U.S. patent application number 09/238591 was filed with the patent office on 2001-08-30 for disc transfer mechanism.
This patent application is currently assigned to MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.. Invention is credited to KOSHINO, KATSUHIKO, NAKAMURA, TAKESHI.
Application Number | 20010017835 09/238591 |
Document ID | / |
Family ID | 11948554 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010017835 |
Kind Code |
A1 |
KOSHINO, KATSUHIKO ; et
al. |
August 30, 2001 |
DISC TRANSFER MECHANISM
Abstract
It is an object of he present invention to provide a disc
transfer mechanism that allows a disc to be reliably installed and
removed. As shown in FIG. 3, this invention includes a damper means
provided between a base (2) and a tray (1) to reduce the moving
speed of the tray (1) using the urging force of a spring (3). The
damper means comprises a first damper (45) interposed between the
tray (1) and the base (2) to reduce the tray moving speed during
all the tray moving steps and a second damper that operates,
separately from the first damper (45), during the step of
delivering a disc set on a turntable to the tray.
Inventors: |
KOSHINO, KATSUHIKO;
(KADOMA-SHI, JP) ; NAKAMURA, TAKESHI; (KADOMA-SHI,
JP) |
Correspondence
Address: |
CHARLES A WENDEL
PARKHURST & WENDEL
1421 PRINCE STREET
SUITE 210
ALEXANDRIA
VA
223142805
|
Assignee: |
MATSUSHITA ELECTRIC INDUSTRIAL CO.,
LTD.
|
Family ID: |
11948554 |
Appl. No.: |
09/238591 |
Filed: |
January 28, 1999 |
Current U.S.
Class: |
720/611 ;
G9B/33.035 |
Current CPC
Class: |
G11B 17/056 20130101;
G11B 33/14 20130101 |
Class at
Publication: |
369/77.1 |
International
Class: |
G11B 017/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 1998 |
JP |
10-17606 |
Claims
What is claimed is:
1. A disc transfer mechanism for setting on a turntable a disc
placed on a tray in response to the drawing-out and -back of said
tray, comprising: a spring provided between said tray and a base
that supports said tray in the direction in which said tray is
drawn out and back, in order to urge the tray in the direction in
which it is pushed out from the base; and a damper means provided
between the base and said tray, and adapted to reduce the speed of
the tray movement effected by the urging force of said spring; said
damper means comprising: a first damper interposed between said
tray and the base that supports the tray in the direction in which
the tray is drawn out and back, in order to reduce the tray moving
speed during all the steps in which the tray is moved by the urging
force of the spring; and a second damper that operates during the
step of delivering the disc set on the turntable to the tray.
2. A disc transfer mechanism comprising: an elevating mechanism for
elevating and lowering a turntable in response to the drawing-out
and -back of a tray to allow the turntable to be installed on and
removed from a disc placed on the tray; a disc receiving member
provided at the front end of said tray and adapted to freely slide
in the direction in which the tray is drawn out and back, and
having a positioning protrusion that can abut on the outer
circumference of the disc being loaded while said disc receiving
member is urged toward the internal end of the tray; said disc
receiving member being arranged to abut on the fixed side when the
central hole of the disc placed on the tray reaches a position over
said turntable and to move toward the front end of the tray
relative to the movement of the tray toward the internal end
thereof; a spring provided between said tray and the base that
supports said tray in the direction in which it is drawn out and
back, in order to urge said tray in the direction in which it is
pushed out from the base; and a damper means provided between the
base and said tray in order to reduce the speed of the tray
movement effected by the urging force of the spring; said damper
means comprising: a first damper interposed between said tray and
the base that supports the tray in the direction in which the tray
is drawn out and back, in order to reduce the tray moving speed
during all the steps in which said tray is moved by the urging
force of the spring; and a second damper interposed between the
base that supports the tray in the direction in which the tray is
drawn out and back and an elevating mechanism for elevating and
lowering the turntable in response to the drawing-out and -back of
the tray, in order to operate during the step of delivering the
disc set on the turntable to the tray.
