JPS5936357A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To stabilize the operation of a magnetic recording/reproducing device, by driving a capstan and a reel driving disk by a motor and driving with friction the reel driving disk with a slip torque in a record/reproduction mode and with a synchronous torque in a fast forward/rewind mode respectively. CONSTITUTION:The slip torque of a motor is extracted by the 1st pulley 12 with forward revolutions of the motor in a record/reproduction mode, and a reel driving disk 22b of the take-up side is revolved toward an arrow E. While the synchronous torque of the motor is extracted by a pulley 8, and a capstan 4 is revolved toward an arrow F. Then a pinch roll 27 moves away from the capstan 34 in a fast forward/rewind mode, and a cam follower 45 hits an expanded part 46a of a cam 46. Thus a roll 42 touches pulleys 12 and 41 at a time. Therefore the synchronous torque is extracted from the pulley 12, and the 1st belt 37 hits a rotor 38b via the 2nd pulley 36. Thus a satisfactory take-up torque is obtained. In such a way, a stable operation is possible for a magnetic recording/reproducing device.

Description

[Detailed Description of the Invention] The present invention relates to a magnetic recording and reproducing device, and more specifically,
Relating to a magnetic recording and reproducing device in which a magnetic tape in a tape cassette drawn out by a tape guide is wound around the outer periphery of a rotating drum containing a rotating magnetic head, such as used in a video tape recorder, etc. It is something.

Conventionally, when an electric motor is used for driving a video tape recorder, for example, a capstan shaft is made to correspond to the output shaft of a synchronous motor, and a lee for winding the tape is used.
The I+/axis has been provided with a separate motor to serve as a power source, or the driving force has been obtained from a synchronous motor via an idler or a belt. However, the former example requires two or more electric motors. Further, in the latter example, since the rotational speed of the gear spindle shaft and the rotational speed of the μ-shaft do not always have a constant relationship, a mechanical sliding mechanism is required to rotate the reel shaft. However, these sliding mechanisms not only have characteristics that change over time, but also have the problem of insufficient driving torque during fast forwarding and rewinding.

In order to solve the following two problems, this invention has the following problems: 1. Despite using one electric motor equipped with a synchronous torque output shaft and a slip/reflex output shaft, the Lee/lz motor in the recording/reproducing mode is By obtaining the driving force from the slip torque output shaft, stable operation is possible, and by obtaining the driving force for the reel shaft in fast forward/rewind mode from the synchronous torque output shaft, sufficient driving force can be obtained. The purpose is to provide a recording/playback device.

Embodiments of the present invention will be described below with reference to the drawings.

First, a description will be given of an electric motor which is an example of a forward/reverse rotation drive mechanism (1) for driving a capstan shaft and a reel shaft in the illustrated magnetic recording/reproducing apparatus.

In Figures NG10 to 12, the coil housing (2) made of an insulator such as glass is cut into a cutting board (
3), and a bearing (
4) is formed, and the coil /l/ (5) and the magnetic flux detection element (6) are held together.

The synchronous torque output shaft (7) has a pulley (8) integrally fixed to one end thereof, and is fitted to rotate freely on a bearing. A rotor disc (9) has a rotor magnet a1 and is coaxially fixed to the rotor disc (9).This rotor disc (9) is made of, for example, an electromagnetic soft iron plate.Rotor magnet 00 is N every 45 degrees of mechanical angle.

The rotor disk (9) also serves as the magnetic circuit for the rotor magnet θ (see the magnetic circuit). The rotor Qυ, which is made of a material with hysteresis characteristics such as a hard magnetic material, also serves as a magnetic circuit for the spatial magnetic flux from the rotor magnet 0.This rotor aυ
is fitted to rotate freely with respect to the synchronous torque output shaft (7), and is integrally provided with a pinion, which is an example of the first pulley θ. rotor magnet) 0
An attractive force due to magnetic force acts between → and rotor 0σ.

This suction force is applied to the end face (Il
a) Generates a frictional force at the contact point with. Here, the rotating body consisting of the rotor disk (9) and the rotor magnet (00) is referred to as the 10th rotor, and the rotor Qυ is referred to as the 20th rotor. The 20th motor 0p can rotate independently with respect to the 10th motor (1), and receives the above-mentioned frictional force at the end surface 018]. Therefore, the rotational force of the 10th motor (1, 1) contributes to the rotational force of the 20th motor 01 via the frictional force.

In the above configuration, if the magnetic flux of the rotor magnet 01 is detected by the magnetic flux detection element (6) and the drive current is supplied to the coil (5) by the control circuit (not shown), a two-phase eight-pole synchronous motor can be obtained. υThe first rotor θ1 rotates. The input of the coil/l/(5) is determined by comparing the external synchronization signal with the control signal generated by the rotor disk (9) (detected by known electromagnetic or optical methods, not shown). By controlling , the rotation of the tenth rotor θ1 can be controlled to a desired rotation speed.

