JPH0476847A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain the optimum torque required at the time of traveling a cassette tape at a fixed speed and a high speed respectively by providing a rotary body for generating high torque and a rotary body for generating low torque independently and constituting a transmission of rotating force of the rotary bodies respectively via a friction transmission means. CONSTITUTION:Rotating force transmitted from a motor 7 to a pulley 11 is restricted to suitable torque for high speed traveling of the tape by a friction block 60, and this torque is transmitted from a friction plate 31 through a spring receiver 30 and moreover a driving shaft 10 to an FF gear 35. Then, by drawing 1st torque from the FF gear 35, the prescribed high torque can be obtained. Then, the rotating force transmitted to the FF gear 35 is restricted to suitable torque for fixed speed traveling of the tape by the block 60, and this torque is transmitted via a friction member 39 to a play gear 37. Consequently, by drawing the rotating force from the play gear 37, the prescribed low torque is obtained. By this method, the required torque control is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION Fields of Industrial Application This invention relates to the structure of a magnetic recording and reproducing apparatus equipped with a torque generating means that provides the optimum torque required when a cassette tape is running at a constant speed and when running at high speed. It is related to.

[Prior Art] In general, in magnetic recording and reproducing devices, when the tape is running at a constant speed during recording and playback, the reel stand that winds the tape has a relatively low torque (generally about 35 mm for compact cassettes).
g-cm), while during high-speed tape running such as fast forwarding and rewinding, the reel stand has a relatively high torque (generally about 70 to 100 g-cm for compact cassettes).
m) is wound and rotated. For this purpose, a low torque generation mechanism and a high torque generation mechanism are provided independently in the device.
The cassette tape was run at a constant speed or at a high speed by transmitting the torque generated from each mechanism to a predetermined reel stand.

However, such a tape traveling mechanism has a large number of parts and a large loss of space, making it difficult to downsize the device and reduce manufacturing costs.

A magnetic recording/reproducing device that overcomes this drawback is disclosed, for example, in Japanese Utility Model Publication No. 2-6519. This magnetic recording/reproducing device discloses a structure in which a low torque generating means and a high torque generating means are provided coaxially. FIG. 21 is a plan structural view of the magnetic recording/reproducing apparatus shown in the above-mentioned publication, and FIG. 22 is a sectional structural view of the reel stand drive mechanism shown in FIG. 21. A conventional magnetic recording/reproducing device includes a drive motor 102, a pulley 122 to which the rotational force of the motor is transmitted via a belt 120, a supply reel stand 103 that engages with a cassette tape, a take-up reel stand 104, and a pulley 122 to which the rotational force of the motor is transmitted via a belt 120. The rotational force transmitted to 122 is transferred to a predetermined supply reel stand 103 or take-up reel stand 10.
4 and a reel stand drive mechanism. The reel stand drive mechanism includes an intermediate gear 123 and a drive gear 125, which are provided coaxially with the pulley 122. Pulley 122
A first slipping clutch 124 is provided between the intermediate gear 123 and the intermediate gear 123.
is interposed between the intermediate gear 123 and the drive gear 125, and a second slip clutch 126 is provided between the intermediate gear 123 and the drive gear 125. The drive gear 125 and the intermediate gear 123 are connected to the first and second slip clutches 124 and 126 by the spring 127.
It is pressed against the pulley 122 via.

In operation, when running the tape at a constant speed requiring low torque, the rotational force of the pulley 122 is reduced to a predetermined low torque via the first slip clutch 124 and the second slip clutch 126, and then the drive gear 125 takes up the tape. reel stand 10
It is transmitted to the 4th side.

In addition, when the tape is running at high speed, which requires high torque, the rotational force of the pulley 122 is transmitted to the intermediate shaft 123 via the first slip clutch 124 in a slightly reduced manner, and is further transmitted to the take-up reel via the rotating gear 129. It is transmitted to the stand 104 or the supply reel stand 103. At this time, the rotating gear 129
engages intermediate gear 123 and drive gear 125 simultaneously. This locks the second slip clutch 126 so that it does not function.

[Problems to be Solved by the Invention] However, conventional magnetic recording and reproducing devices have the following problems.

(1) First of all, it is difficult to set the high torque value taken from the rotary gear 129 and the low torque value taken from the drive gear 125 to optimal values. . This is due to the structure in which the first slip clutch 124 and the second slip clutch 126 are pressed by one compression spring 127. That is, the first and second sliding clutches 124 and 126 are constructed by sandwiching felt made of wool or the like between two rotating bodies, and applying pressure from one direction with a spring to generate a desired torque by sliding friction. It is something that is communicated. Therefore, the transmitted torque is influenced by the friction coefficient between the two rotating bodies and the felt and the compressive force applied to the two rotating bodies.

The coefficient of friction between the two rotating bodies and the felt varies widely and is greatly influenced by the environment, especially humidity. Therefore, in setting the transmission torque, it is necessary to accurately set the load of the compression spring. However, as mentioned above, one compression spring 127 is used for two slipping clutches 124.
When compressing 126, it is difficult to set the optimal compression force to each. Therefore, it has been difficult to set both the high torque and low torque values to optimal values due to the conventional structure.

(2) Secondly, in order to obtain high torque, the intermediate gear 12
3 and the drive gear 125 at the same time, it must be taken out from the pulley 122 via the first slipping clutch 124 via the rotary gear 129 that meshes with the drive gear 125. The rotating gear 129 must be brought into mesh with the intermediate gear 123 and the drive gear 125 at the same time from the separated state. If the intermediate gear 123 and the drive gear 125 are aligned, meshing will be performed smoothly, but if they are not aligned, one of the gears must be moved relatively and rotated so that the tooth surfaces of the two gears are aligned. The moving gear 129 must be pressed. However, a second slip clutch 126 having a frictional force is interposed between the intermediate gear 123 and the drive gear 125.

However, in order to cause the rotary gear 129 to mesh with both gears, it is necessary to press with a force that overcomes the frictional force of the second slip clutch 126. For this purpose, the rotary gear 12
If the rotational force of 9 is performed using the rotational force from the drive motor, a high driving force will be required from the motor, leading to an increase in cost. Further, when the rotary gear 129 is engaged, if the engagement is not performed smoothly due to the above-mentioned circumstances, abnormal noise such as gear noise may occur.

Therefore, this invention has been made to solve the above-mentioned problems of the present invention, and it is possible to extract the low torque required when the cassette tape is running at a constant speed and the high torque required when the cassette tape is running at high speed at an optimum value. An object of the present invention is to provide a magnetic recording/reproducing device equipped with a torque generating means.

[Means for Solving the Problems] The invention according to claim 1 is a magnetic recording/reproducing device having a recording/reproducing mode in which a loaded cassette tape is run at a constant speed and a fast forward and 7 rewind mode in which the loaded cassette tape is run at a high speed, a pair of first and second reel means that engage with the cassette tape and wind the magnetic tape of the cassette tape in a predetermined direction; a motor that generates rotational force; and a forward torque generation means that is connected to the motor. , a reverse torque generating means linked to the forward torque generating means, and a rotational force transmitting means interposed between the forward torque generating means, the reverse torque generating means, and the first and second reel means.

The positive direction torque generating means includes a pulley that receives rotational force from the motor, a first rotating body disposed coaxially with the pulley,
a first friction transmitting means interposed between the pulley and the first rotating body, which reduces the rotational force received by the pulley to a predetermined value and transmits it to the first rotating body; and a second friction transmitting means disposed coaxially with the pulley. It has a rotating body and a second friction transmission means interposed between the first rotating body and the second rotating body to further reduce the rotational force of the first rotating body and transmitting the torque to the second rotating body.

Further, the reverse direction torque generating means has a fifth rotary body that engages with the first rotary body of the forward direction torque generating means and rotates in a direction opposite to the first rotary body.