3. A disc transfer mechanism comprising: an elevating mechanism for
elevating and lowering a turntable in response to the drawing-out
and -back of a tray to allow the turntable to be installed on and
removed from a disc placed on the tray; a disc receiving member
provided at the front end of said tray and adapted to freely slide
in the direction in which the tray is drawn out and back, and
having a positioning protrusion that can abut on the outer
circumference of the disc being loaded while said disc receiving
member is urged toward the internal end of the tray; said disc
receiving member being arranged to abut on the fixed side when the
central hole of the disc placed on the tray reaches a position over
said turntable, and to move toward the front end of the tray
relative to the movement of the tray toward its internal end; a
spring provided between said tray and the base that supports said
tray in the direction in which it is drawn out and back, in order
to urge said tray in the direction in which it is pushed out from
the base; and a damper means provided between the base and said
tray in order to reduce the speed of the tray movement effected by
the urging force of the spring; said damper means comprising: a
first damper attached to the base that supports the tray in the
direction in which the tray is drawn out and back, and engaging
with a first rack formed to extend from the front end to internal
end of said tray; and a second damper attached to said base and
engaging with a second rack formed only at the front end of the
tray.
4. A disc transfer mechanism according to any one of claims 1 to 3,
wherein the spring for urging the tray in the direction in which it
is pushed out from the base is provided on the top surface of the
base in a tray moving path, such that the spring extends along a
path bent around rollers provided on the base.
5. A disc transfer mechanism for setting on a turntable a disc
placed on a tray in response to the drawing-out and -back of said
tray, comprising: a spring provided between said tray and a base
that supports said tray in the direction in which said tray is
drawn out and back, in order to urge the tray in the direction in
which it is pushed out from the base; said spring being provided on
the top surface of the base in a tray moving path, such that the
spring extends along a path bent around rollers provided on the
base.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a disc transfer mechanism
having a tray used to install and eject a disc.
BACKGROUND OF THE INVENTION
[0002] The disc transfer mechanism described in Japanese Patent
Application Laid-Open No. 63-191361 has a tray that moves in the
horizontal direction between a disc installation and removal
position at which a disc has been drawn out from the apparatus and
a position at which the disc has been drawn into the apparatus
body; and a disc holder provided on the tray and on which the disc
is placed.
[0003] The apparatus body additionally includes a turntable that
rotationally drives the disc, a damper that sandwiches the disc
between itself and the turntable, an optical pickup, and a traverse
mechanism for moving the optical pickup in the radial direction of
the disc.
[0004] The tray and the disc holder have such a relation as to be
configured so that the tray moves in the horizontal direction to
lead the central hole of the disc placed on the disc holder to a
position immediately before the turntable, and so that when the
tray further moves in the same direction toward the internal end,
the disc holder starts descending toward the turntable and loads
the disc on the turntable provided on a fixed side so that the disc
is sandwiched by the turntable and the clamper.
[0005] In addition, Japanese Patent Application Laid-Open No.
63-191361 uses the urging force of a spring to push out the tray in
order to eject the disc and includes a damper to prevent the tray
from being rapidly pushed out by this urging force.
[0006] Despite the reduced speed at which the tray is pushed out,
such a disc transfer mechanism is likely to fail to deliver the
disc removed from the turntable 9 to a normal position of the tray,
so the installation and removal of the disc are not so
reliable.
DISCLOSURE OF THE INVENTION
[0007] It is an object of the present invention to provide a disc
transfer mechanism in which the configuration of the tray to be
moved is simple and in which the installation and removal of the
disc are reliable even if an urging force of a spring is used to
push back the tray.
[0008] A disc transfer mechanism according to this invention is
characterized in that a damper means for reducing the tray moving
speed comprises a first damper interposed between a tray and a base
that supports the tray in the direction in which the tray is drawn
out and back, in order to reduce the tray moving speed during all
the steps in which the tray is moved by the urging force of a
spring; and a second damper that operates during the step of
delivering the disc set on the turntable to the tray.
[0009] This configuration can provide a disc transfer mechanism
that can install and remove the disc reliably.
