U.S. patent application number 09/196509 was filed with the patent office on 2002-01-24 for chucking device for disc drive.
Invention is credited to OMORI, KIYOSHI.
Application Number | 20020009036 09/196509 |
Document ID | / |
Family ID | 27454950 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020009036 |
Kind Code |
A1 |
OMORI, KIYOSHI |
January 24, 2002 |
CHUCKING DEVICE FOR DISC DRIVE
Abstract
A disc chucking device comprises a first magnet for drawing down
a chucking pulley downward toward the pulley support member when a
disc is chucked comprises the first magnet embedded at the center
of the chucking pulley and the first yoke provided in close contact
with the upper side of the first magnet, and a second magnet for
drawing up the chucking pulley from the pulley support member when
a disc is unloaded comprises the second magnet embedded at the
level position upper than that of the first yoke at the center of
the chucking pulley and a top cover. Disc chucking is performed
strongly and the whole optical disc drive is made thin.
Inventors: |
OMORI, KIYOSHI; (TOKYO,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
FOURTH FLOOR, 1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Family ID: |
27454950 |
Appl. No.: |
09/196509 |
Filed: |
November 20, 1998 |
Current U.S.
Class: |
720/604 ;
G9B/17.006 |
Current CPC
Class: |
G11B 17/056 20130101;
G11B 17/0288 20130101; G11B 17/0285 20130101 |
Class at
Publication: |
369/75.2 ;
369/270 |
International
Class: |
G11B 033/02; G11B
023/00; G11B 025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 1997 |
JP |
P09-323038 |
Dec 18, 1997 |
JP |
P09-349015 |
Feb 20, 1998 |
JP |
P10-038599 |
Jan 20, 1998 |
JP |
P10-008467 |
Claims
What is claimed is:
1. A disc drive comprising: a disc tray for loading and ejecting a
disc thereon; a disc table that is lifted from the lower position
to the upper position after loading of said disc, engaged upward in
the center hole of said disc, and lifts said disc to the space
above said disc tray; and a disc clamp that is supported at the
position upper than said disc, and chucks said disc on said disc
table by being magnetically attracted to said disc table engaged in
said center hole of said disc supportingly; said disc clamp having:
pressing means for pressing upward to the position upper than that
of the chucking position of said disc when said disc is unloaded;
and guide means for positioning said disc at the upper pressing
position to the center rotation shaft of a spindle motor.
2. A disc drive as claimed in claim 1, wherein said guide means has
a projection guide portion formed on a fixing member positioned
above the disc drive and a recess groove formed on the top surface
of the disc clamp.
3. A disc drive as claimed in claim 1, wherein said guide means has
a recess groove formed on the fixing member positioned above the
disc drive and a projection guide portion formed on the top surface
of the disc clamp.
4. A disc drive as claimed in claim 2, wherein said fixing member
is a top plate of a disc drive container box.
5. A disc drive as claimed in claim 1, wherein said disc drive has
a projection guide portion positioned beneath said disc clamp for
being engaged in the positioning hole formed at the center of said
disc table when said disc is loaded.
6. A disc chucking device comprising: a disc tray for loading and
ejecting a disc thereon; a disc table which comprises a magnetic
material that is lifted from the lower position to the upper
position after loading of said disc, engaged upward in the center
hole of said disc, and lifts said disc above said disc tray; a
chucking pulley, being supported at the position upper than that of
said disc by a pulley support member, being lifted to the space
above the said pulley support member by said disc table engaged in
the center hole of said disc supportingly, and chucking said disc
on said disc table; first magnetic attraction means for drawing
down said chucking pulley to said disc table side when said disc
table is lifted from said lower position to said upper position
after loading of said disc; and second magnetic attraction means
for drawing up said chucking pulley from said pulley support member
when said disc table is lowered from said upper position to said
lower position to unload said disc.
7. A disc chucking device as claimed in claim 6, wherein said
pulley support member supports the center of said chucking
pulley.
8. A disc chucking device as claimed in claim 6, wherein said
centering member has a centering pin which extends downward from a
top cover consisting of magnetic material, and said centering pin
is inserted loosely into the center hole formed at the center of
said chucking pulley at least in the vertical direction.
9. A disc chucking device as claimed in claim 6, wherein said disc
chucking device is provided with a center pin extending downward
from the center of the bottom surface of said chucking pulley, and
a center hole formed at the center of the top surface of the
centering guide of said disc table in which said center pin is
inserted downward.
10. A disc chucking device comprising: a disc tray for loading and
unloading a disc thereon; a disc table which comprises magnetic
material that is lifted from the lower position to the upper
position after loading of said disc to engage in the center hole of
said disc supportingly and to lift said disc to the space above
said disc tray; a chucking pulley, being supported by a pulley
support member at the position upper than that of said disc, being
lifted to the space above said pulley support member by said disc
table inserted in the center hole of said disc supportingly, and
chucking said disc on said disc table; first magnetic attraction
means for drawing down said chucking pulley to said disc table side
when said disc table is lifted from said lower position to said
upper position after loading of said disc; and second magnetic
attraction means for drawing up said chucking pulley apart from
said pulley support member when said disc table is lowered from
said upper position to said lower position to unload said disc,
said first magnetic attraction means being provided with a first
magnet fixed on said chucking pulley having a prescribed magnetic
attraction force and a first yoke provided above said first magnet,
and said second magnetic attraction means being provided with a
second magnet having a magnetic attraction force smaller than that
of said first magnet fixed above said first yoke of said chucking
pulley and a magnetic member fixed at the position upper than said
first magnet.
11. A disc chucking device as claimed in claim 10, wherein: said
chucking pulley consists of synthetic resin, said first magnet and
said first yoke are shaped in the form of approximately coaxial
rings, said first magnet and said first yoke which is in close
contact with said first magnet thereon are embedded horizontally at
the center of said chucking pulley; said first magnet is magnetized
to have an S-pole and an N-pole on both ends of said first magnet
in the diametrical direction; and said second magnet shaped in the
form of a disc having a diameter smaller than that of said first
magnet is embedded horizontally at the center position of said
chucking pulley at the position upper than that of said first
yoke.
