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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for recording and/or
reproducing information by reciprocating an information recording medium
relative to a recording/reproducing head and, more particularly, to a card
carrier mechanism for stably reciprocating a card-like information
recording medium.
The form of the information recording medium may be of a disk-like medium
(e.g., a magnetic disk, an optical disk, and a magneto-optical disk), a
tape-like medium (e.g., a magnetic tape and an optical tape), or a
card-like medium (e.g., a magnetic card and an optical card). Among these
media, the card-like information recording medium (to be referred to as a
card hereinafter) has been popular due to its easy access, easy
fabrication, and portability. In particular, an optical card can be used
in high-density recording, and extensive studies thereon has been made in
recent years. An optical card will be exemplified below.
A conventional information recording/reproducing apparatus using such a
card scans data tracks in the card by reciprocating the card relative to a
recording/reproducing head to achieve information recording/reproduction.
FIG. 1A is a perspective view of a card drive mechanism in a conventional
information recording/reproducing apparatus, FIG. 1B is a schematic
sectional view of the apparatus taken along a direction of arrow A
thereof, and FIG. 1C is a schematic sectional view of a card insertion
portion.
An optical card 1 has a recording area 2, and information is recorded as a
pit train in the recording area 2. The pit trains are defined as
information tracks 3, respectively. Each information track 3 is scanned to
reproduce information. Information recording/reproduction can be performed
by using an optical beam 34 from a head 4.
The optical card 1 is clamped between drive rollers 5a, 5b, and 5c and
press rollers 6a, 6b, and 6c and can reciprocate along directions of the
double-headed arrow B. For illustrative convenience, the drive roller 5a
and the press roller 6a constitute a roller pair a; the rollers 5b and 6b,
a roller pair b; and the rollers 5c and 6c, a roller pair c.
The press rollers 6a, 6b and 6c are, rotatably supported by a connecting
plate 7. Both ends of the connecting plates 7 are connected to a frame 9
through springs 8a and 8b as biasing means. The press rollers 6a, 6b, and
6c are biased by the springs 8a and 8b to press the drive rollers 5a, 5b,
and 5c respectively.
The rotating shafts of the drive rollers 5a, 5b, and 5c rotatably extend
through the frame 9. Pulleys 10a, 10b, and 10c are fixed on the rotating
shafts, respectively. A rotational force of a motor 11 is transmitted to
the pulleys 10a, 10b, and 10c through a motor pulley 12 and timing belts
13a, 13b, and 13c, so that the drive rollers 5a, 5b, and 5c are rotated.
The nonclamped side of the optical card 1 clamped and reciprocated by the
roller pairs a, b, and c is urged by a leaf spring 14, and the clamped
side of the optical card 1 abuts against the frame 9. Therefore, the
optical card 1 receives the driving force upon rotation of the roller
pairs a, b, and c and reciprocates along the frame 9.
The head 4 can be moved at a position corresponding to the roller pair b
along directions of double-headed arrow D and emits a light beam onto the
recording area 2, as shown in FIG. 1B.
In order to reciprocate the optical card 1, the motor 11 is rotated in the
opposite directions. Position sensors 15 and 16 are arranged at two ends
of the moving range of the optical card 1 so as to provide the reversing
timings. A sensor 18 is arranged near a card insertion portion 17 to
detect that the optical card 1 has been inserted therefrom.
As shown in FIG. 1C, a gap t1 in the card insertion portion 17 and a
thickness t2 of the optical card 1 satisfy relation t2<t1, and a card
having a thickness exceeding a predetermined thickness cannot be inserted
in the card insertion portion 17.
In the conventional apparatus described above, since the optical card 1
reciprocates while clamped between the leaf spring 14 and the frame 9, the
surface at the nonclamped side of the optical card 1 is deviated in
directions (variations in surface level) of double-headed arrow E, as
shown in FIG. 1B. For this reason, the distance between the card surface
and the head 4 varies. It is thus difficult to always cause a focusing
servo circuit to accurately focus the beam from the head 4 onto the
optical card 1. As a result, recording and/or reproducing operation is
unstable. In the worst case, recording and/or reproduction cannot be
performed.
An objective lens in the head 4 may be driven by using an actuator having a
wide movable range so as to compensate for the distance variations.
