable area.

FIG. 12 shows a simple block diagram of a reproduction signal processing circuit for reproducing the optical disk shown in FIGS. 9 and 10. As shown in FIG.
Are scanned by the optical head 107. Data detected by the optical head 107 is digitized by a digital circuit 109, a reproduction clock is extracted by a PLL circuit, and the clock is applied to a switch 108. The data detected by the optical head is also sent to the additional land detector 113. Each time an additional land is detected, the additional land detector switches terminals A and B of switch 108. Terminal A is connected to timing generator 111 and demodulator 112. Thereby, data from the rewritable area is processed. Terminal B is connected to the timing generator 115 and the demodulator 1
16 are connected. Thereby, the data from the reproduction-only area is processed.

As described above, in the optical disc according to the second embodiment of the present invention, one turn of the first track on the inner circumference side of the rewritable area is defined as the start track land. One rotation of the last track on the outer peripheral side of the rewritable area is defined as the last track land. Start track land 11s and end track land 11a
, It is possible to catch either the header first half 24 or the header second half 25, which is shifted by half the track width from the groove track in the rewritable area close to. As a result, no crosstalk occurs between the shifted header portion data and the adjacent rewritable area data.

Further, the area between the rewritable area and the reproduction-only area can be easily detected.

With the optical disk and the signal format according to the present invention, the first header area can be reproduced in the rewritable area regardless of whether the groove track or the land track is tracked. For the optical disc according to the present invention, it is not necessary to provide another header area for the groove track and the land track in the rewritable area.

Further, by making the format of the data area (2418 byte area) between the rewritable area and the read-only area the same data format, the sector management in the rewritable area is the same as that of the read-only area. It can be compatible. As a result, the reproduction circuit may have a common circuit such as a digital circuit and a PLL circuit used for data from the rewritable area and the reproduction-only area.

The first header area and the second header area are formatted by the same modulation code using the same data string and the same data capacity. The data format of the first data recording area is also An optical disc including a rewritable area and a read-only area according to the present invention has the same data capacity as the data format of the second data recording area having data modulated using the same modulation code. Therefore, a common reproducing circuit can be used for reproducing signals from the rewritable area and the reproduction-only area. It is not necessary to provide two reproduction signal processing circuits (one for the rewritable area and the other for the reproduction-only area). Therefore, the required circuit scale is
The size is smaller than that of the conventional optical disk reproducing circuit. If the optical disk according to the present invention is used, it has a simple circuit configuration, and
A very high reliability reproduction signal processing circuit can be realized.

Although the present invention has been described above, it is clear that various modifications can be made. Such modifications are not deemed to depart from the spirit and scope of the present invention. Such modifications that would readily occur to one skilled in the art would clearly be included in the following claims.

[0102]

The optical disk of the present invention has a configuration in which the land and the groove are switched on a switching line (a virtual line extending in the radial direction from the center of the optical disk). Is always performed on the switching line. This makes it easy to search for a track and manage (control) the track. Also, the location of the switching line between the rewritable area and the reproduction-only area can be easily found.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical disc according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of the optical disc according to the first embodiment of the present invention.

FIG. 3 is a plan view schematically showing a track of the optical disc according to the first embodiment of the present invention.

FIG. 4 is an enlarged plan view near a switching line between a rewritable area and a read-only area of the optical disc according to the first embodiment of the present invention.

FIG. 5 is an enlarged explanatory diagram of an address portion in a rewritable area of the optical disc according to the present invention.

FIG. 6 is a detailed explanatory diagram of a data format of a sector area in a rewritable area.

FIG. 7 is a detailed explanatory diagram of a data format of a sector area in a read-only area according to the first embodiment of the present invention.

FIG. 8 is a block diagram of a reproduction circuit of the optical disc according to the first embodiment of the present invention.

FIG. 9 is a partially enlarged perspective view of an optical disc according to a second embodiment of the present invention.

FIG. 10 is an enlarged plan view near a switching line between a rewritable area and a read-only area of an optical disc according to a second embodiment of the present invention.

FIG. 11 is a detailed explanatory diagram of a data format of a sector area in a read-only area according to the second embodiment of the present invention.