12. A disc chucking device of an optical disc drive as claimed in
claim 10, wherein said magnetic member fixed at the position upper
than that of said second magnet is structured with said top cover
made of a plate metal provided above said pulley support means.
13. A disc chucking device comprising: a disc tray for loading and
unloading a disc thereon; a disc table which comprises a magnetic
material that is lifted from the lower position to the upper
position after loading of said disc to be engaged in the center
hole of said disc supportingly and to lift said disc to the space
above said disc tray; and a chucking pulley, being supported by a
pulley support member at the position upper than that of said disc,
being lifted to the space above said pulley support member by said
disc table inserted in the center hole of said disc supportingly,
and chucking said disc on said disc table; wherein: the cylindrical
center portion where a magnet is embedded, a disc-shaped disc
pressing plate formed horizontally on the periphery of the bottom
end of said center portion, a cylindrical peripheral wall portion
which rises upward from the periphery of said disc pressing plate,
and a disc-shaped flange formed horizontally on the outer periphery
of the top end of said center portion and provided inside the
peripheral wall portion are formed combinedly of synthetic resin;
and said pulley support member formed on the bottom surface of said
top cover is inserted in the inside of peripheral wall portion of
said chucking pulley to support said flange of said chucking
pulley.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a disc chucking device of an
optical disc drive which loads an optical disc using a disc tray,
and chucks the loaded optical disc on a disc table using a chucking
pulley.
[0003] 2. Description of Related Art
[0004] A sort of optical disc drive which the inventors of the
present invention have applied is described with reference to FIGS.
11 to 18. In detail, as shown in FIG. 17, an optical disc 1 is
placed horizontally in a pit 3 formed on the upper surface of a
disc tray 2, thereafter, when a front panel 2a of the disc tray 2
is pressed lightly in the direction indicated by an arrow a.sub.1,
a loading switch (not shown in the drawing) is turned on, the disc
tray 2 is drawn horizontally from the direction indicated by the
arrow a.sub.1 namely the loading direction into the optical disc
drive through a tray gate 4 by means of a loading mechanism which
will described hereinafter as shown in FIG. 18, and as the result,
the optical disc 1 is automatically loaded horizontally on a disc
table of a spindle motor.
[0005] After loading, the optical disc 1 is rotated at high speed
by the spindle motor in response to a recording and/or reproducing
command signal supplied from a host computer, data in the optical
disc 1 is recorded and/or reproduced by an optical pickup. After
reproduction of the optical disc 1, the disc tray 2 is unloaded
automatically in the direction of the arrow a.sub.2 namely the
unloading direction to the outside of the optical disc drive
through the tray gate 4 in response to an unloading command signal
supplied from the host computer as shown in FIG. 17.
[0006] Next, as shown in FIGS. 11 to 16, the disc tray 2 consists
of synthetic resin, and a slotted hole bottom aperture 8 is formed
along a tray center P.sub.1 extending from the center of the pit 3
to the rear end 2b side. A pair of right and left guide rails 9 is
formed combinedly in parallel to the tray center P.sub.1 on the
right and left side edges of the disc tray 2. On one end of the
bottom surface of the disc tray 2, J-shaped parallel rack 10 and
guide groove 11 are formed combinedly. The linear portions 10a and
11a of the rack 10 and the guide groove 11 are formed in parallel
to the tray center P.sub.1, and on the end of the front panel 2a
side, the circular portions 10b and 11b are formed.
[0007] Next, a box-shaped chassis formed of synthetic resin is
provided in the internal of the optical disc drive 5, and the pair
of right and left guide rails 9 of the disc tray 2 is guided by a
plurality of tray guides 15 formed combinedly on the inside of the
right and left side plates 14a of the chassis 14 and slid in the
direction of arrows a.sub.1 and a.sub.2. A lift frame 16 formed of
synthetic resin is attached on the bottom 14b of the chassis 14.
Insulator fixing members 17 and 18 are formed combinedly at two
positions on the right and left sides of the rear end 16a side of
the lift frame 16 and at the center position of the front end 16b
of the lift frame 16, namely total three positions, and three
insulators 19 and 20, which are dampers consisting of elastic
material such as rubber, are fixed to these insulator fixing
members 17 and 18.
[0008] The right and left insulators 19 fixed to the rear end 16a
of the lift frame 16 are fixed on the bottom 14b of the chassis 14
with a fixing screw 21 inserted through the center of these
insulators 19, one insulator 20 fixed to the front end 16b of the
lift frame 16 is fixed on the end of the lift driving lever 23 with
a fixing screw 22 inserted through the center of the insulator 20.
The lift driving lever 23 is disposed perpendicularly to the tray
center P.sub.1 and the base of the lift driving lever 23 is
attached on the bottom 14b of the chassis 14 with a pair of
horizontal right and left support pins 24 so that the lift driving
lever 23 is rotatable in the vertical direction namely in the
direction of arrows b.sub.1 and b.sub.2.
[0009] In other words, the lift frame 16 is structured so as to be
driven vertically in the direction of arrows c.sub.1 and c.sub.2
correspondingly to rotational movement in the vertical direction
around the pair of right and left insulators 19 of the rear end 16a
side by the lift driving lever 23. A shallow groove 25 is formed on
the upper surface of the lift frame 16.
[0010] The loading mechanism 27 is mounted on one side of the front
end 16b side of the lift frame 16 on the bottom 14b of the chassis
14. The loading mechanism 27 is provided with a loading motor 28, a
pinion 29 which is rotated in forward-reverse direction by the
loading motor 28, a pinion lever 31 which moves a center shaft 29a
of the pinion 29 swingingly in the direction of arrows d.sub.1 and
d.sub.2 in the horizontal plane around a vertical rocking lever
shaft 30, a cam lever 34 which is driven by the pinion lever 31
with interposition of a pair of partial gears 32 and rotated in the
direction of the arrows e.sub.1 and e.sub.2 in the horizontal plane
around a vertical rocking lever shaft 33, a cam groove 35 formed
circularly around the rocking lever shaft 33 of the cam lever 34
having a level difference in the vertical direction, and a cam
driven pin 36 formed combinedly on one side of the end of the lift
driving lever 23 and engaged movably in the cam groove 35. The
pinion 29 is engaged in the rack 10 of the disc tray 2, and the
center shaft 29a of the pinion 29 is engaged movably in the guide
groove 11.
