JP2571718B2 - Mode switching device for auto-reverse tape recorder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an auto-reverse type tape recorder that detects the end of a tape and switches the tape running direction, and more particularly to a tape running direction when detecting a tape end in a high-speed feed mode. The present invention relates to a mode switching device having a simple configuration in which the high-speed feed mode is released in place of switching.

(Related Art) Generally, in an auto-reverse type tape recorder, a rotation force from a motor is transmitted, and the end of the tape is detected from the rotation stop of the reel shaft on the tape winding side, and the rotation is performed. The transmission mechanism is switched so as to reverse the running direction of the tape. These features are:
This is very convenient in a playback mode in which recording and playback operations are performed by running the tape at a constant speed. However, in the high-speed feeding mode in which the tape is fast-forwarded or rewound at a high speed, it is preferable to stop the tape running itself when the end of the tape is detected.

By the way, about the auto shut-off technology that detects the end of the tape in the high-speed feed mode and sets the stop state,
For example, it is disclosed in JP-A-61-160855. In the technology disclosed in this publication, when the end of the tape is detected during the high-speed feed mode, the lock of the high-speed feed push button lever that is held at the pressing position and sets the high-speed feed mode is released, and the stop state is returned by return. To set.

(Problems to be Solved by the Invention) However, such an auto-shut-off mechanism is incorporated in an auto-reverse tape recorder, and when the end of the tape is detected in the playback mode, the tape running direction is switched. If it is detected that the automatic shutoff operation is performed, the configuration is unavoidably complicated. That is, the tape running direction switching mechanism and the auto shut-off mechanism are separately configured in association with the tape end detecting mechanism, and the mechanism is set according to whether the mode is the playback mode or the high-speed feeding mode when the tape end is detected. Must be operated alternatively, and it cannot be denied that the device configuration including the control mechanism for the operation becomes complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to perform a switching operation of a tape running direction and an automatic shut-off operation at the time of detecting a tape end according to an operation mode at that time, that is, a playback mode. Another object of the present invention is to provide a mode switching device of an auto-reverse type tape recorder having a simple structure which can be reliably operated depending on whether the mode is a high-speed feeding mode.

(Means for Solving the Problems) According to the present invention, when a pushbutton lever for reproduction or a pushbutton lever for high-speed feed is pushed in against a return spring, the pushbutton lever is locked at a pressed position by a locking plate. The playback mode or the high-speed feeding mode is set according to the push button lever locked at the pushing position, and one of the pair of left and right reel shafts is driven to rotate. The present invention relates to an auto-reverse type tape recorder in which a tape running direction switching mechanism is operated to switch a tape running direction when a rotation stop of a reel shaft is detected. In particular, the rotation of the reel shaft is stopped by the tape end detecting mechanism. Is detected, a mechanism for moving the locking plate forward by a fixed amount (L) in conjunction with the detection is provided, and the regeneration push button of the locking plate is provided. Movement amount required for the unlocking of the bar and (L _2), the moving amount required for the unlocking of the fast feed push button lever of the locking plate and _{(L 1, L 3),} L 2>L> L _1, is characterized in that set L ₃ becomes relevant.

(Operation) According to the present invention configured as described above, when the end of the tape is detected by the operation of the end-of-tape detecting mechanism, the tape traveling direction switching mechanism is operated in the reproducing mode or the high-speed feeding mode. Operates, but at this time, the locking plate moves forward by a fixed amount (L) in conjunction with the tape running direction switching mechanism. Then, in the playback mode, even if the locking plate is moved, the locking at the pressed position of the reproduction push button lever is not released, but in the high speed feeding mode, the movement of the locking plate causes the push button lever for the high speed feeding to be released. Since the lock at the pushing position is released, the stop state is set in this high-speed feeding mode before the switching of the running direction of the tape is completed.

Therefore, the mode switching according to the operation mode set at that time can be performed by a simple configuration in which the tape running direction switching mechanism is operated when the end of the tape is detected and the locking plate is moved by a fixed amount (L) at the same time. Can be realized.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In the following description, “left” and “right” are defined as “left” and “right” in a plan view (FIG. 1).

FIG. 1 is a plan view showing a schematic configuration of an automatic reverse type tape recorder incorporating a mode switching device according to the present invention, and FIG. 2 is a bottom view thereof.

