JP2001283488A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording and reproducing device capable of obtaining a stable pinch pressing force even if a plate thickness is reduced in a pinch-arm part. SOLUTION: With the purpose of moving the two loading and unloading positions, for the pinch-arm in which the axis of a pinch-roller is provided, a two section link mechanism is used, nearly equalizing a distance between the engaging point of the link and the rotary center of the pinch-arm to a distance between the rotary center of the pinch-arm and the axis of the pinch- roller. A pinch pressing spring generating the pressing force is constructed with a compressing spring and arranged inside the link mechanism, thereby directly imparting the spring load to the engaging point on the pinch-arm of the link mechanism. Further, in the loading state, all the engaging points of the link are designed to be positioned nearly in a straight line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus using a magnetic tape.

[0002]

2. Description of the Related Art A cassette type magnetic recording / reproducing apparatus which draws out a magnetic tape from a tape cassette, winds the magnetic tape around an outer periphery of a rotary head cylinder, and records / reproduces a video signal utilizing interaction with a head provided on the rotary cylinder is known. Is known. In this type of apparatus, it is necessary to run a magnetic tape at a constant speed during recording and reproduction. For this,
A magnetic tape is sandwiched between a capstan attached to a motor that rotates at a constant speed and a driven pinch roller made of an elastic body, and the magnetic tape is driven in a predetermined traveling direction. In the case of a magnetic recording / reproducing apparatus in which the capstan is in contact with the outer surface (magnetic surface) of the magnetic tape, the pinch roller is arranged so as to be in contact with the inner surface (non-magnetic surface) of the magnetic tape. When the magnetic tape is not wound around the rotary head cylinder, the pinch roller is waiting in the magnetic tape loop of the tape cassette at a position away from the capstan. As the magnetic tape is wound around the rotary head cylinder, the magnetic tape is simultaneously sandwiched between the capstan and the pinch roller. At this time, it is necessary to press the pinch roller against the capstan with a predetermined force (hereinafter, referred to as pressure bonding).

[0003] If the pressing force (hereinafter referred to as the pressing force) is too low, the slip between the capstan and the magnetic tape becomes large and it becomes difficult to run at a constant speed. If the crimping force is too high, the magnetic tape will be damaged, the motor current will increase,
Further, this leads to a problem such as a reduction in the life of the capstan bearing. Therefore, the crimping force must be a stable value satisfying the above conditions. The crimping mechanism of the pinch roller
First, the pinch roller waits away from the capstan
(A position in the unloading state) and a second position (the loading position) where the magnetic tape is interposed and pressed against the capstan, and a mechanism that can generate a stable pressing force is required. And A conventional pinch roller pressing mechanism in a magnetic recording / reproducing apparatus will be described below. FIG. 6 is a plan view of an essential part of a pinch roller pressing mechanism of a conventional magnetic recording / reproducing apparatus in an unloaded state, FIG. 7 is a plan view of a loading state of the pinch roller pressing mechanism, and FIG. It is a side sectional view of a part.

In FIG. 8, a pinch roller 1 is rotatably mounted on a pinch roller shaft 34 caulked by a pinch arm 2 via a bearing 35. A pinch arm boss 21 is caulked at the center of rotation of the pinch arm 2 and forms a rotation bearing of the pinch arm 2. A pinch charge arm boss 37 is caulked to the pinch charge arm 36. The pinch arm 2 and the pinch charge arm 36 are engaged by inserting the pinch charge arm boss 37 on the outer periphery of the pinch arm boss 21 so that their centers of rotation coincide with each other.

In FIG. 6, the pinch arm 2 is biased so as to rotate clockwise, and the pinch charge arm 36 is biased so as to rotate counterclockwise. 2a, and the other end 4b is attached to a stopper 36a of the pinch charge arm 36. A cam gear 12 driven via a loading motor and various reduction gear trains for transmitting its power, which are not shown in FIGS. 6 and 7, is mounted on the main chassis 102. The cam gear 12 is provided with a cam groove 12a.
The main arm 39 having the cam follower pin 39a is installed so as to rotate with respect to the main chassis 102 at the center of rotation 39b. Cam follower pin 3
9 a is inserted into the cam groove 12 a of the cam gear 12.