However, the control system is complicated, and an expensive actuator must
be used. Therefore, the above arrangement does not provide a best
solution.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the conventional problem
described above and to provide a card drive mechanism capable of
minimizing variations in surface level of a card and an information
recording/reproducing apparatus using the card drive mechanism.
According to an aspect of the present invention, there is provided a drive
mechanism for reciprocating a card-like information recording medium,
comprising:
first guiding means adapted to be brought into contact with one end of the
information recording medium parallel to a card reciprocating direction;
second guiding means adapted to be brought into contact with the other end
of the information recording medium, the other end defining a plane
parallel to a plane of the card reciprocating direction; and
at least one roller for obliquely urging a ridge of the other end of the
information recording medium, the roller being adapted to urge the
information recording medium against the first and second guiding means.
According to another aspect of the present invention, there is provided a
drive mechanism for reciprocating a card-like information recording
medium, comprising: guiding means for guiding the card-like information
recording medium in the card reciprocating direction, and urging means for
urging the information recording medium against the guiding means, the
information recording medium being urged by a recess formed in the urging
means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a card drive mechanism in a conventional
information recording/reproducing apparatus;
FIG. 1B is a schematic sectional view of the apparatus of FIG. 1A when
viewed from a direction of arrow A;
FIG. 1C is a schematic sectional view of a card insertion portion;
FIG. 2A is a schematic view of a card drive mechanism in an information
recording/reproducing apparatus according to an embodiment of the present
invention;
FIG. 2B is a schematic perspective view of the drive mechanism in FIG. 2A;
FIGS. 3 and 4 are schematic views respectively showing modifications of the
card drive mechanism of FIG. 2A;
FIG. 5A is a schematic plan view of a card drive mechanism in an
information recording/reproducing apparatus according to another
embodiment of the present invention;
FIG. 5B is a front view of the card drive mechanism in FIG. 5A;
FIG. 6A is a schematic sectional view of a card drive mechanism in an
information recording/reproducing apparatus according to still another
embodiment of the present invention;
FIG. 6B is a schematic perspective view of a guiding means and an urging
means in the card drive mechanism in FIG. 6A;
FIGS. 7 and 8 are schematic perspective views respectively showing
modifications of the guiding and urging means in the drive mechanism in
FIG. 6A;
FIG. 9A is a schematic plan view showing guiding and urging means in a
drive mechanism in an information recording/reproducing apparatus
according to still another embodiment of the present invention;
FIG. 9B is a front view of the guiding an urging means in the drive
mechanism in FIG. 9A;
FIG. 10A is a schematic plan view showing guiding and urging means in a
card drive mechanism in an information recording/reproducing apparatus
according to still another embodiment of the present invention;
FIG. 10B is a front view of the guiding and urging means in FIG. 10A;
FIG. 11 is a schematic front view showing a modification of the card drive
mechanism in FIGS. 10A and 10B; and
FIG. 12 is a diagram showing an information recording/reproducing apparatus
according to still another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2A is a schematic sectional view of a card drive mechanism in an
information recording/reproducing apparatus according to an embodiment of
the present invention, and FIG. 2B is a schematic perspective view
thereof. The same reference numerals as in FIGS. 1A to 1C denote the same
parts in FIGS. 2A and 2B, and a detailed description thereof will be
omitted.
Referring to FIGS. 2A and 2B, an optical card 1 clamped by roller pair b
receives a driving force in one of the directions of double-headed arrow B
upon rotation of the roller pair b. One side edge of the optical card 1 is
in contact with a frame 9 as a guiding means. The lower surface portion at
the other side edge of the optical card 1 is in contact with a guide
surface 36 of a guide frame 35. A plate 37 is fixed on the guide frame 35.
Rollers 38a, 38b, and 38c are rotatably mounted on a bent portion (bent at
an angle of 45.degree.) of the plate 37. The rollers 38a, 38b, and 38c can
be brought into cantact with a ridge 1' of the optical card 1 to obliquely
urge the optical card 1.
The optical card 1 is thus positioned by the frame 9 and the guide frame 35
and can stably reciprocate in directions of double-headed arrow 8 without
variations in its surface level.
