Rewritable DVD-RAM disc

Details Rewritable DVD-RAM disc Rewritable DVD-RAM disc

2000-01-21

2002-11-19

Cao, Allen (Department: 2652)

Dynamic information storage or retrieval

Dynamic mechanism subsystem

Specific detail of storage medium support or motion production

C369S291100

Reexamination Certificate

active

06483799

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application Ser. No. 88122148, filed Dec. 16, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates in general to a DVD-RAM disc. More particularly, this invention relates to rewritable DVD-RAM disc.
2. Description of the Related Art
One specification of the DVD-RAM version 2.0 disc has been provided in July, 1999. In this specification, the area and the parameters of the DVD-RAM have been defined. The specification includes a track pitch of 0.615 micron and a total capacity of 4.726 Giga-bytes. Referring to FIG.
1
A and
FIG. 1B
, an area distribution of a conventional DVD-RAM disc is shown. In FIG.
1
A and
FIG. 1B
, the DVD-RAM disc comprise a user area
14
of 4.7 Giga-bytes, a spare area of 146 Mega-bytes, a lead-in area
10
and a lead-out area
16
.
The spare area
12
further comprises a main spare area
12
and a backup spare area. The main spare area
12
has a capacity of 26 Mega-bytes, and the backup spare area has a capacity of 120 Mega-bytes. The range of the backup spare area covers a portion of the last area (the 34th area) of the user area
14
. That is, the backup spare area is included in the user area
14
.
In a general operation, the user may use the above user area
14
only. There are two occasions to use the spare area for a user. One is when the DVD-RAM disc is produced and a quality inspection is performed to find out that the user area
14
is not writable. For example, as shown in
FIG. 1C
, the DVD tester automatically extends the user area
14
with an original compensation area
18
towards the main spare area
12
. The dimension of the original compensation area
18
is equivalent to that of the original damage area
20
. Therefore, to write the DVD-RAM disc, it starts from the original compensation area
18
and then enters the user area
14
. While necessary, the original damage area
20
is skipped until the writing operation is complete.
The other occasion to use the spare area is when the user writes the DVD-RAM disc, the user area
14
is not writable. For example, as shown in
FIG. 1D
, when a damage area
24
occurs in the user area
14
, the writing machine may obtain a compensation area
22
from the main spare area
12
, and the compensation area
22
has a dimension the same as that of the damage area
24
. Referring to
FIG. 1D
, when the writing machine writes along the direction that the arrow
102
points at and reaches the damage area
24
, the writing machine then jumps to the in the compensation area
22
where the arrow
104
points at. After the compensation is written, the writing machine jump back to the user area
14
at the position that the arrow
106
points at and continues writing. The same steps are repeated until the writing is complete.
In the above two occasions, if the main spare area
12
is run out, the backup spare area
26
as shown in
FIG. 1E
is open, so that the coverage of the user area
14
is thus reduced.
In the prior technique, the total capacity of the main spare area
12
and the backup spare area
26
is 146 Mega-bytes. While the backup spare area
26
is open, the user area is reduced to 4.58 Giga-bytes. The ratio of the spare area to the user area
14
is 3.2% (146/4580=3.2%). Generally speaking, the ratio is too low for practical application since the spare area is easily run out.
SUMMARY OF THE INVENTION
The invention provides rewritable DVD-RAM disc. The location and dimension of the DVD-RAM disc is changed to enlarge the usable area. The enlarged area can be flexibly applied to the user area, the main spare area or the backup spare area.
The invention provides a rewritable DVD-RAM disc with a track pitch of 0.615 microns, and a diameter of 120 mm. The DVD-RAM disc comprises a lead-out area starting side and a lead-out area ending side. The lead-out area starting side is distant from a center of the DVD-RAM disc with a length of about 57.889 mm to about 58.145 mm. The lead-out area ending side is distant from the center of the DVD-RAM disc with a length of about 58.493 mm to about 58.516 mm.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.


REFERENCES:
patent: 5734787 (1998-03-01), Yonemitsu et al.
patent: 5914926 (1999-06-01), Maeno et al.
patent: 5986997 (1999-11-01), Chanllener, IV
patent: 6125101 (2000-09-01), Kikukawa et al.
patent: 6167021 (2000-12-01), Yoshida et al.
patent: 6195326 (2001-02-01), Yoshinari et al.
patent: 6226256 (2001-05-01), Utsunomiya et al.
patent: 6256282 (2001-07-01), Yamagami et al.
patent: 6269070 (2001-07-01), Kikuchi et al.
patent: 6279959 (2001-08-01), Nishizawa

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