[0010] According to the disc transfer mechanism as set forth in
claim 1 of this invention, there is provided a disc transfer
mechanism for setting on a turntable a disc placed on a tray in
response to the drawing-out and -back of the tray, comprising: a
spring provided between the tray and a base that supports the tray
in the direction in which the tray is drawn out and back, in order
to urge the tray in the direction in which it is pushed out from
the base; and a damper means provided between the base and the tray
for reducing the speed of the tray movement effected by the urging
force of the spring; the damper means comprising a first damper
interposed between the tray and the base to reduce the tray moving
speed during all the steps in which the tray is moved by the urging
force of the spring, and a second damper that operates during the
step of delivering the disc set on the turntable to the tray. Thus,
when a disc ejecting operation is started, the tray and an
elevating mechanism can be operated slowly and stably.
[0011] The disc transfer mechanism set forth in claim 2 of this
invention comprises: an elevating mechanism for elevating and
lowering a turntable in response to the drawing-out and -back of a
tray to allow the turntable to be installed on and removed from a
disc placed on the tray; a disc receiving member provided at the
front end of the tray and adapted to freely slide in the direction
in which the tray is drawn out and back, and having a positioning
protrusion that can abut on the outer circumference of the disc
being loaded while said disc receiving member is urged toward the
internal end of the tray; the disc receiving member being arranged
to abut on the fixed side when the central hole of the disc placed
on the tray reaches a position over said turntable and to move
toward the front end of the tray relative to the movement of the
tray toward its internal end; a spring provided between the tray
and the base that supports the tray in the direction in which the
tray is drawn out and back, in order to urge the tray in the
direction in which it is pushed out from the base; and a damper
means provided between the base and the tray in order to reduce the
speed of the tray movement effected by the urging force of the
spring; the damper means comprising a first damper interposed
between the tray and the base to reduce the tray moving speed
during all the steps in which the tray is moved by the urging force
of the spring, and a second damper provided between the base that
supports the tray in the direction in which the tray is drawn out
and back and an elevating mechanism for elevating and lowering the
turntable in response to the drawing-out and -back of the tray, in
order to operate during the step of delivering the disc set on the
turntable to the tray. Thus, by simply providing in the tray a disc
receiving member of a simple configuration, the disc can be
installed and removed stably as in conventional mechanisms having a
tray of a complicated configuration. Moreover, the spring for
urging the tray in the direction in which it is pushed out from the
base is provided between the tray and the base that supports the
tray in the direction in which it is drawn out and back and since
the damper means for reducing the speed of the tray movement
effected by urging force of the spring is provided between the base
and the tray. Consequently, despite the ejection of the disc using
the urging force of the spring, the disc can be reliably delivered
to the tray from the turntable in such a way as to maintain the
correct posture.
[0012] The disc transfer mechanism set forth in claim 3 comprises:
an elevating mechanism for elevating and lowering a turntable in
response to the drawing-out and -back of a tray to allow the
turntable to be installed on and removed from a disc placed on the
tray; a disc receiving member provided at the front end of the tray
and adapted to freely slide in the direction in which the tray is
drawn out and back, and having a positioning protrusion that can
abut on the outer circumference of the disc being loaded while said
disc receiving member is urged toward the internal end of the tray;
said disc receiving member being arranged to abut on the fixed side
when the central hole of the disc placed on the tray reaches a
position over said turntable, and to move toward the front end of
the tray relative to the movement of the tray toward its internal
end; a spring provided between said tray and the base that supports
said tray in the direction in which it is drawn out and back, in
order to urge said tray in the direction in which it is pushed out
from the base; and a damper means provided between the base and
said tray in order to reduce the speed of the tray movement
effected by the urging force of the spring; said damper means
comprising: a first damper attached to the base that supports the
tray in the direction in which the tray is drawn out and back, and
engaging with a first rack formed to extend from the front end to
internal end of said tray; and a second damper attached to said
base and engaging with a second rack formed only at the front end
of the tray. Thus, when the ejection of the disc is started, the
tray and the elevating mechanism can be operated slowly and
stably.
