Disc cartridge

Details Disc cartridge Disc cartridge

2002-01-28

2004-08-24

Klimowicz, William (Department: 2652)

Dynamic magnetic information storage or retrieval

Record medium

In container

C720S725000

Reexamination Certificate

active

06781793

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2001-62668 filed on Oct. 11, 2001, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a disc cartridge accommodating a disc which is an information recording and/or reproducing medium, and more particularly, to a disc cartridge in which dust therein can be efficiently discharged.
2. Description of the Related Art
Referring to
FIG. 1
, a typical disc cartridge
10
accommodating a disc D used in a disc drive
20
includes upper and lower cases
11
and
12
forming an inner space where the disc D is accommodated, and a shutter
13
which selectively opens or closes an opening
12
a
formed in the lower case
12
so that an optical pickup
21
of the disc drive
20
can access the disc D. Reference numeral
22
denotes an opening lever installed in the disc drive
20
to open/close the shutter
13
. As the cartridge
10
enters the disc drive
20
, an end portion of the opening lever
22
, as shown in
FIGS. 2A and 2B
, is rotated by being caught by a hooking step
13
a
of the shutter
13
, to thereby open the shutter
13
.
The most important reason for using the disc D in the cartridge
10
is to protect the disc D from foreign material such as dust. That is, because, in the case of using a high density disc, foreign material such as dust adhering to the surface of the disc D is more likely to prevent accurate signal processing during recording or reproduction of data on/from the disc. Accordingly, the disc is used by being accommodated in the cartridge
10
to prevent such contamination. Nevertheless, it is unavoidable that some dust still flows into the cartridge
10
through the opening
12
a
because the shutter
13
necessarily opens inside the disc drive
20
to allow the optical pickup
21
to access the disc D. Although the dust flowing inside the cartridge
10
may exit the cartridge through the opening
12
a
, a large amount of dust remains inside the cartridge
10
.
FIG. 3A
shows the result of a simulation of the pattern of air flow formed inside the cartridge D as the disc D rotates.
FIG. 3B
shows the result of a simulation of a path along which dust particles flowing in the cartridge D are moved by the air flow. Here, it is assumed that the disc D rotates at a velocity of 5,000 r.p.m. counterclockwise and that the density and diameter of the dust particles are about 0.6 g/cm
3
and 1 &mgr;m, respectively. First, as shown in
FIG. 3A
, as the disc D rotates at the above stated velocity, the flow of air is formed in the cartridge
10
according to the direction in which the disc D rotates. Since the disc D rotates counterclockwise at a high velocity, air flow outside the cartridge
10
is drawn inward at the left side of the opening
12
a
due to a difference in pressure while part of the air flow inside the cartridge
10
is discharged at the right side of the opening
12
a
due to a centrifugal force. The dust flowing into the cartridge
10
, in which the air flow is formed as stated above, rotates along with the air flow and creates a path as illustrated in FIG.
3
B. Here, it can be seen that the dust is moved toward the opening
12
a
after rotating inside the cartridge
10
about two turns. The dust flowing in the cartridge
10
through the left side of the opening
12
a
is not discharged through the right side of the opening
12
a
after rotating only one turn, and therefore usually remains inside the cartridge
10
for a time of more than one turn. That is, the velocity at which the dust is discharged from the cartridge
10
is less than half of the velocity at which the dust flows into the cartridge
10
. Accordingly, the amount of dust remaining in the cartridge
10
gradually increases. The difference between the flowing-in velocity and the discharge velocity is inversely proportional to the size of a dust particle. This is because the smaller the mass of the dust particle, the less a centrifugal force needed for discharging a dust particle from the cartridge
10
through the opening
12
a.
To solve the above problems, a method of installing an additional filter in the cartridge
10
has been proposed. However, when the filter is used for a long time, it becomes saturated, and inconveniently needs to be replaced repeatedly. If the filter is not timely replaced, the dust collected by the filter may contaminate the disc D. Thus, an improved structure by which dust in the cartridge can be appropriately discharged from the cartridge without using an additional filter is required.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved disc cartridge which can effectively discharge dust introduced externally by using the flow of air produced during the rotation of a disc.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing a disc cartridge comprising a case to accommodate a disc, a shutter to open or close an opening formed in the case to enable a recording and/or reproducing operation with respect to the disc, a discharge path provided at one side of the case to allow the flow of air formed therein during rotation of the disc, and an opening/closing mechanism to open/close the discharge path.


REFERENCES:
patent: 4636891 (1987-01-01), Barski
patent: 6563672 (2003-05-01), Yamamoto et al.
patent: 8221929 (1996-08-01), None
patent: 10302427 (1998-11-01), None
patent: 11066801 (1999-03-01), None
patent: WO 9854717 (1998-12-01), None
Office Action dated Jan. 19, 2004 of Chinese Patent Application No. 02102358.1.

Affiliated with

Also associated with

Rating

Disc cartridge does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Disc cartridge, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disc cartridge will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3320229