[0011] The loading mechanism 27 allows the pinion 29 to move along
the J-shaped rack 10 of the disc tray 2 by guiding the center shaft
29a of the pinion 29 along the approximately J-shaped guide groove
11 of the disc tray 2. In detail, when a disc is loaded on the disc
tray 2, the pinion 29 which is driven in forward-reverse direction
by the loading motor 28 drives the linear portion 10a of the rack
10 linearly toward the front panel 2a side from the rear end 2b
side of the disc tray 2 and thereby draws the disc tray 2 in the
optical disc drive 5 horizontal in the direction of the arrow a.
Continuous forward rotation of the pinion 29 by the loading motor
28 allows the pinion 29 to swing in the direction of the arrow d
along the circular portion 10b of the rack 10, when, the pinion
lever 31 rotates the cam lever 34 in the direction of the arrow
e.sub.1 with interposition of the pair of partial gears 32.
[0012] The cam driven pin 36 of the lift driving lever 23 is
elevated upward namely in the direction of the arrow b.sub.1 in the
cam groove 35 of the cam lever 34, thereby the lift frame 16 is
lifted upward in the direction of the arrow c.sub.1 around the pair
of right and left insulators 19 using the lift driving lever 23
with interposition of the insulator 20 from the lower position with
downward inclination as shown in FIG. 15 to the lifted horizontal
upper position as shown in FIG. 16. When the disc tray 2 is
unloaded, the reversed loading operation is operated, in detail,
the cam lever 34 is rotated in the direction of the arrow e.sub.2
while the pinion 29 which is reversibly rotated by the loading
motor 28 is swung in the direction of the arrow d.sub.2 along the
circular portion 10b of the rack 10, the cam driven pin 36 is
driven downward in the direction of the arrow b.sub.2 namely
downward along the cam groove 35, and the lift driving lever 23
drives the lift frame 1b downward in the direction of the arrow
c.sub.2 around the pair of right and left insulators 19 with
interposition of the insulator 20 from the upper position shown in
FIG. 16 to the lower position shown in FIG. 15. In continuous
reverse rotation of the pinion 29 driven by the loading motor 28,
the pinion 29 drives linearly the linear portion 10a of the rack 10
from the front panel 2a side to the rear end 2b of the disc tray 2,
and the disc tray 2 is pressed out in the direction of the arrow
a.sub.2 to the outside of the optical disc drive 5.
[0013] In the shallow groove 25 of the lift frame 16, a spindle
motor 39 is fixed vertically on the mounting member 38 formed at
the position deviated to the front end 16b, a disc table 40
consisting of magnetic metal material such as stainless steel is
fixed on the top end of the motor shaft 39a. A conical trapezoid
centering guide 40a to be engaged into the center hole 1a of the
optical disc 1 is formed combinedly on the upper center of the disc
table. An optical pickup 41 is fixed horizontally on the rear side
from the spindle motor 39 in the shallow groove 25 of the lift
frame 16. The optical pickup 41 has a carriage 44 on which an
objective lens 42 and light reflection type skew sensor 43 are
fixed upward vertically, and an optical block 45 for transmitting a
laser beam to the objective lens is fixed combinedly on the side of
the carriage 44.
[0014] A carriage moving mechanism 47 for moving linearly the
carriage 44 in the direction of the arrows a.sub.1 and a.sub.2
along a pair of right and left guide shafts 46 is fixed on the lift
frame 16, and the carriage moving mechanism 47 is provided with a
pinion 50 which is rotationally driven forward-reversibly by a
carriage driving motor 48 with interposition of a gear train 49 and
a rack 51 fixed on one side of the carriage 44 which rack 51 is
driven linearly by the pinion 50. The spindle motor 39 and the
objective lens 42 are disposed on the tray center P.sub.1, and the
mechanism is structured so that the objective lens is moved in the
direction of the arrows a.sub.1 and a.sub.2 along the tray center
P.sub.1.
[0015] A disc chucking device 61 for chucking an optical disc 1 on
the disc table 40 has a structure described herein under.
[0016] In detail, a pulley support member 62 formed of synthetic
resin is spanned between the top ends of the right and left side
plates 14a of the chassis 14 across the upper space of the disc
tray 2, and a chucking pulley 63 formed of synthetic resin in the
form of disc is held horizontally in a circular hole 64 formed at
the position just above the disc table 40 and at the center
position of the pulley support member 62 movably in the vertical
and horizontal direction within a certain range. A horizontal
pillow block 62a for supporting the horizontal flange 63a formed
combinedly to the periphery of the upper edge of the chucking
pulley 63 thereon is formed combinedly to the periphery of the
circular hole 64 of the pulley support member 62. A disc magnet 65
is embedded at the center of the chucking pulley 63. A top cover 26
consisting of magnetic material such as metal plate is attached
across the pulley support member 62 in the upper space of the
chassis 14.