The main arm 39 has an elongated cam portion 3.
9c is provided, and a cam pin 36b provided on the pinch charge arm 36 is inserted into the cam portion 39c. 6 and 7, the capstan 3 is disposed on the main chassis 102. The illustration of a capstan motor section for rotating the capstan 3 is omitted. First, the unloading state shown in FIG. 6 will be described. The pinch roller 1 is in a loop of the magnetic tape 100 of the tape cassette (not shown).

Next, the operation for shifting to the loading state of FIG. 7 will be described. In the unloading state shown in FIG. 6, when the cam gear 12 rotates clockwise by a loading motor (not shown), the main arm 39 also rotates clockwise. As a result, the cam portion 39c provided on the main arm 39 drives the cam pin 36b provided on the pinch charge arm 36, and the pinch arm 2 and the pinch charge arm 36 start rotating clockwise by the pinch arm shaft 26. As the cam gear 12 continues to rotate further, the pinch roller 1 moves upward in FIG.
It reaches the position in contact with the capstan 3 with 0 interposed.

Although the cam gear 12 continues to rotate, the pinch roller 1 hits the capstan 3 so that the pinch arm 2 cannot rotate any further. However, since the pinch charge arm 36 further continues to rotate clockwise, the other end 4b of the pinch press-fit spring 4 is pushed by the stopper 36a of the pinch charge arm 36 and rotates clockwise to move between the two stoppers 2a and 36a. Open. As a result, one end 4a pushes the stopper 2a of the pinch arm 2 by the elastic force of the pinch crimp spring 4. Due to the elastic force of the pinch compression spring 4 pressing the stopper 2a, the pinch roller 1
The magnetic tape 100 is sandwiched and pressed to the capstan 3.
The cam gear 12 stops rotating in this state. The cam gear 1 moves from the loading position to the unloading position.
It operates reversibly by rotating 2 in the opposite direction.

[0009]

In the conventional pinch roller press-fitting mechanism, the pinch press-fit spring 4 of the torsion coil spring is used.
Wants to reduce the diameter of the torsion coil to reduce its occupied space. However, the diameter cannot be reduced too much to maintain the desired elasticity. Since the distance between the pinch roller shaft 34 and the pinch arm shaft 26 is about four times as large as the distance between the stopper 2a of the pinch arm 2 and the pinch arm shaft 26, the urging force of the pinch compression spring 4 needs to be correspondingly increased. There is. Therefore, the pinch arm 2 and the pinch charge arm 36 that support the load of the pinch crimp spring 4 need to be made of a relatively thick metal plate because the pinch arm 2 and the pinch charge arm 36 need to have sufficient strength to withstand the load and transmit the necessary crimp force. there were. In addition, the torsion coil spring generates not only a force in the torsion direction but also a twisting force that is a force for inclining the pinch charge arm boss 37 with respect to the pinch arm boss 21. Therefore, when loading pinch arm boss 2
When the pinch charge arm boss 37 and the pinch charge arm 37 move relative to each other,
Friction occurs due to sliding between them. This friction is a hindrance to maintaining a stable crimping force, and has a problem that the crimping force tends to be unstable. The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a pinch roller press-fitting mechanism that is compact, inexpensive, and can obtain a stable press-fitting force.

[0010]

According to the present invention, there is provided a magnetic recording / reproducing apparatus, comprising: a mechanism for pressing a pinch roller on a capstan for driving a magnetic tape to travel; the mechanism includes a pinch roller and a pinch arm for supporting a pinch roller shaft. A pinch connecting arm connected to the pinch arm via a spring and a pinch driving arm connected to the pinch connecting arm with a pin for moving between the loading position and the unloading position. In the above configuration, the distance between the point of engagement with the pinch connection arm on the pinch arm and the rotation center of the pinch arm, and the distance between the center of the pinch roller and the rotation center of the pinch arm are substantially It is characterized by being equal.

