Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
1999-02-02
2002-07-16
Korzuch, William (Department: 2653)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S047220, C369S030110, C369S030220
Reexamination Certificate
active
06421308
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk device in which information is recorded in both of grooves (which sometimes may be abbreviated as “G”) and lands (which may be abbreviated as “L”) in a spiral form about the axis of rotation of an optical disk which is a recording medium, and reproducing the recorded information, and in particular to a state detection device for detecting the state of an optical disk device based on an error detection code (IED) contained in a header of a recording sector of the optical disk, and an optical disk device using such a state detecting device to achieve recording and reproduction at a higher accuracy.
Recently, a standard of an optical disk (DVD-RAM) adopting a single spiral-land/groove (SS-L/G) recording format has been proposed, in which information is recorded in both of grooves and lands of a disk, in order to increase the recording density, and the land s and grooves are alternated every revolution to form a single continuous recording track. When this standard is adopted, the recording track pitch can be halved, provided that the groove pitch is unchanged, and there is therefore a great contribution to a higher density, and the products adopting this standard are believed to be promising.
The configuration of this optical disk is shown in FIG.
9
and FIG.
10
. In the figure, grooves
104
are formed on the disk substrate, with the result that lands
105
are formed between the grooves
104
, and a recording film
101
is formed thereon. Recording pits
102
are formed on both of the grooves
104
and lands
105
by a light spot which is scanned by an optical disk device, not shown. As shown in
FIG. 10
, tracks formed of the grooves
104
and lands
105
are alternated every revolution to form a single continuous recording track.
The optical disk is separated into a plurality of regions called zones (in the illustrated example, three zones Z
1
, Z
2
, Z
3
), and the number of recording sectors per revolution is constant within each zone, and is increased by a certain number, e.g., one, every transition from one zone to a radially outward, adjacent zone.
The track format of this disk is next described.
FIGS. 11A and 11B
show the configuration of the recording sectors of the optical disk.
FIG. 11B
is a schematic diagram showing the disposition of identification signals and address values in the recording sectors at a boundary, or connecting points, between lands and grooves.
FIG. 11A
is a schematic diagram showing the disposition of identification signals and address values in the recording sectors at parts other than the boundary (see ECMA/TC31/97/60).
In the drawings, each of identification information parts forming a header of a recording sector includes four address regions PID (physical ID) containing address information of the recording sector, and is formed of a front part (two PIDs in front) and a rear part (two PIDs at the back), with respect to the order of scanning of the light spot. The front part is shifted radially outward by half a track pitch, and the rear part is shifted radially inward by half a track pitch. In this connection, it is noted that the width of a groove is the same as the width of the land, and half a track pitch equals to the width of the groove. In this way, the front and rear parts are disposed in a staggering manner.
In FIG.
11
A and
FIG. 11B
, it is assumed for the time being that the identification information part consists of PIDs. However, as will be later described with reference to
FIG. 12
, the identification information part additionally includes a region (VF
0
) containing information for PLL (phase-locked loop) control, a region (AM) containing synchronization information for address reproduction, and a region (IED) containing error detection codes for detection and correction of errors in the physical address.
The address of a recording sector in a groove is included in the rear part of the identification information part immediately preceding a user information part in the recording sector, and shifted radially inward by half a track pitch from the center of the groove track, while the address of a recording sector in a land is included in the front part of the identification information part immediately preceding the user information part, and shifted radially inward by half a track pitch from the center of the land track (and hence shifted radially outward by half a track pitch from the center of the groove track, which is radially inward of and adjacent to the land track in question).
The identification information is shifted by half a track pitch from the center of the track because this enables the identification information to be shared between a groove track and a land track adjacent to each other, so that the identification information of equal quality can be read whichever of a groove track or a land track is being scanned.
As explained above,
FIG. 11B
shows the disposition of identification signals at a boundary, and address values represented by the identification signals. As shown in
FIG. 10
, there is a radially extending boundary line at which groove tracks and land tracks are connected.
The connecting point is detected for example in t he following manner. In a state in which a tracking is achieved, the directions of shifting of the front and rear parts of the identification information part can be detected by referring to the tracking error signal. That is, if the tracking error signal indicates a radially inward tracking error in the front part, and then a radially outward tracking error in the rear part (which means that the front part of the identification information part is deviated radially outward and the rear part is deviated radially inward with reference to the scanning light spot), then the light spot is recognized as scanning a groove track. In contrast, if the tracking error signal indicates a radially outward tracking error in the front part, and then a radially inward tracking error in the rear part (which means that the front part is deviated radially inward and the rear part is deviated radially outward with reference to the scanning light spot), then the light spot is recognized as scanning a land track.
The address read from the identification information part is related to each sector in the following manner. That is, the rear part of the identification information part shifted radially inward by half a track pitch contains the address of a sector (groove sector) in a groove track, and the front part of the identification information part shifted radially outward by half a track pitch contains the address of a sector (land sector) in a land track.
An optical disk device which records and reproduces information in and from an optical disk of the above described configuration judges which of a groove track and a land track is being scanned on the basis of the tracking error signal, and recognizes the information obtained from the rear part of the identification signal as the address of the sector when a groove track is judged to be scanned, and recognizes the information obtained from the front part of the identification signal as the address of the sector when a land track is judged to be scanned.
FIG. 12
shows details of the identification information part. The identification information part is comprised of header regions H
1
-H
4
. Each of the header regions H
1
to H
4
includes a VFO, AM (address mark regions), PID (address region), and IED (address error detection region), and PA (post-amble region). The VFO, AM, PID, IED, and PA are associated with suffixes 1 to 4, depending on which of the four header regions H
1
to H
4
, they belong to. The reference marks VFO, AM, PID, IED, and PA are used not only for denoting the regions, but also the information or signals read from the respective regions.
The VFO is a region of a single frequency pattern used for generation of a synchronous clock and detection timing signals during reproduction. These are used in pull-in operation of a PLL which generates re
Hiratsuka Yukari
Kizu Naoki
Matsui Shigeru
Sugiyama Kazuhiro
Yashima Noboru
Chu Kim-Kwok
Korzuch William
Mitsubishi Denki & Kabushiki Kaisha
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