JPH04265552A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording and reproducing device provided with a tape take-up mechanism discriminating the tape take-up state of the magnetic recording and reproducing device capable of recording/reproducing in forward and reverse directions. CONSTITUTION:The transport system of the magnetic recording and reproducing device is provided with a motor, a pully receiving the rotation of the motor, a forward rotor arranged coaxially to the pully, a reverse rotor engaging all time with the forward rotor and rotating in the reverse direction, first and second reel mounts engaging with the respective reels of a cassette tape, a movable rotor engaging with the forward rotor and the first reel mount at the time of forward rotation and engaging with the reverse rotor and the second reel mount at the time of reverse rotation. A reflection plate detecting the rotation of the first reel mount or the second reel mount is fixed on either the forward or reverse rotors. At a position opposite to the reflection plate, a light emitting element detecting the rotation of the rotating plate is arranged.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus, and more particularly to the structure of a magnetic recording and reproducing apparatus equipped with means for determining whether a cassette tape is wound up or not.

0002

2. Description of the Related Art Conventional magnetic recording and reproducing devices are equipped with an auto-stop function that detects the completion of winding a cassette tape and automatically stops the motor that drives the reel. FIG. 17 is a schematic plan view showing the structure of a tape drive portion of a conventional magnetic recording/reproducing device, and FIG. 18 is a cross-sectional view taken along cutting line E-E in FIG. FIG. 19 is a schematic plan view of the structure taken along arrow FF in FIG. 17. Note that FIG. 17 and FIG. 19 have a relationship between a top view and a bottom view. Figures 17 to 19
Referring to FIG. 1, the cassette 75 engages with the two reel stands 76 and 77 in a loaded state. The magnetic tape in the cassette 75 is loaded so as to pass between one capstan 78 and a pinch roller 80, and then between the other capstan 79 and a pinch roller 81. The illustrated magnetic recording/reproducing device has a drive mechanism capable of running at a constant speed in the forward direction and at a constant speed in the reverse direction. When running at a constant speed in the forward direction, the tape is held between the capstan 78 and the pinch roller 80, and the FOR reel table 76 takes up and rotates in the forward direction X, and the capstan 78 and the pinch roller 80 rotate at a constant speed. Send the tape in the forward direction a.

When running at a constant speed in the reverse direction, the magnetic tape is held between the capstan 79 and the pinch roller 81, and the REV reel stand 77 rotates in the reverse direction Y and the capstan 79 and the pinch roller 81 rotate at a constant speed in the reverse direction. The rotation sends out the magnetic tape in the opposite direction b.

Conventional magnetic recording and reproducing devices are equipped with an auto-stop mechanism for automatically stopping the device when a running tape reaches its end. The detection mechanism for detecting the end of the tape has the following configuration. First, a reflection plate 70 is attached coaxially with the FOR reel stand 76. As shown in FIG. 19, the reflection plate 70 has portions with high light reflectance and portions with low light reflectance arranged alternately at constant angles around its rotation axis. rotating plate 70
A light emitting/receiving element 71 is attached at a position facing the. Furthermore, a rotation detection device for electrically detecting the rotational movement of the rotary plate 70 is connected to the light emitting/receiving element 71 .

FIG. 20 shows a rotating plate 70 and a light emitting/receiving element 71.
FIG. 21 is a schematic diagram showing the positional relationship with the rotating plate 70.
FIG. 2 is a block diagram showing a rotation detection device for detecting rotational movement of the vehicle. The light emitting/receiving element 71 irradiates the rotary plate with light, receives reflected light from the reflecting plate 70, and converts the intensity of the light into an electrical signal. The frequency/voltage converter 72 converts the frequency of the periodic signal given from the light emitting/receiving element 71 into a voltage and outputs an output voltage v1. The comparator 73 receives the output voltage v1 from the frequency/voltage converter 72, and further receives the output voltage v1 from the frequency/voltage converter 72 when the frequency of the signal output from the light emitting/receiving element 71 is 0.
0, and if v1 - v0 < 0, High,
If v1 - v0 = 0, it outputs Low. moreover,
The tape winding determiner 74 receives the output from the comparator 73, and determines that if the output is High, the tape is being wound, and if the output is Low, the tape winding has ended. Then, when the tape winding end determiner 74 determines that the tape winding has ended, the rotation of the drive motor is stopped.

[0006]

[Problem to be Solved by the Invention] However, in the above-mentioned mechanism for detecting the tape winding state, there are cases where the auto-stop mechanism cannot operate even though the tape should be stopped. There was a problem. This state will be explained using FIGS. 22 and 23. FIG. 22 is a schematic view of the tape drive in the forward direction showing the operating state of the tape drive system during constant speed running in the forward direction, and FIG. 23 is a schematic diagram of the tape drive in the reverse direction.