The above-mentioned spring is constituted by a compression spring,
One end is attached to the pinch connecting arm, and the other end is brought into contact with an engagement point on the pinch arm to apply a spring load. Further, in the loading state, the three points of the pinch arm and the pinch connection arm, the pinch connection arm and the pinch drive arm, and the rotation center of the pinch drive arm are substantially aligned. And

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS. 1 to 5. FIG. Components that are substantially the same as those in the conventional example are denoted by the same reference numerals. FIG. 1 is a plan view showing an unloading state (a state in which a magnetic tape is not sandwiched between a capstan and a pinch roller) in an embodiment of the magnetic recording / reproducing apparatus of the present invention, and FIG. (Referred to as a state where is sandwiched between a capstan and a pinch roller). FIG. 3 shows an arrow A in FIG.
FIG. 3 is a side sectional view as viewed from the direction of FIG. FIG. 4 is a side sectional view of FIG. 2 viewed from the direction of arrow B. FIG. 5 is a plan view showing a state halfway from the unloading state in FIG. 1 to the loading state in FIG.

In FIGS. 1 and 2, a tension post 1 is a group of known pull-out posts for pulling out a magnetic tape 100 from a tape cassette 101 indicated by a chain line.
7, drawer post 20, drawer post 22, drawer post 27, drawer post 28, pinch roller 1,
The drawer posts 29 are all operated by the power of the loading motor 14. That is, the loading motor 14
Is transmitted to the mode gear 16 via the reduction gear train 15 and further transmitted to the cam gear 12. Power is distributed from the cam gear 12 to a mechanism for operating each of the pull-out post groups. Cam gear 1 of the conventional device shown in FIG.
2 is located at the lower right of the apparatus, but in FIG. 1 it is located at the lower left. In FIG. 1, the driving force by the cam gear 12 is transmitted to the lower left pinch drive arm 7 via the main plate 8. The mode gear 16 generates an electric signal when the movement of the drawer post group to the predetermined position is completed, and controls the rotation of the loading motor 14 to be stopped.

In the unloading state shown in FIG. 1, the pull-out post group is located in the loop of the magnetic tape 100 of the tape cassette 101. Thus, the tape cassette 101 can be mounted. When the loading motor 14 and the mode gear 16 operate, the tension arm 31 with the tension post 17 planted, the drawer post 20, and the boat 2 with the drawer post 22 planted thereon.
3. The drawer post 27, the boat 30 on which the drawer post 28 is planted, the pinch arm 2 on which the pinch roller 1 is arranged, and the planted drawer post arm 32 of the drawer post 29 are brought to the loading state shown in FIG. Moving. As a result, the magnetic tape 100 is wound around the cylinder 24 by a predetermined angle, and a predetermined tape path formed by the fixed post 18, the fixed post 19, and the capstan 3, which is the fixed post group, is formed in addition to the drawer post group. . In the loading state shown in FIG. 2, the pinch roller 1 is pressed against the capstan 3 with the magnetic tape 100 interposed therebetween. When the capstan 3 is rotated, the magnetic tape 100 can run in a predetermined direction.

Next, the driving mechanism of the pinch arm 2 according to the present invention will be described in detail. In FIG. 3, the cam gear 12 is rotatably inserted into the guide shaft 10 erected on the main chassis 102, and the movement in the thrust direction is restricted by the retaining ring 201. The main plate 8 is sandwiched between the cam gear 12 and the main chassis 102. As shown in FIGS. 1 and 2, the main plate 8 has a long groove 8a and a long groove 8b in the left-right direction in the figure. The long groove 8a and the long groove 8b are respectively provided in the main chassis 1
The main plate 8 is inserted into the guide shaft 10 and the guide shaft 11 erected at 02 and can be moved only in the left-right direction in the figure. A cam follower pin 13 is erected on the main plate 8. The cam follower pin 13 is inserted into a cam groove 12 a provided in the cam gear 12, whereby the main plate 8 is driven. A pinch drive arm 7 located above the main plate 8 is attached to the guide shaft 11, and a retaining ring 202 is provided.
Is provided so as not to fall upward in the figure. A link pin 9 is erected on the main plate 8, and the link pin 9 is inserted into a cam groove 7 a provided on the pinch drive arm 7.