In the figure, reference numeral 1 denotes a chassis, on the upper surface of which a pair of left and right reel shafts 2a and 2b, capstan shafts 3a and 3b, and pinch rollers 4a and 4b are arranged symmetrically. A thin motor 5 is mounted on the lower surface of the chassis 1 at the same distance from the reel shafts 2a and 2b. As shown in FIG. 2, a motor pulley 6 and a capstan pulley 7 are provided at the lower end of the rotating shaft 5a of the motor 5 and the left and right capstan shafts 3a and 3b.
a and 7b are attached respectively. An endless belt 9 is wound between these pulleys 6, 7a, 7b via an idle pulley 8. The rotational force of the motor 5 is transmitted to the left and right capstan shafts 3a and 3b via the endless belt 9, and the capstan shafts 3a and 3b are driven to rotate in opposite directions in the respective tape feeding directions. It has become.

On the other hand, the left and right pinch rollers 4a, 4b are rotatably mounted on one end of a pair of pinch roller arms 11a, 11b rotatably supported on the upper surface of the chassis 1 via shafts 10a, 10b as shown in FIG. Attached to. These pinch rollers 4a, 4b are selectively pressed against the capstan shafts 3a, 3b by alternate rotation of the pinch roller arms 11a, 11b.

A head mounting plate 12 on which a reproducing magnetic head 13 is mounted is mounted on the upper surface of the chassis 1 so as to be movable in the directions of arrows A and B. When the head mounting plate 12 moves in the direction of arrow A, the magnetic head 13 mounted thereon contacts the tape to perform a reproducing operation.
Moves back in the direction of arrow B, thereby separating the magnetic head 13 from the tape.

By the way, on the lower surface of the chassis 1, there is a push button lever 1 for stopping.
4, Left high-speed feed pushbutton lever 15, Playback pushbutton lever 16,
Right high-speed feed pushbutton levers 17 are arranged side by side so as to be movable in the directions of arrows A and B, respectively. Each of these pushbutton levers 14, to 1
In FIG. 7, a pair of long holes 14a, 15a, 16a, 17a formed in the main surface thereof are fitted into guide protrusions 23, 24, 25, 26 projecting from the chassis 1 as shown in FIG. And are urged in the direction of arrow B by return springs 18, 19, 20, 21 respectively.

On the lower surface of the chassis 1, the push button levers 14, 17
A locking plate 27 is mounted so as to intersect with and move in the directions of arrows C and D. The locking plate 27 has elongated holes 29, 3 provided in the main surface thereof.
0, 31, 32 are fitted and mounted on the guide projections 23, 26 respectively, and are always urged in the direction of arrow C by the return spring 41. This locking plate 27 is used to stop the push button lever 14.
When each of the push button levers 15, 17 is depressed respectively, the push button levers 15, 17 are locked at the pressed position, and the push button levers locked at the pressed position are
The reproduction mode or the high-speed feed mode is set according to 15, 17.

The locking of the push button levers 15, 17 at the pushing position by the locking plate 27 is performed by first, second, and third locking provided on the locking plate 27 corresponding to the push button levers 15, 17 respectively. This is performed by engaging the parts 33, 34, 35 with the locked parts 36, 37, 38 provided on the push button levers 15, 17 respectively.

That is, each of the push button levers 15, 17 for left high-speed feed, reproduction, and right high-speed feed is provided with the
1, Inclined surface 36 in sliding contact with second and third locking portions 33, 34, 35, respectively
a, 37a, 38a are provided, and the above-described locked portions 36, 3
7, 38 are formed continuously at the ends of these inclined surfaces. When the push button levers 15, 17 are pushed in, the locking portions 33, 34, 35 slidingly contacting the inclined surfaces 36a, 37a, 38a.
Is pressed, the locking plate 27 moves against the return spring 41 by the arrow D
Go back and forth. And when the push button levers 15, 17 are pushed to a predetermined position, the locking portions 33, 34, 35 are inclined surfaces 36a, 37a,
As a result, the locking plate 27 is returned by the return spring 41 in the direction of arrow C. At this time, the first, second,
The locked portions 3 of the respective push button levers 15, 17 are attached to the third locking portions 33, 34, 35.
By the engagement of 6, 37 and 38, the respective push button levers 15, 17 are locked and held at the pressed positions.

Note that each of the push button levers 15, to 1 locked and held at the pushing position
7, the locking plate 27 is moved in the direction of arrow D against the return spring 41, and the first, second, and third locking portions 33, 34, 35 of the locking plate 27 and the respective pushbutton levers 15 are moved. , To 17 are disengaged from the locked portions 36, 37, 38.

The movement of the locking plate 27 in the direction of arrow D is basically performed by pushing the engaging projection 38 of the locking plate 28 with the inclined surface 40 by the forward operation of the stop push button lever 14. .

