Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
2001-07-24
2004-06-01
Huber, Paul W. (Department: 2653)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S044320
Reexamination Certificate
active
06744716
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a pickup moving mechanism and a pickup moving method for an optical disk apparatus for introducing a laser beam into an optical disk to record or reproduce information. More particularly, the present invention relates to a pickup moving mechanism and a pickup moving method for an optical disk apparatus having a control function, or a so-called tilt servo mechanism, for maintaining perpendicularity between the optical disk and an optical axis of an optical pickup.
BACKGROUND ART
In an optical disk apparatus, it is essential that the angle between an optical disk (hereinafter, referred to as disk) and the optical axis of an optical pickup for introducing a laser beam to the disk and recording or reproducing information is an angle at which the optical disk is perpendicular to the optical axis. In an actual apparatus, however, the above-stated angle is deviated from the latter angle at which the optical disk is perpendicular to the optical axis because of warpage of the disk, tolerance accumulation of a mechanism section or the like, a mechanism for adjusting or controlling this angle is devised.
As an apparatus for adjusting the angle formed between the disk and the optical axis of the optical pickup, there is known an apparatus shown in Japanese Unexamined Patent Publication No. 10-116479. The constitution of the apparatus will be described based on FIG.
5
.
A disk motor
2
rotating and supporting a disk (not shown) is fixed onto a base
1
, and an optical pickup
3
introducing a laser beam to the disk and recording or reproducing information is supported by a pair of guide members
4
and
5
so that the optical pickup
3
is movable in the diameter direction of the disk. A pickup driving motor
6
for driving the optical pickup
3
is fixed to the base
1
and the motor
6
transmits a driving force to a screw member
7
supported by bearings
1
a
and
1
b
provided on the base
1
to be rotatable about a axial core through gears
8
and
9
. An engagement member
10
having an inclined portion
10
a
engaged with the screw member
7
and converting the rotation of the screw member
7
into the movement of the optical pickup
3
is fixed to the optical pickup
3
. One ends of the guide members
4
and
5
are supported by support portions
11
and
12
and tiltable about the support portions
11
and
12
, respectively. The other ends of the guide members
4
and
5
are in contact with the tip ends of adjustment screws
14
and
15
which are engaged with the female threaded portions of a beam member
13
fixed to the base
1
and which move in the direction of the optical axis
3
a
of the optical pickup
3
by their own rotation while being pressed by urging means, respectively.
With the above-stated constitution, if the angle of the optical axis
3
a
of the optical pickup
3
with respect to the disk is deviated from the angle at which the optical axis
3
a
is perpendicular to the disk due to tolerance accumulation of the mechanism portion or the like, the deviation is detected by a signal from the optical pickup
3
or a tilt detection element, not shown. Due to this, by rotating the adjustment screws
14
and
15
, the guide members
4
and
5
are tilted about the support portions
11
and
12
, respectively, in the direction of the optical axis
3
a,
the optical pickup
3
supported by the guide members
4
and
5
is inclined with respect to the base
1
and the deviation of the optical axis
3
a
is adjusted. This angle adjusting device can be developed to an angle control device by driving the adjustment screws
14
and
15
using a motor.
As an optical disk apparatus utilizing angle control, there is known an apparatus shown in Japanese Unexamined Patent Publication No. 9-198687. The constitution of the apparatus will be described based on FIG.
6
.
This optical disk apparatus is almost the same in constitution as that shown in FIG.
5
. Namely, a disk motor
2
rotating and supporting a disk
16
is fixed on a base
1
and an optical pickup
3
introducing a laser beam to a disk
16
and recording or reproducing information is supported by a pair of guide members
4
and
5
so that the optical pickup
3
is movable in the diameter direction of the disk
16
.
It is noted, however, a tilt detection element
17
for detecting the angle between the disk
16
and the optical axis
3
a
of the optical pickup
3
is provided on the optical pickup
3
. Also,a pickup driving motor
6
for driving the optical pickup
3
is fixed to the base
1
, and driving gears
18
and
19
engaged with the driving shaft of this pickup driving motor
6
are rotatably supported. An engagement member
10
which is engaged with this driving gear
19
and to which the driving force of the pickup driving motor
6
is transmitted through the driving gears
18
and
19
is provided to be fixed to the optical disk
3
.
One ends of the guide members
4
and
5
are supported by support portions
11
and
12
, respectively, while the other ends of the guide members
4
and
5
are supported by an elevation member
20
provided to be movable in a direction perpendicular to the base
1
. The guide members
4
and
5
are tiltable about the support portions
11
and
12
, respectively by the elevation member
20
. The perpendicular movement of the elevation member
20
is based on the engagement of cam followers
20
a
formed on the both sides of the elevation member
20
with eccentric cams
22
fixed to the output shaft of tilt motors
21
fixed to the base
1
, respectively.
With the above-stated constitution, if the angle of the optical axis
3
a
of the optical pickup
3
with respect to the disk
16
is deviated from an angle at which the optical axis
3
a
is perpendicular to the disk
16
, the deviation is detected by a tilt detection element
17
. Based on the detected deviation, the tilt motors
21
rotate, the elevation member
20
engaged with these tilt motors
21
through the eccentric cams
22
and the cam followers
20
a
move in the perpendicular direction, respectively, whereby the guide members
4
and
5
tilt about the support portions
11
and
12
in the direction of the axis
3
a,
respectively. As a result, the optical pickup
3
supported by the guide members
4
and
5
are inclined with respect to the base
1
and the deviation of the optical axis
3
a
is adjusted.
However, if the angle adjusting device shown in Japanese Unexamined Patent Publication No. 10-116479 is developed to an angle control device for driving adjustment screws by a motor, the following problems occur. If the optical pickup
3
is moved in the disk diameter direction, it is necessary to exercise movement control while detecting the position of the optical pickup
3
. To do so, detection means such as a photo-interrupter is normally attached to either the pickup driving motor
6
or the screw member
7
, or the pickup driving motor
6
is used as a stepper motor and the position of the optical pickup
3
is detected using the driving pulse of the motor
6
, and the optical pickup
3
is moved to a predetermined position based on a detection result. In that case, the optical axis
3
a
of the optical pickup
3
thus moved does not sometimes agree with a target position on the disk to and from which information is to be recorded or reproduced. If the axis
3
a
does not agree with the target position, the optical characteristics of the optical pickup
3
may possibly deteriorate or the optical pickup
3
may be possibly required to be moved again, thereby disadvantageously increasing access time. The problems stated above will be described with reference to FIG.
7
.
FIG. 7
is a view showing the essential parts of the device described with reference to
FIG. 5
seen from a different observation point. FIG.
7
(
a
) is a top view seen from the direction of the optical axis
3
a
of the optical pickup
3
and FIG.
7
(
b
) is a side view of FIG.
7
(
a
) except for the screw member
7
. In FIG.
7
(
b
), reference symbol
10
a
denotes an incline
Huber Paul W.
Parkhurst & Wendel L.L.P.
LandOfFree
Pickup moving mechanism for optical disk apparatus and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pickup moving mechanism for optical disk apparatus and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pickup moving mechanism for optical disk apparatus and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3359968