U.S. patent application number 11/155558 was filed with the patent office on 2005-10-27 for recording and/or reproducing apparatus.
This patent application is currently assigned to Sony Corporation. Invention is credited to Kurita, Kazuhito, Yamada, Takahiro.
Application Number | 20050237869 11/155558 |
Document ID | / |
Family ID | 29544931 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050237869 |
Kind Code |
A1 |
Kurita, Kazuhito ; et
al. |
October 27, 2005 |
Recording and/or reproducing apparatus
Abstract
A disc recorder/player that prevents foreign matter such as dust
or the like from adhering to a drive shaft for assuring a highly
accurate position control of the movable write and/or read unit. In
the disc recorder/player, an electromechanical transducer is used
as a drive source provided in a feeding mechanism for an optical
pickup to expand and contract a drive shaft installed on the
electromechanical transducer, and a dustproof cover unit is
provided on a base to cover the top of the drive shaft. When the
optical pickup supported on the drive shaft is moved, the dustproof
cover unit can prevent dust, having entered when a disc cartridge
is introduced into or removed from the disc recorder/player, from
adhering to the drive shaft.
Inventors: |
Kurita, Kazuhito; (Kanagawa,
JP) ; Yamada, Takahiro; (Saitama, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Sony Corporation
TOKYO
JP
|
Family ID: |
29544931 |
Appl. No.: |
11/155558 |
Filed: |
June 20, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11155558 |
Jun 20, 2005 |
|
|
|
10421767 |
Apr 24, 2003 |
|
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Current U.S.
Class: |
369/44.11 ;
720/619; 720/695 |
Current CPC
Class: |
G11B 33/1446 20130101;
G11B 17/046 20130101; G11B 7/08582 20130101 |
Class at
Publication: |
369/044.11 ;
720/619; 720/695 |
International
Class: |
G11B 007/00; G11B
017/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2002 |
JP |
P2002-140592 |
Claims
1: A recording and/or reproducing apparatus comprising: a loading
unit configured to load a disc-shaped recording medium; a rotation
drive unit configured to rotate said disc-shaped recording medium
loaded in said loading unit; a recording and/or reproducing unit
configured to record an information signal to said disc-shaped
recording medium rotated by said rotation drive and/or reproduce
the information signal from said disc-shaped recording medium; and
a moving unit including: a drive shaft configured to support said
recording and/or reproducing unit to be movable along a radial
direction of said disc-shaped recording medium; and an
electromechanical transducer provided at a first end of said drive
shaft and configured to move said drive shaft along an axial
direction of said drive shaft by expansion and contraction of said
electromechanical transducer along said axial direction, said
recording and/or reproducing unit being moved along said radial
direction of said disc-shaped recording medium and a movement of
said recording and/or reproducing unit being controlled by moving a
speed of a movement of said drive shaft along said axial direction;
and a cover unit provided on said loading unit and configured to
cover said drive shaft of said moving unit.
2: A recording and/or reproducing apparatus according to claim 1,
wherein said cover unit includes a first cover portion configured
to cover a top of said drive shaft.
3: A recording and/or reproducing apparatus according to claim 2,
wherein said cover unit further includes a second cover portion
configured to cover a lateral side of said drive shaft at a side of
said recording and/or reproducing unit.
4: A recording and/or reproducing apparatus according to claim 3,
wherein a guide recess is formed in said recording and/or
reproducing unit along said radial direction of said disc-shaped
recording medium, and said second cover portion is engaged in said
guide recess.
5: A recording and/or reproducing apparatus according to claim 3,
wherein said second cover portion is substantially comb-shaped and
elastically deformable.
6: A recording and/or reproducing apparatus according to claim 5,
wherein a first part of said second cover portion is bent at a side
of said first cover portion and a second part of said second cover
portion covers the lateral side of said drive shaft at the side of
said recording and/or reproducing unit.
7: A recording and/or reproducing apparatus according claim 1,
wherein said rotation drive unit is provided on a base, and said
cover unit is provided integrally on said base.
8: A recording and/or reproducing apparatus according to claim 1;
wherein said rotation drive unit is provided on a base, and said
cover unit is provided on a cover member separate from said
base.
9: A recording and/or reproducing apparatus according to claim 8,
wherein said cover unit includes: a first cover portion configured
to cover a top of said drive shaft; and a second cover portion
configured to cover a lateral side of said drive shaft at a side of
said recording and/or reproducing unit, said second cover portion
being substantially comb-shaped and elastically deformable, wherein
said cover unit is provided on said base rotatably, and when said
disc-shaped recording medium is unloaded in said loading position,
said first cover portion covers the top of said drive shaft and a
first part of said second cover portion is bent at the side of said
first cover portion and a second part of said second member covers
the lateral side of said drive shaft at the side of said recording
and/or reproducing unit, and when said disc-shaped recording medium
is loaded in said loading position, said cover unit is rotated by
pushing said disc-shaped recording medium and said second cover
portion is separated from said recording and/or reproducing
unit.
10: A recording and/or playback apparatus comprising: a base; a
rotation drive unit provided on the base to rotate a disc-shaped
recording medium; a recording and/or playback unit exposed to the
disc-shaped recording medium placed on the rotation drive unit
through an opening formed in the base to write an information
signal to the disc-shaped recording medium and/or read the
information signal from the disc-shaped recording medium; a moving
unit including a drive shaft to support the recording and/or
playback unit to be movable radially along the disc-shaped
recording medium; an electromechanical transducer installed at a
first end of the drive shaft and configured to be expanded and
contracted axially along the drive shaft to displace the drive
shaft in a longitudinal direction, to move the recording and/or
playback unit radially along the disc-shaped recording medium and a
movement of said recording and/or playback unit being controlled by
causing a speed of a movement of the electromechanical transducer
to displace the drive shaft; and a cover unit provided on the base
to cover the drive shaft of the moving unit.
11: The apparatus as set forth in claim 10, wherein the cover unit
includes a first cover portion configured to cover a top of the
drive shaft.
12: The apparatus as set forth in claim 11, wherein the cover unit
further includes a second cover portion configured to cover a
lateral side of the drive shaft at a side of the recording and/or
playback unit.
13: The apparatus as set forth in claim 10, wherein the cover unit
is provided integrally on the base.
14: The apparatus as set forth in claim 10, wherein the cover unit
is provided on a cover member separate from the base.
15: The apparatus as set forth in claim 12, wherein the second
cover portion is generally comb-shaped and elastically
deformable.
16: The apparatus as set forth in claim 10, wherein: the
disc-shaped recording medium is encased rotatably in a cartridge
body; and the base has a cartridge receptacle in which the
cartridge body is received.