Here, the arrow C of the locked part 36-38 of each push button lever 15-17,
The lengths L ₁ , L ₂ , and L ₃ in the D direction are determined as follows with respect to the length L ₄ of the inclined surface 40 of the stop pushbutton lever 14 in the directions of arrows C and D (the _fourth direction). See Figure 10).

L ₃ = L ₁ <L ₂ ≦ L ₄ That is, the lengths L ₁ and L ₃ of the locked portions 36 and 38 of the push button levers 15 and 17 for the left high-speed feed and the right high-speed feed are the reproduction push buttons. It is set to be shorter than the length L ₂ of the engaging portion 37 of the lever 16. When the stop push button lever 14 is pressed, the locking plate 27 is pressed.
When but moving over the width L ₄ in the direction of arrow D, first width L
_By moving ₁ (= L ₃ ), the locking of the push button levers 15 and 17 for the left high-speed feed and the right high-speed feed at the pressed position is released, and the reproduction push button lever 16 is started only when the push button lever 16 moves to the width L _2.
Is released at the pushed position. In other words, the locking of the push button levers 15 and 17 for the left high-speed feed and the right high-speed feed at the pressed positions is performed by the width L ₁ (= L
Is released by the movement of _3), locking at the pushed-in position of the reproducing push button lever 16 of the locking plate 27, which is intended to be released by further movement of the large width L _2.

The tape running direction switching mechanism 42 includes left and right rotating arms 43a and 43b and a switching plate 44, and rotating levers 57a and 57b and a swinging plate 62, which will be described later, as shown in FIG. The rotating arms 43a and 43b are mounted on the upper surface of the chassis 1 so as to be rotatable around left and right capstan shafts 3a and 3b. Further, a slit 1a provided in the chassis 1 is provided on a tip end side of a substantially intermediate portion between the respective rotating arms 43a and 43b (see FIG. 1).
Through the lower surface of the chassis 1.

Thus, the transmission gears 45a, 45b which always mesh with the capstan gears 46a, 46b integrally formed on the upper surfaces of the capstan pulleys 7a, 7b are provided with the respective rotating arms 43a, 45a, As shown in FIG. 3, they are rotatably supported on the distal end side of 43b. Each of these transmission gears 45a, 45b includes a high-speed feed gear 48 attached to the lower end of the left and right reel shafts 2a, 2b via a slip mechanism (not shown) by the rotation of the rotation arms 43a, 43b.
a and 48b are alternatively engaged.

Each high-speed feed gear 48a, 48b is a constant-speed feed gear 47.
It is integrally formed coaxially with a and 47b. And, together with the above-mentioned reel shafts 2a, 2b, they are pivotally supported on the upper surface side of the gear brackets 52a, 52b fixed to the chassis 1. The left and right rotating arms 43a and 43b are biased by springs 59a and 59b, respectively, as shown in FIG. 2, in a direction in which the transmission gears 45a and 45b mesh with the high-speed feed gears 48a and 48b.

Thus, in a state in which the left and right high-speed feed push button levers 15 and 17 are not pushed in, as shown in FIG. 11, the contact pieces 49 and 50 of the push button levers 15 and 17 are turned on the rotating arms 43a and 43b. Each of the rotating arms 43a, 4 abuts against the contacted piece 51a, 51b.
The amount of rotation by the springs 59a and 59b of the 3b is regulated. The transmission gears 45a and 45b are separated from the corresponding high-speed feed gears 48a and 48b by the rotation amount regulation.

Each of the transmission gears 45a and 45b is the capstan gear 46 described above.
a, 46b and the constant speed feed gears 47a, 47b together with the rotation transmission mechanism 53a,
The rotation transmission mechanisms 53a and 53b include first-stage gears 54a and 54b and second-stage gears 5a.
5a, 55b, and third gears 58a, 58b rotatably supported by the gear brackets 52a, 52b are also included.