[0017] Therefore, when a disc is loaded, the chucking pulley 63 is
lowered downward to the space under the pulley support member 62
with the dead load as shown in FIG. 15, the flange 63a of the
chucking pulley 63 is hung in contact with the top of the pulley
pillow block 62a of the pulley support member 62, the optical disc
1 is placed horizontally in the pit 3 of the disc tray 2, and the
optical disc 1 is loaded horizontally in the direction of the arrow
a.sub.1 into the optical disc drive 5 by the disc tray 2. After
loading, as shown in FIG. 1, when the lift frame 16 is lifted in
the direction of the arrow c.sub.1 up to the upper horizontal
position, the disc table 40 is inserted upward from the bottom
aperture 8 of the disc tray 2, and a center ring guide 40a of the
disc table 40 is engaged upward into the center hole 1a of the
optical disc 1. The optical disc 1 is lifted upward in the
direction of the arrow b.sub.1 in the pit 3 of the disc tray 2,
simultaneously the chucking pulley 63 is lifted upward in the
direction of the arrow b.sub.1 together with the optical disc 1,
and the flange 63a is lifted upward to the space above the pulley
pillow block 62a of the pulley support member 62, when, the
chunking pulley 63 chucks the optical disc 1 horizontal on the disc
table 40 from the direction of the arrow b.sub.2 by means of
magnetic attraction of the magnet 65 of the chucking pulley 63 to
the disc table 40.
[0018] The spindle motor 39 rotates the optical disc 1 at high
speed in response to a recording and/or reproducing command signal
supplied from the host computer, the carriage 44 of the optical
pickup 41 is moved in the direction of the arrows a.sub.1 and
a.sub.2 by the carriage moving mechanism 47, and the objective lens
42 is moved in the direction of the arrows a.sub.1 and a.sub.2
along the tray center P.sub.1. A laser beam emitted from the
optical block 45 irradiated onto the bottom face of the optical
disc 1 through the objective lens 42, and the reflective beam is
received by the optical block 45 through the objective lens 42,
thereby the data of the optical disc 1 is recorded and/or
reproduced.
[0019] The pinion 50 which is driven forward-reversibly by the
carriage driving motor 48 with interposition of the gear train 49
drives linearly the rack 51, thereby the carriage moving mechanism
47 moves the carriage 44 in the direction of the arrows a.sub.1 and
a.sub.2 along the pair of right and left guide shafts 46. The lift
frame 16 is lowered in the direction of the arrow c.sub.2 up to the
lower position in response to an unloading command signal supplied
from the host computer as shown in FIG. 15, and the disc table 40
is isolated downward from the optical disc 1 and the chucking
pulley 63, thereafter the optical disc 1 is placed horizontally in
the pit 3 of the disc tray 2, and the optical disc 1 is unloaded
horizontally in the direction of the arrow a.sub.2 to the outside
of the optical disc drive 5 by the disc tray 2. When, the flange
63a of the chucking pulley 63 is brought into a contact with the
pulley pillow block 62a of the pulley support member 62 in the
direction of the arrow b.sub.2 and brought to a stop when the disc
table 40 is lowered in the direction of the arrow c.sub.2, as the
result, the disc table 40 is separated forcedly from the chucking
pulley 63 against magnetic attraction force of the magnet 65.
[0020] In the exemplary chucking device 61 of the previously
applied invention, as shown in FIG. 15, when an optical disc 1 is
loaded or unloaded horizontally in the direction of the arrows
a.sub.1 and a.sub.2 by the disc tray 2, the chucking pulley 63 is
lowered to the space beneath the pulley support member 62 with the
dead load and the flange 63a of the chucking pulley 63 is hung in a
contact with the top of the pulley pillow block 62a of the pulley
support member 62, therefore when an optical disc 1 is loaded or
unloaded, a clearance L should be secured between the bottom
surface of the hung chucking pulley 63 and the top surface of the
optical disc 1 placed horizontally in the pit 3 of the disc tray 2
so that the optical disc 1 does not interfere with the chucking
pulley 63. Therefore, in the example of an optical disc drive of
the previously applied invention, when an optical disc 1 is loaded
or unloaded, in order to secure further a clearance L between the
chucking pulley 63 and the optical disc 1 in the state that the
chucking pulley 63 is lowered from the pulley support member 62 by
the clearance L.sub.2, a large space namely L.sub.1+L.sub.2 is
necessary between the pulley support member 62 and the top surface
of the optical disc 1, as the result, the space causes the large
total thickness T of the optical disc drive 5, and the large
thickness is a problem.
[0021] In the exemplary disc chucking device 61 of the previously
applied invention, the circular hole 64 is formed at the center of
the pulley support member 62 provided horizontally beneath the top
cover 26 across over the chassis 14, and the chucking pulley 63 is
pressed in the circular hole movably in the vertical and horizontal
direction within a certain range, the pulley support member 62
supports the periphery of the chucking pulley 63.
[0022] On the other hand, two types of use of optical disc drive 5
of this sort have been practically employed. One is the horizontal
type in which the apparatus is placed horizontally on a desk for
using and the other is the vertical type in which the apparatus is
placed vertically on a desk for using. In particular, in the case
of the vertical use, when an optical disc 1 is loaded or unloaded
by the disc tray 2, the optical disc 1 moved toward the chucking
pulley 63 from the disc tray 2 (shifted horizontally), and the top
surface of the optical disc 1 (the side facing to the chucking
pulley) can happen to be in contact with the chucking pulley 63 and
the pulley support member 62. If the top surface of the optical
disc 1 contacts with the pulley support member 62 fixed to the
chassis 14, a scratch is caused on the top surface of the optical
disc 1 due to a large contact resistance. Particularly in the case
of an optical disc 1 for DVD (digital video disc) having
information on both top and bottom surfaces, if scratching is
caused on the top information recorded surface due to contact with
the pulley support member 62, then the information can be
impossible to be recorded and/or reproduced, this is a serious
problem.
SUMMARY OF THE INVENTION
[0023] The present invention has been accomplished in order to
solve the above-mentioned problem, it is the object of the present
invention to provide a disc chucking device of an optical disc
drive for eliminating occurrence of scratching due to a contact of
the top surface of an optical disc with a pulley support member
even if the optical disc is lifted part from a disc tray when the
optical disc is loaded or unloaded in the case that the optical
disc drive is in vertical use.
[0024] To achieve the above-mentioned object, the disc chucking
device of an optical disc drive of the present invention is
provided with a first magnetic attraction means for drawing down a
chucking pulley to the disc table side when the disc table is
lifted from the lower position to the upper position after an
optical disc is loaded, and a second magnetic attraction means for
drawing up the chucking pulley from the pulley support member when
the disc table is drawn down from the upper position to the lower
position to unload the optical disc, and further the pulley support
member is structured with a centering guide which supports the
center of the chucking pulley.