First, using FIG. 22, when running at a constant speed in the forward direction, the tape is kept at a constant speed by the FOR reel stand 76 that constantly rotates in the X direction, and the capstan 78 and pinch roller 80 that send out the magnetic tape in the same direction. is sent from the REV reel stand 77 side to the FOR reel stand 76 side, and the FOR
The cassette tape 75 is wound onto a reel that engages with the reel stand 76 . Assume that during this forward constant speed running, the rotation of the FOR reel stand 76 stops due to some abnormality. In this case, the capstan 78 will continue to feed the tape in the forward direction in order to maintain its rotational motion. On the other hand, when the rotation of the FOR reel stand 76 stops, the rotation of the reflection plate 70 provided coaxially therewith also stops. Then, the rotation detecting means determines that the tape has finished winding, and the auto-stop mechanism operates to stop the drive motor. This also stops the rotation of the capstan 78.

However, referring to FIG. 23, when the vehicle is running at a constant speed in the reverse direction, the normal stopping operation is not performed as when the vehicle is running in the forward direction. In other words, when traveling at a constant speed in the reverse direction, the RE
The V-reel stand 77 rotates in the Y direction, and the capstan 79 and pinch roller 81 feed the tape in the same direction at a constant speed. As a result, the magnetic tape of the cassette tape 75 is moved from the reel side engaging the FOR reel stand 76 to the RE.
It is wound up at a constant speed toward the reel that engages with the V-reel stand 77.

At this time, it is assumed that the rotation of the REV reel stand 77 has stopped due to some abnormality. Even when the rotation of the REV reel stand 77 stops, the capstan 79 and the pinch roller 81 maintain their rotational motion and continue to feed out the magnetic tape. Then, by the tape feeding operation of the capstan 79 and the pinch roller 81, the FOR
The reel stand 76 also maintains rotational motion. Therefore, F.O.
The reflection plate 70 attached to the R reel stand 76 also still maintains its rotating state. Therefore, the rotation detecting device determines that the tape is being wound and does not operate the auto-stop mechanism. Therefore, the capstan 79 and the pinch roller 81
The magnetic tape sent out by the REV reel stand 77
A situation occurs in which the magnetic tape is continuously pushed out between the magnetic tape and the reel engaged with the cassette tape 75, and the magnetic tape is drawn out from the cassette tape 75 for a long time. In this case, the problem arises that the magnetic tape is damaged and becomes unusable.

[0010] Therefore, the present invention has been made to solve the above-mentioned problems, and detects abnormal rotation of the tape reel when running in either the forward or reverse direction and automatically stops the tape running. It is an object of the present invention to provide a magnetic recording/reproducing device equipped with a tape rotation detection mechanism capable of stopping operation.

[0011]

A magnetic recording and reproducing apparatus according to the present invention has a recording/reproducing mode in which a loaded cassette tape is run at a constant speed in the forward and reverse directions. A pair of first and second reel means that engages with the cassette tape and winds the magnetic tape of the cassette tape in a predetermined direction, a motor that generates rotational force, and a pulley that receives the rotational force from the motor. have Further, a first rotating body is arranged coaxially with the pulley and rotates in response to the rotational force of the pulley. A third rotating body that rotates in the opposite direction to the first rotating body engages with the first rotating body. Furthermore, the magnetic recording/reproducing device has a second rotating body. The second rotating body simultaneously engages with the first rotating body and the first reel means when the cassette tape runs in the forward direction, and transmits the rotational force of the first rotating body to the first reel means. Further, when the cassette tape runs in the reverse direction, it engages with the third rotary body and the second reel means simultaneously, and transmits the rotational force of the third rotary body to the second reel means. Further, a rotation detection device is provided, which includes a rotation detection body that rotates while engaging with either the first rotation body or the third rotation body, and a detection device that electrically detects the rotational movement of the rotation detection body. ing.

0012

[Operation] The magnetic recording and reproducing apparatus according to the present invention is mounted so that the rotation detecting body engages with either the first rotating body or the third rotating body and rotates. The first rotating body is connected to the first reel means via the second rotating body when the cassette tape runs in the forward direction. Therefore, if the first reel means stops for some reason, the first rotating body also stops. Also, when the cassette tape is running in the reverse direction, the third
It is connected to the second reel means via the rotating body and the second rotating body. Therefore, if the second reel means stops for some reason, this first rotating body also stops. Therefore, when a rotation detection body is attached to the first rotation body,
When the cassette tape is running in the forward direction or in the reverse direction, the first rotating body and the rotation detecting body are stopped due to the abnormal stop of the first and second reel means, and the stopped state of the cassette tape is determined.