17: A recording and/or reproducing apparatus comprising: means for
loading a disc-shaped recording medium; means for rotating said
disc-shaped recording medium loaded in said means for loading;
means for recording an information signal to said disc-shaped
recording medium rotated by said means for rotating and/or
reproducing the information signal from said disc-shaped recording
medium; means for moving said recording and/or reproducing means
including: means for supporting said means for recording and/or
reproducing to be movable along a radial direction of said
disc-shaped recording medium; and means for moving said means for
supporting along a moving direction of said means for recording
and/or reproducing based on an input voltage, said means for
recording and/or reproducing being moveable along said radial
direction of said disc-shaped recording medium and a movement of
said recording and/or reproducing means being controlled by a speed
of a movement of said means for supporting along said moving
direction; and means for covering said means for supporting.
18: A recording and/or reproducing apparatus according to claim 17,
wherein said means for covering includes first means for covering a
top of said means for supporting.
19: A recording and/or reproducing apparatus according to claim 18,
wherein said means for covering further includes second means for
covering a lateral side of said supporting means at a side of said
means for recording and/or reproducing.
20: A recording and/or reproducing apparatus according to claim 19,
further comprising: means for engaging with said means for covering
and for guiding said means for recording and/or reproducing to move
along the radial direction of said disc-shaped recording medium.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This document claims priority on Japanese Patent Application
No. 2002-140592 filed on May 15, 2002, the entire contents of which
are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a recording and/or
reproducing apparatus in which a recording and/or reproducing unit
driven by a drive shaft is moved along the drive shaft by
displacing the drive shaft by an electromechanical transducer, and
the drive shaft is protected from dust or the like by a cover
unit.
[0004] 2. Description of the Background Art
[0005] A disc recorder/player that records or reproduces data to or
from an optical disc that is a disc-shaped recording medium
includes a disc rotation drive mechanism to rotate the optical
disc, an optical pickup to write or read an information signal to
or from the optical disc being rotatably driven by the disc
rotation drive mechanism, and a pickup feeding mechanism to move
the optical pickup radially along the optical disc. These
components are disposed on a base of the apparatus body.
[0006] The disc rotation drive mechanism has a disc table
integrally installed to a drive shaft of a spindle motor and on
which an optical disc is to be placed. The optical pickup writes
data to the optical disc by focusing a light beam emitted from a
light source onto a signal recording layer of the optical disc
through an objective lens to write data to the optical disc. The
optical pickup reads data from the optical disc by detecting, from
the optical disc, a return light from the optical disc (a part of
the light beam focused on the signal recording layer).
[0007] The pickup feeding mechanism that feeds the above optical
pickup radially along the optical disc includes a guide shaft to
support the optical pickup to be movable radially along the optical
disc, and a feed screw that is rotated by a drive motor to feed the
optical pickup radially along the optical disc. The optical pickup
is moved from the inner circumference to outer circumference of the
optical disc, for example, along the guide shaft as the feed screw
is rotated by the drive motor and data is written or read.
SUMMARY OF THE INVENTION
[0008] The present inventors have recognized the benefits of a disc
recorder/player using an electromechanical transducer in the pickup
feeding mechanism. The pickup feeding mechanism has the optical
pickup installed to a drive shaft that is displaced by the
electromechanical transducer, and the drive shaft is displaced by
applying a ramp voltage to the electromechanical transducer. Thus,
the optical pickup installed to the drive shaft can be moved along
the drive shaft. Since this pickup feeding mechanism needs no gear
or the like for moving the optical pickup, it can be constructed
with a reduced number of parts and an apparatus having the pickup
feeding mechanism adopted therein can be designed to be
smaller.
[0009] However, since the pickup feeding mechanism is to move the
optical pickup by displacing the drive shaft, it is difficult to
control the position of the optical pickup with a high accuracy if
foreign matter such as dust adheres to the drive shaft.
[0010] It is therefore an object of the present invention to
provide a novel recording and/or reproducing apparatus that can
prevent foreign matter such as dust from adhering to a drive shaft
when an electromechanical transducer is used in a pickup feeding
mechanism, and that can accurately control the position of a
recording and/or reproducing unit to be moved by the drive
shaft.
[0011] It is another object of the present invention to provide a
novel recording and/or reproducing apparatus in which a dustproof
cover unit can be simply constructed to prevent foreign matter such
as dust from adhering to the drive shaft.
[0012] The above object can be attained by providing a novel
recording and/or reproducing apparatus including, according to the
present invention, a base, a rotation drive unit provided on the
base to rotate a disc-shaped recording medium, a recording and/or
reproducing unit exposed to the disc-shaped recording medium placed
on the rotation drive unit through an opening formed in the base to
write an information signal to the disc-shaped recording medium
placed on the rotation drive unit and/or read an information signal
from the disc-shaped recording medium, a moving unit including a
drive shaft to support the recording and/or reproducing unit to be
rotatable radially along the disc-shaped recording medium, an
electromechanical transducer installed at one end of the drive
shaft and that is expanded and contracted axially along the drive
shaft to display the drive shaft longitudinally, to move the
recording and/or reproducing unit radially along the disc-shaped
recording medium by causing the electromechanical transducer to
displace the drive shaft, and a dustproof cover unit provided on
the base to cover the drive shaft of the moving unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of the recorder/player
according to the present invention.
[0014] FIG. 2 is also a perspective view of the disc cartridge
placed on a base in the recorder/player.
[0015] FIG. 3 is a plan view of the recorder/player.
[0016] FIG. 4 is a sectional view of the recorder/player.
[0017] FIG. 5 shows the waveform of an excitation voltage applied
to the electromechanical transducer.
[0018] FIG. 6 is a sectional view of the dustproof cover unit to
prevent dust or the like from adhering to the drive shaft.
[0019] FIG. 7 is a perspective view of a variant of the dustproof
cover unit.
[0020] FIG. 8 is a sectional view of the dustproof cover unit in
FIG. 7.
[0021] FIG. 9 is a perspective view of another variant of the
dustproof cover unit.
[0022] FIG. 10 is a perspective view of the dustproof cover unit
shown in FIG. 9.
[0023] FIG. 11 is a sectional view of the dustproof cover unit in
FIG. 10.
[0024] FIG. 12 is an exploded perspective view of a still another
variant of the dustproof cover unit.
[0025] FIG. 13 is also an exploded perspective view of the
dustproof cover unit in FIG. 12.
[0026] FIG. 14 is a sectional view of the dustproof cover unit
shown in FIGS. 12 and 13 when the disc cartridge is not placed in
the cartridge receptacle.
[0027] FIG. 15 is a sectional view of the dustproof cover unit
shown in FIGS. 12 and 13 when the disc cartridge is placed in the
cartridge receptacle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The disc recorder/player according to the present invention
is described in detail with reference to the accompanying drawings.
The disc recorder/player is portable, for example, and uses a disc
cartridge as a recording medium.