More specifically, the first-stage gears 54a and 54b
5a, 45b are always meshed with each other, and are small-diameter second-stage gears 55a, 55b.
Together with b, they are supported on gear brackets 52a and 52b. Rotating levers 57a and 57b are rotatably provided on the gear brackets 52a and 52b via shafts 56a and 56b. One end of each of the rotating levers 57a and 57b is provided with a constant speed feed gear. 47a, 47b
The third stage gears 58a, 58b which are always meshed with the gears are rotatably supported.
The third-stage gears 45a, 45b engage and disengage with the second-stage gears 55a, 55b with the rotation of the rotation levers 57a, 57b. The pivot levers 57a and 57b are also provided with the springs 59a and 5b.
By 9b, the third-stage gears 58a, 58b and the second-stage gears 55a, 55b are rotationally urged in a direction in which they mesh. When the head mounting plate 12 is returning in the direction of arrow B, the third
As shown in the figure, the engaging portions 60a, 6 of the left and right rotating levers 57a, 57b
0b is engaged with engaging pieces 61a, 61b projecting from the head mounting plate 12, whereby the rotation of the left and right rotating levers 57a, 57b by the springs 59a, 59b is restricted, and the third Step gear 58a, 5
8b is separated from the second gears 55a and 55b.

In this state, when the push button lever 16 for reproduction is pushed in the direction of arrow A and the head mounting plate 12 is moved in the same direction, the engaging pieces 61a, 61b are disengaged from the engaging portions 60a, 60b of the rotating levers 57a, 57b. Come off. Then, one of the rotating levers 57a, 57b, that is, one of the rotating levers 57a (57b) is rotated by the urging force of the spring 59a (59b), and meshes with the corresponding third gear 58a (58b). I do. At this time, the other rotating lever 57b (57a) is brought into contact with a contact piece 67b of the swinging plate 62 interlocking with the head mounting plate 12 as described later.
(67a), the rotation is continuously prohibited. Therefore, the third gear 58b (58a) pivotally supported by the other rotating lever 57b (57a) does not mesh with the corresponding second gear 55b (55a).

In this manner, the left and right third gears 58a and 58b and the second gears 55a and 55b are selectively engaged with each other with respect to the tape running direction switching mechanism 42 including the swing plate 62.

Here, as shown in FIG. 5, the rocking plate 62 is provided with a pin 64 projecting from the head mounting plate 12 in a long hole 63 provided in the center thereof.
Are inserted, and the contact pieces 67a, 67b are
The contact surfaces 68a and 68b of 7b are opposed to each other from the side. An engaging piece 65 provided at the end of the swinging plate 62 in the direction of arrow B has a substantially triangular shape projecting from the switching plate 44 which is selectively set to move in the left-right direction (directions of arrows C and D). It is loosely inserted in the guide hole 66.

Thus, the rocking plate 62 moves in the same direction as the head mounting plate 12 with the front edge of the long hole 63 being pressed by the pin 64 of the head mounting plate 12 moving in the direction of arrow A. At this time, when the switching plate 44 is at the position moved in the direction of arrow D, the swing plate 62
5, as shown in FIG. 5, the engagement piece 65 is rotated clockwise in FIG. 5 while sliding the engagement piece 65 against the left inclined side edge 66a of the guide hole 66 of the switching plate 44. Then, the left contact piece 67a is brought into contact with the contact piece 68a of the rotating lever 57a,
The rotation of a is restricted.

Conversely, when the switching plate 44 is in the position moved in the direction of arrow C, the swing plate 62 moves in the direction of arrow A, and
Is brought into sliding contact with the right inclined side edge 66b of the guide hole 66 of the switching plate 44 to rotate counterclockwise. And the right contact piece 67
b controls the rotation of the rotation lever 57b. Such rocking plate
By the operation of 62, the selective engagement between the third-stage gears 58a and 58b and the second-stage gears 55a and 55b is controlled.

Here, the switching plate 44 will be described. The switching plate 44 has engaging step portions 69a, 69b located inside the engaging protrusions 70a, 70b of the respective rotating arms 43a, 43b. The switching plate 44 is connected to one of the rotating arms, for example, the rotating arm 43b.
Is rotated in the counterclockwise direction in FIG.
The engagement step 69b is pressed by b and moves in the direction of arrow C.
At this time, as shown in FIG. 1 or FIG. 11, the amount of elastic deformation of the reversing spring 82, one end of which is attached to the switching plate 44, gradually increases. ), The elastic force of the reversing spring 82 acts to move the switching plate 44 in the direction of arrow C. Therefore, until the reversal spring 82 exceeds the dead point,
When the switching plate 44 is moved by the rotating arm 43b, the switching plate 44 is further moved by the elastic force of the reversing spring 82 thereafter. When the switching plate 44 moves in the direction of arrow C, the right inclined side edge 66b of the guide hole 66 provided in the switching plate 44 presses the engaging piece 65, and the moving plate 62 is moved counterclockwise in FIG. To rotate.