The rotational force transmission means simultaneously engages the second rotating body of the forward torque generating means and the first reel means when the cassette tape runs at a constant speed in the recording/playback mode, and transmits the rotational force of the second rotating body to the first reel. A third rotary body transmitting power to the reel means is simultaneously engaged with the first rotary body of the forward torque generating means and the first reel means when the cassette tape is running at high speed in the fast forward mode, and the rotational force of the first rotary body is transmitted to the reel means. is transmitted to the first reel means, and the fifth reel of the reverse direction torque generating means is transmitted to the first reel means during high-speed running in the rewind mode.
It has a fourth rotary body that engages the rotary body and the second reel means at the same time and transmits the rotational force of the fifth rotary body to the second reel means.

In the invention according to claim 2, the first friction transmission means of the magnetic recording and reproducing device includes a first friction material that slides into contact with the pulley, and a first suppression that applies a predetermined pressing force to the first friction material. and means. Furthermore, the second friction transmission means:
It has a second friction material that slides into contact with the first rotating body, and a second suppression means that is provided independently of the first pressing means and applies a predetermined pressing force to the second friction material.

In the invention according to claim 3, the rotational force transmitting means of the magnetic recording and reproducing device includes a rotational center shaft, and a rotational force transmitting means mounted on the rotational center shaft and performing rocking motion independently of each other about the rotational center axis. 1 and a second swinging member.

The third rotating body is attached to the first swinging member, and the third rotating body is attached to the first swinging member.
The rotating body is attached to the second swinging member.

In the invention according to claim 4, the rotational force transmitting means is arranged such that the rotation center axis is located on a right-angled bisector of a line connecting the first reel means and the second reel means, and a locus of the third rotating body that rotates from a position where it engages with the means to a position where it engages with the second reel means, and a locus of the third rotating body that rotates from a position where it engages with the first reel means to a position where it engages with the second reel means; The trajectory of the fourth rotating body substantially coincides with that of the fourth rotating body.

The invention according to claim 5 provides a magnetic recording and reproducing device having a recording/reproducing mode in which a loaded cassette tape is run at a constant speed in the forward and reverse directions, and a fast forward and 7 rewind mode in which the loaded cassette tape is run at high speed in the forward and reverse directions. a pair of first and second reel means that engage with the cassette tape and wind the magnetic tape of the cassette tape in a predetermined direction, a motor that generates rotational force, and a forward torque generation that is linked to the motor. a reverse torque generating means linked to the forward torque generating means, and a rotational force transmitting means engaging the forward and reverse torque generating means.

The positive direction torque generating means includes a pulley that receives rotational force from the motor, a first rotating body disposed coaxially with the pulley,
a first friction transmission means that is interposed between the pulley and the first rotating body and reduces the rotational force received by the pulley to a predetermined value and transmits it to the first rotating body; and a second rotating body that is disposed coaxially with the pulley. and a second friction transmission means that is interposed between the first rotary body and the second rotary body and further reduces the rotational force of the first rotary body and transmits the torque to the second rotary body.

The reverse torque generating means is provided coaxially with a fifth rotary body that engages with the first rotary body of the forward torque generating means and rotates in a direction opposite to the first rotary body. The sixth rotating body is engaged with the second rotating body of the forward torque generating means and rotates in the opposite direction to the second rotating body.

The rotational force transmitting means simultaneously engages the second rotating body of the forward torque generating means and the first reel means when the cassette tape runs at a constant speed in the forward direction, and transfers the rotational force of the second rotating body to the first reel.
The torque is transmitted to the reel means, and when the cassette tape runs at a constant speed in the reverse direction, the sixth rotating body of the reverse torque generating means and the second reel means are simultaneously engaged, and the rotational force of the sixth rotating body is transmitted to the second reel means. A third rotating body for transmitting data, and a first rotating body of a forward torque generating means when the cassette tape runs in the forward direction at high speed.
The fifth rotating body of the reverse direction torque generating means and the second reel means are simultaneously engaged with the reel means to transmit the rotational force of the first rotating body to the first reel means, and the fifth rotating body of the reverse direction torque generating means and the second reel means are simultaneously engaged when traveling in the reverse direction at high speed. and a fourth rotating body that transmits the rotational force of the fifth rotating body to the second reel means.

In the invention according to claim 6, in addition to the magnetic recording and reproducing apparatus according to claim 5, a rotational force transmitting means is attached to the rotational center shaft and on the rotational center shaft, and the rotational force transmitting means is mounted on the rotational center shaft and rotates relative to each other about the rotational center axis. It has first and second swinging members that perform dynamic movement. The third rotating body is attached to the first swinging member, and the fourth rotating body is attached to the second swinging member.

In the invention according to claim 7, in addition to the magnetic recording and reproducing apparatus according to claim 5, each of the first and second reel means rotatably supports a reel stand on which the cassette tape is placed and a reel stand. a reel shaft and a seventh rotary member provided on the reel stand and engaged with the third rotating body when the cassette tape runs at a constant speed.
It includes a rotating body and an eighth rotating body that engages with the fourth rotating body when the cassette tape runs at high speed.

In the invention according to claim 8, the forward direction torque generating means and the reverse direction torque generating means are arranged approximately symmetrically about a right-angled bisector of a line connecting the rotation centers of the first and second reel means. , and the forward torque generating means is close to the first reel means, and the reverse torque generating means is close to the second reel means.

The rotational force transmitting means is arranged such that its rotational center axis is located on the above-mentioned right-angled bisector.

[Function] The magnetic recording and reproducing device according to claim 1 is provided with a first rotating body that generates a high torque and a second rotating body that generates a low torque, and the first and second rotations of each of the first and second rotating bodies are independently provided. It is configured to transmit rotational force via the fourth and third rotating bodies that engage with the body.

The rotational force set to a predetermined high torque value by the first friction transmission means is transmitted from the first rotating body to the fourth rotating body. Further, the rotational force set to a predetermined low torque value by the second friction transmission means is transmitted from the second rotating body to the third rotating body. Since this rotational force is transmitted by engagement of each pair of rotating bodies, it is smooth and does not generate abnormal noise.

In the invention according to claim 2, by independently providing the first suppressing means of the first friction transmitting means and the second pressing means of the second friction transmitting means, the pressure applied to each friction material is reduced. Pressure can be set individually. This makes it possible to set the rotational force extracted from the first rotating body and the rotational force extracted from the second rotating body to predetermined values.

In the invention according to claim 3, the space of the rotational force transmission means can be saved by arranging the pair of first and second swinging members constituting the rotational force transmission means on the same axis.

Furthermore, in the invention according to claim 4, further space saving can be achieved by making the rotation locus of the third rotor substantially coincide with the rotation locus of the fourth rotor.

In the invention according to claim 5, by providing the reverse direction torque generating means with a sixth rotary body that engages with the first rotary body and rotates in the opposite direction, playback is possible when the tape runs in the reverse direction. This enables a so-called auto-reverse mechanism.

In the invention according to claim 6, space can be saved by the configuration similar to claim 3.

In the invention according to claim 7, space can be saved by arranging the seventh and eighth rotating bodies coaxially.

In the invention according to claim 8, the third rotating body and the fourth rotating body of the rotational force transmitting means are arranged so that the third rotating body and the fourth rotating body of the rotational force transmitting means engage with the first rotating body, the first J-ru means, and the second rotating body, respectively. A force is applied in the direction in which the rotating body and the second reel means engage with each other, and smooth engagement with these rotating bodies can be maintained.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The magnetic recording/reproducing device according to the present invention is equipped with a so-called auto-reverse mechanism. Then, forward recording/playback mode (FF mode: forward play state), forward fast forward mode (FF mode: fast forward state),
A reverse recording/playback mode (RP mode: reverse play state) and a rewind mode (REW mode: rewind state) can be performed.

1, 3, and 5 are planar structural views of the magnetic recording/reproducing device according to the present invention, with FIG. 1 mainly showing the structure of the operating section, and FIG. 3 showing a block diagram of the driving parts. , 5th
The figure shows the structure of the drive system. Note that FIGS. 1 and 3 show the magnetic recording device in a stopped state, and FIG. 5 shows the FF mode. 2 is a partial cross-sectional structural view of FIG. 1, FIG. 4 is a partial cross-sectional structural view of FIG. 3, and FIG. 6 is a partial cross-sectional structural view of FIG. FIG.