[0029] As shown in FIGS. 1 and 2, the disc recorder/player,
generally indicated by reference 1, uses a disc cartridge 2. The
disc cartridge 2 is formed from a cartridge body 2c including a
pair of cartridge halves 2a and 2b butted together and in which,
e.g., a magneto-optical disc 3 is rotatably encased.
[0030] The magneto-optical disc 3 includes at the center thereof a
clamping plate 3a that is to be engaged on a disc table 13 forming
a disc rotation drive mechanism in the disc recorder/player 1. The
clamping plate 3a is made of a metal or the like and is
magnetically attracted by a magnet provided at the disc table 13.
That is, the magneto-optical disc 3 magnetically attracted to the
disc table 13 will rotate along with the disc table 13.
[0031] The cartridge body 2c in which the magneto-optical disc 3 is
rotatably encased includes write/read openings 4 formed in the
generally central front portions of the upper and lower halves 2a
and 2b, respectively, opposite to each other and through which a
part of the signal recording layer of the magneto-optical disc 3 is
externally exposed. The opening 4 in the upper half 2a is provided
for allowing a magnetic head applying a magnetic field to the
magneto-optical disc 3 to go into the cartridge body 2c, and the
opening 4 formed in the lower half 2b is provided for allowing the
optical pickup 8 to face the magneto-optical disc 3.
[0032] Also, on the front portion of the cartridge body 2c, a
shutter member 5 that covers and uncovers the write/read openings 4
is slidably installed. The shutter member 5 is formed from a flat
plate bent in the form of a generally C shape parallel to the
surfaces of the cartridge body 2c. Each of the main sides of the
shutter member 5 is formed to have sufficient dimensions to cover
the write/read openings 4. The shutter member 5 uncovers the
openings 4 only when the cartridge disc 2 is loaded in the disc
recorder/player 1, and covers the openings 4 when the disc
cartridge 2 is not being used.
[0033] Also, in the center of the lower half 2b of the cartridge
body 2c, a generally circular disc drive opening 6 is formed
through which the clamping plate of the magneto-optical disc 3 is
externally exposed. When the disc cartridge 2 is loaded in the disc
recorder/player 1, the disc table 13 goes into the cartridge body
2c through the opening 6 and the clamping plate 3a and disc table
13 engage with each other.
[0034] The disc cartridge 2 is loaded first at the side thereof
perpendicular to the front end of the cartridge body 2c into the
disc recorder/player 1. Then, the shutter member 5 slides along the
front surfaces of the cartridge body 2c in a direction parallel to
the disc cartridge inserting direction, and thus uncovers the
write/read openings 4 to enable writing to or reading from the
magneto-optical disc 3.
[0035] It is also noted that in the cartridge body 2c other discs
may be encased in place of the magneto-optical disc, such as a
read-only optical disc having data pre-recorded therein as bit
patterns, a recordable optical disc whose recording layer is formed
from an organic dye material and that can record data to the
recording layer, a rewritable optical disc whose recording layer is
formed from a phase-change material and in which data can be
rewritten, a magnetic disc, etc.
[0036] The disc recorder/player 1 using the aforementioned disc
cartridge 2 as the recording medium is now described. The disc
recorder/player 1 includes an apparatus body having a cartridge
receptacle in which the disc cartridge 2 is received, and a lid
member (not shown) that covers and uncovers the cartridge
receptacle included in the apparatus body. As shown in FIGS. 1 to
3, a housing forming the apparatus body includes a base 10 having
formed at one side thereof the cartridge receptacle in which the
disc cartridge 2 is placed. The base 10 has installed pivotably
thereon a cartridge holder 11 that holds the disc cartridge 2. The
cartridge holder 11 is pivotable along with the lid member that
forms a part of the housing. For playing the disc cartridge 2 in
this disc recorder/player 1, the lid member is moved to uncover the
cartridge receptacle, the disc cartridge 2 is introduced into the
cartridge holder 11 and held therein, and the lid member is pivoted
in a direction of covering the cartridge receptacle in the base 10
to put the disc cartridge 2 thus held in the cartridge holder 11
into the cartridge receptacle formed in the base 10. Thus, the disc
recorder/player 1 is enabled to write data to or read data from the
magneto-optical disc 3 in the disc cartridge 2. More specifically,
with the disc cartridge 2 being received in the cartridge
receptacle, the write/read openings 4 are uncovered as the shutter
member 5 is slid along the front surfaces of the cartridge body 2c,
the disc table 13 goes into the cartridge body through the
generally central opening 6 in the lower half 2b of the cartridge
body 2c, and the clamping plate 3a is magnetically attracted by the
disc table 13 into engagement with each other.
[0037] Provided on the base 10 included in the housing of the
apparatus body are a disc rotation drive mechanism 7 to rotate the
magneto-optical disc 3 encased in the cartridge body 2c and the
optical pickup 8 to write or read information signals to or from
the magneto-optical disc 3, as shown in FIGS. 1 to 3.
[0038] The disc rotation drive mechanism 7 includes a spindle motor
12 to rotate the magneto-optical disc 3. The spindle motor 12 has a
drive shaft 12a provided nearly in the bottom center of the base 10
to project to the upper side of the base 10. The drive shaft 12a
has fixed thereto the disc table 13 that is to be engaged with the
clamping plate 3a of the magneto-optical disc 3. The disc table 13
has built therein a magnet that magnetically attracts the clamping
plate 3a, and which can thus rotate the magneto-optical disc 3
magnetically attracted thereon.
[0039] The optical pickup 8 provided on the base 10 includes an
optical system including a semiconductor laser (not shown) as a
source of a light bean, an objective lens 14 to focus a light beam
emitted from the semiconductor laser, a photodetector (not shown)
to detect a return light from the magneto-optical disc 3, etc. The
light beam emitted from the semiconductor laser is focused by the
objective lens 14 onto the signal recording layer of the
magneto-optical disc 3. A return light reflected at the signal
recording layer of the magneto-optical disc 3 is converted by the
photodetector into an electrical signal and the electrical signal
is supplied to an RF amplifier (not shown).
[0040] The optical pickup 8 also includes an objective lens 14
drive mechanism to displace the objective lens 14 in the
optical-axial direction. The objective lens drive mechanism is a
uniaxial actuator to displace the objective lens 14 in the focusing
direction as the direction of the optical axis of the objective
lens 14. The objective lens drive mechanism includes a magnet
provided on a base of the optical pickup 8, for example, and a coil
provided on a holder of the objective lens 14 opposite to the
magnet. A current flowing through the coil correspondingly to a
focusing servo signal and a magnetic field produced by the magnet
yield a driving force that displaces the objective lens 14 in the
focusing direction.