Conversely, when the left rotating arm 43a rotates counterclockwise in the figure, contrary to the above operation, after the switching plate 44 moves in the direction of arrow D to reverse the reversing spring 82, The switching plate 44 is further moved in the same direction by the elastic force of the spring 82. Then, by the movement of the switching plate 44 in the direction of arrow D, the engaging piece 65 is pressed by the left inclined side edge 66a of the guide hole 66, and the moving plate 62 is rotated clockwise. Such a switching plate 44
Of course, the left and right pinch roller arms 11a and 11b are also switched and rotated in association with the movement of the left and right pinch roller arms 11a and 11b.

By the way, when one of the left and right rotating arms 43a and 43b rotates, the locking plate 27 moves in the direction of arrow D by a certain amount (L).

That is, when the left rotating arm 43a rotates clockwise, the engaging piece 71a bent at a position in the direction of arrow B from the center of rotation rotates the left end 28 of the locking plate 27 in the direction of the arrow. Press in the D direction. Conversely, when the right rotation arm 43b rotates counterclockwise, an engagement piece 71b provided at a position in the direction of arrow A from the center of rotation protrudes from the right end side of the locking plate 27. The right edge 72a of the engaged hole 72 is pressed in the direction of arrow D. Such engagement between the pivot arm 43a, even when the one of the 43b rotates, the engaging plate 27 is moved forward in the arrow D direction, the forward amount (L) of L _2> L> L _1, the arrows C of the engaging portion 36, 38 of the L ₃ right and left, are employed as the high feed push button lever 15 and 17, greater than the length L _1, L ₃ of the D direction, and the reproduction for a push button lever 16 arrow C of the engaging portion 37 is set smaller than the D-direction length L _2. Therefore, the rotating arm 43a,
When the locking plate 27 moves forward with the rotation of 43b, only the release of the high-speed feed push button levers 15 and 17 locked by the locking plate 27 is performed, and the engagement of the reproduction push button lever 16 is performed. The suspension is not released.

Incidentally, the tape running direction switching mechanism 42 configured as described above operates upon receiving a mechanical detection signal transmitted from the left and right tape end detecting mechanisms 73a and 73b.

Each of the tape end detecting mechanisms 73a and 73b includes detection disks 74a and 74b attached to the reel shafts 2a and 2b via a slip mechanism (not shown) as described below, and the detection disks 74a and 74b.
Pressing projections 78a, 78b protrudingly formed on the outer peripheral edges of a, 74b, and detection levers 75a, 75b, one end of which is rotatably supported on the lower surface of the chassis 1 via shafts 79a, 79b, the transmission gear 45a, 45
The eccentric cams 76a and 76b are formed integrally with the eccentric cams 76a and 76b, respectively, and the engaging projections 77a and 77b are formed on the upper surfaces of the eccentric cams 76a and 76b.

The other end of each of the levers 75a and 75b has a cam sliding contact surface 80.
a, 80b and engaged portions 81a, 81b are provided, and the cam surfaces of the eccentric cams 76a, 76b can slide on the cam sliding surfaces 80a, 80b.

The engagement projections 77a, 77b on the upper surfaces of the eccentric cams 76a, 76b are provided at positions farthest from the center of rotation, and are engaged with the engaged portions 81a,
Contact with 81b is possible. During the rotation of the reel shafts 2a and 2b, the pressing protrusions 78a and 78b of the detection disks 74a and 74b continue to press the protrusions 84a and 84b of the detection levers 75a and 75b, and the cam sliding of the detection levers 75a and 75b continues. The contact surfaces 80a, 80b and the eccentric cam 76a,
The outer peripheral surface of 76b keeps sliding. As a result, detection lever 7
5a and 75b are eccentric cams 7 while the reel shafts 2a and 2b are rotating.
With the rotation of the shafts 6a and 76b, the shafts 79a and 79b continue to make a reciprocating swinging motion around the shafts 79a and 79b, whereby the engaging projections 77a and 77b and the engaged portion 81
Contact with a, 81b is avoided. However, when the tape reaches the end and the rotation of the reel shafts 2a, 2b stops, the detection levers 75a, 7b
With the stop of the swing of 5b, the engagement projections 77a and 77b come into contact with the engaged portions 81a and 81b.

At this time, for example, when the right reel shaft 2b is on the tape winding side, the left detection disk 74a tends to rotate in a direction away from the left detection lever 75a. However, as shown in FIG. 11, the rotation angle of the detection disk 74a is
Because it is limited by the arc-shaped opening 86 provided in
There is no problem that the pressing projection 78a makes one rotation in the opposite direction and pushes the projection 84a from the opposite side. Of course, a similar arc-shaped opening 86 is provided on the right side.