[0013] According to the disc transfer mechanism set forth in claims
4 and 5, the spring for urging the tray in the direction in which
it is pushed out from the base is provided on the top surface of
the base and in a tray moving path, such that the spring extends
along a path bent around rollers provided on the base. As a result,
this mechanism can be compactified compared to conventional
apparatuses wherein the spring is provided outside the tray moving
path. In addition, this mechanism allows the use of a longer spring
than in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view showing a state in which a tray
has been drawn out from a transfer mechanism according to an
embodiment of this invention;
[0015] FIG. 2 is a perspective view showing a state in which the
tray has been pushed back according to the same embodiment;
[0016] FIG. 3 is an exploded perspective view showing a state in
which the tray has been removed from the base according to the same
embodiment;
[0017] FIG. 4 is a perspective view showing the disc transfer
mechanism according to the same embodiment as seen from the rear
(the internal end) side;
[0018] FIG. 5 is an exploded perspective view of the entire disc
transfer mechanism according to the same embodiment;
[0019] FIG. 6 is a plan view of the neighborhood of a coupling
lever during a loading process according to the same
embodiment;
[0020] FIG. 7 is a plan view of the bottom surface of the front end
portion of the tray according to the same embodiment;
[0021] FIG. 8 is a sectional view showing the relationship between
the tray, a disc and a turntable observed while a large-diameter
disc is being loaded according to the same embodiment;
[0022] FIG. 9 is a plan view of the tray according to the same
embodiment;
[0023] FIG. 10 is a sectional view showing the relationship between
the tray, the disc and the turntable observed while a
small-diameter disc is being loaded according to the same
embodiment;
[0024] FIG. 11 is an exploded perspective view of the integral part
of another embodiment; and
[0025] FIG. 12 is an exploded perspective view of the integral part
of yet another embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0026] Embodiments of this invention will be described below with
reference to FIGS. 1 to 12.
[0027] FIG. 1 shows a disc transfer mechanism in a disc
installation and removal position in which a tray 1 has been drawn
out from a base 2. FIG. 2 shows a state in which the tray 1 has
moved in the horizontal direction to a loading completion
position.
[0028] In the disc transfer mechanism according to this embodiment,
instead of using a motor, a tension spring 3 is passed between a
spring engaging locking portion 4 of the base 2 and a spring
engaging locking portion 5 formed on the bottom surface of the
internal end portion of the tray 1 in order to drive the tray 1, as
shown in FIG. 3. The middle portion of the tension spring 3 passes
through grooved rollers 6 and 7 pivotably supported on the base
2.
[0029] A damper gear 45 used as a first damper is attached to a
shaft 44 formed at the front end of the base 2, with the teeth of
the damper gear 45 meshing with a rack 46 formed in the bottom
surface of the tray 1 in such a way as to extend from its front end
to internal end. A highly viscous grease is applied to the shaft
44.
[0030] Reference numeral 8 denotes a playing apparatus that is a
unit composed of a turntable 9 rotationally driving a disc, an
optical pickup 10, and a traverse mechanism (not shown) for moving
the optical pickup in the radial direction of the disc.
[0031] As shown in FIGS. 4 and 5, sliders 11a and 11b are provided
on the top surface of the base 2 at positions covered by the tray 1
so as to slide in the direction in which the tray 1 is drawn out
and back. The internal ends of the sliders 11a and 11b are coupled
together via a coupling lever 13 having its center pivotably
supported on a shaft 12 of the base 2. A spring 15 installed
between the coupling lever 13 and a protrusion 14 from the base 2
urges the coupling lever 13 in such a way as to push the slider 11a
toward the front end of the base 2 (the direction shown by arrow A)
and draw the slider 11b toward the internal end of the base 2 (the
direction shown by arrow B).
[0032] A cam groove 16a is formed in a part of the inside of the
slider 11a and close to its front end. Cam grooves 16b and 16c are
formed inside the slider 11b and close to its front and internal
ends, respectively. The cam grooves 16a and 16b extend in opposite
directions, while the cam grooves 16b and 16c extend in the same
direction.
[0033] Horizontal shafts 17a, 17b, and 17c are formed in a housing
of the playing apparatus 8 and engage with vertical grooves 19 in
guides 18a, 18b, and 18c formed on the base 2 to support the
playing apparatus 8 over the base 2 so as to elevate and lower it.
