Dynamic information storage or retrieval – Storage medium structure – Adjuncts or adapters
Reexamination Certificate
1997-05-14
2003-02-18
Miller, Brian E. (Department: 2652)
Dynamic information storage or retrieval
Storage medium structure
Adjuncts or adapters
C360S133000
Reexamination Certificate
active
06522621
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to disc cassettes for use in a photo-electromagnetic disc player, and more particularly to the disc cassettes of a type having a shutter.
2. Description of the Related Art
In order to clarify the object of the present invention, one conventional disc cassette DC of the above-mentioned type will be described with reference to
FIGS. 9A and 9B
of the drawings which figures show front and back perspective views of the disc cassette DC, respectively.
The disc cassette DC shown in the drawings is of a type which writes and read information onto and from a photo-electromagnetic disc using so-called “magnetic modulation overwrite method”. The disc cassette DC comprises a rectangular case
1
in which a photo-electromagnetic disc
2
is rotatably installed. To a center portion of the disc
2
, there is fixed a hub
2
a
which, upon need of playing the disc
2
, is held by a chucking member of a disc player (not shown). The case
1
comprises an upper half part
1
a
and a lower half part
1
b
which are coupled to have a thin space defined therebetween. As is seen from
FIG. 9B
which shows a back view of the disc cassette DC, the lower half part
1
b
is formed at its side rear portions with respective positioning openings
3
. Upon insertion of the disc cassette DC into the disc player, positioning pins of the disc player are brought into engagement with the positioning openings
3
, thereby to position the disc cassette DC relative to the disc player. The lower half part
1
b
of the case
1
has near one of the positioning openings
3
a slot in which a miss-write protection pawl
4
is slidably received. When the pawl
4
is moved to one given position, the disc
2
is prevented from recording or writing information thereon. The case
2
is formed at its side front portions with cassette pulling grooves
5
. That is, when the disc cassette DC is inserted into a certain position of the disc player, cassette pulling pins of the player become engaged with the grooves
5
and pull the disc cassette DC to a certain bottom position of the disc player.
As is seen from
FIGS. 9A and 9B
, the upper and lower half parts
1
a
and
1
b
of the case
1
are respectively formed with rectangular openings
6
a
and
6
b
through which upper and lower surfaces of the disc
2
are partially exposed. The lower opening
6
b
is larger than the upper opening
6
a
and is so sized as to expose the hub of the disc
2
.
Each opening
6
a
or
6
b
has a bridge
1
e
defined by the case
1
, which extends across a mouth portion of the opening, as shown.
A slide bar
8
is mounted on a front edge
1
C of the case
1
in a manner to slide in the direction of the arrow “A”. Connected to the slide bar
8
is a shutter
7
which comprises upper and lower shutter plates
7
a
and
7
b.
Thus, in response to the sliding movement of the slide bar
8
, the upper and lower openings
6
a
and
6
b
are selectively closed and opened by the upper and lower shutter plates
7
a
and
7
b.
Although not shown in the drawings, a torsion spring is installed in the case
1
to bias the shutter
7
in the direction to close the openings
6
a
and
6
b.
FIGS. 9A and 9B
show a condition wherein the shutter
7
assumes its full open position. The slide bar
8
has a thickness somewhat smaller than that of the disc
2
in the case
1
.
FIG. 10
shows a condition wherein the disc cassette DC is properly set in the disc player. Under this condition, the shutter
7
of the disc cassette DC assumes its full open position and the hub
2
a
of the disc
2
is tightly held by the chucking member (not shown) of the disc player. Upon energization of a spindle motor (not shown) by which the chucking member is driven, the disc
2
is rotated about its axis. Within the disc player, there are installed a magnetic head
28
and an optical head
29
which are arranged to put therebetween the disc
2
. These heads
28
and
29
face the upper and lower openings
6
a
and
6
b
of the case
1
, respectively, and are mounted on a same head carriage
24
which is linearly movable in the direction of the arrow “B” in
FIG. 10
, that is, in the radial direction of the disc
2
. The head carriage
24
moves between an outermost position as shown by a phantom line and an innermost position as shown by a solid line. Due to movement of the carriage
24
, the two heads
28
and
29
are slid radially along the upper and lower openings
6
a
and
6
b
while making an interaction therebetween to write or read information on or from the disc
2
.
Usually, the disc players used as a supplemental memory device of a computer are restricted by size. As is seen from
FIG. 10
, assuming that the length of the disc player is “L” and a part “L
0
” of the length “L” represents the length of a space for containing other mechanisms, the head carriage
24
has to be arranged within a limited zone having the length “L
1
”. The length of an arm
27
through which the head
28
is connected to the head carriage
24
is so determined that when the head carriage
24
is located at the outermost position as shown by the phantom line, the head
28
is located at the outermost recording position of the disc
2
. Thus, the innermost position of the head
28
is automatically determined when the head carriage
24
comes into abutment with the slide bar
8
of the disc cassette DC. However, in this case, it sometimes. occurs that the innermost recording area (i.e., the area having the width “E”) of the disc
2
cannot be practically used, due to the limited movement of the heads
28
and
29
in the inward direction.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a disc cassette which can provide the head carriage of the disc player with a more satisfactory moving area, thereby permitting effective usage of the recording area of the disc.
According to a first aspect of the present invention, there is provided a disc cassette which comprises a case in which a disc recording medium is rotatably received, the case having an opening through which at least an information recording area of the medium is exposed; a bridge defined by the case, the bridge extending across a mouth portion of the opening; a slide bar arranged beside the bridge in a manner to move axially therealong; and a shutter connected to the slide bar to move therewith, the shutter selectively opening and closing the opening in accordance with axial movement of the slide bar, wherein the slide bar has a base portion which comes beside the bridge when the shutter takes the open position, the base portion being formed with a recess which faces in a direction away from the center of the disc recording medium.
According to a second aspect of the present invention, there is provided a disc cassette which comprises a case in which a disc recording medium is rotatably received, the case having an opening through which at least an information recording area of the medium is exposed; a bridge defined by the case, the bridge extending across a mouth portion of the opening; a slide bar arranged beside the bridge in a manner to move axially therealong; and a shutter connected to the slide bar to move therewith, the shutter selectively opening and closing the opening in accordance with axial movement of the slide bar, wherein the slide bar comprises a base portion which comes beside the bridge when the shutter takes the open position and a projection which is to be pressed by a shutter opening pin of a disc player, the projection protruding outward from the base portion.
REFERENCES:
patent: 4945530 (1990-07-01), Sandell et al.
patent: 4991048 (1991-02-01), Ikebe et al.
patent: 5077625 (1991-12-01), Shiba et al.
patent: 5121277 (1992-06-01), Ikebe et al.
patent: 5121380 (1992-06-01), Fujita et al.
patent: 5166922 (1992-11-01), Akiyama et al.
patent: 5325257 (1994-06-01), Akiyama et al.
patent: 5444691 (1995-08-01), Akiyama
patent: 5495467 (1996-02-01), Tanaka et al.
patent: 0336637 (1989-03-0
Aoki Sunao
Funawatari Takatsugu
Kanazawa Takakiyo
Ohmori Kiyoshi
Maioli Jay H.
Miller Brian E.
Sony Corporation
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