Also, since the detection lever 75a on the tape supply side is not pushed by the detection disk 74a, the locked portion 81a will not
, The tape running direction switching mechanism 42 may be switched regardless of the arrival of the end of the tape.

As a countermeasure, here, as shown in FIG. 11, a bar spring 88 is supported on the chassis 1 via a support pin 87 at an intermediate position thereof, and left and right detection levers 75a, 75 are provided at both ends of the bar spring 88.
b is pressed against the eccentric cams 76a and 76b. In the reproduction mode, one of the contact pieces 67a and 67b of the rocking plate 62 pushes one end of the rod spring 88 on the tape winding side to press the corresponding contact piece 67a.
The levers a and 67b are separated from the detection levers 75a and 75b, and the detection levers 75a and 75b are kept pressed only at the end of the bar spring 88 on the tape supply side. Also, in the high-speed feed mode, one end 15a, 17a of the high-speed feed push button lever 15, 17 pushes the end of the rod spring 88 on the tape winding side to separate the corresponding contact piece 67a, 67b from the detection lever 75a, 75b, The detection lever is kept pressed only at the end of the bar spring 88 on the tape supply side.

Next, the operation of the embodiment apparatus configured as described above will be described.

1 to 3 show a stopped state. The first
In FIG. 2 and FIG. 2, reference numeral 83 denotes a tape cassette. In this stopped state, the head mounting plate 12 and each push button lever
14 to 17 are all at positions returned in the direction of arrow B, and both the left and right pinch rollers 4a, 4b are separated from the capstan shafts 3a, 3b. Also, as shown in FIG.
45a and 45b are separated from the high-speed feed gears 48a and 48b, respectively, and the third-stage gears 58a and 58b are also separated from the second-stage gears 55a and 55b, respectively.

[Reproduction Operation] In such a stopped state, when the reproduction push button lever 16 is pushed in the direction of the arrow A, the head mounting plate 12 moves in the direction of the arrow A, and subsequently, the swing plate 62 also moves in the same direction. Then, the push button lever 16 is held at the pushed-in position by engaging the locked portion 37 with the second locking portion 34 of the locking plate 27.

At this time, the motor switch (not shown) becomes conductive (ON) in conjunction with the movement of the locking plate 27, and the motor circuit (not shown)
Is connected to a power source (AA batteries x 2) 85, the motor 5 rotates, and the left and right capstan shafts 3a, 3b rotate. Further, with the movement of the head mounting plate 12 in the direction of arrow A, the engagement pieces 61a, 61b are disengaged from the positions facing the engagement portions 60a, 60b of the rotary levers 57a, 57b. Assuming that the switching plate 44 is at the position moved in the direction of the arrow D, the engaging piece 65 of the swinging plate 62 moves to the left inclined side edge 66a of the guide hole 66 as the head mounting plate 12 moves.
The swinging plate 62 rotates clockwise about the pin 64 as shown in FIG. By this rotation, one of the contact pieces 67
a comes into contact with the contact surface 68a of the rotation lever 57a (see FIGS. 4 and 5), and the amount of rotation of the rotation lever 57b in the clockwise direction by the spring 59a is regulated.

At this time, the right rotating lever 57b is rotated counterclockwise by the spring 59b, and the third gear 58b is meshed with the second gear 55b as shown in FIG. Therefore, the right reel shaft 2b is driven to rotate in the tape winding direction.

Further, as the head mounting plate 12 moves in the direction of arrow A, the pinch rollers 4a, 4b approach the corresponding capstan shafts 3a, 3b. However, when the switching plate 44 is at the position moved in the direction of the arrow D, the amount of rotation of the left pinch roller arm 11a is limited by the switching plate 44, so that the right pinch roller 4
Only b presses against the corresponding capstan shaft 3b. At the same time, the magnetic head 13 comes into contact with the tape by the movement of the head mounting plate 12 in the direction of arrow A, whereby the tape runs at a constant speed from the left reel shaft 2a to the right reel shaft 2b.
Here, the reproducing operation is performed (the state shown in FIG. 4).

When the stop push-button lever 14 is pushed in the direction of arrow A in this reproducing operation state, the inclined surface 40 comes into sliding contact with the engaging projection 39 of the locking plate 28, and the locking plate 27 resists the urging force of the spring 41. length
Since L ₄ minutes by moving the arrow D direction, the engagement portion 37 of the reproducing push button lever 16 is disengaged from the second locking portion 34 of the locking plate 27. As a result, the reproduction push button lever 16 is moved and returned in the direction of the arrow B by the return spring 20, and the motor 5 is stopped in accordance with this, and the motor 5 is stopped.