First, referring to FIG. 5, the main components of the magnetic recording/reproducing apparatus are placed on a main chassis 1. As shown in FIG.

The drive block 2 has rotating parts mounted on a drive block plate 2a, and is attached to the main chassis 1 with screws.

On the main chassis 1 are a motor 7, a FOR flywheel 5 supported by a FOR capstan shaft 5a, and a REV.
A REV flywheel 6 supported by a capstan shaft 6a is arranged. Motor pulley 7a fixed to the output shaft of motor 7, FOR flywheel 5 and REV
A flybelt 8 is suspended on the flywheel 6. The motor 7 always rotates counterclockwise. And F.O.
The R capstan shaft 5a and the FOR flywheel 5 are rotated counterclockwise, and the REV capstan shaft 6a and the R
The EV flywheel 6 rotates clockwise.

A pulley 11 supported by a drive shaft 10 is rotatably mounted on a drive block plate 2a of the drive block 2. A drive belt 9 is suspended between the pulley 11 and a fly pulley 5b of the FOR flywheel 5. This causes the pulley 11 to constantly rotate counterclockwise. Furthermore, on the drive block play) 2a, a substantially T-shaped play idler lever 12 and a substantially T-shaped FF/REW idler lever 13 are mounted on the shaft 2b.
are located coaxially. And this play idler lever 12 and FF/REW idler lever 13
is mounted rotatably around the shaft 2b.

Next, mainly referring to FIG. 1, a FOR pinch roller block 14 and a REV pinch roller block 15 are arranged symmetrically on the main chassis 1. The FOR pinch roller block 14 is rotatably mounted around the shaft 1a, and the REV pinch roller block 15 is rotatably mounted around the shaft 1b. The head plate 16 is a shaft IC 11 provided on the main chassis 1.
d and can reciprocate in the directions of arrows A and B in the figure, and is always urged in the direction of arrow B by a spring (not shown). A magnetic head (not shown) is mounted on the head plate 16, and when the head plate 16 moves in the direction of arrow A against the spring force by rotation of a first cam (not shown), the cassette It operates to obtain proper contact with the magnetic tape of the tape. In addition, Tsumugi 1
c.

1d is provided on the right-angled bisector of a line connecting the rotation center axis 2c of the FOR reel stand 3 and the rotation center axis 2d of the REV reel stand 4, and is further configured symmetrically with respect to this right-angle bisector. ing. Further, a guide hole 16a is provided at the tip of the head plate 16. The guide hole 16a is a long hole 16 that prohibits the pin 12a provided on the play idler lever 12 from moving in the directions of arrows C and D in the figure.
a1, oblique sides 16a-2, 16a-3, and an opening 16a-4 that allows the pin 12a to move in the direction of arrow CSD.

The reverse plate 17 is guided by shafts 16b and 16c provided on the head plate 16 and is attached to be able to reciprocate in the direction of arrow C1D. The reverse plate 17 is always urged in the direction of arrow C by a spring (not shown), and is movable in the direction of arrow C by the operation of a second cam (not shown). As shown in FIG. 1, in the stopped state, the reverse plate 17 is located in the direction of arrow C.

Next, a mechanism for switching to FF/REW mode will be explained. The FF lever 18 for switching to FF mode and the REW lever 19 for switching to REW mode are connected to shafts 1e, If and 1g provided in main chassis 1.
, lh guide reciprocating motion in the directions of arrows A and B, respectively. Both levers 18 and 19 are biased in the direction of arrow B by springs (recesses shown). The FF lever 18 and the REW lever 19 are arranged symmetrically with respect to a right-angled bisector of a line connecting the rotation centers of both reel stands 3.4. The FF lever 18 has a protruding piece 18a in the direction of arrow A, and similarly, the REW 19 has a protruding piece 19a. The protruding piece 18a of the FF lever 18 is FF/R.
Opposed to the left arm 13a of the EW idler lever 13,
Projecting piece 19 a l of REW lever 19;! F F/R
It faces the right arm 13b of the EW idler lever 13.

Further, an FF operation part and a REW operation part (not shown) are provided on the arrow B sides of the FF lever 18 and the REW lever 19, respectively.

The FF/REW idler lever 13 is rotatably mounted around a shaft 2b provided on the drive block plate 2a. A portion of the FF/REW idler lever 13 has a stepped shape connected by a connecting portion 13c. FF/R is on the outer peripheral surface 13d of the bearing part of the shaft 2b.
The coil portion of the EW torsion spring 22 is fitted.

Both arms of the torsion spring 22 hold the connecting portion 13c of the FF/REW idler lever 13. Also,
A drive block plate 2a is installed between the connecting portion 13c of the FF/REW idler lever 13 and the outer peripheral surface 13d of the bearing portion.
A protrusion 21 protruding from the surface is directed. And the connection part 13c of the FF/REW idler lever 1.3
The width of the drive block plate 2a and the width of the protrusion 21 of the drive block plate 2a are configured to have the same dimension. With such a configuration, F
The F/REW idler lever 13 is maintained at a position where it does not rotate either clockwise or counterclockwise by the action of a torsion spring 22.

Next, the rotation transmission system will be explained. In the rotation transmission system, all rotating parts except the motor, flywheel, and pinch roller belt are grouped into a drive block 2. Referring to FIGS. 3, 4, and 6, the drive block plate 2a of the drive block 2 is integrally formed with a boss 2g having a through hole 2h for screws for attachment to the main chassis 1. . Furthermore, drive block plate 2a
On the top is the play idler lever 12 and FF/REW.
A shaft 2b for the idler lever 13, a shaft 2c for the FOR reel stand 3, a shaft 2d for the REV reel stand 4, and a shaft 2e for the reverse gear and the REW gear are provided, and a bearing for the drive shaft 10 is further provided. FOR reel stand 3
The pitch between the shaft 2c of the REV reel stand 4 and the shaft 2d of the REV reel stand 4 is, for example, 42.degree. 5 mm, which matches the reel pitch of a compact cassette tape. Further, the shaft 2b is located at the same distance from the rotation center axes 2c and 2d of the two-wheel stand 3.4, and is located on the arrow B side from the bearing of the drive shaft 10. Furthermore, the bearings for the reverse gear shaft 2e and the drive shaft 10 are the rotation center shafts 2 of the FOR reel stand 3 and the REW reel stand 4.
They are arranged symmetrically with respect to the right-angled bisector of the line connecting C% 2 d. The drive block 2 is screwed and fixed to a predetermined position of the main chassis 1 via a boss 2g. In the drive block 2, both reel shafts 2c and 2d are arranged at predetermined setting positions with respect to both capstan shafts 5aN6a.

For example, the distance between the axes of both reel shafts 2c and 2d and the axes of both capstan shafts 5as6a is 31°3 mm.

With reference to FIGS. 3 and 6, the friction block 6
0 will be explained. The drive shaft 10 is rotatably inserted into a bearing 2f provided on the drive block plate 2a. Rotating parts are respectively attached to a portion of the drive shaft 10 that projects downward (in the direction of arrow E) and a portion that projects upward (in the direction of arrow F) from the drive block plate 2a.

First, in the lower part of the drive shaft 10, the spring receiver 30 is press-fitted and fixed to the lower part of the drive shaft 10.