The structure of the pinch drive arm 7 and the pinch arm 2 will be described in detail with reference to FIGS.
In FIG. 4, a link pin 6 is erected on the pinch drive arm 7, and the pinch connection arm 33 is attached to the link pin 6.
Is rotatably mounted at one end. The pinch connection arm 33 has a long groove 33a, in which the pinch crimp spring 40 and the link pin 5 of the pinch arm 2 are inserted. The pinch arm 2 has a pinch roller shaft 34
Has been planted. The pinch roller 1 having a bearing 35 therein is attached to the pinch roller shaft 34. The pinch roller 1 is held by the cap 25 so as to rotate without falling out of the pinch roller shaft 34. A pinch arm boss 21 is swaged at the center of rotation of the pinch arm 2, and a link pin 5 having a flange 5 a is swaged at the pinch arm 2.

The link pin 5 is slidably inserted into the long groove 33a of the pinch connecting arm 33. Link pin 5
Is a pinch crimp spring 40 formed of a coiled compression spring.
As a result, it is pressed against the wall surface 33b on the opposite side of the connection portion with the link pin 6 in the long groove 33a. Pinch arm 2
The crimped pinch arm boss 21 is rotatably fitted to a pinch arm shaft 26 erected on the main chassis 102 together with a drawer post arm 32 having a base formed in a U-shape, and pulled out by a retaining ring 203. Not to be done.

Next, the operation will be described in detail. In FIG. 1, the rotation of the loading motor 14 causes the cam gear 12 to rotate.
Is rotated counterclockwise, the cam follower pin 13 slides in the cam groove 12a, and the main plate 8 moves to the left in FIG. As a result, the link pin 9 also moves to the left, and applies a rotational force to the cam groove 7a of the pinch drive arm 7. Therefore, the pinch drive arm 7 is
Rotate counterclockwise around 1 as the center of rotation. As a result, the link pin 9 is pulled to the left and enters the bent portion at the lower end of the V-shaped groove 7a. In this position, the pinch roller shaft, the link pins 5 and 6 at both ends of the pinch connection arm 33, and the guide shaft 11 are substantially aligned, and press the pinch roller 1 against the capstan 3 with a stable pressing force. When the pinch arm 2 receives no force from the outside, the link pin 5 is pressed against the wall surface 33 b of the long groove 33 a of the pinch connecting arm 33 by the force of the pinch crimp spring 40. In this state, the distance between the link pin 5 and the link pin 6 is kept constant, and both the connecting portions of the link pin 5 and the link pin 6 are rotatable, so that the pinch connecting arm 33 functions as a two-node link member.

When the pinch drive arm 7 rotates counterclockwise, the pinch arm 2 rotates clockwise about the pinch arm shaft 26 by the link function of the pinch connection arm 33. The pinch arm 2 rotates clockwise,
As shown in FIG. 5, when the pinch roller 1 contacts the capstan 3 with the magnetic tape 100 interposed therebetween, the pinch arm 2 does not rotate any more. In FIG. 5, the pinch drive arm 7
Is further rotated counterclockwise, the distance between the link pins 5 and 6 becomes shorter. Accordingly, the link pin 5 moves in the long groove 33a and compresses the pinch crimp spring 40.
With this configuration, the pinch connection arm 33 functions as a two-node link member in which the distance between the link pin 5 and the link pin 6 changes. When the pinch drive arm 7 further rotates and finally the link pin 5, the link pin 6, the link pin 9 and the guide shaft 11 come to a position substantially aligned as shown in FIG. The rotation angle of the mode gear 16 that has been rotated to reach the position is detected by a known detection unit, and the loading motor 14 stops rotating.