[End-of-tape detection operation in reproduction operation] When the tape is wound around the right reel shaft 2b and the end of the tape is reached during the reproduction operation, the right reel shaft 2b is rotated by the tape tension. Stops. Then, as shown in FIG. 6, the engagement projection 77b comes into contact with the engaged portion 81b of the detection lever 75b. The rotation arm 43b is connected to a transmission gear 45.
6 rotates counterclockwise around the capstan shaft 3b by receiving a rotational force in the counterclockwise direction in FIG.

With this rotation, the rotation arm 43b presses the right edge 72a of the engagement hole 72 of the locking plate 27 with the engagement piece 71b, and the amount of movement of the locking plate 27 in the direction of arrow D due to this. (L), since the arrow C of the engaging portion 37 of the reproducing push button lever 16, less than D in length L _2, not retained solved in depressed position of the reproducing push button lever 16.

However, on the other hand, the switching plate 44 is moved in the direction of arrow C with the rotation of the rotating arm 43b, and the switching plate 44 is moved to its end position by the reversing elastic force of the reversing spring 82. Along with the movement of the switching plate 44, the right inclined side edge 66 of the guide hole 66 is provided.
At b, the engaging piece 65 of the swing plate 62 is pressed in the direction of arrow D, and the swing plate 62 rotates around the pin 64 in the counterclockwise direction in FIG.

Then, the right contact piece 67b of the swinging plate 62 pushes back the contact piece 68b of the rotating lever 57b to move the third gear 58b to the second gear 55b.
Away from Instead, the left contact piece 67a of the swinging plate 62 releases the pressing of the rotating lever 57a against the contact piece 68a, and the third gear 58a on the left meshes with the second gear 55a. Let it. Also, with the movement of the switching plate 44 in the direction of arrow C,
The right pinch roller 4b separates from the capstan shaft 3b,
Instead, the pinch roller 4a on the left is the capstan shaft 3a.
Press against As a result, the running direction of the tape is switched from the right reel shaft 2b to the left reel shaft 2a, and the reproducing operation is subsequently performed (the state of FIG. 7).

[Fast-Forward Operation] In the stop state shown in FIGS. 1 to 3, for example, when the right high-speed feed push button lever 17 is pushed in the direction of arrow A, the locked portion 38 of the locking plate 27 Since the push button lever 17 for high-speed feeding is locked by the stop portion 35, the push button lever 17 is held at the pushed position. Then, in conjunction with the locking plate 27, a motor switch (not shown) is turned on (ON), and the motor rotates to rotate the left and right capstan shafts 3a, 3b and the transmission gears 45a, 45b. When the high-speed feed push button lever 17 is pushed in this way, the contact piece 50 is disengaged from the contacted piece 51b of the rotating arm 43b, and the rotating arm 43b is biased by the spring 59b. Rotating in the clockwise direction, the transmission gear 45b meshes with the right high-speed feed gear 48, and the state shown in FIG. 8 is obtained.

Therefore, the tape is wound at a high speed from the left reel shaft 2a to the right reel shaft 2b. When the left high-speed feed push button lever 15 is pressed, the tape is wound at high speed from the right reel shaft 2b to the left reel shaft 2a, contrary to the above operation.

[Tape end detection operation in fast-forward operation] For example, when the tape reaches the end of the tape while the tape is being wound from the left reel shaft 2a to the right reel shaft 2b at a high speed, the right end of the tape is pulled by the tape tension. The rotation of the reel shaft 2b stops. Then, as in the case shown in FIG.
Since the engaging projection 77b abuts on the engaged portion 81b of the base member 75b, the rotating arm 43b is rotated counterclockwise in FIG. 8 around the capstan shaft 3b by the rotational force of the transmission gear 45b.

Along with this rotation, the engagement piece 71b of the rotation arm 43b is
The locking plate 27 is moved forward in the direction of arrow D by pressing one side edge 72a of the engagement hole 72 of the 27, and the switching plate 44 is moved in the direction of arrow C. At this time, the amount of forward movement (L) of the locking plate 27 in the direction of arrow D is determined by the arrow of the locked portion 38 of the high-speed feed pushbutton lever 17.
C, is greater than D direction length L _3, the locking portion 38 of the high-speed feeding push button lever 17 is released from the third engaging portion 35 of the locking plate 27. As a result, the high-speed feed push button lever 17 is
According to 21, the movement is returned in the direction of arrow B.