[0025] Because the disc chucking device of an optical disc drive of
the present invention having the structured described herein above
is capable of keeping the chucking pulley above the pulley support
member using the second magnetic attraction means in unloading
state of an optical disc, the optical disc will not receive
interference from the chucking pulley when the disc tray loads the
optical disc. Because the chucking pulley can be drawn down
strongly toward the pulley support member by the first magnetic
attraction means when the disc table is lifted from the lower
position to the upper position after loading of the optical disc,
the optical disc can be chucked strongly on the disc table by the
chucking pulley. On the other hand, because the chucking pulley can
be kept above the pulley support member when the optical disc is
unloaded, the clearance to be secured in unloading between the
chucking pulley and the optical disc is reduced to a clearance
L.sub.8 which is sufficiently smaller than L.sub.1+L.sub.2 in the
previously applied invention. Because the pulley support member is
structured with the centering guide which supports the center of
the chucking pulley, the top surface of the optical disc is
prevented from being scratched due to contact with the centering
guide even if the optical disc is lifted far apart from the disc
tray when the optical disc is loaded and unloaded in the case that
the optical disc drive is placed vertically for use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an enlarged partial cross sectional side view in
unloading operation for illustrating the first embodiment of a disc
chucking device of an optical disc drive in accordance with the
present invention.
[0027] FIG. 2 is an enlarged partial cross sectional view in disc
chucking operation of the disc chucking device shown in FIG. 1.
[0028] FIG. 3 is a partially cut away plan view of a chucking
pulley of the disc chucking device shown in FIG. 1.
[0029] FIG. 4 is a cross sectional side view in unloading operation
of the whole optical disc drive shown in FIG. 1.
[0030] FIG. 5 is a cross sectional side view in disc chucking
operation of the whole optical disc drive shown in FIG. 1.
[0031] FIG. 6 is an enlarged partial cross sectional side view in
unloading operation for illustrating the second embodiment of a
disc chucking device of an optical disc drive in accordance with
the present invention.
[0032] FIG. 7 is an enlarged partial cross sectional view in disc
chucking operation of the disc chucking device shown in FIG. 6.
[0033] FIG. 8 is a cross sectional side view for illustrating the
third embodiment of a disc chucking device of an optical disc drive
in accordance with the present invention.
[0034] FIG. 9A and FIG. 9B are cross sectional views for
illustrating the fourth embodiment of a disc chucking device of an
optical disc drive in accordance with the present invention.
[0035] FIG. 10A and FIG. 10B are cross sectional views for
illustrating the fifth embodiment of a disc chucking device of an
optical disc drive in accordance with the present invention.
[0036] FIG. 11 is a partially cut away plan view for illustrating
an optical disc drive in accordance with the previously applied
invention.
[0037] FIG. 12 is an exploded perspective view for illustrating a
chucking pulley, clamp support plate, disc tray, and disc table of
the optical disc drive in accordance with the previously applied
invention.
[0038] FIG. 13 is an exploded perspective view for illustrating a
head moving mechanism and a lift frame of the optical disc drive in
accordance with the previously applied invention.
[0039] FIG. 14 is an exploded perspective view for illustrating a
loading mechanism and a chassis of the optical disc drive in
accordance with the previously applied invention.
[0040] FIG. 15 is a cross sectional side view in unloading
operation of the optical disc drive in accordance with the
previously applied invention.
[0041] FIG. 16 is a cross sectional side view in disc chucking
operation of the optical disc drive in accordance with the
previously applied invention.
[0042] FIG. 17 is a perspective view in unloading operation of the
whole optical disc drive in accordance with the previously applied
invention.
[0043] FIG. 18 is a perspective view in loading operation of the
whole optical disc drive in accordance with the previously applied
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Embodiments of a disc chucking device of an optical disc
drive in accordance with the present invention will be described in
detail hereinafter with reference to FIGS. 1 to 7. The same
components as shown in FIGS. 11 to 18 are given the same characters
as shown in FIGS. 11 to 18, and duplicated description is
omitted.
First Embodiment of a Disc Chucking Device
[0045] A disc chucking device of the first-embodiment of the
present invention will be described with reference to FIGS. 1 to
5.
[0046] In detail, the disc chucking device 161 is provided with the
first magnetic attraction means 67 for drawing down a chucking
pulley 163 in the direction of the arrow b.sub.2 with a strong
magnetic attraction force in the direction of the arrow b.sub.2 to
the space beneath the pulley support member 162, and the second
magnetic attraction means 72 for drawing up the chucking pulley 163
with a weak magnetic attraction force in the direction of the arrow
b.sub.1 to the space above the pulley support member 162.
[0047] The first magnetic attraction means 67 comprises the first
magnet 68 and the first yoke 69 formed in the ring shape having the
same diameter, the first yoke 69 is placed horizontally on the top
surface of the first magnet 68 in close contact, and the first
magnet 68 and the first yoke 169 which are in close contact are
embedded horizontally and co-axially on the periphery of the center
P.sub.2 at the center portion 163b of the chucking pulley 163. The
second magnetic attraction means 71 is composed of the disc-shaped
second magnet 72 having a smaller diameter than that of the first
magnet 68, the second magnet 72 is embedded horizontally at the
center P.sub.2 of the central portion 163b of the chucking pulley
163 at the level higher than the first yoke 69.