Focusing on the pinch arm 2 in this state, the pinch arm 2 receives a clockwise rotation force about the pinch arm shaft 26 by the pinch crimping spring 40 and the pinch roller 1 from the capstan 3.
, Receives a counterclockwise rotation force as a reaction force.
The pinch arm 2 stops in a state where the clockwise and counterclockwise rotational forces in different directions are balanced, and the capstan 3
And the force applied to the contact portion of the pinch roller 1 is the pressure force.
The pressing force is determined by the force of the pinch pressing spring 40, the distance from the pinch arm shaft 26 to the pinch roller shaft 34, and the distance from the pinch arm shaft 26 to the link pin 5. Since both the distances are constant and the link pins 5, 6, 9 and the guide shaft 11 are substantially aligned, the compression amount of the pinch crimp spring 40 is constant.
Therefore, the pressing force of the pinch roller 1 is stable. In an actual design, the lower pin 6 of the pinch arm 33 is slightly to the left of the straight line formed by the link pins 5, 6 and 9, that is, to the side opposite to the first position where the tape cassette stands by when the tape cassette is mounted. The position where the pinch arm 33 is tilted by several degrees is preferably set as the second stop position. This second position is
This is the position where the pinch roller is pressed against the capstan for recording and reproduction. By doing so, the link pins 5, 6, 9
2 formed by the pinch arm 33 and the pinch drive arm 7 connecting
Even if there is some error in the joint link mechanism, a stable compressive force to the pinch roller 1 can be obtained. Since the link pin 5, the link pin 6, the link pin 9 and the guide shaft 11 are substantially aligned, even if the position of the link pin 9 determined by the cam gear 12 or the main plate 8 in the left and right direction is slightly varied, the pressing force is reduced. Has almost no effect, and a stable crimping force can be obtained from this point as well.

From the pinch arm shaft 26 to the pinch roller shaft 3
4 and the link pin 5 from the pinch arm shaft 26
The distance to is set to be almost the same. Therefore, a pinch compression spring 40 having an extension force substantially equal to the required compression force of the pinch roller 1 determined from known conditions or the like for driving the magnetic tape 100 stably may be used.
Therefore, it is not necessary to provide the pinch arm 2 with excessive strength, and the thickness of the pinch arm 2 can be reduced as compared with the prior art. Further, unlike the conventional art, since a plurality of bosses such as the pinch charge arm boss 37 other than the pinch arm boss 21 are not attached to the rotation center of the pinch arm 2, the pinch arm shaft 26 is pulled out and the post arm 32 is pinched with the post arm 32. It can be easily shared with the arm 2, the number of parts can be reduced, the cost can be reduced, and the thickness of the device can be reduced.

[0022]

As described in detail in the above embodiments, according to the present invention, a stable pressing force of the pinch roller to the capstan can be obtained, and the pinch arm portion constituting the pinch roller pressing mechanism. Since the strength of the magnetic recording / reproducing apparatus can be reduced, the thickness of the parts can be reduced, and the cost and the size of the magnetic recording / reproducing apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of a magnetic recording / reproducing apparatus according to the present invention in an unloaded state.

FIG. 2 is a plan view of a magnetic recording / reproducing apparatus according to an embodiment of the present invention in a loading state.

FIG. 3 is a side sectional view of a main part of the embodiment of the magnetic recording / reproducing apparatus of the present invention as viewed from the direction of arrow A in FIG. 1;

FIG. 4 is a sectional side view of a main part of the embodiment of the magnetic recording / reproducing apparatus of the present invention as viewed from the direction of arrow B in FIG. 2;

FIG. 5 is a plan view of a magnetic recording / reproducing apparatus according to an embodiment of the present invention, which is in transition to a loading state;

FIG. 6 is a plan view of an unloading state showing a pinch roller pressing mechanism of a magnetic recording / reproducing apparatus according to the related art.

FIG. 7 is a plan view of a loading state showing a pinch roller pressing mechanism of a magnetic recording / reproducing apparatus according to the related art.

FIG. 8 is a sectional side view of a main part showing a pinch roller pressing mechanism of a magnetic recording / reproducing apparatus according to a conventional technique.

