Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Reexamination Certificate
1999-05-21
2001-09-25
Huber, Paul W. (Department: 2651)
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
C369S044150, C369S044220, C369S112290
Reexamination Certificate
active
06295255
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application Nos. 98-18384, filed May 21, 1998, 98-21325, filed Jun. 9, 1998 and 98-52512, filed Dec. 2, 1998, in the Korean Patent Office, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical pickup for irradiating light onto a recording medium to record information in the recording medium and to read information therefrom, and more particularly, an optical pickup having a tilt mechanism to adjust an optical axis of an incident light beam to compensate for tilting of a recording medium such as an optical disk.
2. Description of the Related Art
In general, an optical recording/reproducing apparatus such as a disk player, for recording information in a recording medium such as an optical disk and reproducing information therefrom, comprises an optical pickup for reading information from light that is irradiated onto the optical disk and then reflected therefrom. In a conventional optical pickup, as shown in
FIGS. 1 and 2
, a base plate
21
is installed on a fixed base
20
, and a bobbin
23
in which an objective lens
19
is mounted is movably supported by wires
28
in a fixed block
22
situated on the base plate
21
. Also, a focusing coil
26
for controlling the focus of a spot of light formed on an optical disk
30
, and a tracking coil
27
for laterally moving the objective lens
19
such that the spot of light formed on the optical disk
30
accurately tracks the tracks (not shown) of the optical disk
30
, are installed in the bobbin
23
. The bobbin
23
moves by an electromagnetic force due to interaction between a current flowing through the focusing coil
26
and the tracking coil
27
, and the magnetic field produced by a magnet
25
and a yoke
24
installed in the base plate
21
. A reflecting mirror
18
for changing an optical path, and a fixed optical system
10
for irradiating light from the reflecting mirror
18
to the optical disk
30
and receiving the light reflected by the optical disk
30
are placed below the objective lens
19
. As shown in
FIG. 1
, the fixed optical system
10
includes a light source
11
, a beam splitter
13
, a collimating lens
14
, a detecting lens
15
and a photodetector
12
. Also, each semispherical base of the fixed base
20
and the base plate
21
contact each other and are coupled by a plurality of adjusting screws
41
,
42
and
43
, such that the tilt of the base plate
21
with respect to the fixed base
20
can be adjusted by tightening the plurality of adjusting screws
41
,
42
and
43
. This structure is suitable for correcting an error through the controlling of the fightness of the adjusting screws
41
,
42
and
43
during the assembly process in the case when an optical axis C of light incident through the objective lens
19
perpendicularly onto the optical disk
30
is tilted, that is, when the light is obliquely incident, not perpendicularly, onto the optical disk
30
. Reference numeral
50
represents a controller for controlling the focusing and tracking operations, and reference S represents a compression spring.
However, the optical disk
30
may be tilted due to vibration during the recording/reproducing operation as well as during the assembly process, and the optical disk
30
may not be level due to minute deformations of the optical disk
30
itself. However, the conventional optical disk can not cope with such a problem. In other words, even when the tilt of the optical axis C during the assembly can be corrected, the tilting of the optical axis C during the recording/reproducing operation after the assembly process cannot be corrected. As a result, the intensity of light formed on the optical disk is not strong enough for the recording operation and a playback signal is deteriorated, so that it is difficult to accurately reproduce the information.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an optical pickup adopting an enhanced structure in which the tilt of an optical axis of a light being incident onto and reflected from an optical disk through a reflecting mirror and an objective lens is controlled such that the light is perpendicularly incident onto and reflected from the recording medium at all times.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To achieve the above and other objects of the present invention, according to an aspect of the object, there is provided an optical pickup comprising: a fixed base; a base plate rotatably installed with respect to the fixed base; a bobbin seated on the base plate, being movably supported by wires; an objective lens for focusing an incident light to form a spot of light on a recording medium, the objective lens mounted in the bobbin; a focusing coil serving as a current flow path for a focusing operation, the focusing coil installed on the bobbin; first magnets and first yokes for producing magnetic fields perpendicular to the current flowing through the focusing coil to produce an electromagnetic force for driving the bobbin, the first magnets and first yokes installed on the base plate; a fixed optical system for irradiating the incident light toward the recording medium and receiving the light reflected by the recording medium and then passed through the objective lens; a reflecting mirror for changing the traveling path of the incident light, the reflecting mirror arranged between the objective lens and the fixed optical system, and fixed to the base plate; a support arm having one end fixed to the fixed base and the other end rotatably supporting the reflecting mirror, serving as a rotary shaft of the base plate to which the reflecting mirror is fixed; and a tilt mechanism for rotating the base plate using the support arm as a rotary shaft, to adjust the tilt of an optical axis passing through the objective lens and the reflecting mirror.
To achieve the above and other objects of the present invention, according to another aspect of the object, there is provided an optical pickup comprising: a fixed base; a base plate installed rotatable with respect to the fixed base; a hollow boss formed to protrude on the base plate; a bobbin coupled to the boss to be movable in the vertical direction; an objective lens for focusing an incident light to form a spot of light on a recording medium, the objective lens mounted in the bobbin; focusing coils serving as a current flow path for a focusing operation, the focusing coils installed on the bobbin; first magnets and first yokes for producing magnetic fields perpendicular to the current flowing through the focusing coils to produce an electromagnetic force for driving the bobbin, the first magnets and first yokes installed on the base plate; a fixed optical system for irradiating the incident light toward the recording medium and receiving the light reflected by the recording medium and then passed through the objective lens; a reflecting mirror for changing the traveling path of the incident light, the reflecting mirror arranged between the objective lens and the fixed optical system, and fixed to the base plate; a support arm having one end fixed to the fixed base and the other end rotatably supporting the reflecting mirror, serving as a rotary shaft of the base plate to which the reflecting mirror is fixed; and a tilt mechanism for rotating the base plate using the support arm as a rotary shaft, to adjust the tilt of an optical axis passing through the objective lens and the reflecting mirror.
To achieve the above and other objects of the present invention, according to still another aspect of the object, there is provided an optical pickup comprising: a fixed base; a base plate positioned within the fixed base, and supported by springs to be rotatable relative to the fixed base; a bobbin seated on the base
Cheong Young-min
Choi Han-kook
Park Hee-deuk
Park In-sik
Seo Young-sun
Huber Paul W.
Samsung Electronics Co,. Ltd.
Staas & Halsey , LLP
LandOfFree
Optical pickup having a tilt mechanism to adjust an optical... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical pickup having a tilt mechanism to adjust an optical..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical pickup having a tilt mechanism to adjust an optical... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2436639