Since the rollers 38a, 38b, and 38c simply urge the optical card 1, they
may be made of a material of a high rigidity or elasticity. It is
desirable to use an elastic member such as a spring to constitute the
plate 37.
If the rollers 38a, 38b, and 38c obliquely urge the ridge 1 of the optical
card, the shape of the rollers are not limited to the one illustrated in
FIGS. 2A and 2B but can be modified as shown in FIGS. 3 and 4.
FIGS. 3 and 4 are schematic views showing the modifications of the card
drive mechanism in FIGS. 2A and 2B.
As shown in FIG. 3, a plate 37' is fixed on the guide frame 35, and
frustoconical rollers 39a, 39b, and 39c are rotatably mounted on the plate
37' to obliquely urge the ridge 1' of the optical card 1.
As shown in FIG. 4, frustoconical rollers 40a, 40b, and 40c are rotatably
mounted on a plate 37" fixed on the guide frame 35 to obliquely urge the
ridge 1' of the optical card 1.
FIG. 5A is a schematic plan view of a card drive mechanism according to
another embodiment of the present invention, and FIG. 5B is a front view
thereof.
As shown in FIGS. 5A and 5B, rollers 41a, 41b, and 41c serve as the driving
and guiding means. An outer surface of each roller which is brought into
contact with an optical card 1 constitutes a V-shaped recess. A ridge 1'
of the optical card 1 is obliquely urged against a guide frame 35 and the
rollers 41a, 41b, and 41c by rollers 38a, 38b, and 38c. Upon rotation of
the rollers 41a, 41b, and 41c, the optical card 1 can stably reciprocate
without variations in its surface level.
In this embodiment, most of the surface of the card 1 can be used, and a
recording area 2, and therefore the recording capacity, can be increased.
In addition, since the optical card 1 is not brought into contact with a
frame 9, the number of sliding portions and hence the load of the drive
system can be reduced.
In each of the card-like recording medium drive mechanisms in FIGS. 2A to
5B, the rollers obliquely urge the ridge of the corresponding card-like
information recording medium, and the information recording medium can be
firmly urged against the first and second guiding means. In particular,
the variations in distance between the surface of the information
recording medium and the recording/reproducing head can be eliminated.
Therefore, stable reciprocal movement of the information recording medium
can be guaranteed.
Accurate focusing can be performed as a result of variation elimination,
and reliability of recording and/or reproduction can be greatly improved.
FIGS. 6A and 6B are views showing a card drive mechanism in an information
recording/reproducing apparatus according to still another embodiment of
the present invention. FIG. 6A is a schematic view showing the card drive
mechanism, and FIG. 6B is a schematic perspective view of guiding and
urging means thereof. The same reference numerals as in FIGS. 1A to 1C
denote the same parts in FIGS. 6A and 6B, and a detailed description
thereof will be omitted.
Referring to FIGS. 6A and 6B, an optical card 1 clamped by a roller pair b
receives a driving force along one of the directions of double-heated
arrow B upon rotation of the roller pair b. One side edge (along
directions of double-headed arrow B) of the optical card 1 is brought into
contact with a frame 9 serving as a guiding means. The other side edge of
the optical card 1 is urged along a recess 52 formed in a leaf spring 51.
When the optical card 1 reciprocates along one of the directions of
double-headed arrow B and is guided by the frame 9, variations in surface
level along directions of double-headed arrow E are eliminated, and the
distance between the surface of the optical card 1 and a head 4 can be
always kept constant.
The recess of the urging means need not be formed by bending the leaf
spring 51 as in the following description. Another material (e.g., a
plastic material having a low friction coefficient) may be used in
consideration of anti-wear and friction load properties of the optical
card 1. Alternatively, the shape of the recess may be arbitrarily
determined in consideration of the thickness of the optical card 1.
As shown in FIG. 7, a plastic member with a V-shaped recess 53 may be
mounted on the leaf spring 51. Alternatively, as shown in FIG. 8, a
,member with a U-shaped recess 54 is mounted on the leaf spring 51, and by
this means variations in surface level of the optical card 1 can be
further prevented.
FIG. 9A is a schematic plan view of guiding and urging means in a card
drive mechanism according to still another embodiment of the present
invention, and FIG. 9B is a front view thereof.