[Explanation of symbols]

 1. Pinch roller 2. Pinch arm 2a. Stopper part 3. Capstan 4, 40. Pinch crimp spring 5. Link pin 5a. Link pin 7. 7. Pinch drive arm 7a. Cam groove Main plate 8a. Long groove 8b. Long groove 9. Link pin 10. Guide shaft 11. Guide shaft 12. 12. Cam gear 12a. Cam follower pin 14. Loading motor 15. Reduction gear train 16. Mode gear 17. Tension post 18. Fixed post 19. Fixed post 20. Drawer post 21. Pinch arm boss 22. Drawer post 23. Boat 24. Cylinder 25. Cap 26. Pinch arm axis 27. Drawer post 28. Drawer post 29. Drawer post 30. Boat 31. Tension arm 32. Drawer post arm 33. Pinch connecting arm 33a. Long groove 33b. Wall surface 34. Pinch roller shaft 35. Bearing 36. Pinch charge arm 36a. Stopper portion 36b. Cam pin 37. Pinch charge arm boss 39. Main arm 39a. Cam follower pin 39b. Center of rotation 39c. Magnetic tape 101. Tape cassette 102. Main chassis 201. Retaining ring 202. Retaining ring 203. Retaining ring

Claims (11)

[Claims] In a mechanism for pressing a pinch roller against a capstan for driving a magnetic tape to travel, a first position in which the pinch roller and a pinch arm supporting the pinch roller stand by when a tape cassette is mounted; Alternatively, a magnetic recording / reproducing apparatus having a two-node link mechanism for moving between a second position to be pressed against the capstan during reproduction. 2. The distance between an engagement point of the link mechanism on the pinch arm and the center of rotation of the pinch arm, and the distance between the center of the pinch roller and the center of rotation of the pinch arm are substantially equal. The magnetic recording / reproducing apparatus according to claim 1, wherein: 3. A pinch press-fit spring for pressing a pinch roller against a capstan is constituted by a compression spring and is disposed in the link mechanism, and a spring load is applied to an engagement point on a pinch arm of the link mechanism. The magnetic recording / reproducing apparatus according to claim 1, wherein: 4. The magnetic recording / reproducing apparatus according to claim 3, wherein when the pinch roller is at the second position, all engagement points of the two-node link are substantially aligned. 5. When the pinch arm is located substantially on a straight line, the pinch arm comes to rest slightly closer to the first position than the position where the two-link mechanism is aligned. The magnetic recording / reproducing apparatus according to claim 4, wherein 6. A mechanism for pressing a pinch roller against a capstan for driving and driving a magnetic tape, wherein a pinch arm supporting the pinch roller and a pinch roller wait for a tape cassette to be mounted.
And a pinch connecting arm, which is connected via a spring to the pinch arm to form a two-node link mechanism, for moving between a position of the pinch arm and a second position for pressing the capstan during recording or reproduction, and A magnetic recording / reproducing apparatus having a pinch drive arm connected to a pinch connection arm with a pin. 7. The magnetic recording / reproducing apparatus according to claim 6, wherein the spring is a compression spring. 8. A distance between an engagement point of the pinch arm with the pinch connection arm and a rotation center of the pinch arm;
7. The magnetic recording / reproducing apparatus according to claim 6, wherein the distance between the center of the pinch roller and the center of rotation of the pinch arm is substantially equal. 9. The magnetic recording / reproducing apparatus according to claim 6, wherein the spring is a compression spring having one end attached to the pinch connection arm and the other end abutting on an engagement point of the pinch arm. . 10. When the pinch roller is at the second position, an engagement point of the pinch arm with the pinch connection arm, a connection point of the pinch connection arm and the pinch drive arm, and a rotation center of the pinch drive arm. 7. The magnetic recording / reproducing apparatus according to claim 6, wherein the three points are arranged substantially on a straight line. 11. When the pinch arm is located substantially on a straight line, the pinch arm comes to rest slightly closer to the first position than the position where the two-link mechanism is aligned. The magnetic recording / reproducing apparatus according to claim 10, wherein