[0041] That is, by including no tracking control drive unit (in
contrast to the background objective lens drive mechanism that
includes a biaxial actuator for control of both focusing and
tracking), the objective lens drive mechanism according to the
present invention is designed to be compact and lightweight. In the
disc recorder/player 1 according to the present invention, a
feeding mechanism 31 for the optical pickup 8, which will be
described in detail below, feeds the optical pickup 8 and a
magnetic head 15 radially along the magneto-optical disc 3 and
controls the tracking of the objective lens 14. In the optical
pickup 8, the objective lens 14 is exposed to the cartridge
receptacle, in which the disc cartridge 2 is placed, through an
optical pickup opening 14a formed in the base 10 correspondingly to
a moving area of the optical pickup 8.
[0042] The optical pickup 8 also includes installed thereto the
magnetic head 15 positioned opposite to the objective lens 14 with
the magneto-optical disc 3 taking a position between them. The
magnetic head 15 is installed at the free end of a head support arm
17 fixed to a coupling 16 that couples the optical pickup 8 and
magnetic head 15 with each other. The head support arm 17 is made
of an elastically flexible member such as a gimbal spring. Head
support arm 17 forces the magnetic head 15 toward the
magneto-optical disc 3 for sliding on the magneto-optical disc 3 to
apply a magnetic field to the magneto-optical disc 3 only at the
time of recording.
[0043] The cartridge receptacle formed at one of the main sides of
the base 10 is provided with a positioning projection 18 to
appropriately position the disc cartridge 2 to be placed into the
base 10, a sensor 19 such as a pressure-sensitive switch that
detects the disc cartridge placed on the base 10, etc.
[0044] As shown in FIG. 1, the cartridge holder 11 installed
pivotably to the base 10 is formed, by bending, a thin resilient
metal plate such as a stainless steel sheet to have sufficient
dimensions to hold the disc cartridge 2. The cartridge holder 11
includes a top plate portion 21 formed generally rectangular to
have sufficient dimensions to cover the upper side of the disc
cartridge 2, and first and second cartridge holding portions 22 and
23 to hold the opposite sides of the disc cartridge 2 inserted in
the cartridge holder 11. Each of the first and second cartridge
holding portions 22 and 23 includes a lateral side wall formed by
bending each lateral side portion of the top plate portion 21
orthogonally and a cartridge holding lug formed by bending the end
portion of the lateral side wall in parallel to the top plate
portion 21. Namely, each of the cartridge holding portions 22 and
23 is formed to have a generally C-shaped section for holding the
lateral sides of the disc cartridge 2.
[0045] The cartridge holder 11 is open at the front thereof
perpendicular to the first and second cartridge holding portions 22
and 23. The disc cartridge 2 is inserted into or ejected from the
cartridge holder 11 though the opening. The disc cartridge 2
introduced into the cartridge holder 11 is held at the front
portion thereof where the shutter member 5 is provided and at the
rear portion thereof in the first and second cartridge holding
portions 22 and 23.
[0046] The lateral side wall included in the first cartridge
holding portion 22 of the cartridge holder 11 has a shutter release
piece 24 formed nearly at the longitudinal center thereof. The
shutter release piece 24 is turned inwardly of the cartridge holder
11. As the disc cartridge 2 is introduced into the cartridge holder
11, the shutter release piece 24 enters a recess formed in one
lateral side of the disc cartridge 2 and elastically deforms a
shutter locking member to unlock the shutter member 5. The shutter
release piece 24 moves the shutter member 5 in a direction opposite
to the direction in which the cartridge body 2c is inserted into
the cartridge holder 11, to thereby uncover the write/read openings
4.
[0047] A shutter member retaining piece 25 is formed in a portion
of the lateral side wall included in the first cartridge holding
portion 22, rather nearer to the cartridge insert/eject opening
than the shutter release piece 24. The shutter member retaining
piece 25 retains the shutter member 5 on the disc cartridge 2
inserted in the cartridge holder 11 in a position where it uncovers
the write/read openings 4. When ejecting the disc cartridge 2 out
of the cartridge holder 11, the shutter member retaining piece 25
holds the shutter member 5 on the cartridge body 2c being moved in
the direction in which the cartridge body 2c is ejected out from
the cartridge holder 11 and moves the shutter member 5 in the
direction of covering the write/read openings 4. The shutter member
retaining piece 25 is formed by making a U-shaped cut in the
lateral wall included in the first cartridge holding portion 22 to
be elastically displaceable along with the lateral side wall. The
shutter member retaining piece 25 is formed to extend from the base
toward the free end of the lateral side wall and has formed at the
free end thereof an engagement projection that is to be engaged in
an engagement hole in the shutter member 5. With the engagement
projection being engaged in the engagement hole in the shutter
member 5, the shutter member retaining piece 25 holds the shutter
member 5 in a position where the shutter member 5 uncovers the
write/read openings 4.
[0048] The top plate portion 21 of the cartridge holder 11 has a
magnetic head opening 26 formed therein. The magnetic head 15
coupled to the optical pickup 8 extends to the top plate portion 21
of the cartridge holder 11 and is exposed to the inside of the
cartridge holder 11 through the magnetic head opening 26. The
magnetic head opening 26 is provided in a position to be aligned
with the write/read openings 4 uncovered by the shutter member 5
moved in one direction when the disc cartridge 2 is received in the
cartridge receptacle formed on the base 10.
[0049] The top plate portion 21 of the cartridge holder 11 has
provided thereon a lifting member 27 that moves the head support
arm 17 having the magnetic head 15 installed at the free end
thereof up or down for moving the magnetic head 15 toward or away
from the magneto-optical disc 3 depending upon a selected mode of
operation. The lifting member 27 includes a pivoting plate 28
located under the head support arm 17 to pivot the head support arm
17. The pivoting plate 28 includes a pair of support arms 29
provided at either side of the base end thereof. Each support arm
29 has a spindle formed at the base end thereof. The lifting member
27 extends across the magnetic head opening 26 formed in the top
plate portion 21 of the cartridge holder 11, and is installed to
the top plate portion 21 with the spindle of each support arm 29
being pivoted to a pivot support piece formed by cutting and
raising a part of the top plate portion 21. The lifting member 27
is pivoted by a drive mechanism (not shown) to move the magnetic
head 15 toward or away from the magneto-optical disc 3 in the disc
cartridge 2 received in the cartridge receptacle on the base 10.
When recording data to the magneto-optical disc 3, the lifting
member 27 lowers the magnetic head 15 until the magnetic head 15
slides on the magneto-optical disc 3. When reading data from the
magneto-optical disc 3, stopping a recording, finishing playback,
or ejecting the disc cartridge 2, the lifting member 27 will move
the magnetic head 15 to lift up the magnetic head 15 away from the
magneto-optical disc 3.
[0050] The cartridge holder 11 also includes bearing holes 30a
formed at the base ends of the first and second cartridge holding
portions 22 and 23 and the base 10 has spindles 30b formed thereon.