[0048] The magnetic attraction, namely the magnetic force, of the
first magnet 68 is strengthened by magnetizing the first magnet 68
to have S namely the S pole and N namely the N pole on both ends of
the first magnet 68 in the diametrical direction f. On the other
hand, the magnetic attraction force of the second magnet 72 is
structured so as to be weaker than the magnetic attraction force of
the first magnet 68. A magnetic attraction target of the first
magnetic attraction means 67 consists of metal magnetic material
such as stainless steel, and this target is a disc table 40
disposed beneath the chucking pulley 163. A magnetic attraction
target of the second magnetic attraction means 71 consists of
magnetic material such as metal plate, and the top cover 26 fixed
horizontally above the chucking pulley 163 functions also as the
magnetic attraction target. A conical trapezoid center pit 163c
having a larger diameter than that of the center ring guide 40a of
the disc table 40 is formed on the bottom side of the center
portion 63b of the chucking pulley 163, a center pin 163d is formed
combinedly downward vertically at the center P.sub.2 of the center
pit 163c, and a center hole 40b is formed at the center P.sub.2 of
the center ring guide 40a of the disc table 40.
[0049] The first embodiment of the disc chucking device 161 of the
present invention is structured as described herein above, as shown
in FIG. 1 and FIG. 4, in unloading operation of the optical disc 1,
a magnetic attraction force F.sub.2 which is directed upward namely
in the direction of the arrow b.sub.1 generated by a magnetic flux
.phi..sub.2 having a low magnetic flux density is generated between
the second magnet 72 of the second magnetic attraction means 71 and
the top cover 26 consisting of magnetic material, and the weak
magnetic attraction force F.sub.2 draws up the chucking pulley 163
in the direction of the arrow b.sub.1 to the space above the
support member 162. When, the chucking pulley 163 has been lifted
in the direction of the arrow b.sub.1 by a distance of clearance
L.sub.3 from the pulley support member 162, and a clearance L.sub.4
is formed between the bottom surface of the chucking pulley 163 and
the top surface of the optical disc 1 placed horizontally on the
disc tray 2.
[0050] Therefore, as shown in FIG. 1 and FIG. 4, in loading
operation of the optical disc 1, the optical disc 1 is loaded
horizontally from the direction of the arrow a.sub.1 in the optical
disc drive 5 by the disc tray 2, when, the optical disc 1 is loaded
safely without any interference of the chucking pulley 163 due to
the existence of the clearance L.sub.4. After loading of the
optical disc 1, as shown in FIG. 2 and FIG. 5, when the spindle
motor 39 and the disc table 40 are lifted together in the direction
of the arrow c.sub.1 from the lower position to the upper position
and come up to the horizontal position, the center ring guide 40a
of the disc table 40 is engaged into the center hole 1a of the
optical disc 1 supportingly, the optical disc 1 is moved apart by
the clearance L.sub.5 in the direction of the arrow b.sub.1 in the
pit 3 of the disc tray 2 by the disc table 40, the center hole 40b
of the center ring guide 40a is engaged to the center pin 163d of
the chucking pulley 163 from the direction of the arrow
b.sub.1.
[0051] When, the center ring guide 40a of the disc table 40
consisting of magnetic material takes an access to the first magnet
68 of the first magnetic attraction means 67, and a strong magnetic
attraction force F.sub.1 generated by magnetic flux .phi..sub.1
between the first magnet 68, first yoke 67, and the centering guide
40a is generated downward in the direction of the arrow b.sub.2.
The magnetic attraction force F.sub.1 of the first magnetic
attraction means 67 is a strong magnetic attraction force F.sub.1
which is stronger than the second magnetic attraction means 71,
therefore, the chucking pulley 163 is drawn down by the clearance
L.sub.6 in the direction of the arrow b.sub.2 to the space beneath
the pulley support member 162, thereby, the optical disc 1 is
chucked horizontally on the disc table 40 strongly and stably by
the chucking pulley 163. In this chucking state of the optical disc
1, the flange 163a of the chucking pulley 163 is distant apart by
the clearance L.sub.7 above the pulley pillow block 162a of the
pulley support member 162.
[0052] Because the optical disc 1 is chucked strongly on the disc
table 40 as described herein above, even when the optical disc 1 is
rotated at high speed by the disc table 40 of the spindle motor 39,
the optical disc 1 does not slip and is rotated stably at high
speed, the information is high density recorded and/or reproduced
precisely at high speed rotation in the optical disc 1 such as
DVD-ROM.
[0053] When the optical disc 1 is unloaded after recording and/or
reproducing, as shown in FIG. 1 and FIG. 4, the disc table 40 is
lowered together with the spindle motor 39 from the upper position
to the lower position in the direction of the arrow c.sub.2 by the
lift frame 16, and the disc table 40 is moved apart from the
optical disc 1 in the direction of the arrow c.sub.2. When, the
strong magnetic attraction force F.sub.1 generated in the direction
of the arrow b.sub.2 between the chucking pulley 163 and the disc
table 40 by the first magnetic attraction means 67 is shut down,
the chucking pulley 63 is lifted again in the direction of the
arrow b.sub.1 to the position distant apart from the pulley support
member 162 by the distance of the clearance L.sub.3 by means of the
weak magnetic attraction force F.sub.2 generated in the direction
of the arrow b.sub.1 by means of the second magnetic attraction
means 71, and the clearance L.sub.4 is formed again between the
bottom surface of the chucking pulley 163 and the top surface of
the optical disc 1 on the disc tray 2. Therefore, when the optical
disc 1 is unloaded horizontally in the direction of the arrow
a.sub.2 to the outside of the optical disc drive 5 by the disc tray
2, thereafter, the optical disc 1 is unloaded safely without any
interference of the chucking pulley 163.