[0013] Furthermore, a similar function is achieved when a rotation detecting body is attached to the third rotating body. That is, when traveling in the forward direction, the third rotating body is engaged with the first rotating body that rotates while being connected to the first reel means with the second rotating body interposed therebetween. Therefore, when the first reel means stops, the stopped state is transmitted via the second rotating body and the first rotating body. Further, when traveling in the reverse direction, since the second reel means is connected via the second rotating body, the rotation state is transmitted via the second rotating body when the second reel means is stopped. Therefore, when the first and second reel means stop abnormally, both when traveling in the forward direction and when traveling in the reverse direction, the third reel means
The rotating body stops. Therefore, the rotation detecting body attached to this third rotary body also stops, and it is determined whether the cassette tape is stopped.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

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

FIGS. 1, 3, and 5 are plan structural views of the magnetic recording/reproducing apparatus according to the present invention. FIG. 1 mainly shows the structure of the operating section, and FIG. 3 shows a block diagram of the driving parts. 5 shows the structure of the drive system. In addition, Figures 1 and 3
5 shows the stopped state of the magnetic recording device, and FIG. 5 shows the FP mode. 2 is a partial cross-sectional structural diagram of FIG. 1, FIG. 4 is a partial cross-sectional structural diagram of FIG. 3, and FIG. 6 is a cross-sectional structural diagram taken along the cutting line A-A in FIG. It is.

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.

[0018] On the main chassis 1, a motor 7, an FO
A FOR flywheel 5 supported by an R capstan shaft 5a and a REV flywheel 6 supported by a REV capstan shaft 6a are arranged. Motor pulley 7a fixed to the output shaft of motor 7 and FOR flywheel 5
A fly belt 8 is suspended on the REV flywheel 6. The motor 7 always rotates counterclockwise. Then, the FOR capstan shaft 5a and the FOR flywheel 5 rotate counterclockwise, and the REV capstan shaft 6a and the REV flywheel 6 rotate clockwise.

Drive block plate 2 of drive block 2
A pulley 11 supported by a drive shaft 10 is rotatably mounted on a. 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, a substantially T-shaped play idler lever 12 and a substantially T-shaped FF/REW idler lever 13 mounted on the shaft 2b are coaxially provided on the drive block plate 2a. The play idler lever 12 and the FF/REW idler lever 13 are rotatably mounted 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. F
The OR pinch roller block 14 is mounted so as to be rotatable about the shaft 1a, and the REV pinch roller block 15 is mounted so as to be rotatable about the shaft 1b. The head plate 16 is guided by shafts 1c and 1d provided on the main chassis 1 and can reciprocate in the directions of arrows A and B in the figure, and is constantly urged in the direction of arrow B by a spring (not shown). ing. 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. Note that the axes 1c and 1d are the rotation center axis 2 of the FOR reel stand 3.
It is provided on the right-angled bisector of the line segment connecting c and the rotation center axis 2d of the REV reel stand 4, and is configured symmetrically with respect to this right-angled bisector. Also, head plate 1
A guide hole 16a is provided at the tip of 6. The guide hole 16a includes a long hole 16a-1 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, and oblique sides 16a-2, 16a-3 and the pin 12a as shown in the arrows. Opening hole 16 that allows movement in C and D directions
Consists of a-4.

The reverse plate 17 is the head plate 1
arrow C, guided by shafts 16b and 16c provided in 6;
It is installed so that it can reciprocate in the D direction. 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 D 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, the switching mechanism to FF/REW mode will be explained. The FF lever 18 for switching to the FF mode and the REW lever 19 for switching to the REW mode are connected to shafts 1e and 1f provided in the main chassis 1.
Reciprocating motion in the directions of arrows A and B is guided by shafts 1g and 1h, respectively. And these levers 18 and 19
is urged in the direction of arrow B by a spring (not shown). This FF lever 18 and REW lever 19
are arranged symmetrically with respect to a right-angled bisector of a line segment connecting the rotation centers of both reel stands 3 and 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. Projecting piece 18 of FF lever 18
a is the left arm 13 of the FF/REW idler lever 13
The projecting piece 19a of the REW lever 19 is opposite to the FF/
It faces the right arm 13b of the REW idler lever 13. Furthermore, the FF lever 18 and the REW lever 1
On the arrow B side of 9, there are FF operation parts and REW operation parts (
(not shown) are provided correspondingly to each other. FF/
REW idler lever 13 is drive block plate 2
It is rotatably mounted around a shaft 2b provided on the top of the shaft 2b. The lever portion of the FF/REW idler lever 13 has a stepped shape connected by a connecting portion 13c. A coil portion of the FF/REW torsion spring 22 is fitted into the outer peripheral surface 13d of the bearing portion of the shaft 2b. 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 2i protruding from the surface is directed. The width of the connecting portion 13c of the FF/REW idler lever 13 and the width of the protruding portion 2i of the drive block plate 2a are configured to have the same dimension. With this configuration, the FF
/REW The idler lever 13 is maintained in a position where it does not rotate either clockwise or counterclockwise by the action of the 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. As shown in FIG. Further, on the drive block plate 2a, there is a play idler lever 12 and an FF/
A shaft 2b for the REW 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,
Furthermore, a bearing for the drive shaft 10 is provided. The pitch between the shaft 2c of the FOR reel stand 3 and the shaft 2d of the REV reel stand 4 is, for example, 42.5 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 both reel stands 3 and 4, and is located on the arrow B side from the bearing of the drive shaft 10. Further, the reverse gear shaft 2e and the bearing portion for the drive shaft 10 are arranged symmetrically with respect to the right-angled bisector of the line connecting the rotation center axes 2c and 2d of the FOR reel stand 3 and the REW reel stand 4. There is. 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 set positions with respect to both capstan shafts 5a and 6a. For example, the distance between the axes of both reel shafts 2c and 2d and the axes of both capstan shafts 5a and 6a is 31.3 mm.