The cartridge holder 11 is pivotably supported on the base 10 with
the spindles 30b of the base 10 being borne in the respective
bearing holes 30a of the cartridge holder 11.
[0051] As shown in FIGS. 1, 3, and 4, the head support arm 17
having the magnetic head 15 fixed to the free end thereof is
coupled to the optical disc 8 by the coupling 16. The optical
pickup 8 is supported by the optical pickup feeding mechanism 31 to
be movable radially along the magneto-optical disc 3 in the disc
cartridge 2 received in the cartridge receptacle on the base 10.
The optical pickup feeding mechanism 31 includes a guide shaft 33
supporting a fixing block 32 to which the optical pickup 8 is
installed to be movable radially along the magneto-optical disc 3,
a drive shaft 34 disposed parallel to the guide shaft 33, an
electromechanical transducer 35 installed at one end of the drive
shaft 34, a fixture 36 to fix the electromechanical transducer 35,
and a coupling 37 supported on the drive shaft 34 to be axially
slidable and that couples the fixing block 32 and drive shaft 34
with each other.
[0052] The guide shaft 33 is disposed radially along the
magneto-optical disc 3 and has opposite ends thereof fixed with a
pair of support members 38 provided around the optical pickup
opening 14a formed in the base 10. The fixing block 32 includes
integrally formed therewith a support block 41 having formed
therein a guide hole 39 in which the guide shaft 33 is inserted.
Therefore, with the fixing block 41 being introduced into the guide
hole 39 in the support block 41, the objective lens 14 is exposed
through the optical pickup opening 14a to the cartridge receptacle
in which the disc cartridge 2 is received and the optical pickup 8
is movable radially along the magneto-optical disc 3.
[0053] The drive shaft 34 is long enough to move the fixing block
32 across the magneto-optical disc 3 from the inner circumference
to outer circumference or vice versa. The drive shaft 34 is a
frictional member and has the electromechanical transducer 35
installed at one end thereof. The electromechanical transducer 35
is formed from a piezoelectric material or the like. Applied with
an excitation voltage from a drive circuit (not shown), the
electromechanical transducer 35 expands and contracts axially of
the drive shaft 34. The expansion rate is different from the
contraction rate, and thus the electromechanical transducer 35 will
oscillate the drive shaft 34 axially. The electromechanical
transducer 35 is fixed at one end thereof to the fixture 36, and
thus the fixture 36 works as a balancer when the electromechanical
transducer 35 is oscillating. The fixture 36 is supported on a
fixing member 42 fixed to the rear side of the base 10. More
specifically, the fixture 36 is installed at one end of the fixing
member 42 having formed in the other end thereof a support hole 43
in which the other end of the drive shaft 34 is supported. The
other end of the drive shaft 34 is engaged in the support hole 43
to be oscillatable axially thereof. That is, the drive shaft 34 is
supported on the fixing member 42 to be movable axially thereof
under the effect of the displacement of the electromechanical
transducer 35.
[0054] The coupling 37 includes a first coupling piece 45 and a
second coupling piece 44 formed integrally with the fixing block
32. The first coupling piece 45 is formed to project from an end of
the fixing block 32 opposite to the support block 41 toward the
drive shaft 34. The second coupling piece 44 is formed from an
elastically displaceable material such as a leaf spring or the like
and is fixed, by screwing or otherwise, to the fixing block 32 in a
cantilevered state. These coupling pieces 44 and 45 are disposed
opposite to each other and the drive shaft 34 is provided between
them so that the fixing block 32 is supported to be slidable
axially along the drive shaft 34. Therefore, the fixing block 32
has the guide shaft 33 inserted in the guide hole 39 in the support
block 41 thereof and supports the coupling 37 to be slidable
axially along the drive shaft 34, so that the fixing block 32 is
supported to be movable axially along the guide shaft 33 and drive
shaft 34, and radially along the magneto-optical disc 3.
[0055] The optical pickup feeding mechanism 31 constructed as above
slides the coupling 37 axially along the drive shaft 34 by applying
an excitation voltage as a drive signal to the electromechanical
transducer 35, which will thus expand and contact to displace the
drive shaft 34 axially. Thus, the fixing block 32 supporting the
optical pickup 8 and magnetic head 15 can be moved radially along
the magneto-optical disc 3.
[0056] More particularly, the electromechanical transducer 35 is
applied with an excitation voltage, as a drive signal shown in FIG.
5, in which each pulse first rises steeply up to a first
predetermined voltage Vb at the leading edge thereof, gradually
rises linearly to a second predetermined voltage Va, then holds the
second predetermined voltage Va for a predetermined period of time,
and falls steeply down to 0 V at the trailing edge thereof. It
should be noted that the electromechanical transducer 35 will not
activate until a voltage reaches the first predetermined voltage
Vb, and will start acting at the first predetermined voltage
Vb.
[0057] More particularly, when moving the fixing block 32 linearly
in one direction, the electromechanical transducer 35 is applied
with an excitation voltage as shown in FIG. 5. That is, at the
leading edge of the excitation voltage, the electromechanical
transducer 35 will not activate until the applied excitation
voltage rises steeply or vertically up to the first predetermined
voltage Vb at which time the electromechanical transducer 35 will
start acting. Namely, the electromechanical transducer 35 will not
start acting at the leading edge of the excitation voltage. Next,
after the excitation voltage rises up to the first predetermined
voltage Vb and then gradually rises linearly up to the second
predetermined voltage Va, the electromechanical transducer 35 will
gradually expand while the drive shaft 34 will correspondingly move
gradually in one direction. At this time, the fixing block 32 is
retained on the drive shaft 34 under the action of friction between
the coupling 37 and drive shaft 34 and moves along with the drive
shaft 34 in one direction. On the other hand, when the excitation
voltage falls steeply or vertically down to 0 V at the trailing
edge of the excitation voltage, the electromechanical transducer 35
will quickly contract and the drive shaft 34 will correspondingly
move quickly in the other direction. At this time, the coupling 37
slips due to an inertia and against the friction on the drive shaft
34, and thus only the drive shaft 34 moves in the other direction.
As a result, the fixing block 32 will slide in one direction in
relation to the drive shaft 34.
[0058] With the excitation voltage shown in FIG. 5 being applied
repeatedly to the electromechanical transducer 35, the optical
pickup feeding mechanism 31 can slide the fixing block 32 coupled
with the drive shaft 34 by the coupling 37 continuously in one
direction in relation to the drive shaft 34. It should be noted
that for linear movement of the fixing block 32 in the other
direction, it suffices to apply a reverse excitation voltage to the
electromechanical transducer 35.
