Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Disk record
Reexamination Certificate
1999-09-24
2001-06-12
Klimowicz, William (Department: 2652)
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Disk record
C360S099120
Reexamination Certificate
active
06246539
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a disk chucking mechanism, and more particularly, to a disk chucking mechanism that uses a magnet to attract a hub provided on a magnetic disk.
2. Description of the Related Art
The conventional floppy disk chucking mechanism has involved a metallic hub positioned at the center of a magnetic disk or other recording medium.
FIG. 1
, for example, shows an expanded view of the vicinity of a hub
102
A of a lower grade or ordinary floppy disk
100
A. As shown in the diagram, a hub
102
A made of a magnetic metal, that is, a metal that is attracted by a magnet, is positioned in the center of the magnetic disk
103
A. A roughly square chucking hole
104
A is formed in a bottom portion
107
of the hub
102
A. Additionally, a similarly roughly square positioning hole
105
is formed in the bottom portion
107
of the hub
102
A at a position offset from the position of the chucking hole
104
A.
FIG. 2A
is a schematic diagram of a disk chucking mechanism
110
mounted on a conventional magnetic disk drive into which a lower grade or ordinary floppy disk
100
has been loaded. As shown in the diagram, the disk chucking mechanism
110
comprises a turntable
111
, a spindle
112
, a chuck magnet
114
and a drive pin
115
.
The turntable
111
is supported by the spindle
112
via a supporting portion
113
. The spindle
112
is constructed so as to be rotatably driven by a disk motor not shown in the diagram. The chuck magnet
114
is formed in the shape of a ring and positioned on top of the turntable
111
in such a way as to surround the supporting portion
113
.
The drive pin
115
is positioned so as to correspond to the position at which the positioning hole
105
noted above is formed. This drive pin
115
is constructed so as to be movable in the Z
1
-Z
2
direction depicted in the diagram by a leaf spring positioned at the bottom of the drive pin
115
.
FIG. 2B
shows a state in which the lower grade or ordinary floppy disk has been loaded into the disk chucking mechanism
110
. At the time the lower grade or ordinary floppy disk
100
A is loaded the hub
102
A is attracted to the chuck magnet
114
and set upon the turntable
111
. In such a state, it is sometimes the case that although the spindle
112
penetrates the chucking hole
104
A the drive pin
115
does not penetrate the positioning hole
105
. It should be noted that in this case the drive pin
115
moves in the Z
2
direction due to the elastic deformation of the leaf spring
116
.
If in the state described above the disk motor drives the turntable
111
via the spindle
112
, then this rotation matches the positioning hole
105
to the drive pin
115
and the rotational force of the disk motor is then transmitted to the hub
102
A.
That is, in the disk chucking mechanism
110
as described above, the rotational force of the disk motor is transmitted to the lower grade or ordinary floppy disk
100
A via the drive pin
115
and, at the same time, serves both to position the hub
102
A on top of the turntable
111
and to support the hub
102
A. As a result, the attractive force of the chuck magnet
114
does not contribute to the rotating of the lower grade or ordinary floppy disk. Accordingly, the attractive force of the chuck magnet
114
should be relatively weak, that is, just enough so that the hub
102
A does not separate from the turntable
111
. Separately, an index signal is emitted at the lower grade or ordinary floppy disk drive in order to determine the starting point of the disk that rotates in tandem with the position of the drive pin
115
.
However, ever-larger capacity floppy disks and magnetic disk drives using these large-capacity floppy disks to magnetically record and reproduce have been and continue to be developed for the lower grade or ordinary floppy disk
100
A and magnetic disk drive noted above. With the higher grade or high-density floppy disk drive the load that the magnetic head imparts to the rotation of the disk is small and moreover the load that the protective liner inside the disk cartridge imparts to the disk is set so as to be low, so there is no expectation of accurate positioning and support by the drive pin
115
. Further, there is no emission of an index signal linked to the drive pin
115
.
As a result, as shown by the expanded view depicted in
FIG. 3
a circular chucking hole
104
B is provided on a central portion
108
of the hub
102
B of the higher grade or high-density floppy disk
100
B and, at the same time, a peripheral portion of the hub
102
B is formed into a ring-like projection
106
. Unlike the lower grade or ordinary floppy disk
100
A, the load torque on the rotation of the higher grade or high-density floppy disk
100
B decreases and therefore the spindle
112
and the drive pin
115
cannot be expected to support the hub
102
B, with the result that the positioned state is maintained only by the friction between the hub
102
A and the turntable
111
.
However, a so-called compatible magnetic disk drive has been proposed that makes it possible to magnetically record and reproduce on both the lower grade or ordinary floppy disk
100
A and the higher grade or high-density floppy disk
100
B using a single floppy disk drive. The compatible disk drive makes it possible to use the conventional lower grade or ordinary floppy disk
100
A as is.
Conventionally, the disk chucking mechanism mounted on the compatible disk drive is the same disk chucking mechanism
110
mounted on the lower grade or ordinary floppy disk drive described above.
FIG. 2C
shows a state in which the higher grade or high-density floppy disk
100
B is loaded into the disk chucking mechanism
110
. When loading, the center portion
108
of the hub
102
B provided on the higher grade or high-density floppy disk
100
B is attracted to the chuck magnet
114
and set on top of the turntable
111
. In this condition, the spindle
112
enters the chucking hole
104
B.
However, when the lower grade or ordinary floppy disk drive disk chucking mechanism is used as the disk changing mechanism of the convertible disk drive, the position of the floppy disk on top of the turntable
111
fluctuates due to external vibrations.
Increasing the strength of the chuck magnet
114
is one possible method of eliminating these fluctuations. In so doing, however, the great strength of the chuck magnet
114
causes the hub
102
A of the lower grade or ordinary floppy disk
100
A to stop where it lands on top of the turntable
111
, the hub
102
A does not rotate on top of the turntable
111
and, accordingly, the drive pin
115
may not enter the positioning hole
105
.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a disk chucking mechanism in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a disk chucking mechanism capable of achieving a satisfactory clamping of the floppy disks to the turntable even when both the higher grade or high-density floppy disk as well as the lower grade or ordinary floppy disk are loaded and driven.
The above-described objects of the present invention are achieved by a disk chucking mechanism comprising:
a first disk having a first hub, the first hub having a chucking hole into which and through which a spindle is inserted and a positioning hole into which and through which a drive pin is inserted;
a second disk having a second hub, the second hub having a second chucking hole into which and through which the spindle is inserted and a ring-like projection;
a first magnet provided on an inner periphery of the turntable, the first magnet configured so as to attract the first hub and the second hub; and
a second magnet provided on an outer periphery of the turntable, the second magnet having an attracting surface positioned further toward the outer periphery of the turntable than an attracting surface of the first magnet and opposite the projection formed on the second hub.
Anderson Kill & Olick P.C.
Klimowicz William
Teac Corporation
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