The tips of the horizontal shafts 17a to 17c engage with the cam
grooves 16a to 16c.
[0034] When the tray 1 is pushed toward the internal end of the
base 2 against the urging force of the tension spring 3, this
configuration allows the sliders 11a and 11b to interlockedly slide
through the process shown in FIGS. 6(a) to (c).
[0035] Specifically, when the tray 1 is pushed toward the internal
end, a protrusion 20 formed on the bottom surface of the tray 1
shown in FIG. 6(a) starts to engage an engaging portion 21 of the
slider 11a as shown in FIG. 6(b). When the tray 1 is further pushed
in, the slider 11a slide toward the internal end (the direction
shown by arrow B) while the slider 11b slide toward the front end
(the direction shown by arrow A), as shown in FIG. 6(c). As the
sliders 11a and 11b move in the longitudinal direction in response
to the pushing-in of the tray 1, the housing of the playing
apparatus 8 moves from a lowered position to an elevated
position.
[0036] As shown in FIG. 5, a slide hole 22 is drilled at the front
end of the tray 1. A protrusion 24 formed on the bottom surface of
a disc receiving member 23 is inserted into the slide hole 22, and
a spring 25 is installed on the bottom surface of the tray 1
between the tray 1 and the protrusion 24 of the disc receiving
member 23 as shown in FIG. 7 to urge the disc receiving member 23
toward the internal end of the tray 1.
[0037] When the tray 1 reaches the internal end, a lock claw 27
formed on an operation lever 50 urged by a spring 26 provided on
the base 2 is engaged with and locked by an engaging portion 28
provided at the front end of the tray 1. When the operation lever
50 is operated to rotationally move the lock claw 27 against the
urging force of the spring 26, the lock claw 27 is disengaged from
the engaging portion 28 and the tray 1 returns to the disc
installation and removal position due to the urging force of a
tension spring 13. In this case, the housing of the playing
apparatus 8 moves from the elevated position to the lowered
position.
[0038] In addition, as shown in FIG. 5, a damper gear 48 used as a
second damper is attached to a shaft 47 formed at the internal end
of the base 2, with the teeth of the damper gear 48 meshing with a
rack 49 formed only at the internal end of the slider 11a. A highly
viscous grease is applied to the shaft 47.
[0039] The mechanisms for moving the tray 1 in the horizontal
direction relative to the base 2 and for elevating and lowering the
playing apparatus 8 in response to this horizontal movement are
configured as described above. The tray 1 is further configured as
follows.
[0040] As shown in FIG. 1, the tray 1 includes a
large-diameter-disc receiving portion 29 and a small-diameter-disc
receiving portion 32 formed in the large-diameter-disc receiving
portion 29 and having a receiving surface 31 lower than a
large-small-diameter-disc receiving surface 30. Furthermore, A
large- and small-diameter-disc positioning protrusions 33a and 33b
are formed in a disc receiving member 23 slidably provided at the
front end of the tray 1.
[0041] FIG. 8 shows a process for loading a large-diameter disc 34.
The cam grooves 16a, 16b, and 16c are formed as follows.
[0042] In FIG. 8(a), the large-diameter disc 34 is placed on the
tray 1 drawn to the disc installation and removal position. At this
point, the large-diameter disc 34 is placed in the inside defined
by the large-diameter-disc positioning protrusion 33a and
large-diameter-disc receiving portion 29 of the disc receiving
member 23.
[0043] When the tray 1 is pushed in against the tension spring 3
until its protrusion 20 abuts on the engaging portion 21 of the
slider 11a, and the tray 1 is further pushed in toward the internal
end. Then, in response to the horizontal movement of the tray 1
toward the internal end, the slider 11a slides toward the internal
end, while the slider 11b slides toward the front end, thereby
causing the playing apparatus 8 to start elevating.
[0044] As shown in FIGS. 8(b) to (c), the moment the central hole
35 of the large-diameter disc placed on the tray 1 reaches a
position over the turntable 9, the protrusion 24 of the disc
receiving member 23 abuts on an engaging piece 36 of the base 2.
Then, when the tray 1 is further pushed in toward the internal end,
the relative position between the disc receiving member 23 and the
tray 1 changes against the urging force of the spring 25, as shown
in FIG. 8(d).