[0059] As mentioned above, the optical pickup feeding mechanism 31
applies to the electromechanical transducer 35 an excitation
voltage as an operation start voltage for the electromechanical
transducer 35 that rises vertically up to the first predetermined
voltage Vb. Therefore, it is possible to save power as compared
with the application of an excitation voltage that rises linearly
from 0 V to the second predetermined voltage Va. Also, it is
possible to eliminate the time for which the electromechanical
transducer 35 does not operate, and thus smoothen the operation of
the optical pickup 8.
[0060] In the aforementioned optical pickup feeding mechanism 31,
the fixing block 32 can be held stably in an arbitrary position in
the moving direction under the effect of friction between the drive
shaft 34 and coupling 37 even while the fixing block 32 is not in
any driven state, by adjusting the friction between the drive shaft
34 and coupling 37 and adjusting elasticity of the second coupling
piece 44 applied to the drive shaft 34. Also, this optical pickup
feeding mechanism 31 does not incur any backlash experienced when a
gear train is used as in a background optical pickup feeding
mechanism, and the driving of the optical pickup feeding mechanism
31 can be controlled with a tracking resolution on the order of
nano-millimeters. Therefore, the tracking of the objective lens 14
can also be controlled. Further, the optical pickup feeding
mechanism 31 can be driven with no noise in an ultrasound domain of
more than 20 kHz, and thus can operate with a reduced operating
sound. Moreover, the optical pickup feeding mechanism 31 can be
designed to be considerably compact as compared with a background
one in which a rotation of a drive motor is converted to a linear
motion via a gear train and rack member.
[0061] As shown in FIG. 3, the optical pickup opening 14a formed in
the base 10 and through which the objective lens 14 is exposed to
the cartridge receptacle is formed to have sufficient dimensions to
cover the drive shaft 34 included in the optical pickup feeding
mechanism 31 and a part of the base 10 covering the drive shaft 34
is formed as a dustproof cover unit 51 that prevents foreign matter
such as dust or the like from adhering to the drive shaft 34. When
the disc cartridge 2 is loaded into or removed from the disc
recorder/player 1, a lid (not shown) connected with the cartridge
holder 11 uncovers the cartridge receptacle formed on the base 10
where the disc cartridge 2 is received, and thus foreign matter
such as dust or the like will come into the cartridge receptacle
from the cartridge insert/eject opening for the disc cartridge 2
thus uncovered. The dustproof cover unit 51 is provided to prevent
the foreign matter having entered into the cartridge insert/eject
opening from adhering to the drive shaft 34. It should be noted
that the drive shaft 34 is covered only at the receptacle side
thereof by the dustproof cover unit 51 but not at other directional
portions thereof because the base 10 is disposed outside the outer
casing and no foreign matter such as dust will enter from other
directions than the cartridge receptacle.
[0062] Note that the dustproof cover unit 51 is provided integrally
with the base 10 but otherwise a cover unit formed, as the
dustproof cover unit 51, from a sheet or the like separately from
the base 10 may be attached near the optical pickup opening 14a in
the base 10 to cover the top of the drive shaft 34. In this case,
the dustproof cover unit 51 can easily be attached near the optical
pickup opening 14a in the base 10 without any change applied to the
design of the base 10.
[0063] The disc recorder/player 1 constructed as above functions as
described herebelow. First, a lid (not shown) is pivoted in a
direction of uncovering the inside of the apparatus body forming,
along with the lid, the disc recorder/player 1 to open the
cartridge receptacle formed inside the apparatus body. In this
condition, the disc cartridge 2 is introduced first with the one
lateral side perpendicular to the front side where the shutter
member 5 is provided into the apparatus body through the disc
insert/eject opening defined for the disc cartridge 2 when the lid
uncovers the cartridge receptacle, as shown in FIG. 1. Then, the
disc cartridge 2 is held in the cartridge holder 11 cooperating
with the lid. At this time, the shutter member 5 is unlocked by the
shutter release piece 24 provided on the cartridge holder 11, to
slide along the front end face of the cartridge body 2c to uncover
the write/read openings 4 in the cartridge body 2c. The shutter
member 5 is retained by the shutter member retaining piece 25 at
the uncovered openings 4, and thus the signal recording layer of
the magneto-optical disc 3 is exposed at its area from the inner to
outer circumference thereof to outside the cartridge body 2c.
[0064] When the lid uncovering the inside of the apparatus body is
pivoted in a direction of covering the inside of the apparatus
body, the disc cartridge 2 held in the cartridge holder 11 is
placed in the cartridge receptacle formed on the base 10. Then, the
disc table 13 included in the disc rotation drive mechanism 7
enters the disc cartridge 2 through the opening 6 formed nearly in
the center of the lower half 2b of the cartridge body 2c. The disc
table 13 is engaged with the clamping plate 3a provided on the
magneto-optical disc 3, and is magnetically attached by the
clamping plate 3a, so that the magneto-optical disc 3 can be
rotated along with the disc table 13.
[0065] Next, data writing to the magneto-optical data 3 in the disc
cartridge 2 set in the cartridge receptacle will be described.
First, when the user presses a record start button on a control
panel of the disc recorder/player 1, the spindle motor 12 is
activated and the magneto-optical disc 3 is thus rotated. The
semiconductor laser included in the optical pickup 8 is excited to
emit a light beam at an output level for data recording.
[0066] Also, the electromechanical transducer 35 of the optical
pickup feeding mechanism 31 is excited by the drive circuit. More
particularly, an excitation signal as shown in FIG. 5 is applied to
the electromechanical transducer 35. Namely, the drive circuit
applies the electromechanical transducer 35 with an excitation
voltage in which each pulse first rises steeply up to the first
predetermined voltage Vb at the leading edge thereof, then
gradually rises linearly up to the second predetermined voltage Va,
then maintains the second predetermined voltage Va for a
predetermined period of time, and then falls steeply down to 0 V at
the trailing edge thereof. The electromechanical transducer 35 is
not sensitive to the voltage up to the first predetermined voltage
Vb and the fixing block 32 will not start moving. Then, when the
excitation voltage rises up to the first predetermined voltage Vb
and then gradually rises linearly up to the second predetermined
voltage Va, the electromechanical transducer 35 will gradually
expand while the drive shaft 34 will correspondingly move gradually
in one direction. At this time, the fixing block 32 is retained on
the drive shaft 34 under the action of friction between the
coupling 37 and drive shaft 34 and moves along with the drive shaft
34 in one direction. When the excitation voltage falls steeply or
vertically down to 0 V, the electromechanical transducer 35 will
quickly contract and the drive shaft 34 correspondingly moves
quickly in the other direction. At this time, the coupling 37 slips
due to an inertia and against the friction on the drive shaft 34,
and thus only the drive shaft 34 moves in the other direction. As a
result, the fixing block 32 will slide in one direction in relation
to the drive shaft 34.