The lower end surfaces of the spring receiver 30 and the drive shaft 10 are aligned. Then, the drive shaft 10 and the spring receiver 30 rotate integrally. A first compression spring 32 is placed on the upper surface of the flange of the spring receiver 30. The friction plate 31 is the first compression spring 3
2 is pressed down onto the upper surface of the spring receiver 30, and is inserted into the center of the friction plate 31 or the outer peripheral surface 30b of the press-fitted portion 30a of the spring receiver 30 so as to be movable up and down. A first friction member 33 is placed on the upper surface of the friction plate 31, and a pulley 1 is further attached to the upper surface. After the pulley 11 is inserted into the drive shaft 10, the stop washer 34 is attached to the groove 10a provided in the drive shaft 10. Note that a rotation stopper (not shown) is provided between the friction plate 31 and the spring receiver 30, so that the friction plate 31 and the spring receiver 30 rotate integrally. The rotational force from the motor 7 is transmitted to the pulley 11 by the drive belt 9. The rotation of the pulley 11 is caused by the friction plate 31 via the first friction member 33.
It is transmitted to the spring receiver 30 and the rotating shaft 10. The load of the first compression spring 32 is supported between the spring receiver 30 and the pulley 11 supported by the stop washer 34. A first maximum transmission torque (high torque) is set by the first friction member 33 made of felt such as wool and the first compression spring 32. This first maximum transmission torque is a torque suitable for running the tape at high speed, and is, for example, 80 g-Cm.゛If the torque transmitted from the motor 7 to the pulley 11 is 100 g-am, then the torque of 20 g-Cm is transmitted between the pulley 11 and the friction plate 3.
1 by slipping between the two. The above structure is referred to as a first friction mechanism. The first maximum transmission torque set by the first friction mechanism is transmitted to the upper side of the bearing 2f by the drive shaft 10.

Next, the second friction mechanism located above the bearing 2f will be explained. A flat washer 40 (trade name: polyslider washer) made of a low-friction material is inserted into the drive shaft 10 protruding upward from the bearing 2f of the drive block plate 2a. Next, the FF gear 35 is press-fitted onto the drive shaft 10. The FF gear 35 is mounted so that its upper surface and the upper end of the drive shaft 10 are aligned. The FF gear 35 rotates integrally with the drive shaft 10. After this, the way the friction block 60 is thrust is adjusted. The thrust direction is the entire length of the drive shaft 10 and the FF gear 35 attached to the drive shaft 10.
, the bearing 2f, the washer 40.34, the pulley 11, and the overall length of the spring receiver 30. This thrust angle is adjusted to, for example, 0.05 to Q, about 2 mm.

After adjusting the thrust direction, the second friction member 39 is attached to the upper surface of the FF gear 35. Further, a play gear 37 is attached to the upper surface of the second friction member 39. The play gear 37 has a large diameter gear portion 37a and a small diameter gear portion 37b. A second compression spring 38 is placed in the recessed portion of the upper surface of the play gear 37, and from above the spring receiver press-fits and fixes the plate 36 to the outer peripheral surface 35d of the press-fit portion 35b of the FF gear 35. This structure constitutes the second friction mechanism. The FF gear 35 rotates integrally with the drive shaft 10, and the play gear 37 rotates with a predetermined rotational force via the second friction member 39. Second compression spring 38
The load of the spring bearing is supported by the plate 36 and the FF gear 35. A second maximum transmission torque (low torque) is set by the second friction member 39 and the second compression spring 38.

This second maximum transmission torque is a value lower than the above-mentioned first maximum transmission torque, and is set to the torque necessary to run the tape at a constant speed. For example, the value is 35g-cm
It is. As mentioned above, if the maximum torque of the first friction mechanism is 80 g-Cm, the second friction mechanism will reduce the torque by 45 g-0 m.

In this way, the first and second friction mechanisms are coaxially provided on the drive shaft 10. The bearing 2f and the drive block plate 2a are provided at the upper and lower parts of the drive block plate 2a so as to be separated from each other. Therefore, the vibrations of the rotating bodies do not interfere with each other.

Here, to summarize the operations of the first and second friction mechanisms described above, the rotational force transmitted from the motor 7 to the pulley 11 is limited by the first friction mechanism to the first torque suitable for high-speed running of the tape. This first torque is transmitted from the friction plate 31 to the FF gear 35 through the spring receiver 30 and further through the drive shaft 10. By extracting this first torque from the FF gear 35, a predetermined high torque can be obtained. Next, the rotational force transmitted to the FF gear 35 is limited by the second friction mechanism to a second torque suitable for running the tape at a constant speed, and is transmitted to the play gear 37. Therefore, when the rotational force is extracted from the play gear 37, a predetermined low torque can be obtained.

The FF gear 35 serving as a high-torque drive source and the play gear 37 serving as a low-torque drive source are provided adjacent to each other with a very thin second friction member 39 interposed therebetween. Also, F
The diameters of the F gear 35 and the play gear 37 are the same.

With this configuration, the entire friction block 60 is made compact. Therefore, the rotation transmission system that engages with this friction block 60 is also made more compact.

Next, the structure of the reel portion will be explained. The FOR reel stand 3 and the REV reel stand 4 have blade portions 3CN4 that engage with the reel hub of the cassette tape and wind up the tape.
It has C. It is rotatably attached to a shaft 2c12d provided on the drive block plate 2a. Further, the FOR reel stand 3 and the REV reel stand 4 each have large diameter gears 3a, 4a and small diameter gears 3b, 4b coaxially and integrally provided. Both reel stands 3.4 both shaft 2c
, 2d are provided with stop washers to ensure an appropriate clearance with the drive block plate (2a) and to restrict vertical movement. The large diameter gears 3a and 4a of the reel stand are the small diameter gear 2 of the play idler gear 20.
0b, the tape runs at a constant speed, and the small diameter gears 3b, 4
b is the large diameter gear 21a of the FF/REW idler gear 21
It meshes with the tape and runs the tape at high speed.

Next, a mechanism related to running the tape in the reverse direction will be explained. This mechanism has a REW gear 50 and a reverse gear 51.
including. A shaft 2e is attached to a predetermined position of the drive block plate 2a.
has been erected. The REW gear 50 is rotatably mounted on the shaft 2e.

After inserting the REW gear 50 into the shaft 2e, a stop washer is assembled into the groove provided on the shaft 2e, and the REW gear 50 is inserted into the shaft 2e.
is allowed to have an appropriate backlash in the longitudinal direction of the shaft 2e, and its vertical movement is restricted. Further, a reverse gear 51 is inserted into the shaft 2e, and a stop washer is installed at the upper end of the shaft 2e. The reverse gear 51 is also allowed to have an appropriate play in the axial direction of the shaft 2e. The large diameter portions 51a of the REV gear 50 and the reverse gear 51 are formed to have approximately the same diameter. And REW
The gear 50 is always in mesh with the FF gear 35, and the large diameter gear 51a of the reverse gear 51 is in mesh with the large diameter gear 3 of the play gear 37.
It is always engaged with 7a. As a result, the REW gear 50 rotates in the opposite direction to the FF gear 35, and the reverse gear 51
rotates in the opposite direction to the play gear 37.

Furthermore, the mechanisms of the play idler lever 12 and the FF/REW idler lever 13 will be explained. Referring to FIG. 2 and FIG. 6, FF/REW)-John spring 2
2 and the FF/REW idler lever 13 is rotatably inserted. The idler lever 13 has a stop washer attached to a groove 2b-1 provided in the shaft 2b to ensure an appropriate thrust direction and to restrict vertical movement. Furthermore, the play idler lever 1 is attached to the shaft 2b.
Insert 2. The play idler lever 12 is provided with a snap hit part (having a structure in which a locking piece is provided at the tip of an elastic piece, not shown), and when inserted to a predetermined position, this snap hit part engages the drive block plate. Locked to 2a. When the drive block 2 is attached to the main chassis 1, the play idler lever 12 is restricted from moving upward by the lower surface of the main chassis 1. A play idler gear 20 and an FF/REW idler gear 2 having two-stage gears are connected to the play idler lever 12 and the FF/REW idler lever 13 through rotating shafts 12d and 13e, respectively, at their tips.
1 are rotatably attached. Idler gear 2
0 and FF/REW idler gear 21 are respectively rotating shaft 1
2d and 13e are restrained from vertical movement by stop washers while ensuring an appropriate thrust direction.

The rotation centers of the play idler lever 12 and the FF/REV idler lever 13 are located on the shaft 2b as described above, and the distance history from this rotation center to the rotation center of the play idler gear 20 and the FF /REW The distance L2 to the rotation center of the idler gear 21 is set to be approximately the same dimension. However, strictly speaking, History 2 is earlier and larger. Further, the large diameter gear 20a of the play idler gear 20 and the large diameter gear 21a of the FF/REW idler gear 21 are formed to have the same diameter.