The friction block 60 will be explained with reference to FIGS. 3 and 6. 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, a 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. The first compression spring 3 is mounted on the upper surface of the flange of the spring receiver 30.
2 is placed. The friction plate 31 is the first compression spring 32
is pushed down onto the upper surface of the spring receiver 30, and the center portion of the friction plate 31 is inserted into the outer circumferential surface 30b of the press-fitting portion 30a of the spring receiver 30 so as to be movable up and down. The first friction member 33 is placed on the top surface of the friction plate 31, and the pulley 11 is further attached to the top 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 transmitted to the friction plate 31, the spring receiver 30, and the rotating shaft 10 via the first friction member 33. 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 friction member 3 made of felt such as wool
3 and the first compression spring 32, a first maximum transmission torque (high torque) is set. This first maximum transmission torque is 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·cm, the torque corresponding to 20 g·cm will be reduced by slipping between the pulley 11 and the friction plate 31. 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 that protrudes 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 has its upper surface and the drive shaft 1
It is attached so that the upper end of 0 coincides with the upper end. The FF gear 35 rotates integrally with the drive shaft 10. After this, the thrust play of the friction block 60 is adjusted. The thrust backlash is caused by the difference between the total length of the drive shaft 10 and the total lengths of the FF gear 35, bearing 2f, washers 40, 34, pulley 11, and spring receiver 30 attached to the drive shaft 10. This thrust backlash is adjusted to, for example, about 0.05 to 0.2 mm. After adjusting this thrust play, the second friction member 39 is attached to the top surface of the FF gear 35. Furthermore, the second
A play gear 37 is attached to the upper surface of the friction member 39. The play gear 37 has a large diameter gear portion 37a and a small diameter gear portion 37.
It has b. The upper surface of the play gear 37 has a second
The compression spring 38 is mounted, and the spring receiving plate 36 is press-fitted and fixed to the outer circumferential surface 35d of the press-fitted part 35b of the FF gear 35 from above. 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. The load of the second compression spring 38 is supported by the spring receiving 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. The value is, for example, 35 g·cm. If the maximum torque of the first friction mechanism is 80 g·cm as described above, the torque of 45 g·cm is reduced by the second friction mechanism.

As described above, 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 motor 7 causes the pulley 11 to
The rotational force transmitted to is limited by the first friction mechanism to a first torque suitable for high-speed running of the tape, and this first torque is transmitted from the friction plate 31 to the spring receiver 30 and then to the FF gear 35 through the drive shaft 10. communicated. and F
By extracting this first torque from the F gear 35, a predetermined high torque can be obtained. Next, FF gear 35
The rotational force transmitted to the play gear 37 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 serves as the drive source for this high torque.
The play gear 37, which serves as a low-torque drive source, is provided in close proximity to the play gear 37 with a very thin second friction member 39 interposed therebetween. Further, the diameters of the FF 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 3c, 4c for engaging with a reel hub of a cassette tape and winding the tape. The drive block plate 2a is rotatably attached to shafts 2c and 2d provided on the drive block plate 2a. Further, the FOR reel stand 3 and the REV reel stand 4 are each provided with large diameter gears 3a, 4a and small diameter gears 3b, 4b coaxially and integrally. Both reel stands 3, 4
Appropriate clearance with the drive block plate 2a is ensured through stop washers in grooves provided on the shafts 2c and 2d, respectively, and vertical movement is regulated. The large diameter gears 3a and 4a of the reel stand are play idler gears 20
The small diameter gears 3b and 4b mesh with the large diameter gear 21a of the FF/REW idler gear 21 to run the tape at a constant speed.

