Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
2001-06-27
2003-08-05
Psitos, Aristotelis M. (Department: 2653)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S030930
Reexamination Certificate
active
06603721
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to technology for accurately moving a turntable comprising a plurality of disk mounting portions to a scanning position and, more particularly, to a method and an apparatus for controlling the rotation of a turntable which is capable of instantly and accurately moving a disk mounting unit selected by a user to a scanning point regardless of rotation speed variation or aging of parts etc. due to variation of load quantity.
2. Description of the Prior Art
Generally, a disk player is utilized for reproducing data recorded on a disk in video or audio format. However, because all data cannot be recorded on one disk, e.g., when the quantity of data provided to the one disk is too large or the kind of data varies, such as a movie, etc., several disks are required in order to record the data. In this case, a user has to change the disk to record all the data. Accordingly, in order to solve the above-mentioned inconvenience, a disk player is utilized which comprises a disk mounting portion for accommodating a plurality of disks.
FIG. 1
is a plan view illustrating a general turntable which is capable of containing five disks. The turntable
1
comprises an upper surface
1
a
and back surface
1
b.
The turntable
1
, installed rotatively, comprises five disk mounting portions
2
A,
2
B,
2
C,
2
D,
2
E at the upper surface
1
a
in order to mount five disks, and the disk mounting portions
2
A~
2
E comprise a pickup moving slot
3
in order to make a pickup P movable from a main body unit and irradiate a disk. The disk mounting portion is formed so as to accommodate mountable disks having 8 cm diameter and 12 cm diameter.
A rib
4
for distinguishing each disk mounting portion is placed on the back surface
1
b
of the turntable by forming a protrusion portion having a certain number of sawteeth at a position of concentric circles of a rotation center of the turntable
1
. The rib
4
comprises a plurality of position sensing ribs
4
A (the number of position sensing ribs in
FIG. 1
is five) for generating different number of pulses at a certain position respectively, and a position sensing auxiliary rib
4
B placed among the position sensing ribs
4
A in order to generate pulses with a certain interval. Each position sensing rib
4
A is formed on a lead position of the each disk mounting portions
2
A~
2
E on the centering around rotation direction of the turntable
1
, and the position sensing auxiliary rib
4
B is formed among the position sensing ribs
4
A. Accordingly, as depicted in
FIG. 3
, each position sensing rib
4
A for recognizing the first disk mounting portion
2
A comprises two ribs
4
A
1
a,
4
A
1
b
and a slot
4
A
2
, and the position sensing rib
4
A for recognizing the second disk mounting portion
2
B further comprises a rib and a slot. And, as depicted in
FIG. 3
, the position sensing auxiliary rib
4
B comprises four ribs
4
B
1
a,
4
B
1
b,
4
B
1
c,
4
B
1
d
sequentially among a plurality of auxiliary slots
4
B
2
a,
4
B
2
b,
4
B
2
c.
In addition, as depicted in
FIG. 2
, the turntable
1
is installed rotatively on a base
8
, and a position sensor
6
, including a luminous unit
6
A and a light receiving unit
6
B, is installed on a printed circuit board placed on the base
8
so as to correspond to the rib
4
. When the turntable
1
rotates, because the rib
4
passes between the luminous unit
6
A and light receiving unit
6
B, the position sensor
6
outputs a high or a low pulse corresponding to a shape of the rib
4
, the high or low pulse being provided to a control unit such as a microcomputer through the printed circuit board
7
.
Herein, a guide rib
5
having a circular shape is formed on the outer side of the rib
4
. A protrusion supporting unit
8
A is formed on the base
8
so as to correspond to the guide rib
5
and a felt
9
, as a friction member, is fixedly adhered to the protrusion supporting unit
8
A. Accordingly, because the guide rib moves along the felt
9
, installed on the correspondence surface of the lower part, sag of the turntable
1
can be prevented.
The operation in accordance with the prior art will now be described as follows:
Because the turntable
1
comprises the five disk mounting portions
2
A~
2
E, five disks can be mounted at the same time. One disk mounting portion selected by a user is rotatively moved to a reproducing position, namely, the scanning position of the pickup P. Accordingly, data recorded on the pertinent disk is reproduced. As described above, in order to retrieve a user select disk among the plurality of disks, original numbers are given to the disk mounting portions
2
A~
2
E, respectively. A microcomputer (not shown) controls the rotation of the turntable
1
while grasping the present position of the disk mounting portions
2
A~
2
E by using the circular shaped ribs
4
installed on the backward center of the turntable
1
and position sensor
6
, and makes the pertinent disk mounting unit stop at the reproducing position.
In other words, as depicted in
FIG. 1
, when a motor (not shown) operates and the rotating force is transmitted to the turntable
1
, the turntable rotates in the clockwise direction. As depicted in
FIG. 2
, when the turntable
1
rotates, the rib
4
passes between the luminous unit
6
A and light receiving unit
6
B of the position sensor
6
. Herein, as depicted in
FIG. 3
, when the rib
4
is placed between the luminous unit
6
A and light receiving unit
6
B, because light projected from the luminous unit
6
A is blocked by the rib
4
, the light is not incident to the light receiving unit
6
B, and the position sensor
6
outputs a low pulse. However, when a slot is positioned between the luminous unit
6
A and light receiving unit
6
B, the light is incident to the light receiving unit
6
B; and, accordingly, the position sensor
6
outputs a high pulse.
For example, when the turntable
1
rotates in the arrow direction in
FIG. 1
, the position sensing rib
4
A for recognizing the first disk mounting portion
2
A passes between the luminous unit
6
A and light receiving unit
6
B of the position sensor
6
, followed by the position sensing auxiliary rib
4
B passes. As depicted in
FIG. 3
, a high pulse
10
is outputted by the position sensing slot
4
A
2
, and three high pulses
12
,
13
,
14
including a high pulse
11
at a boundary portion are outputted sequentially by the auxiliary slots
4
B
2
a,
4
B
2
b
and
4
B
2
c
of the position sensing auxiliary rib
4
B.
FIG. 5
is a flow chart illustrating a method for controlling the rotation of the turntable in accordance with the conventional art. In order to make the first disk mounting portion
2
A stop at a reproducing position, when the motor operates and the rotating force is transmitted to the turntable
1
(step S
1
), because the slot is one and one high signal occurs when the position sensing rib
4
A passes, the microcomputer recognizes the first disk mounting portion
2
A (step S
2
).
Herein, the microcomputer senses the high signal
12
informing the passage of the first auxiliary slot
4
B
2
a
of the position sensing auxiliary rib
4
B, and cuts off the operating voltage by commanding a stop signal after a certain time Td in order to stop the rotation of the motor (steps S
3
, S
4
, S
5
). According to this procedure, although the driving force of the motor is not transmitted, the turntable
1
rotates more by the rotational inertia force, and stops.
By the same principle, when the position sensing rib
4
A for recognizing the second disk mounting portion
2
B passes between the luminous unit
6
A and lighting unit
6
B of the position sensor
6
, two high pulses are outputted, and when the position sensing rib
4
A for recognizing the fifth disk mounting portion
2
E passes therebetween, five high pulses are outputted.
As described above, the microcomputer moves a user select disk mounting portion to a retrieval position by controlling the rotation of the turntable
1
on the basis of the position senso
Kim Dong Sik
Lee Dong Woo
Birch & Stewart Kolasch & Birch, LLP
LG Electronics Inc.
Psitos Aristotelis M.
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