Next, the positional relationship of each gear in the height direction will be explained.

The large diameter gear 21a of the FF/REW idler gear 21 is F.
Small diameter gear 3b of OR reel stand 3 and REW reel stand 4
It is provided at the same height as the small diameter gear 4b. FF/R
The small diameter gear 21b of the EW idler gear 21 is connected to the FF gear 35 and the REW gear 50 of the friction block 60.
is placed at the same height. On the other hand, the large diameter gear 20a of the play idler lever 20 is provided at the same height as the small diameter gear 37b of the play gear 37 and the small diameter gear 51b of the reverse gear 51. Play idler gear 20
The small diameter gear 20b is provided at the same height as the large diameter gear 3a of the FOR reel stand 3 and the large diameter gear 4a of the REW reel stand 4.

Next, the operation of the above magnetic recording/reproducing apparatus according to the present invention will be explained.

First, the stopped state will be explained with reference to FIG. In the stopped state, the play idler lever 12 is held in its position by the head plate 16, the FF/REW idler lever 13 is held in its position by the FF/REW torsion spring 22, and the play idler gear 20 and the FF/REW idler gear 21 are It is located on the center line between the reel shafts 2C12d, and the play idler gear 20 and the FF/REW idler gear 21 are located so as to substantially overlap each other in a plane. At this time, the large diameter gear 20a of the play idler gear 20 is connected to the small diameter gear 37b of the play gear 37 and the reverse gear 51.
The small diameter gear 20b of the play idler gear 20 is separated from the large diameter gear 3a of the FOR reel stand 3 and the large diameter gear 4a of the REV reel stand 4. On the other hand, the large diameter gear 21a of the FF/REW idler gear 21 is separated from the small diameter gear 3b of the FOR reel stand 3 and the small diameter gear 4b of the REV reel stand 4, and the small diameter gear 21b is separated from the FF gear 35 and the REW gear 50. are doing. Therefore, even if the pulley 11 rotates in response to the rotational force from the motor 7, both reel stands 3.4 do not rotate.

Next, the forward play mode will be explained. This mode corresponds to the forward play mode and the forward record mode. FIG. 7 is a plan structural diagram showing the positional relationship of rotating parts in forward play mode. Referring to FIGS. 5 to 7, the head plate 16 moves in the direction of arrow A from the above-mentioned stopped state by the operation of the first cam, and the reverse plate 17 moves the play idler lever 12
is rotated clockwise around the shaft 2b, and the small diameter gear 20b of the play idler gear 20 is engaged with the large diameter gear 3a of the FOR reel stand 3, and the large diameter gear 20a is engaged with the small diameter gear 37b of the play gear 37. After these gears are engaged, the pressing force of the reverse plate 17 is elastically absorbed by the left arm portion 12b having elasticity.

Similarly, when the head plate 16 is moved in the direction of arrow A by the first cam, the bent piece 17a of the reverse plate 17 moves the FOR pinch roller spring 14b in the direction of arrow A.
direction, FOR pinch roller block 14
The pinch roller 14a rotates clockwise around a and presses the FOR capstan shaft 5a to pinch the tape.

Then, the tape is driven at a constant speed in the direction of arrow C. moreover,
The bent piece 17b of the reverse plate 17 presses the left arm portion 12b of the play idler lever 12.

At this time, the head plate 16 has moved to some extent in the direction of arrow A, and the pin 12 of the play idler lever 12
a is a long hole 16a of the guide hole 16a of the head plate 16
- Extracted from 1. Therefore, the play idler lever 12 is rotatable around the shaft 2b, and the play idler lever 12 is rotated clockwise around the shaft 2b by the reverse plate 17.

The rotation transmission path in this forward play mode is as follows.

Motor 7 (counterclockwise) - Boo'J7a (counterclockwise)
→ Fly belt 8 → FOR flywheel 5 (counterclockwise) - Flyboo IJ5b (counterclockwise) → Drive belt 9 → Pulley 11 (counterclockwise) → First friction mechanism → Friction plate 31 (counterclockwise) → Spring receiver 30 (counterclockwise) → Drive shaft 10 (counterclockwise) → FF gear 35 (counterclockwise) → Second friction mechanism - play gear 37
(Counterclockwise direction)→Play idler gear 20→FOR reel stand 3 (Counterclockwise direction) Therefore, the FOR reel stand 3 generates a low torque, for example, 35g-C, through the second friction mechanism.
The tape is run at a constant speed in the forward direction at m.

Next, the reverse play mode will be explained.

This mode corresponds to reverse play mode and reverse record mode. FIG. 8 is a plan structural diagram showing the positional relationship of rotating parts, and FIG. 9 is a cutting line B--
FIG. Also, the 10th
The figure is a plan structural diagram showing the positional relationship between rotating parts and operating parts.

Referring to FIGS. 8 to 10, a second cam is triggered by the reverse play operating means, and this second cam causes the reverse plate 17 to move from the head plate 16 to the head plate 16.
and move in the direction of the arrow.

Upon completion of the movement of the reverse plate 17, the trigger means (
(not shown) causes the first cam to operate and the head plate 16 to move in the direction of the arrow, entering the reverse play mode. This operation will be explained in more detail as follows. When the reverse plate 17 has completed its movement in the direction indicated by the arrow, the bent piece 17c of the reverse plate 17 faces the arm of the REV pinch roller spring 15b of the REV pinch roller block 15, and the bent piece 17d faces the right side of the play idler lever 12. It faces the arm 12c. Then, when the head plate 16 moves in the direction of the arrow,
The bent piece 17c of the reverse plate 17 presses the REV pinch roller spring 15b in the direction of arrow A, and the REV pinch roller block 15 rotates counterclockwise about the shaft 1b.

The pinch roller 15a is connected to the REV capstan shaft 6.
Press a to grip the tape and drive the tape at a constant speed in the direction of the arrow. As a result, the head performs a recording or reproducing operation on the tape. Furthermore, reverse plate 1
The bent piece 17d of No. 7 presses the right arm 12c of the play idler lever 12, which is made of an elastic body. At this time, the play idler lever 12 is rotatable about the shaft 2b, similar to the mode switching from the stop state to the forward play state described above. Therefore, the play idler lever 12 rotates counterclockwise about the shaft 2b. Then, the small diameter gear 2 of the play idler gear 20
0b meshes with the large diameter gear 4a of the REV reel stand 4, and the large diameter gear 20a meshes with the small diameter gear 51b of the reverse gear 51. After these gears are engaged, the reverse plate 17
The elastic right arm 12c absorbs the pressing force. The rotation transmission path in this reverse play mode is as follows.

Pulley 11 (counterclockwise) → first friction mechanism →
Friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35
→ Second friction mechanism → Play gear 37 (counterclockwise) - Reverse gear 51 (clockwise) → Play idler gear 20 (counterclockwise) → REV reel stand 4 (clockwise) Therefore, the REV reel stand 4 Low torque, e.g. 35g, through the friction mechanism of 2
The tape is run at a constant speed in the opposite direction at -cm.

Next, the forward fast forward mode (FF mode) will be explained. FIG. 11 is a plan structural diagram showing the positional relationship of rotating parts, and FIG. 12 is a cutting line C-C in FIG. 11.
FIG. Moreover, FIG. 13 is a plan structural diagram showing the positional relationship of rotating parts and operating parts.

11 and 13, when the FF lever 18 is moved in the direction of arrow A, the FF/REW idler lever 13 rotates clockwise about the shaft 2b, and the FF/REW
The large diameter gear 21a of the EW idler gear 21 meshes with the small diameter gear 3b of the FOR reel stand 3, and the small diameter gear 21b is FF.
It meshes with the gear 35a of the gear 35. After these gears are engaged, the pressing force of the FF lever 18 is elastically absorbed by the elastic left arm 13a. The rotation transmission path in this FF mode is as follows.