Next, a mechanism related to running the tape in the reverse direction will be explained. This mechanism includes a REW gear 50 and a reverse gear 51. A shaft 2e is provided upright at a predetermined position on the drive block plate 2a. REW gear 50 is shaft 2
It is rotatably attached to e. After the REW gear 50 is inserted into the shaft 2e, a stop washer is installed in the groove provided on the shaft 2e, and the REW gear 50 is allowed to have an appropriate play 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. Reverse gear 5
1 is also allowed to have an appropriate play in the axial direction of the shaft 2e. REW
The large diameter portions 51a of the gear 50 and the reverse gear 51 are formed to have approximately the same diameter. The REW gear 50 is always in mesh with the FF gear 35, and the large diameter gear 5 of the reverse gear 51 is in mesh with the FF gear 35.
1a is always in mesh with the large diameter gear 37a of the play gear 37. 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 play idler lever 12 and F
The mechanism of the F/REW idler lever 13 will be explained. Referring to FIGS. 2 and 6, an FF/REW idler lever 13 is attached to a shaft 2b provided on a drive block plate 2a together with an FF/REW torsion spring 22.
is rotatably inserted. The idler lever 13 is the shaft 2
By attaching a stop washer to the groove 2b-1 provided in b, appropriate thrust play is ensured and vertical movement is regulated. Furthermore, the play idler lever 12 is inserted into the shaft 2b. 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. Play idler lever 1
A play idler gear 20 and an FF/REW idler gear 21 having a two-stage gear are rotatably attached to the tip portions of the idler lever 2 and the FF/REW idler lever 13 through rotating shafts 12d and 13e, respectively. The vertical movement of the idler gear 20 and the FF/REW idler gear 21 is restricted with respect to the rotating shafts 12d and 13e, respectively, while ensuring appropriate thrust play with stop washers. Play idler lever 12 and FF/RE
The rotation center of the W idler lever 13 is located on the shaft 2b as described above, and the distance from this rotation center to the rotation center of the play idler gear 20 and the FF/REW from the rotation center are
The distance is set to be approximately the same as the distance to the rotation center of the idler gear 21. However, strictly speaking, the latter is larger than the former. Furthermore, 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 connected to the small diameter gear 3b of the FOR reel stand 3 and the RE
It is provided at the same height as the small diameter gear 4b of the W reel stand 4. Small diameter gear 21b of FF/REW idler gear 21
is the FF gear 35 and R of the friction block 60.
It is provided at the same height as the EW gear 50. 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. The small diameter gear 20b of the play idler gear 20 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 tape winding detection mechanism, which is a feature of the present invention, will be explained. Referring to FIGS. 1, 3, 5, and 6, a reflection plate (rotation detection body) 70 is disposed coaxially with a reverse gear 51 (third rotation body) with respect to the axis 2e, and rotates as one. rotating plate 70
On the surface of the disc, two types of parts with different reflectances of light are arranged alternately at fixed angles around the center point of the disc. A light emitting/receiving element 71 is fixed at a position facing the reflecting plate 70 of the main chassis 1 . The emitting light-receiving element 71 irradiates the reflection plate 70 with its own light beam, and the reflection plate 70
is placed at a suitable position to receive the reflected light from the surface of the Furthermore, the light emitting light receiving element 71 is connected to a frequency/voltage converter 72, a comparator 73, and a tape winding end determiner 74 as shown in FIG. The configuration of the tape winding detection device is the same as the conventional configuration shown in FIG. 21, so the description will be omitted here, referring to the description of the conventional technology.

The reflecting plate 70 is not limited to a structure fixed to the reverse gear 51, but may be provided coaxially with the drive shaft 10 so as to be able to rotate integrally with the play gear 37 (first rotating body). In this case, the light-receiving/emitting element 71 needs to be mounted at a position facing the surface of the reflecting plate 70 located coaxially with the drive shaft 10 .