[0067] With the excitation voltage shown in FIG. 5 being applied
repeatedly to the electromechanical transducer 35, the optical
pickup feeding mechanism 31 can slide the fixing block 32 coupled
with the drive shaft 34 by the coupling 37 continuously in one
direction in relation to the drive shaft 34. Thus, the optical
pickup 8 is moved to the inner circumference of the magneto-optical
disc 3, and the objective lens drive mechanism executes focus servo
control based on a focus servo signal. The optical pickup 8 will
thus start reading data for a location of a recorded address of the
data.
[0068] When an address of recorded data is thus located, the
magnetic head 15 is moved to near the magneto-optical disc 3 as the
lifting member 27 is pivoted. The magneto-optical disc 3 is
illuminated with a light beam emitted from the optical pickup 8,
heated to a higher temperature than the Curie temperature, and
applied with a magnetic field from the magnetic head 15. Thus, data
recording is started.
[0069] At this time, the drive circuit of the electromechanical
transducer 35 included in the optical pickup feeding mechanism 31
is supplied with a tracking servo signal. Then, the drive circuit
applies the electromechanical transducer 35 with an excitation
voltage as shown in FIG. 5 on the basis of the tracking signal to
move the optical pickup 8 radially along the magneto-optical disc 3
for tracking control of the objective lens 14. That is, the optical
pickup feeding mechanism 31 makes fine tracking control of the
objective lens 14 and coarsely feeds the optical pickup 8 radially
along the magneto-optical disc 3.
[0070] For reading data from the magneto-optical disc 3 in the disc
cartridge 2, the magnetic head 15 is spaced by the lifting member
27 away from the magneto-optical disc 3 since the magneto-optical
disc 3 does not need to have any magnetic field applied thereto. A
light beam is projected from the optical pickup 8 onto the
magneto-optical disc 3, and a return light from the magneto-optical
disc 3 is detected to read data. Also for this data reading, the
optical pickup feeding mechanism 31 feeds the optical pickup 8
radially along the magneto-optical disc 3 while executing tracking
control of the objective lens 14 based on a tracking servo signal.
Also, focus control of the objective lens 14 is made by the
objective lens drive mechanism.
[0071] Using the optical pickup feeding mechanism 31, the disc
recorder/player 1 can be constructed of a considerably reduced
number of parts and can be more compact and lightweight as compared
with a background one in which a rotation of a drive motor is
converted to a linear motion via a gear train and rack member.
Also, in the disc recorder/player 1 according to the present
invention, the fixing block 32 can be moved by the optical pickup
feeding mechanism 31 using the electromechanical transducer 35 to
execute tracking control and feeding of the optical pickup 8, so
that the objective lens drive mechanism for the optical pickup 8
does not have to use any tracking control coil and magnet. Thus,
the disc recorder/player 1 can be designed to be more simple and
compact. Further in the disc recorder/player 1, the drive shaft 34
included in the optical pickup feeding mechanism 31 is covered with
the dustproof cover unit 51 provided integrally with the base 10.
Therefore, when inserting or removing the disc cartridge 2, foreign
matter such as dust can be prevented from entering through the
cartridge insert/eject opening and adhering to the drive shaft 34.
Thus, the optical pickup feeding mechanism 31 can execute tracking
control of the objective lens 14 with a high accuracy in addition
to accurately moving the optical pickup 8 radially along the
magneto-optical disc 3.
[0072] In the above explanation, the dustproof cover unit 51
provided integrally with the base 10 has been described as a unit
covering the top of the drive shaft 34 included in the optical
pickup feeding mechanism 31. Alternatively, the dustproof cover
unit 51 may be constructed as shown in FIG. 6. As shown, the
dustproof cover unit indicated by reference 55 includes a first
covering portion 56 to cover the top of the drive shaft 34 and a
second covering portion 57 formed by bending down the free end of
the first covering portion 56, both being provided on the base 10.
The second covering portion 57 is engaged in a guide recess 58
formed in the fixing block 32 along the moving direction of the
optical pickup 8. Of this dustproof cover unit 55, the first
covering portion 56 can prevent foreign matter (indicated with
arrow A) from adhering to the drive shaft 34 from above, while the
second covering portion 57 can prevent foreign matter (indicated
with arrow B) from adhering to the drive shaft 34 from a lateral
side. Therefore, the dustproof cover unit 55 can prevent foreign
matter from adhering to the drive shaft 34 more effectively than
the dustproof cover unit 51. Further, since the dustproof cover
unit 55 is formed integrally with the base 10, it can be
constructed of a number of parts not larger than in the dustproof
cover unit 51 and more simply to prevent foreign matter from
adhering to the drive shaft 34.
[0073] The dustproof cover unit 55 is formed integrally with the
base 10. However, the dustproof member may be provided separately
from the base 10 as shown in FIGS. 7 and 8. As shown, the dustproof
member indicated by reference 61 is formed from a cover unit 65
such as a sheet or the like. The cover unit 65 includes a first
covering portion 62 to cover the top of the drive shaft 34, and a
second covering portion 63 formed by bending down the free end of
the first covering portion 62. Of this cover unit 65, the first
covering portion 62 has an adhesive layer 64 provided on a part of
the rear side thereof. The cover unit 65 is attached with the
adhesive layer 64 thereof to near the optical pickup opening 14a in
the base 10. The second covering portion 63 is engaged in a guide
recess 66 formed in the fixing block 32 along the moving direction
of the optical pickup 8 when the cover unit 65 is attached as
above. Of the dustproof member 61, the first covering portion 62
can prevent foreign matter (indicated with arrow A) from adhering
to the drive shaft 34 from above, while the second covering portion
63 can prevent foreign matter (indicated with arrow B) from
adhering to the drive shaft 34 from a lateral side. Therefore, the
dustproof member 61 can prevent foreign matter from adhering to the
drive shaft 34 more effectively than the dustproof cover unit 51.
Also, with only the guide recess 66 formed in the fixing block 32,
the cover unit 65 including the first and second covering portions
62 and 63 can easily be attached near the optical pickup opening
14a in the base 10 without having to change the design of the base
10.
[0074] Further, the dustproof member 61 formed separately from the
base 10 may be constructed as shown in FIGS. 9 to 11. As shown, the
dustproof member indicated by reference 71 is a flexible cover unit
72 that includes a first covering portion 73 to cover the top of
the drive shaft 34, and a second covering portion 74 formed by
bending down the free end of the first covering portion 73. The
second covering portion 74 is formed generally like a comb having
parallel cuts formed therein. The second covering portion 74 is
raised at a portion thereof lying above the fixing block 32 by the
fixing block 32 and at portions other than above the fixing block
32 are generally perpendicular to the first covering portion 73.