Pulley 11 (counterclockwise) - first friction mechanism -
Friction plate 31 → Spring receiver 30 → Drive shaft 1O-FF gear 35
(Counterclockwise) - FF/REV idler gear 21 (clockwise) → FOR reel stand 3 (counterclockwise) Therefore, the FOR reel stand 3 can generate high torque, for example, 80g, by using only the first friction mechanism.
-Cm to run the tape in the forward direction at high speed. In addition, in this mode, the play idler lever 12
is held in its original resting position.

Furthermore, the rewind mode (REW mode) will be explained. FIG. 14 is a plan structural diagram showing the positional relationship of rotating parts, and FIG. 15 is a cutting line D-D in FIG. 14.
FIG. Further, FIG. 16 is a plan structural diagram showing the positional relationship between rotating parts and operating parts. Referring to FIGS. 14 to 16, when the REW 19 is moved in the direction of arrow A from the stopped state, the FF/
The REW idler lever 13 rotates counterclockwise around the shaft 2b, and the large diameter gear 21a of the FF/REW idler gear 21 meshes with the small diameter gear 4b of the REV reel stand 4.
The small diameter gear 21b meshes with the REW gear 50. After these gears are engaged, the pressing force of the REW lever 19 is elastically absorbed by the elastic right arm 13b. This R
The rotation transmission path in the EW mode is as follows.

Pulley 11 → first friction mechanism → friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35 → REW gear 5
0-+FF/REW idler gear 21 → REV reel stand 4 Therefore, the REV reel stand 4 can generate high torque, for example, 80 g, by using only the first friction mechanism.
-cm to run the tape in the reverse direction at high speed. Note that in the REW mode, the play idler lever 12 is maintained at the stopped position.

The above is the explanation regarding the basic operation of the magnetic recording/reproducing apparatus of the present invention.

The magnetic recording/reproducing device as described above has the following features.

(1) The structure of the drive block 2 is compact.

That is, the structure of the drive block 2 is configured to satisfy the following three conditions.

■ The rotation angle of the play idler lever 12 from the stopped state to the play forward mode is θ1, the rotation angle from the stopped state to the play reverse mode is θ2, FF/REW
If the rotation angle of the idler lever 13 from the stopped state to the FF mode is θ3, and the rotation angle from the stopped state to the REW mode is θ4, the relationship θ,=θ2=63=θ4 should be established.

■ Regarding the rotation radius t, "i t2" of the play idler gear 20 and the FF/REV idler gear 21, 1
Having the relationship l=L2.

■ The diameters of the play idler gear 20 and the FF/REW idler gear 21 are the same.

If this condition is met, play idler gear 20 and FF
/REW The movable range of the idler gear 21 can be made equal. Due to this characteristic, the play idler lever 12 with the play idler gear 20 attached and the FF
By arranging the FF/REW idler lever 13 and the FF/REW idler lever 13 to which the /REW idler gear 21 is attached coaxially and overlappingly, the structure of the drive block 2 can be made compact. In addition, by appropriately setting the value of the rotation transmission ratio from the motor during constant-speed tape running and high-speed tape winding running, the play idler lever 12, play idler gear 20, FF/REW idler lever 13, and FF/REW idler gear can be adjusted. It is possible to set the movable ranges of 21 to be strictly equal.

(2) A compact auto-reverse mechanism is constructed by providing the REW gear 50 and reverse gear 51 coaxially.

(3) In all operating modes, the play idler gear 20 and the FF/REW idler gear 21
It is configured to receive a force acting in the biting direction on the gears that mesh with each other.

This configuration will be explained below.

FIG. 17 is a plan view of the structure in a forward play state. Referring to FIG. 17, the small diameter gear 37b of the play gear 37 rotating counterclockwise causes the large diameter gear 20a of the play idler gear 20 to rotate clockwise. That is, the play idler gear 20 receives a tangential force of vector A1 at the intersection between the large diameter gear 20a and the small diameter gear 37b of the play gear 37. On the other hand, the small diameter gear 20b of the play idler gear 20 rotating clockwise rotates the large diameter gear 3a of the FOR reel stand 3 counterclockwise. That is, the play idler gear 20 serves as a driving source for the FOR reel stand 3. Therefore, the FOR reel stand 3 has a vector B at the intersection of the small diameter gear 20b of the play idler gear 20 and the large diameter gear 3a of the FOR reel stand 30.
, receives a tangential force in the opposite direction. Then, the play idler gear 20 receives a reaction force having a load equal to the vector B1. Therefore, the play idler gear 20 has vector A
It receives the weight of the composite vector C1 of 1 and vector B.

This resultant force acts on the play gear 37 and the FOR reel stand 3 in the biting direction. Therefore, in the forward play mode, the play idler gear 20 receives a force acting in the biting direction.

FIG. 18 is a plan view of the drive mechanism in reverse play mode. Referring to FIG. 18, the small diameter gear 51b of the reverse gear 51 rotating clockwise causes the large diameter gear 20a of the play idler gear 20 to rotate counterclockwise. That is, the reverse gear 51 serves as a driving source for the play idler gear 20. Therefore, the play idler gear 20 receives a tangential force of vector A2 at the intersection between the large diameter gear 20a of the play idler gear 20 and the small diameter gear 51b of the reverse gear 51.

On the other hand, the play idler gear 20 rotates counterclockwise.
The small diameter gear 20b rotates the large diameter gear 4a of the REV reel stand 4 clockwise. That is, the play idler gear 20 serves as a driving source for the REV reel stand 4. Therefore, the REV reel stand 4 has a large diameter gear 4a of the REV reel stand 4 and a small diameter gear 20b of the play idler gear 20.
At the intersection with vector B2, a tangential force in the direction opposite to vector B2 is applied. Then, play idler gear 20 is vector B
It receives a reaction force as a load of 2. Therefore, the play idler gear 20 receives a load of a composite vector C2 of vector A2 and vector B2. This load C
2 acts on the reverse gear 51 and the REV reel stand 4 in the biting direction. Therefore, even in the reverse play mode, the play idler gear 20 receives a force acting in the biting direction.

FIG. 19 is a plan structural diagram of the drive mechanism in FF mode. Referring to FIG. 19, F rotates counterclockwise.
The F gear 35 rotates the small diameter gear 21b of the FF/REW idler gear 21 clockwise. That is, the FF gear 35 serves as a driving source for the FF/REW idler gear 21. Therefore, the FF/REW idler gear 21
receives a tangential force of vector A3 at the intersection of the FF gear 35 and the small diameter gear 21b of the FF/REW idler gear 21. On the other hand, the large diameter gear 21a of the FF/REW idler gear 21 rotating clockwise is connected to the FOR reel stand 3.
Rotate the small diameter gear 3b counterclockwise. That is,
The FF/REV idler gear 21 serves as a driving source for the FOR reel stand 3. Therefore, the FOR reel stand 3 receives a tangential force in the direction opposite to the vector B3 at the intersection of the small diameter gear 3b of the FOR reel stand 3 and the large diameter gear 21a of the FF/REW idler gear 21. And FF/R
The EV idler gear 21 receives a reaction force as a load of vector B3. Therefore, the FF/REW idler gear 21 receives a load of a composite vector C3 of vector A3 and vector B3. The direction of action of this resultant force C3 is FF
This is the direction in which it bites into the gear 35 and the FOR reel stand 3.

Therefore, even in the FF mode, the FF/REW idler gear 21 receives a force acting in the biting direction.

FIG. 20 is a plan view of the drive mechanism in REW mode. Referring to FIG. 20, rotate R clockwise.
The EW gear 50 rotates the small diameter gear 21b of the FF/REW idler gear 21 counterclockwise. That is, R.E.
The W gear 50 serves as a driving source for the FF/REW idler gear 21.

Therefore, the FF/REW idler gear 21 is
/REW small diameter gear 21b of idler gear 21 and REW
It receives a tangential force of vector A4 at the intersection with gear 50. On the other hand, the large diameter gear 21a of the FF/REW idler gear 21, which rotates counterclockwise, rotates the small diameter gear 4b of the REV reel stand 4 clockwise. That is, F.F.
/REV idler gear 21 serves as a driving source for REV reel stand 4. Therefore, the REV reel stand 4 is
At the intersection between the small diameter gear 4b of the EV reel stand 4 and the large diameter gear 21a of the FF/REW idler gear 21, a tangential force in the direction opposite to the vector B4 is applied.