Next, the operation of the 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 connected to the FF/RE by the head plate 16.
The W 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 2
1 is located on the center line between the pair of reel shafts 2c and 2d,
Further, the play idler gear 20 and the FF/REW idler gear 21 are positioned 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 separated from the small diameter gear 37b of the play gear 37 and the small diameter gear 51b of the reverse gear 51,
Also, the small diameter gear 20b of the play idler gear 20 is FO
It is separated from the large diameter gear 3a of the R 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 R
It is separated from the EW gear 50. Therefore, pulley 11
Even if the reel stands 3 and 4 rotate in response to the rotational force from the motor 7, both reel stands 3 and 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 view showing the positional relationship of rotating parts in forward play mode. Referring to FIGS. 5 to 7, from the above-mentioned stopped state, the head plate 16 moves in the direction of arrow A by the operation of the first cam, and the reverse plate 17 moves the play idler lever 12 clockwise about the shaft 2b. Rotate the small diameter gear 20b of the play idler gear 20 to the FOR reel stand 3.
The large diameter gear 3a and the large diameter gear 20a are connected to the play gear 3.
It meshes with the small diameter gear 37b of No.7. 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 is pressed against the FOR pinch roller spring 1.
4b in the direction of arrow A, the FOR pinch roller block 14 rotates clockwise about the shaft 1a, and the pinch roller 14a presses the FOR capstan shaft 5a to clamp the tape. Then, the tape is driven at a constant speed in the direction of arrow C. Further, 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 12a of the play idler lever 12 is inserted into the long hole 1 of the guide hole 16a of the head plate 16.
Extracted from 6a-1. Therefore, the play idler lever 12 is rotatable around the shaft 2b,
The play idler lever 12 is rotated clockwise about the shaft 2b by the reverse plate 17.

The rotation transmission path in this forward play mode is as follows. Motor 7 (counterclockwise) → Pulley 7a (counterclockwise) →
Fly belt 8 → FOR flywheel 5 (counterclockwise) → fly pulley 5b (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) → Play idler gear 20→FOR reel stand 3 (counterclockwise) Therefore, the FOR reel stand 3 generates 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 plan view showing the positional relationship of rotating parts.
FIG. Also, Figure 10
FIG. 2 is a structural plan view showing the positional relationship between rotating parts and operating parts.

Referring to FIGS. 8 to 10, the second cam is triggered by the reverse play operation means, and the second cam moves the reverse plate 17 in the direction of arrow D through the head plate 16. Upon completion of the movement of the reverse plate 17, the first cam is operated by a trigger means (not shown), and the head plate 16 moves in the direction of arrow A, entering the reverse play mode. This operation will be explained in more detail as follows. When the reverse plate 17 completes its movement in the direction of arrow D, the bent piece 17c of the reverse plate 17 opposes the arm of the REV pinch roller spring 15b of the REV pinch roller block 15, and the bent piece 17d opposes the right side of the play idler lever 12. It faces the arm 12c. When the head plate 16 moves in the direction of arrow A, 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 moves counterclockwise around the shaft 1b. Rotate. Then, the pinch roller 15a presses the REV capstan shaft 6a, pinches the tape, and drives the tape at a constant speed in the direction of arrow D. As a result, the head performs a recording or reproducing operation on the tape. Further, the bent piece 17d of the reverse plate 17 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. And the small diameter gear 20b of the play idler gear 20
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 pressing force of the reverse plate 17 is elastically absorbed by the elastic right arm 12c. 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 3
7 (counterclockwise) → reverse gear 51 (clockwise) → play idler gear 20 (counterclockwise) → REV reel stand 4 (clockwise) Therefore, the REV reel stand 4 is Low torque, for example 35g・c
Run the tape at a constant speed in the opposite direction at m.

Next, forward fast forward mode (FF mode)
I will explain about it. FIG. 11 is a plan structural diagram showing the positional relationship of rotating parts, and FIG. 12 is a cross-sectional structural diagram taken along the cutting line CC in FIG. 11. Further, FIG. 13 is a plan structural diagram showing the positional relationship between 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 large diameter of the FF/REW idler gear 21 is rotated. The gear 21a meshes with the small diameter gear 3b of the FOR reel stand 3, and the small diameter gear 2
1b meshes with gear 35a of FF gear 35. After these gears are engaged, the pressing force of the FF lever 18 is elastically absorbed by the elastic left arm 13a. and,
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 10 → FF gear 35 (counterclockwise) → FF/REW idler gear 2
1 (clockwise) → FOR reel stand 3 (counterclockwise) Therefore, the FOR reel stand 3 generates high torque, for example, 80g・c, through only the first friction mechanism.
Make the tape run at high speed in the forward direction with m. In addition,
In this mode, the play idler lever 12 is held in its original stopped 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 cross-sectional structural diagram taken along the cutting line DD in FIG. 14. 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 EW mode is as follows.

Pulley 11 → first friction mechanism → friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35 →
REW gear 50 → FF/REW idler gear 21 → R
EV reel stand 4 Therefore, the REV reel stand 4 can generate high torque, for example 80 g, by using only the first friction mechanism.
・Make the tape run at high speed in the reverse direction at cm. Note that in the REW mode, the play idler lever 12 is maintained at the stopped position.

The above is an explanation of the basic operation of the magnetic recording/reproducing apparatus of the present invention. Next, the operation of the tape winding detection mechanism will be explained.

First, in the forward play mode,
As described above, the rotation transmission path is configured as follows.