[0054] As described herein above, according to the disc chucking
device 161 of the present invention, as shown in FIG. 1 and FIG. 4
for description of unloading operation of the optical disc 1,
because the clearance L.sub.4 is formed between the bottom surface
of the chucking pulley 163 and the top surface of the optical disc
1 in the state that the chucking pulley 163 is kept drawn up by a
distance of the clearance L.sub.3 in the direction of the arrow
b.sub.1 to the position from the position of the pulley support
member 62 by the weak magnetic attraction force F.sub.2 directed to
the direction of the arrow b.sub.1 by the second magnetic
attraction means 71, and as the result as shown in FIG. 1, the
clearance L.sub.8 between the top surface of the optical disc 1
which is placed horizontally in the pit 3 of the disc tray 2 for
loading and/or unloading and the bottom surface of the chucking
pulley 163 can be reduced in comparison with the clearance
L.sub.1+L.sub.2 in the previously applied invention by the
clearance L.sub.3, which is the drawn up distance of the chucking
pulley 163 from the pulley support member 162. Because the relation
between clearances is represented by L.sub.8<L.sub.1+L.sub.2 in
those structures as described herein above, the thickness T.sub.2
of the whole optical disc drive can be reduced by the clearance
L.sub.3 in comparison with the thickness T.sub.1 in the previously
applied invention. In other words, T.sub.2=T.sub.1-L.sub.3. Use of
the top cover 26 also as the magnetic member of the second magnetic
attraction means 71 leads to the reduced cost due to reduction of
the number of component parts and fabrication man-hour, and leads
to the realization of the thinned optical apparatus as a whole.
[0055] According to the disc chucking device 161 of the present
invention, as shown in FIG. 2 and FIG. 5, after loading of the
optical disc 1, the first magnetic attraction means 67 which
magnetically attracts the chucking pulley 163 in the direction of
the arrow b.sub.2 to the disc table 40 side comprises the first
ring magnet 68 and the first ring yoke 69 which is in close contact
horizontally with the top surface of the first magnet 68, and the
first magnet 68 is magnetized to have S namely S-pole and N namely
N-pole on both ends of the first magnet 68 in the diametrical
direction f, thereby, the strong magnetic attraction force is
generated consistently with least leakage magnetic flux between the
first magnet 68 and the centering guide 40a of the disc table 40.
Therefore, the magnetic attraction force F.sub.1 of the first
magnetic attraction means 67 is served as a strong magnetic
attraction force which is stronger consistently than the magnetic
attraction force F.sub.2 of the second magnetic attraction means
71, the strong magnetic attraction force F.sub.1 draws down
strongly the chucking pulley 163 in the direction of the arrow
b.sub.2, and as the result, the optical disc 1 is chucked strongly
and stably on the disc table 40 horizontally.
[0056] The first and second magnets 68 and 72 which are independent
each other are provided to the first and second magnetic attraction
means 67 and 71 respectively, and the magnetic flux of the first
and second magnets 58 and 72 are adjusted, thereby, the magnetic
attraction forces F.sub.1 and F.sub.2 are adjusted simply and
without any restriction, therefore, the chucking operation after
loading of the optical disc 1 and drawing up operation of the
chucking pulley 163 for unloading of the optical disc 1 are
performed consistently.
Second Embodiment of Disc Chucking Device
[0057] Next, the second embodiment of the disc chucking device of
the present invention will be described with reference to FIG. 6
and FIG. 7.
[0058] In detail, in the disc chucking device 261 of the present
invention, the centering pin 74 which extends downward from the top
cover 26 forms the centering member, and the centering member forms
the pulley support member. The top end of the centering pin 74 is
fixed to the top cover 26, and the bottom end side of the centering
pin 74 which extends downward from the top cover 26 is inserted
into the center hole 75 formed at the center of the top surface of
the chucking pulley 263. A large diameter hole 76 is formed under
the center hole 75 of the chucking pulley 263, and a slip down
preventing flange 77 is formed on the periphery of the bottom end
of the centering pin 74. The diameter of the centering pin 74
relative to the diameter of the center hole 75, the diameter of the
large hole 76 relative to the diameter of the flange 77, and the
vertical depth of the large diameter hole 76 relative to the
vertical thickness of the flange 77 are made large sized, thereby,
the chucking pulley 263 is supported by the centering pin 74
movable as desired in the vertical and horizontal direction in a
certain range. The second magnet 72 having weak magnetic attraction
is embedded co-axially on the periphery of the center hole 75 on
the top surface of the chucking pulley 263.
[0059] As described herein above, in the second embodiment of the
disc chucking device of the present invention, the centering pin 74
which is a component of the pulley support member supports the
center of the chucking pulley 263, therefore, in the case that the
optical disc drive 5 is placed vertically on a desk for use, when
the optical disc 1 is loaded and/or unloaded, the optical disc 1 is
lifted far apart upward (to chucking pulley side) from the disc
tray 2, as the result, possible contact of the top surface 1b of
the optical disc 1 with the chucking pulley 263 will not cause
contact of the top surface 1b of the optical disc 1 with the
centering pin 74 which is fixed to the top cover 26, and thus does
not cause any scratching on the top surface. Possible contact of
the top surface of the optical disc 1 on the chucking pulley 263
seldom causes scratching on the top surface of the optical disc 1
because the chucking pulley 263 is formed of synthetic resin and
the chucking pulley can move in the vertical and horizontal
direction upon contact.
[0060] According to the second embodiment of the disc chucking
device of the present invention, even in the case that an optical
disc 1 such as DVD in which the information is recorded on both top
and bottom sides is used, when the optical disc 1 is loaded and/or
unloaded the top surface 1b of the optical disc 1 will not be
scratched, not only on the bottom surface 1c but also on the top
surface 1b of the optical disc 1, the information is recorded
and/or reproduced highly precisely, and thus the optical disc drive
5 excellent in performance and reliability is realized.
[0061] Further, when the optical disc 1 is chucked as shown in FIG.
7, because of centering effect of the chucking pulley 63 due to the
centering pin 74, the center pin 263d of the chucking pulley 263 is
engaged into the center hole 40a of the disc table 40 smoothly and
consistently, and as the result centering of the chucking pulley 63
to the disc table 40 is ensured. Therefore, the eccentric load due
to deviation from the axis of the chucking pulley will not be
generated, the optical disc 1 is rotated stably, and the
information is recorded and/or reproduced highly precisely.
Third Embodiment of Disc Chucking Device
[0062] Next, the third embodiment of the disc chucking device of
the present invention will be described with reference to FIG.
8.
