Dynamic information storage or retrieval – Storage or retrieval by simultaneous application of diverse... – Magnetic field and light beam
Reexamination Certificate
2000-05-05
2002-04-09
Dinh, Tan (Department: 2651)
Dynamic information storage or retrieval
Storage or retrieval by simultaneous application of diverse...
Magnetic field and light beam
C369S013340
Reexamination Certificate
active
06370088
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a photomagnetic recording/reproduction apparatus (so-called mini-disk (MD) recorder) for performing photomagnetic recording on a disk-like recording medium (photomagnetic disk) and reproduction therefrom by converting an analog signal such as an audio signal, or the like, into a digital signal.
A photomagnetic recording/reproduction apparatus (MD recorder) for performing recording on a photomagnetic disk by converting an analog audio signal into a digital signal has been recently rapidly popularized as an audio signal recording/reproduction apparatus in place of an analog cassette recorder. Various techniques have been proposed to attain improvement of handling property of the photomagnetic recording/reproduction apparatus. For example, Japanese Patent Publication No. 9-213031A has disclosed a photomagnetic recording/reproduction apparatus in which searching for a target position can be performed at a high speed. For example, Japanese Patent Publication No. 9-44975A has disclosed a photomagnetic recording/reproduction apparatus in which an editing process such as track dividing, track erasing, etc. can be performed easily.
FIGS. 4
to
7
schematically show a series of operations in such a photomagnetic recording/reproduction apparatus in the case where a photomagnetic disk (hereinafter merely referred to as disk) is loaded into an apparatus body. Incidentally,
FIGS. 4A
,
5
A,
6
A and
7
A are schematic side sectional views and
FIGS. 4B
,
5
B,
6
B and
7
B are schematic top views.
That is, if a user inserts a disk
1
, through an insertion hole
2
a
of an apparatus body
2
, into a movable holder
3
provided in the inside of the apparatus body
2
(in a direction of an arrow X in FIG.
4
), a motor not shown but provided in the inside of the apparatus body
2
is driven so that the disk
1
is led into the movable holder
3
automatically at a point of time when the disk
1
has been inserted to a certain position A (FIG.
5
). At the same time, the movable holder
3
itself is loaded in the X direction to a reproducing position (position shown in
FIG. 6
) opposite to a photo pick-up
4
disposed in the inside of the apparatus body
2
. That is, this is a state in which reproduction is enabled to be started. In this state, the photo pick-up
4
is located on a line L which is in a direction (disk scanning direction) Y perpendicular to the X direction (hereinafter also referred to as loading direction X) and which passes through a center point O of the disk
1
.
When the disk
1
is rotated in this state and the photo pick-up
4
is moved in the disk scanning direction Y on the line L, an audio signal is reproduced from the disk
1
.
On the other hand, in a recording mode, a magnetic head
5
is moved down to a recording position (see
FIG. 7
) so as to come into contact with the disk
1
, so that the reproducing state shown in
FIG. 6
is changed to a recording-enabled state. That is, this is a state in which recording is enabled to be started. In this state, the photo pick-up
4
and the magnetic head
5
vertically opposite to each other are located on the line L which is in the disk scanning direction Y and which passes through the center point O of the disk
1
.
When the disk
1
is rotated in this state and the photo pick-up
4
and the magnetic head
5
are integrally moved in the disk scanning direction Y on the line L, an audio signal is recorded on the disk
1
.
In order to control various operations such as leading of the disk
1
into the movable holder
3
, loading of the movable holder
3
, positioning of the disk
1
and the photo pick-up
4
by the loading in the reproducing position, descending of the magnetic head
5
, positioning of the descended magnetic head
5
and the disk
1
in the recording position, and positioning of the disk
1
and the photo pick-up
4
in the reproducing position by ascending the magnetic head
5
which has been in the descended position, it is necessary to provide detecting switches for detecting the aforementioned positions and states in the apparatus body
2
.
In this occasion, in order to detect the operations one by one accurately, it is ideal to provide an exclusive detecting switch for every operation. It is, however, difficult in terms of cost and practically impossible in terms of complication of an internal mechanism, a problem of arrangement space, etc. to provide a detecting switch for every operation. Therefore, a measure to allow all the operations to be controlled by the smallest number of detecting switches has been taken in the related photomagnetic recording/reproduction apparatus. Although there is a difference in accordance with the structure of the internal mechanism, all the operations can be generally controlled by three detecting switches.
That is, though not shown in
FIGS. 4
to
7
, there are provided an insertion position detecting switch SW
1
for detecting the fact that the disk
1
has been inserted (that is, the disk
1
has been inserted to reach the position A shown in FIG.
5
), a reproducing position detecting switch SW
2
for detecting the fact that the movable holder
3
holding the disk
1
has reached the reproducing position (position shown in
FIG. 6
) of the disk
1
, and a recording position detecting switch SW
3
for detecting the fact that the magnetic head
5
has come into contact with the disk
1
in the reproducing position. Each of the detecting switches SW
1
to SW
3
is constituted by a limit switch.
The aforementioned various operations such as leading of the disk
1
into the movable holder
3
, loading of the movable holder
3
, positioning of the disk
1
and the photo pick-up
4
in the reproducing position by the loading, descending of the magnetic head
5
, positioning of the descended magnetic head
5
and the disk
1
in the recording position, and positioning of the disk
1
and the photo pick-up
4
in the reproducing position by ascending the magnetic head which has been descended, are generally driven by one motor. Accordingly, configuration is made so that the series of operations interlock with one another mechanically. For this reason, the movable holder
3
holding the disk
1
moves delicately, for example, even in the case of a descending or ascending operation of the magnetic head
5
.
As described above, each of the detecting switches SW
1
to SW
3
is constituted by a limit switch. The limit switch can perform accurate positional detection in one direction because the detection is made in a direction (open to close) in which a movable contact point comes into contact with a fixed contact point. There is, however, a problem that the limit switch can hardly perform accurate positional detection in the other direction because the detection is made in a direction (close to open) in which the movable contact point separates from the fixed contact point.
As described above, the reduction in number of detecting switches to the required smallest number, the mechanism configuration in various operations driven by one motor to interlock with one another, and the provision of the detecting switches each constituted by a limit switch make it possible difficult to perform positional detection accurately in one direction while make it difficult to perform positional detection accurately in the other direction. Hence, the following disadvantage occurs.
The disadvantage will be described below with reference to FIG.
8
.
FIG. 8
is a time chart showing the respective detecting switches SW
1
to SW
3
which are arranged rightward in a sequence of detection in the case where a disk I is loaded into the apparatus body
2
. Each of the detecting switches SW
1
to SW
3
is arranged to make an operation of “open to close” when rightward force in
FIG. 8
is applied to the switch. Further, the direction of rotation of the motor to move the disk
1
in a direction (rightward in
FIG. 8
) of insertion of the disk
1
into the apparatus body
2
is defined as a direction of reverse rotation (CCW) whereas the dir
Dinh Tan
Funai Electric Co. Ltd.
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