Motor 7 (counterclockwise) → Pulley 7a (counterclockwise) → Fly belt 8 → FOR flywheel 5
(Counterclockwise) → Fly pulley 5b (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) → Play idler gear 20 →
FOR reel stand 3 (counterclockwise) Also, apart from this transmission path, the large diameter gear 37a of the play gear 37 and the large diameter gear 51a of the reverse gear 51 are engaged. Therefore, in the forward play state, the reverse gear 51 also rotates under the rotational force of the play gear 37. Therefore, the reflection plate 70 fixed to the reverse gear 51 also rotates integrally with the reverse gear 51. Therefore, the light emitting light receiving element 71 is rotated by the reflecting plate 70.
The rotating state of the reverse gear 51 is detected by an electrical determining means upon receiving the periodic signal, thereby detecting that the cassette tape is being wound.

In the forward play mode as described above, when the cassette magnetic tape is wound onto the reel on the FOR reel stand 3 side, the rotation of the FOR reel stand 3 is stopped by the tension of the tape. When the rotation of the FOR reel stand 3 is blocked, the play idler gear 20 and the play gear 37
rotation is stopped. As a result, the rotation of the reverse gear 51, which was rotating while being engaged with the large-diameter gear 37a of the play gear 37, is also stopped, and furthermore, the rotation of the reflection plate 70 fixed to the reverse gear 51 is also stopped. Therefore, the reflector 70
The rotation stop operation is detected by the electrical detection means via the light receiving/emitting element 71, and the tape winding end state is determined. This causes the auto-stop mechanism to operate and stop the operation of the drive device.

[0050] Such a rotation stop operation can be detected, for example, when the FOR reel stand 3 stops due to an abnormal cause.
Even if the winding state of the cassette tape is in the middle of winding, when it is determined that the winding of the tape has ended, the auto-stop mechanism operates and the drive of the tape is stopped.

Next, the reverse play mode will be explained. The rotational force transmission path in reverse play mode is configured as follows.

Pulley 11 → first friction mechanism → friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35 → second friction mechanism → play gear 37 → reverse gear 51 → play idler gear 20 → REV reel stand 4 In this mode, the reverse gear 51 is rotating,
The reflecting plate 70 fixed to this reverse gear 51 also rotates integrally.

When the magnetic tape of the cassette tape is wound onto the reel on the REV reel stand 4 side, the REV reel stand 4
rotation is prevented by the tension of the tape. When the rotation of the REV reel stand 4 stops, the play idler gear 20,
The rotations of reverse gear 51 and play gear 37 are each stopped. Therefore, the rotation of the reflection plate 70 fixed to the reverse gear 51 is also stopped. As a result, it is determined that the tape has finished winding, and the auto-stop mechanism operates to stop the tape drive.

In this mode, for some reason, R
Even in a case where the rotation of the EV reel stand 4 is stopped during the tape winding operation, the auto-stop mechanism is activated by the same operation as described above, and the tape driving state is immediately stopped.

Next, the operation in the forward fast forward mode (FF mode) will be explained. The rotational force transmission path in this FF mode is configured as follows.

Pulley 11 → first friction mechanism → friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35 →
FF/REW idler gear 21→FOR reel stand 3 Furthermore, apart from this rotation transmission path, FF gear 35, second friction mechanism, play gear 37, reverse gear 51
is rotating independently of the drive system. Reverse gear 5
1 rotates, the reflection plate 70 also rotates.

In this mode, when the tape reaches the end of winding, the rotation of the FOR reel stand 3 is inhibited by the tension of the tape. When the FOR reel stand 3 stops rotating, the FF/REW idler gear 21, FF gear 35,
The rotation of the play gear 37 and the reverse gear 51 is stopped. Therefore, the reflector 7 integrated with the reverse gear 51
When the rotation of the cassette tape 0 stops, the tape winding end state is detected, and the auto-stop mechanism operates to stop the drive of the cassette tape.

Furthermore, the rewind mode (REW mode) will be explained. The transmission path of rotational force in REW mode is
It is configured as follows.

Pulley 11 → first friction mechanism → friction plate 31 → spring receiver 30 → drive shaft 10 → FF gear 35 →
REW gear 50 → FF/REW idler gear 21 → R
EV Reel Stand 4 In addition to this rotational force transmission path, the FF gear 35, the second friction mechanism, the play gear 37, and the reverse gear 51 are engaged with each other and rotated by receiving rotational force. The reflecting plate 70 rotates integrally with the reverse gear 51.