FIG. 12 is a block diagram of a reproduction circuit of an optical disc according to a second embodiment of the present invention.

[Explanation of symbols]

1 optical disk, 2, 4, 7 rewritable area, 3, 6
Read-only area, 5 lead-in area, 8 data areas, 10 substrates, 11 lands, 11a end track lands, 11b, 11c additional lands,
11s Track lands at the beginning, 12 grooves, 13
Recording mark, 14 land surface, 15 embossed mark, 16 phase change recording film, 17 light source, 18 lens, 21, 31 header area, 22, 32 information data recording area, 23, 23 'sector, 24 header first half, 25 second half of header, 26 switching line, 107
Optical head, 108, 143 switch, 109 digital circuit, 110, 152 PLL circuit, 111, 115
Timing generator, 112, 116, 155 Demodulator, 113 Additional land detector, 121, 13
0 mirror area, 122 gap area, 123, 12
6 guard data area, 124 single frequency pattern area, 125, 131 data area, 128 buffer area, 139 tracks, 140 split photodetector, 14
1,142 operational amplifier, 144 binarization circuit, 145
Envelope detector, 153 PID regenerator, 154
Timing signal generator, AM address mark area,
IED1, IED2, IED3, IED4 Address error detection area, PA postamble area, PID1, PID
ID2, PID3, PID4 area, Pid1, Pi
d2, Pid3, Pid4 address area, VFO1, V
FO2, VFO3, VFO4 Single frequency pattern area.

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 8-166194 (32) Priority date June 26, 1996 (June 26, 1996) (33) Priority claim country Japan (JP) (72) Inventor Isao Sato 36-12 Narita Higashigaoka, Neyagawa City, Osaka (72) Inventor Kazuhiko Nakane 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Masato Nagasawa Chiyoda-ku, Tokyo Marunouchi 2-3-2 Mitsubishi Electric Co., Ltd. (72) Inventor Yoshinobu Ishida 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. (56) References JP-A-8-22640 (JP, A) JP-A-9-251639 (JP, A) JP-A-8-221821 (JP, A) JP-A-6-203411 (JP, A) Patent 3160298 (JP, B2) Patent 3418065 (JP, B2) International Open 97/038420 (WO, A ) Kazuhiko Nakane, outside 6 people, singles compiler Lumpur - land groove recording of access methods, TV Science Technical Report, February 29, 1996, Vol. 20, No. 16, pp. 29-34 (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 7/24 G11B 20/12

Claims (2)

(57) [Claims] A land and a groove are alternately connected on a switching line assumed on a predetermined radius, and have a rewritable area having one spirally formed recording track having a pitch Pa, and a pitch Pb. An optical disc having a read-only area in which information is recorded in advance by a mark train that is continuous with one spirally formed recording track, wherein the rewritable area has a plurality of recording sectors, Each sector has a header area pre-formatted with marks representing address information and a data recording area for recording data. The header area has 2K physical address areas PID (K is an integer of 2 or more ). _i and each physical address area P
ID _i is an address area Pid for storing at least the sector address information, together with and a single frequency pattern area VFO for a predetermined repetition pattern is recorded, a physical address area _PID 1, · · PID _K are on the groove Only about Pa / 2 from the recording track
Of the physical address area PID
_K + 1, · · _{PID 2K} are positioned shifted to the second radial direction of the optical disk by about Pa / 2 from the recording track on the groove, the physical address area _PID 1, the head of the · · PID _K physical address area PID ₁ is equal to the length of the single frequency pattern area VFO1 in the physical address area PI.
D _2, is configured longer than the length of the single frequency pattern VFO2 included in the physical address area of · · PID _K, the physical address area _PID K + 1, the physical address area _{PID K + 1} beginning of · · _{PID 2K} The length of the single frequency pattern area VFO1 included is configured to be longer than the length of the single frequency pattern VFO2 included in each physical address area of the physical address areas PID _{K + 2} ,..., PID _2K ; An optical disk characterized in that the switching between the read-only area and the read-only area is performed substantially along a switching line assumed on the radius. 2. The optical disk according to claim 1, wherein
Optical disks whose serial Pa and Pb are characterized by a substantially equal this.