In this embodiment, an optical card 1 is urged along a recess 52 in a leaf
spring 51 in the same manner as in the embodiment of FIGS. 6A and 6B.
However, the roller arrangement for reciprocating the optical card 1 in
directions of double-headed arrow B is different from that in the
embodiment of FIGS. 6A and 6B.
As shown in FIGS. 9A and 9B, rollers 55a, 55b, and 55c are positioned at
proper intervals so as to stably drive the optical card 1. Each roller has
a V-shaped outer surface to be brought into contact with the optical card
1. Upon rotation of the rollers 55a, 55b, and 55c, the optical card 1 can
reciprocate along directions of double-headed arrow B. In this embodiment
the rollers 55a, 55b and 55c serve as both the guiding and driving means.
Since the optical card 1 is urged against the V-shaped contact surfaces of
the rollers 55a, 55b, and 55c by the recess 52 in the urging means,
variations in surface level of the optical card 1 can be prevented.
FIG. 10A is a schematic plan view of guiding and urging means according to
still another embodiment of the present invention, FIG. 10B is a front
view thereof, and FIG. 11 is a schematic front view showing a modification
thereof.
As shown in FIGS. 10A and 10B, the optical card 1 is clamped at its both
sides by the rollers 55a, 55b, and 55c each with a V-shaped card contact
surface and rollers 56a, 56b, and 56c. The rollers at one side serve as
press rollers. The driving rollers for reciprocating the optical card 1
along the directions of double-headed arrow B may be the rollers of either
side. The optical card 1 in this embodiment is urged by the rollers 56a,
56b, and 56c each with the V-shaped card contact surface and can be guided
to reciprocate along directions of double-headed arrow B.
The shape of the roller may be of rollers 57a, 57b and 57c and rollers 58a,
58b, and 58c, as shown in FIG. 11. These rollers respectively have annular
guide grooves for receiving the optical card 1. With this arrangement,
variations in surface level of the optical card 1 can be more effectively
prevented.
The drive mechanism for clamping the optical card 1 at both sides thereof
by the rollers guarantees the wide area of the surface of the card 1 and
the recording area 2, thereby greatly increasing the recording capacity.
The card-like information recording medium is urged along the recess in the
urging means, variations in surface level of the optical card 1 in a
direction perpendicular to the reciprocal movement plane for the
information recording medium can be prevented, and stable reciprocal
movement of the recording medium can be performed. As a result, accurate
focusing can be performed, and reliability of recording and/or
reproduction can be greatly improved.
FIG. 12 is a view showing an information recording/reproducing apparatus
with a card drive mechanism of the present invention.
Referring to FIG. 12, a head 4 comprises a laser 19, a collimator lens 20,
a beam splitter 21, an objective lens 22, and a photosensor 23. An output
from the photosensor 23 is input to a preamplifier (PRE-AMP) 24. By using
an output from the preamplifier 24, auto-focusing (to be referred to as an
AF hereinafter) and auto-tracking (to be referred to as an AT hereinafter)
are respectively performed by an AF servocircuit 25 and an AT servo
circuit 26. More specifically, the objective lens 22 is moved in one of
the directions of double-headed arrow C by the AF servo circuit to focus a
beam 34. The objective lens 22 is slightly moved by the AT servo circuit
26 in one of the directions of double-headed arrow B to allow the beam
spot to trace each information track 3.
The output from the preamplifier 24 is decoded by a decoder (DE-CODER) 27,
and the decoded signal is output to an external device through an
interface 29 on the basis of an instruction from a controller 28.
In order to record information, the information is encoded by an encoder 30
to drive a laser driver 31, and a high-power modulated beam is output from
the laser 19 to form a pit train in a recording area 2 of the optical card
1. The head 4 can be driven by a stepping motor 32 in directions of
double-headed arrow B. A motor 11 for reciprocating the optical card 1 is
controlled by a motor servo circuit 33 on the basis of outputs from
positions sensors 15 and 16, and a sensor 18.
In the above description, the optical card is exemplified. However, the
card drive mechanism of the present invention is applicable to a magnetic
card. The present invention is also applicable to a ROM card drive
mechanism for only reproduction when a ROM card is used as an optical card
.
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