Therefore, for the dustproof member 71, no guide recesses 58 and 66
need be provided as in the second covering portions 57 and 63 of
the aforementioned dustproof members 55 and 61, respectively. Since
the second covering portion 74 is easily flexibly deformed, it will
not block the fixing block 32 from moving. Such a cover unit 72 has
an adhesive layer 75 provided on one side thereof, and can be
attached near the optical pickup opening 14a in the base 10.
[0075] Of the cover unit 72, the first covering portion 73 can
prevent foreign matter (indicated with arrow A) from adhering to
the drive shaft 34 from above, while the second covering portion 74
can prevent foreign matter (indicated with arrow B) from adhering
to the drive shaft 34 from a lateral side. Therefore, the cover
unit 72 can prevent foreign matter from adhering to the drive shaft
34 more effectively than the dustproof cover unit 51. Also, the
cover unit 72 of the dustproof member 71, including the first and
second covering portions 73 and 74, can easily be attached near the
optical pickup opening 14a in the base 10 without having to form
the guide recess 66 in the fixing block 32 and without having to
change the design of the base 10.
[0076] Further, the dustproof member may be constructed as shown in
FIGS. 12 to 15. This dustproof member indicated by reference 81 is
installed near the optical pickup opening 14a in the base 10, and
includes a pivoting member 82 that is pivoted by the disc cartridge
2 being inserted into the cartridge receptacle, and a cover unit 83
installed to the pivoting member 82.
[0077] The pivoting member 82 includes a first portion 84 that will
be pressed by the disc cartridge 2 being inserted into the
cartridge receptacle formed on the base 10 and a second portion 85
to which the cover unit 83 is fixed, the first and second portions
84 and 85 being disposed with a predetermined angle between them.
The second portion 85 becomes a first covering portion 85a that
covers the top of the drive shaft 34. The pivoting member 82 has
formed in longitudinal opposite end portions thereof shaft holes 86
in which spindles 87 provided near the optical pickup 14a in the
base 10 and also near the drive shaft 34 are borne to install the
second portion 85 vis-a-vis the optical pickup opening 14a. Also,
the pivoting member 82 has an elastic piece 92 that is pressed to a
pivot limiter 91 provided on the base 10.
[0078] The cover unit 83 is flexible, and secured to the second
portion 85 with an adhesive or the like. The cover unit 83 includes
a fixture 88 working also as a first covering portion and that is
fixed to the second portion 85 covering the top of the drive shaft
34, and a second covering portion 89 formed by bending down the
free end of the fixture 88. The second covering portion 89 is
formed generally like a comb having parallel cuts formed therein.
The second covering portion 89 is raised at a portion thereof lying
on the fixing block 32 by the fixing block 32 and its portions
other than above the fixing block 32 are generally perpendicular to
the fixture 88. Therefore, for the dustproof member 81, no guide
recesses 58 and 66 need be provided as in the second covering units
57 and 63 of the aforementioned dustproof members 55 and 61,
respectively. Such a cover unit 83 is fixed to the second portion
85 of the pivoting member 82 with an adhesive or the like.
[0079] When the disc cartridge 2 is not set on the base 10, the
dustproof member 81 constructed as above is forced at the pivoting
member 82 thereof by an elastic piece 92 engaged on the pivot
limiter 91 to pivot about spindles 87 and 87 in the direction of
arrow D in FIG. 14. Thus, the second portion 85 of the pivoting
member 82 is turned toward the base 10, the first covering portion
85a covers the top of the drive shaft 34, and the second covering
portion 89 fixed to the second portion 85 of the pivoting member 82
covers a lateral side of the drive shaft 34, whereby dust is
blocked from adhering to the drive shaft 34. Also, the first
portion 84 of the pivoting member 82 forming a predetermined angle
with the second portion 85 is projected from the cartridge
receptacle. When the disc cartridge 2 is not in the cartridge
receptacle on the base 10, the cover member is pivoted upward in
relation to the apparatus body with the cartridge insert/eject
opening being uncovered. In this condition, foreign matter could
possibly enter from the cartridge insert/eject opening into the
apparatus body. The dustproof member 81 in consideration is very
effective to avoid invasion of such foreign matter into the
apparatus body.
[0080] When the disc cartridge 2 is set in the cartridge receptacle
on the base 10, the first portion 84 of the pivoting member 82 is
pressed by a portion, near the write/read opening 4, of the lower
half 2b of the disc cartridge 2. Then, the pivoting member 82 is
pivoted about the spindles 87 in the direction of arrow D in FIG.
15. The second portion 85 forming the first covering portion 85a is
pivoted in the direction of projecting from the cartridge
receptacle on the base 10, and thus enters the cartridge body 2c
through the write/read opening 4 in the lower half 2b. Thus, the
second covering portion 89 will be apart from the drive shaft 34
and the optical pickup 8 installed to the fixing block 32 will
smoothly be movable by the optical pickup feeding mechanism 31
radially along the magneto-optical disc 3.
[0081] Since the second covering portion 89 of the dustproof member
81 is not put into contact with the fixing block 32 when the disc
cartridge 2 is set in the cartridge receptacle on the base 10, the
optical pickup 8 can be fed with a high accuracy. Also, since when
the disc cartridge 2 is not set in the cartridge receptacle, the
first covering portion 85a will cover the top of the drive shaft 34
while the second covering portion 89 will cover the lateral side of
the drive shaft 34, it is possible to positively prevent foreign
matter from adhering to the drive shaft 34.
[0082] In the above embodiments, the optical pickup feeding
mechanism 31 that feeds the optical pickup 8 and executes tracking
control of the objective lens 14 and the objective lens drive
mechanism for the optical pickup 8 is formed from the uniaxial
actuator that provides only focusing control, but the present
invention is not limited to this embodiment. The objective lens
drive mechanism for the optical pickup 8 may be formed from a
biaxial actuator as in the background mechanism to execute both
focusing control and tracking control while the optical pickup 8 is
fed by the optical pickup feeding mechanism 31.
[0083] Also, the aforementioned disc recorder/player 1 has the
cartridge holder 11 installed pivotably on the base 10, but the
disc recorder/player 1 may have a cartridge holder 11 that can move
linearly toward and away from the base 10. Further, the disc
recorder/player 1 can be incorporated in an installed type of
apparatus.
[0084] As having been described in detail in the foregoing, the
present invention provides a disc recorder/player using an
electromechanical transducer as a drive source having a drive shaft
installed thereon to move a write and/or read unit fixed on the
drive shaft by expanding and contracting the drive shaft, and in
which a dustproof cover unit is provided to prevent foreign matter
such as dust or the like from adhering to the drive shaft when the
recording medium is introduced or removed from the disc
recorder/player, whereby it is possible to move the write and/or
read unit with a high accuracy.
[0085] Obviously, numerous additional modifications and variations
of the present invention are possible in light of the above
teachings. It is therefore to be understood that within the scope
of the appended claims, the present invention may be practiced
otherwise than as specifically described herein.
* * * * *