Thereafter, the engagement protrusion 77b of the eccentric cam 76b is moved to the detection lever 75b.
Is disengaged from the engaged portion 81b, the rotating arm 43b is
Then, the contact piece 51b is brought into contact with the contact piece 50 of the high-speed feed push button lever 17 again. Also, the locking plate 27 is released from the pressing by the engaging piece 71b, and is returned in the direction of arrow C by the spring 41 to switch the motor switch to (OFF). As a result, the motor 5 stops and enters a stopped state.

Incidentally, the tape end detecting operation at the time of the fast-forward operation in which the left high-speed feed push button lever 15 is pushed in is reversed left and right from the above operation.

(Effects of the Invention) As described above, according to the present invention, the length (L ₁ , L ₁ , L ₂ ) of the locked portion of the high-speed feed push button lever is longer than the length (L ₂ ) of the locked portion of the reproduction operation push button lever. L ₃ ) is shortened, and when the tape running direction switching mechanism operates at the tape end, the locking plate is moved forward by a fixed amount (L ₁ , L ₃ <L <L ₂ ) by the tape running direction switching mechanism. In this way, even when the tape end is reached in the playback mode, the push-button lever for playback operation is held at the depressed position, and when the tape reaches the end in the high-speed feed mode, the push-button lever for high-speed feed is opened and returned, so high-speed feed When the tape reaches the end in the mode, there is no need to provide a mechanism for releasing the holding of the high-speed feed pushbutton lever. Therefore, there is an effect that the switching to the stop state at the end of the tape in the high-speed feeding mode can be automatically performed with a simple configuration.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a plan view showing a mechanism section of an auto-reverse tape recorder to which the present invention is applied, FIG. 2 is a bottom view of the same, and FIGS. Is an operation explanatory view as viewed from the bottom side, FIG. 10 is a view as viewed from the bottom side of the relationship between the locking plate and the peripheral parts, and FIG. 11 is a view as to the relation between the tape running direction switching mechanism and the peripheral parts from the bottom side. FIG. 2a, 2b: Reel axis, 3a, 3b: Capstan axis, 15: Left high-speed feed push button lever, 16: Reproduction push button lever, 17: Right high speed feed push button lever, 19, 20, 21 ... Return spring, 27 … Locking plate, 33-35
... Locking portions, 36 to 38 locked portions, 41 return spring, 42 tape running direction switching mechanism, 53a, 53b rotation transmitting mechanism, 73a, 73b tape end detecting mechanism.

Claims (2)

(57) [Claims] 1. A pair of left and right reel shafts (2)
a, 2b) and a pair of left and right rotation transmission mechanisms (53a, 53b) that can be selectively transmitted to each other, and are juxtaposed so as to be able to move in parallel, and are pushed in against the return springs (20, 21, 22). The reproduction push button lever (16) and the high speed feed push button lever (15, 1) for setting the reproduction mode or the high-speed feed mode by selectively operating the rotation transmission mechanism.
7) and a reciprocating motion is provided in a direction substantially orthogonal to the direction of movement of each of the push button levers. The push button lever is engaged with the pushed push button lever to lock the push button lever at the forward movement position, and a return spring is provided. A locking plate (27) which is moved in opposition to (41) to release the locking of the push button lever; and a rotation drive of the reel shaft provided for the respective reel shafts via the rotation transmission mechanism. The tape end detecting mechanism (73a, 73b) that detects the rotation stop of the reel shaft at the time of operation, activates the tape running direction switching mechanism (42), changes the rotation transmitting mechanism that performs the rotation transmitting operation, and switches the tape running direction.
When the rotation stop of the reel shaft is detected by each of the tape end detecting mechanisms (73a, 73b), the locking plate is moved by a predetermined amount (L) in conjunction with the detection. A forward movement mechanism (71a, 71b) is provided, and a movement amount (L ₂ ) required for releasing the locking of the reproduction push button lever of the locking plate is set to be larger than the fixed amount (L). A moving amount (L ₁ , L ₃ ) required for releasing the lock of the high-speed feed push button lever is set smaller than the predetermined amount (L). The amount of movement (L ₁ , L ₂ , L ₃ ) of the locking plate required to release the locking of each push button lever is determined by the amount of movement of the locking plate between the locking plate and the push button lever. The mode switching device for an auto-reverse type tape recorder according to claim 1, wherein the mode switching device is set as a length in a moving direction.