When the tape reaches the end of winding in the REW mode, rotation of the REV reel stand 4 is inhibited by the tension of the tape. By stopping the rotation of the REV reel stand 4, the FF/REW idler gear 21 and REW gear 5 are activated.
0, the rotation of the FF gear 35 stops. Furthermore, the play gear 3 of the second friction mechanism is connected to the FF gear 35.
7 and reverse gear 51 also stop rotating.

[0061] Accordingly, by stopping the rotation of the rotary plate 70 fixed to the reverse gear 51, the winding end state of the tape is determined, and the auto-stop mechanism is activated to stop the tape drive.

In this way, constant speed in the forward and reverse directions,
The winding and winding end states of the cassette tape can be detected in all high-speed running modes. Then, when it is determined that the tape is at the end of winding, an auto-stop mechanism is activated to quickly stop the drive of the tape.

[0063]

As described above, the magnetic recording and reproducing apparatus according to the present invention has the advantage that the first and third rotating bodies that are linked to the rotational movements of the first and second reels during constant speed running in the forward and reverse directions. By equipping one of them with a rotation detector, it is possible to determine the tape winding state regardless of the tape running direction, so automatic stop operation can be performed reliably in all operating states, and the tape Damage to the cassette tape during abnormal stop can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a plan structural diagram of a rotation transmitting section and an operating 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 a main part of the magnetic recording/reproducing device shown in FIG. 1;

FIG. 3 is a plan view of the drive block.

FIG. 4 is a front structural view of the drive block shown in FIG. 3;

FIG. 5 is a plan view of the structure in forward play mode.

6 is a cross-sectional structural diagram taken along the cutting line AA in FIG. 5. FIG.

FIG. 7 is a plan view showing the positional relationship of rotating parts in forward play mode.

FIG. 8 is a plan view showing the positional relationship of rotating parts in reverse play mode.

9 is a cross-sectional structural diagram taken along the cutting line BB in FIG. 8. FIG.

FIG. 10 is a plan structural view showing the positional relationship of rotating parts and operating parts in reverse play mode.

FIG. 11 is a plan view showing the positional relationship of rotating parts in fast forward mode.

12 is a cross-sectional structural diagram taken along the cutting line CC in FIG. 11. FIG.

FIG. 13 is a plan view showing the positional relationship between rotating parts and operating parts in fast forward mode.

FIG. 14 is a plan view showing the positional relationship of rotating parts in rewind mode.

15 is a cross-sectional structural diagram taken along the cutting line DD in FIG. 14. FIG.

FIG. 16 is a plan view showing the positional relationship between rotating parts and operating parts in rewind mode.

FIG. 17 is a schematic plan view of a main part showing a driving part of a conventional magnetic recording/reproducing device.

18 is a cross-sectional structural diagram taken along the cutting line EE in FIG. 17. FIG.

19 is a plan structural view taken from a direction along arrow FF in FIG. 18. FIG.

FIG. 20 is a structural diagram showing the positional relationship between the rotary plate and the light emitting/receiving element of the winding detection mechanism.

FIG. 21 is a block diagram showing the configuration of a cassette tape winding detection mechanism.

FIG. 22 is a schematic structural diagram for explaining the operation of a conventional magnetic recording/reproducing device during forward direction operation.

FIG. 23 is a planar structural diagram for explaining the operation of a conventional magnetic recording/reproducing device during reverse direction operation.

[Explanation of symbols]

3 FOR reel stand 4 REV reel stand 7 Motor 10 Drive shaft 20 Play idler gear 37 Play Gear 51 Reverse gear 70 Reflector 71 Light emitting light receiving element 72 Frequency/voltage converter 73 Comparator 74 Tape winding judge 75 Cassette

Claims (1)

[Claims] 1. A magnetic recording and reproducing device having a recording/reproducing mode in which a loaded cassette tape runs at a constant speed in the forward and reverse directions, the magnetic recording and reproducing device engaging with the cassette tape;
a pair of first and second reel means for winding the magnetic tape of the cassette tape in a predetermined direction; a motor that generates a rotational force; a pulley that receives the rotational force from the motor; and a pulley coaxially with the pulley. a first rotating body that is arranged and rotates in response to the rotational force of the pulley; a third rotating body that engages with the first rotating body and rotates in a direction opposite to the first rotating body;
When the cassette tape runs in the forward direction, the first rotating body and the first reel means are simultaneously engaged, the rotational force of the first rotating body is transmitted to the first reel means, and the cassette tape is moved in the reverse direction. When traveling in the direction, the third rotating body and the second
a second rotating body that simultaneously engages with the reel means and transmits the rotational force of the third rotating body to the second reel means; and a second rotating body that engages with either the first rotating body or the third rotating body. What is claimed is: 1. A magnetic recording and reproducing device comprising: a rotation detecting body that rotates, and a rotation detecting means having a detection device that electrically detects the rotational movement of the rotation detecting body.