[0045] That is, until the central hole 35 of the large-diameter
disc starts to engage with the turntable 9, the positioning
protrusion 33a of the disc receiving member 23 accurately holds the
large-diameter disc 34 on the tray 1 so as not to shift. When the
turntable 9 starts to engage with the central hole 35 of the
large-diameter disc 35, the protrusion 24 of the disc receiving
member 23 rests at the same position as in FIG. 8(c) while abutting
on the engaging piece 36, whereas only the tray 1 slides toward the
internal end, with the relative relationship between the
large-diameter disc 34 and the positioning protrusion 33a of the
disc receiving member 23 remains unchanged. In these stable
conditions, the insertion of the turntable 9 into the central hole
35 of the large-diameter disc is completed as shown in FIG.
8(d).
[0046] When in FIG. 8(d), the tray 1 is further pushed in toward
the internal end, the playing apparatus 8 further elevates to allow
the turntable 9 to lift the large-diameter disc 34 from the top
surface of the tray 1, and the damper 37 and the turntable 9
sandwiches the large-diameter disc 34 therebetween to rotationally
drive it, as shown in FIG. 8(e).
[0047] The terminals of the cam grooves 16a, 16b, and 16c are
shaped in such a way that the tray 1 continues horizontal movement
toward the internal end for a short period of time after the damper
37 and the turntable 9 sandwiches the large-diameter disc 34
therebetween,
[0048] To remove the large-diameter disc 34, the operation lever 50
is operated to disengage the lock claw 27 from the engaging portion
28 of the tray 1 to return the tray 1 to the disc installation and
removal position due to the urging force of the tension spring 13.
This process is executed in the opposite direction from FIG. 6(d)
to 6(a).
[0049] Specifically, in FIG. 6(d) in which loading has been
completed, a protrusion 51 formed on the coupling lever 13 engages
with a protrusion 52 formed on the bottom surface of the tray 1.
The operation lever 50 is operated to disengage the lock claw 27
from the engaging portion 28 of the tray 1. Then, using as a power
source the force of the spring 15 urging the coupling lever 13 as
shown in FIG. 6(a) and the force of the tension spring 3 urging the
tray 1, the tray 1 starts slow movement while being decelerated by
the damper force of the damper gears 48 and 45, until the
protrusion 51 is disengaged from the protrusion 52. In this case,
the slow sliding movement of the sliders 11a and 11b causes the
playing apparatus 8 to slowly lower, thereby ensuring that the
large-diameter disc 34 can be delivered to the tray 1 from the
turntable 9 while maintaining the correct posture.
[0050] When the large-diameter disc 34 passes through the position
at which it is delivered to the tray 1 while maintaining the
correct posture and the protrusion 52 is disengaged from the
protrusion 51, the damper gear 48 subsequently stops acting on the
transfer system for the tray 1. Thus, using the urging force of the
tension spring 3, the tray 1 is pushed out to the position shown in
FIG. 1 while being decelerated by the damper gear 45.
[0051] Although the relative relationship between the tray 1 and
the disc receiving member 23 and the turntable 9 that can stably
load the large-diameter disc 34 has been described above, this
invention is also configured as follows to enable a small-diameter
disc to be loaded stably.
[0052] In the tray 1, the small-diameter-disc placement surface 31
is formed below the large-diameter-disc placement surface 30. The
timings with which the tray 1 is drawn out and back and with which
the playing apparatus 8 elevates and lowers are the same for both
the large- and small-diameter disc.
[0053] If the center 38 of the small-diameter-disc receiving
portion 32 is identical to the center 39 of the large-diameter-disc
receiving portion 29, the difference in the height of the discs
causes the tray 1 to shift between the position at which the bottom
surface of small-diameter disc aligns with the top surface of the
turntable 9 and the position at which the turntable surface aligns
with the bottom surface of the small-diameter disc. Accordingly,
the center of the turntable 9 fails to align with a center hole of
the disc, thereby precluding the small-diameter disc from being
loaded stably.