[0063] In detail, in the disc chucking device 361 of the present
invention, the chucking pulley 363 is formed of synthetic resin,
and the cylindrical center portion 363b having embedded first and
second magnets 68 and 72 and first yoke 69, a disc-shaped disc
crimp plate 363e formed horizontally on the periphery of the bottom
end of the center portion 363b, a cylindrical peripheral wall
portion 363f which rises upward from the periphery of the disc
crimp plate 363e, and a disc-shaped flange having a small diameter
provided inside the peripheral wall portion 363f formed
horizontally on the periphery of the top end of the center portion
363b are formed combinedly with the chucking pulley 363.
[0064] The pulley support member 362 made of plate metal having a
small diameter is attached on the bottom surface of the top cover
26 made of plate metal, the pulley pillow block 362a formed
horizontally inside the bottom end of the pulley support member 362
is inserted in the inside of the peripheral wall portion 363f of
the chucking pulley 363 to dispose it beneath the flange 363a, the
center portion 363b of the chucking pulley 363a is engaged with
allowance in the vertical and horizontal direction in the circular
hole 64 formed inside the pulley pillow block 362a, and the pulley
support member 62 supports the chucking pulley 63 movable in the
vertical and horizontal direction within a certain range.
[0065] According to the disc chucking device 361 of the present
invention, because the chucking pulley 362 is supported by the
pulley support member 62 inserted into the inside of the peripheral
wall portion 363f, in the case that the optical disc drive 5 is
placed vertically on a desk for using, when the optical disc 1 is
loaded and/or unloaded, the optical disc 1 is lifted far apart to
the pulley support member 362 side in the pit 3 of the disc tray 2,
and even if the optical disc 1 happens to contact on the pulley
support member 362 made of plate metal, the optical disc 1 is
prevented from being in contact directly with the pulley support
member 362 by the disc crimp plate 363e and the peripheral wall
portion 363f which are formed combinedly with the checking pulley
363 made of synthetic resin and cover the under side and periphery
of the pulley support member 362.
[0066] The optical disc 1 consists of synthetic resin, and if the
pulley support member 362 is made of plate metal, and the optical
disc 1 happens to contact directly with the pulley support member
362 fixed at the prescribed position, then the optical disc 1 is
scratched strongly with the hard pulley support member 362 made of
plate metal and the scratching causes easily a serious damage
(large scratch is easily caused) on the optical disc 1.
[0067] However on the other hand, in the disc chucking device of
the present invention, because the under side and periphery of the
pulley support member 362 made of plate metal is covered by the
disc crimp plate 363e and the peripheral wall portion 363f of the
chucking pulley 363, direct contact of the optical disc 1 with the
pulley support member 362 and resultant serious damage on the
optical disc 1 is prevented, and high safety is secured. Because
the pulley support member 362 has a small diameter and it is
inserted in the inside of the peripheral wall portion 363f of the
chucking pulley 363, as shown in FIG. 1 and FIG. 2, the space
factor of the peripheral portion of the chucking pulley 363 in the
inside of the optical disc drive 5 is improved, and the improved
space factor is favorable for realizing a small-sized light-weight
optical disc drive 5.
Fourth Embodiment of Disc Chucking Device
[0068] The fourth embodiment of the disc chucking device of the
present invention will be described with reference to FIG. 9.
[0069] In the embodiment shown in FIG. 9, the top cover 2
consisting of magnetic material is formed combinedly with the clamp
support member 462 formed in the form of cylindrical recess, the
cylindrical center shaft 101 formed combinedly on the upper center
of the disc clamp 463 is inserted through the circular hole 64
formed at the center of the clamp support member from the bottom to
the top, and the stopper ring 164 attached horizontally on the
periphery of the top end of the center shaft 101 is disposed above
the clamp support member 462. The weak magnet 472 embedded in the
form of ring on the top side of the disc clamp 463 and the clamp
support member 462 which is a component of the yoke constitute a
means for pressing upward the disc clamp 463 to the upper position,
and the strong magnet 468 is embedded in the form of ring on the
bottom side of the disc clamp 463. According to this embodiment,
the weak magnetic attraction force exerted between the weak magnet
472 and the clamp support 462 lifts the disc clamp 463 to the
position where the disc clamp 463 is brought into a contact with
the bottom end of the clamp support member 462 when the optical
disc 1 is unloaded.
[0070] The ring recess 168 is formed at the position which is
facing to the magnet 472 on the bottom surface of the clamp support
member 462 so that the magnet 472 is attracted to the clamp support
member 462 with interposition of a space.
[0071] When the optical disc 1 is chucked as shown in FIG. 9(B),
the strong magnetic attraction force exerted between the strong
magnet 468 and the center ring guide 40a of the disc table 40
attracts the disc clamp 463 downward, and the disc clamp 463 chucks
strongly the optical disc 1 on the disc table 40.
[0072] Also in the case of the disc clamp of this type, the
projection guide 114 is provided to the above-mentioned cover 115,
the recess guide groove 121 is provided above the cramp support
member 462, and positioning is performed by the guide 114 and the
guide groove 121 similarly.
Fifth Embodiment of Disc Chucking Device
[0073] Next, the fifth embodiment of the disc clamp used in the
present invention is shown in FIGS. 10A and 10B. In this
embodiment, a ring-shaped gap 167 is provided above the ring-shaped
magnet 568 embedded at the center of the disc clamp 563, thereby,
using one magnet 568, the disc clamp 563 is magnetically attracted
upward in unloading operation, on the other hand, the disc clamp
563 is magnetically attracted downward in chucking operation as
shown in FIG. 10(B) and the disc clamp 563 chucks the optical disc
1 on the disc table 40, the same components as described in the
embodiment shown in FIG. 9 are given the same characters, and the
embodiment shown in FIGS. 10A and 10B exhibits the same operation
and effects.
[0074] Embodiments of the present invention are described
hereinbefore, however, the present invention is by no means limited
to the above-mentioned embodiments, various modifications may be
applied based on the technical spirit of the present invention. For
example, the disc clamp may be pressed up using controllable
electromagnetic force when the optical disc is unloaded.
* * * * *