The FF/REV idler gear 21 is vector B4.
receives a reaction force as a load. Therefore, FF/R
EW idler gear 21 is vector A4 and vector B4
It receives the load of the composite vector C4. This combined force C4
acts in the direction in which the REW gear 50 and the REV reel stand 4 bite. Therefore, the FF/REW idler lever 21 receives an acting force in the biting direction.

In this way, in any operation mode, the play idler gear 20 and the FF/REW idler gear 21
will be subjected to an acting force in the digging direction.

Furthermore, what is more important in the above explanation is the play idler gear 20 and the FF/REW idler gear 2.
Vector loads A, ~A4, B, ~B4 that respectively act on
are all play idler lever 12 and FF/RE
It acts to rotate the W idler lever 13 in the biting direction. This situation occurs when trying to transmit rotational force by interposing a rotational rotation transmitting body between the first rotating body serving as a drive source and the final transmitted rotating body. The meshing is ensured regardless of which of the first rotating body and the final transmitted body the body starts to mesh with first. Therefore, such a structure is excellent in that it increases the degree of freedom in designing the arrangement structure of these rotating bodies. Furthermore, the structure in which an acting force acts on the rotational rotation transmitting body in the biting direction allows, for example, an error in the rotational stroke of the rotational rotation transmitting body to be compensated for by the acting force acting on the rotating rotational transmission body in the biting direction. This improves the degree of freedom in designing the arrangement of the rotating system.

In all the modes described above, the following conditions must be satisfied in order for the play idler gear 20 and the FF/REW idler gear 21 to receive the acting force in the biting direction.

■ The play gear 37 and the reverse gear 51 are located on the arrow A side of the line connecting the rotation centers of the FOR reel stand 3 and the REV reel stand 4, and the line connecting the rotation centers of the FOR reel stand 3 and the REV reel stand 4 is Be placed in a symmetrical position with respect to the right angle bisector.

■ FF gear 35 and play gear 37 arranged on the same axis
Furthermore, the REV gear 50 and the reverse gear 51, which are arranged coaxially, are arranged symmetrically with respect to a right-angled bisector of a line segment connecting the rotation centers of the two reel stands 3.4.

■ The center of rotation 2b of the play idler lever 12 and the FF/REW idler lever 13 is located at arrow B from the line connecting the centers of rotation of the play gear 37 and reverse gear 51.
on the right-angled bisector of the line segment connecting the rotation centers of the two reel stands 3.4.

As described above, in the above embodiment, an example in which the first and second friction mechanisms are provided in the friction block 60 has been described, but it is also possible to further provide a third friction mechanism between the REW gear 50 and the reverse gear 51. It is possible. By providing this third friction mechanism, a torque generating means exclusively for reverse play can be provided. For example, it is possible to make the torque different between the forward play mode and the reverse play mode, and it is also possible to change the torque from the play gear 37 to the REV reel stand 4.
This has the effect that there is no need to take into account the transmission loss of the reverse gear 51 that intervenes before reaching the point.

In addition, in the above embodiment, the play idler lever 1
2, a method of reciprocating the head plate 16 on which the head is mounted has been shown, but a method using an overstroke lever may also be used. This is effective in a magnetic recording/reproducing device having a track interval detection mechanism. Note that the overstroke lever has the following structure. In tape recorders, it is very important to maintain an appropriate contact relationship between the tape and the head during playback and recording. Therefore, an important issue is how far the head moves in the tape contact direction during playback. This amount of movement of the head is called a head stroke. In the above embodiment, the head plate 16 is moved in the direction of arrow A during playback by the operation of the first cam. However, in such a structure, the amount of movement of the head plate 16 varies slightly due to variations in component precision. Therefore, a contact part is provided on the main chassis 1, and when the head plate 16 comes into contact with the contact part, the movement of the head plate 16 is restricted, and the setting is made so that this contact state is the optimum position for the head stroke. ing. However,
If only the first cam operates, the head stroke will vary due to variations in parts. Therefore, an overstroke lever is required. That is, first, the first cam moves the overstroke lever by moving the head plate 16 by a stroke larger than a predetermined required stroke. A tension spring is provided between the overstroke lever and the head plate, and when the overstroke lever moves in the direction of arrow A, the head plate 16 is moved in the direction of arrow A via the tension spring. When the head plate 16 contacts the contact portion of the main chassis 1, the head plate 16 does not move any further in the direction indicated by the arrow. Then, only the overstroke lever moves in the direction of arrow A. During this time, the tension spring expands to absorb the overstroke.

When detecting between tracks, the head position may not match the tape because the head stroke during playback causes severe wear on the head, or the pad pressure on the tape side requires a torque greater than that required for normal high-speed running. Move back slightly within contact range. The amount of retraction from this playback state to the inter-track detection state is typically 1.5 to 2.
．． It is 0mm. If there is no overstroke, this is approximately 1.5 to 2. Play idler gear 20 and FOR reel stand 3 or REV reel stand 4 with only a retraction amount of Omm.
must be disengaged from it. However, when the reverse plate 17 is provided on the overstroke lever, the amount of movement of the overstroke lever from the playback state to the song interval detection state is 1.5 to 100%, based on the amount of retraction of the head plate.
2.0mm plus overstroke, for example 1.
0mm is added. Therefore, about 2.5-3.0mm
Then, play idler gear 20 is set to FO with a margin.
The engagement from the R reel stand 3 or the REV reel stand 4 can be released.

[Effect of the invention] As described above, the magnetic recording and reproducing device according to the present invention has the first
The first rotary body that generates high torque through a friction transmission means and the second rotary body that generates a low torque through a second friction transmission means are provided independently from each other. Torque control becomes easy, and stable tape running operation can be performed in both high-speed running of the tape, which requires high torque, and constant-speed running, which requires low torque. In addition, the first
Since the rotating body and the second rotating body are independent, the structure of the rotation transmitting means for transmitting the predetermined torque generated by both to the reel means is simplified, and the transmission efficiency is increased.

Further, by arranging the third rotary body, the fourth rotary body, and the first and second swinging members coaxially as the rotation transmitting means, the space of the structure can be reduced.

Furthermore, the rotational force transmission means for forward running of the tape and the rotational force transmission means for running in the reverse direction are made to have substantially the same rotational range, thereby realizing a compact structure.

Furthermore, by providing a fifth rotating body and a sixth rotating body that are arranged coaxially and constantly meshing with the first rotating body and the second rotating body that are arranged coaxially, a so-called auto-reverse mechanism can be realized. It can be realized.

Furthermore, by arranging the reel means, the forward torque generation means, the reverse torque generation means, and the rotational force transmission means on the substrate in a predetermined positional relationship, the rotating body of the rotational force transmission means can always act as a drive source when transmitting rotational force. The rotating body to be transmitted is configured to receive a force acting in the biting direction, which enables smooth transmission of rotational force, and improves reliability and transmission efficiency of rotational operation.