[0054] Thus, as shown in FIG. 9, this embodiment is formed in such
a way that the center 38 of the small-diameter-disc receiving
portion 32 is located closer to the internal end than the center 39
of the large-diameter-disc receiving portion 29 to enable the
small-diameter disc to be loaded stably.
[0055] By offsetting the centers 38 and 39 of the small- and
large-diameter-disc receiving portions 32 and 29 from each other in
this manner, the center of the turntable 9 aligns with the central
hole of the disc despite the movement of the tray 1, thereby
enabling stable loading.
[0056] FIGS. 10(a) to (e) show a process for loading a
small-diameter disc 40 and correspond to the process for loading
the large-diameter disc 34, which is shown in FIGS. 8(a) to
(e).
[0057] In FIG. 10(a), a receiving portion 33b of the disc receiving
member 23 positions the front surface of the small-diameter disc
40, while a step 41 between the large- and small-diameter-disc
placement surfaces 30 and 31 of the tray 1 positions its rear
surface.
[0058] Next, the playing apparatus 8 starts to elevate as shown in
FIG. 10(b).
[0059] Since the small-diameter disc 40 is located below the
large-diameter disc 34, the central hole 42 of the small-diameter
disc 40 aligns with the center of the turntable 9 before the
position shown in FIG. 8(c) is reached, as shown in FIG. 10(c). The
playing apparatus 8 slightly elevates to align the bottom surface
of the small-diameter disc 40 with the top surface of the turntable
9.
[0060] The tray 1 moves between the position shown in FIG. 10(c)
and the position shown in FIG. 8(c), so the center 38 of the
small-diameter-disc receiving surface 31 is correspondingly located
closer to the internal end of the tray 1 than the center 39 of the
large-diameter disc receiving surface 30.
[0061] In addition, the protrusion 24 of the disc receiving member
23 abuts on the engaging piece 36 of the base 2. Then, when the
tray 1 is further pushed in toward the internal end, the relative
position between the disc receiving member 23 and the tray 1
changes against the urging force of the spring 25, as shown in FIG.
10(d). Consequently, the position of the disc receiving member 23
remains unchanged despite the further pushing-in of the tray 1.
[0062] The position in FIG. 8(c) is only a passing point for the
small-diameter disc 40. This is also applicable to the position for
the large-diameter disc in FIG. 8(d). Since the small-diameter disc
is located below the large-diameter disc, the position at which the
turntable 9 is located under the bottom surface of the
small-diameter disc 40 before the position in FIG. 8(d) is reached.
Again, the centers are prevented from mutual offset because the
position of the disc receiving surface remains unchanged.
[0063] Furthermore, at the position in FIG. 10(e), the damper 37
sandwiches the small-diameter disc 40 to enable it to be
played.
[0064] The ejection process is similarly executed in the reverse
order, and despite its movement during the lowering of the
turntable 9 between FIGS. 10(e) and (d), the tray 1 can be returned
to a predetermined position because the position of the disc
receiving surface remains unchanged. In addition, in the process
for ejecting the small-diameter disc, the tray 1 starts to move
slowly due to the large damper force of the damper gears 48 and 45,
thereby ensuring that the small-diameter disc 40 can be reliably
delivered to the tray 1 from the turntable 9 in such a way that the
disc maintains the correct posture.
[0065] As described above, the centers of the large- and
small-diameter-disc receiving surfaces are mutually offset to allow
the center of the turntable 9 to align with the central hole of the
disc for operation despite the movement of the tray.
[0066] Although in the above embodiment, the damper gear 48 meshing
with the slider 11a and the damper gear 45 meshing with the rack 46
in the tray 1 are used to appropriately restrict the moving speed
of the tray 1 during ejection, similar effects can be obtained by
using both the damper gear 45 and a damper gear 54 that engages
with a rack 53 formed only at the front end of the tray 1 as shown
in FIG. 1. The damper gear 54 is mounted on a shaft 55 on the base
2, with highly viscous grease applied to the shaft 55.
[0067] In addition, similar effects can be expected by forming
teeth 56 on the rear surface of the coupling lever 13, as shown in
FIG. 12, and using a damper gear 57 that engages with the teeth 56
together with the damper gear 45.
* * * * *