[Brief explanation of drawings]

FIG. 1 is a plan structural diagram of a rotation transmitting section and a scanning section in a stop mode of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional structural diagram of the main part in FIG. 1. FIG. 3 is a plan view of the drive block. FIG. 4 is a front structural view of FIG. 3. FIG. 5 is a plan view of the structure in forward play mode. FIG. 6 is a cross-sectional structural diagram taken along the cutting line A-A in FIG. 5. FIG. FIG. 7 is a plan structural diagram showing the positional relationship of rotating parts in forward play mode. FIG. 8 is a plan structural diagram showing the positional relationship of rotating parts in reverse play mode. FIG. 9 is a cross-sectional structural diagram taken along the cutting line BB in FIG. 8. FIG. 10 is a plan structural diagram showing the positional relationship of rotating parts and operating parts in reverse play mode. FIG. 11 is a plan structural diagram showing the positional relationship of rotating parts in the fast forward mode. FIG. 12 is a cross-sectional structural diagram taken along the cutting line CC in FIG. 11. FIG. 13 is a plan view showing the positional relationship between rotating parts and operating parts in the fast forward mode. FIG. 14 is a plan structural diagram showing the positional relationship of rotating parts in the rewind mode. FIG. 15 is a cross-sectional structural diagram taken along the cutting line DD in FIG. 14. FIG. 16 is a plan view showing the positional relationship between rotating parts and operating parts in the rewind mode. FIG. 17 is a plan view showing the load state of the play idler gear in forward play mode. FIG. 18 is a plan view showing the load state of the play idler gear in the reverse play mode. FIG. 19 is a plan view showing the load state of the FF/REW idler gear in the fast forward mode. FIG. 20 is a plan view showing the load state of the FF/REV idler gear in the rewind mode. FIG. 21 is a plan view of a conventional magnetic recording/reproducing device. FIG. 22 is a cross-sectional structural diagram of the main part of FIG. 21. In the figure, 1 is the main chassis, 2 is the drive block,
3 is a FOR reel stand, 7 is a motor, 10 is a drive shaft, 11 is a pulley, 12 is a play idler lever, 13 is an FF/REW idler lever, 16 is a head plate, 17 is a Reverse plate, 18 is the FF lever, 19 is the REW lever, 20 is the play idler gear, 21 is the FF/REW idler gear, 32 is the first compression spring, 33 is the first friction member,
35 is an FF gear, 37 is a play gear, 38 is a second compression spring, 39 is a second friction member, 50 is a REW gear, 5
1 indicates a reverse gear, and 60 indicates a friction block. Note that the same reference numerals in the figures indicate the same or corresponding parts. 18: FF / (- S, REW / ( 10E! Power axis 11) - Lee - 20 Near Shii Ii Do Kuki 〒 21: FFIRε) V Aji F' Fuki Meno "JllJ2
! 16 Figure jυ Figure 17 omitted Figure 18

Claims (8)

[Claims] (1) A magnetic recording/reproducing device having a recording/reproducing mode in which a loaded cassette tape is run at a constant speed and a fast forward/rewind mode in which the loaded cassette tape is run at high speed, a pair of first and second reel means for winding in a predetermined direction; a motor that generates rotational force; a pulley that receives the rotational force from the motor; and a first rotating body disposed coaxially with the pulley. a first friction transmitting means interposed between the pulley and the first rotating body, which reduces the rotational force received by the pulley to a predetermined value and transmits it to the first rotating body; and a first friction transmitting means coaxial with the pulley. a second rotating body disposed above, and a second rotating body interposed between the first rotating body and the second rotating body, further reducing the rotational force of the first rotating body and transmitting the torque to the second rotating body. forward torque generating means having a fifth rotary body that engages with the first rotary body and rotates in a direction opposite to the first rotary body; and the cassette. When the tape runs at a constant speed in the recording/reproducing mode, the second rotating body and the first rotating body of the forward torque generating means
a third rotary body that simultaneously engages with the reel means and transmits the rotational force of the second rotary body to the first reel means; and a third rotary body that transmits the rotational force of the second rotary body to the first reel means; The reverse torque generating means engages with the first rotary body and the first reel means simultaneously, transmits the rotational force of the first rotary body to the first reel means, and when running at high speed in a rewinding mode. and a fourth rotating body that simultaneously engages with the fifth rotating body and the second reel means and transmits the rotational force of the fifth rotating body to the second reel means. , magnetic recording and reproducing device. (2) The first friction transmission means includes: a first friction material that slides into contact with the pulley; and a first pressing means that applies a predetermined pressing force to the first friction material; The transmission means includes: a second friction material that slides into contact with the first rotating body; and a second pressing means that is provided independently of the first pressing means and applies a predetermined pressing force to the second friction material. The magnetic recording and reproducing device according to claim 1, comprising: (3) The rotational force transmitting means includes a rotational center shaft, and a first and second first and second rotary shaft that are mounted on the rotational center shaft and perform rocking motion independently of each other about the rotational center axis.
The magnetic recording and reproducing apparatus according to claim 1, further comprising a swinging member, wherein the third rotating body is attached to the first swinging member, and the fourth rotating body is attached to the second swinging member. . (4) The rotational force transmitting means is configured such that the rotation center axis is disposed on a right-angled bisector of a line connecting the first reel means and the second reel means, and a trajectory of the third rotating body rotating from a position where it engages with the second reel means to a position where it engages with the second reel means; 4. The magnetic recording and reproducing apparatus according to claim 3, wherein the trajectory of the moving fourth rotating body substantially coincides with the locus of the moving fourth rotating body. (5) A magnetic recording/reproducing device having a recording/reproducing mode in which a loaded cassette tape is run at a constant speed in the forward and reverse directions, and a fast forward/rewind mode in which the loaded cassette tape is run at high speed in the forward and reverse directions, the cassette tape being 1 that engages with the tape and winds the magnetic tape of the cassette tape in a predetermined direction;
a pair of first and second reel means; a motor that generates a rotational force; a pulley that receives the rotational force from the motor; a first rotating body disposed coaxially with the pulley; a first friction transmitting means interposed between the first rotating body and reducing the rotational force received by the pulley to a predetermined value and transmitting the reduced torque to the first rotating body; and a second friction transmitting means disposed coaxially with the pulley. a rotating body; and a second friction transmitting means interposed between the first rotating body and the second rotating body to further reduce the rotational force of the first rotating body and transmitting the torque to the second rotating body. a forward torque generating means; a fifth rotary body that engages with the first rotary body and rotates in a direction opposite to the first rotary body; and a fifth rotary body that is provided coaxially with the fifth rotary body and that is connected to the second rotary body. a sixth rotating body that engages with the second rotating body and rotates in a direction opposite to the second rotating body; and the second rotation of the forward torque generating unit when the cassette tape runs at a constant speed in the forward direction. and the first reel means to transmit the rotational force of the second rotating body to the first reel means, and when the cassette tape runs at a constant speed in the reverse direction, the first reel of the reverse torque generating means a third rotary body that simultaneously engages the sixth rotary body and the second reel means and transmits the rotational force of the sixth rotary body to the second reel means; The first rotating body of the forward direction torque generating means and the first reel means are simultaneously engaged, and the rotational force of the first rotating body is transmitted to the first reel means, and the rotational force of the first rotating body is transmitted to the first reel means. Rotational force transmitting means comprising a fifth rotary body of the directional torque generating means and a fourth rotary body that simultaneously engages with the second reel means and transmits the rotational force of the fifth rotary body to the second reel means. A magnetic recording and reproducing device. (6) The rotational force transmitting means includes a rotational center shaft, and a first and second first and second rotary shaft that are mounted on the rotational center shaft and perform rocking motion independently of each other about the rotational center axis.
The magnetic recording and reproducing apparatus according to claim 5, further comprising a swinging member, wherein the third rotating body is attached to the first swinging member, and the fourth rotating body is attached to the second swinging member. . (7) Each of the first and second reel means includes a reel stand that engages with the cassette tape, a reel shaft that rotatably supports the reel stand, and a reel shaft that is provided on the reel stand and that defines the position of the cassette tape. 6. The magnetic recording and reproducing apparatus according to claim 5, further comprising: a seventh rotating body that engages with the third rotating body when the cassette tape runs at high speed; and an eighth rotating body that engages with the fourth rotating body when the cassette tape runs at high speed. Device. (8) the forward torque generating means and the reverse torque generating means are arranged approximately symmetrically about a right-angled bisector of a line connecting the rotation centers of the first and second reel means;
and the forward direction torque generating means is close to the first reel means, the reverse direction torque generating means is close to the second reel means, and the rotational force transmitting means is arranged so that the rotational center axis is at the right angle to the second reel means. 7. The magnetic recording and reproducing apparatus according to claim 6, wherein the magnetic recording and reproducing apparatus is arranged so as to be located on an equal dividing line.