In this way, it is possible to obtain synchronous rotational torque to the rotor chain (QO), that is, the pulley (8). Incidentally, when it is necessary to reverse the rotation direction, it is possible to use a known method of reversing the polarity of the magnetic flux detection element (6). Further, as described above, a magnetic circuit is constructed by the space magnetic flux of the rotor magnet passing through the 20th rotor θυ. When the rotor magnet θ1 rotates, the 20th
A torque is generated in which eddy current torque, hysteresis torque, or both (the type of torque differs depending on the peeling off of the disc constituting the 20th rotor) is generated at the 20th rotor 0υ. Rotational torque is generated in the same direction as the rotation of the rotor magnet θ. At the same time, the rotation of the first rotor (from +1 Power is also second
It is added to the rotating torque of the 0-taper (II). In this way, the resultant torque L generated at the 20th motor αp is the 20th motor (]
It is possible to take it out to the outside by means of a pinion (6) integrated with 1). The torque generated at the 20th motor 0υ increases as the difference between the rotational speed of the synchronous torque output shaft (7) (synchronous rotational speed) and the rotational speed of the 20th motor 01 increases.

The resultant torque and relative rotational speed (first
The relationship between
Shown in the figure. In the figure, part (I"I) shows that the torque component is based on frictional force and torque is generated regardless of the relative rotation speed. Part (1)) shows the electromagnetic component at the 20th This shows that the generated torque increases in proportion to the relative rotation speed.

In conventional electric motors of this type, the torque that can be extracted from the 20th motor (1) in this manner is utilized as rotational force as electromagnetic and mechanical losses. The rotational force obtained by the 20th rotor (11) can obtain a nearly constant torque regardless of the rotation speed, so if it is adopted for the rotational drive of the magnetic 1-pully μ, the tape winding will be almost constant. Sit torque can be obtained, and stable long-life characteristics can be obtained without the need for a mechanical sliding mechanism.

Note that the pinion O'4 is connected to the slit μ output shaft Q.
acts as a general).

Next, a description will be given of a magnetic recording and reproducing apparatus provided with the above-mentioned electric motor (1) as a drive source for two capstans θ and reel shafts 0ea) 0flb).

In FIGS. 7 and 8, a disk Q7) whose center portion is supported by a substrate (3) is arranged around its center 0.
It is driven to rotate forward and backward over 80 degrees. This disk (
17) A rotating drum containing a rotating magnetic head θ barrel at an eccentric position P (the rotating drum is arranged in an inclined state, and a predetermined positional relationship is maintained above the disk θ around this rotating drum OI, An entrance tape guide (E), an exit tape guide IX) and a pair of inclined pins 00 are installed. In addition, rotating drum OIH, direct
Directly connected to the dophip motor.

On the other hand, the supply side reel stand G! 2a) and a take-up side reel stand (m), and a supply! Tape guide containing J-/l/) and winding-/L'■b) 04
has a notch (A) on its front end surface, and when the magnetic recording/reproducing device is in stop mode, this tape cassette (
When c) is installed on the board (3), as shown in Figure 8, the exit tape guide b) and the pair of inclined pins are accommodated in the cutout (a). A movable pin (a) and a pinch loaf (a movable pin provided swingably on the base plate (3)) are also housed in this notch (a). Note that these movable pins (A) and pinch loaves (A) are connected to the swing arms (A) (5), respectively.
Conventionally, it was configured to be moved by a plunger or the like during loading.

Furthermore, at a predetermined position on the substrate (3) along the magnetic tape running path during loading, an erase head (1), a tape guide (0), a slant pin (to), a fixed magnetic head (
A capstan is provided, and the capstan is always located outside the tape cassette.

Next, the second gouge shown in FIGS. 1 to 6 is composed of a pinion in the illustrated example, and is freely rotatably supported by a guide arm (not shown) attached to the base plate (3). In addition, the 20th motor Q1. of the electric motor (1). a) The first pulley (uniform, that is, slip torque output shaft 0
(b) is interlocked by an endless first belt (b). In other words, the distance between the swing centers of the first pulley and the second pulley is kept constant by the guide arm, and the forward and reverse rotation of the first pulley causes the second pulley to move from side to side. It is designed to be swayed by. On the other hand, as shown in Figs. 1 to 6 and 9, the supply reel stand () and the take-up reel stand (b) are each provided with a (support) (b) concentrically to the rotor. . Therefore, the second pulley) is the rotor (E) C18.
b) A connecting position R (see Figs. 2, 3, 5, and 6) that selectively abuts the first be/l/ It will be swung forward and backward between the neutral position It (see Figures 1 and 4) where it does not come into contact with anything, and in that case, the spring member (not shown) will always maintain the neutral position. Assume that it is elastically biased.

Furthermore, a Fufihoi/L10I is coaxially fixed to the capstan in correspondence with the pulley (8) of the electric motor (1), and these are interlocked by a second Be/L/) wheel.

Furthermore, the clutch mechanism shown in FIGS. 1 to 6 includes the first pulley 04 described above and the third pulley fixed to the synchronous torque output shaft (7) (see FIG. 10) and a roller θ which is brought into contact with and separated from the pair of pulleys θ and θυ at the same time. The loaf 0 is rotatably coupled to the free end of a roughly shaped swinging arm (2) which is pivotally supported on the substrate (3) at its intermediate portion, while
A cam follower of a cup mechanism (to be described later) is pivotally supported at its base end. In addition, a spring is stretched between the swinging arm exposure and the base plate (3), and the spring - always moves the rotor @2) in the direction ( (clutch opening direction).

Next, the cam mechanism includes the cam follower) and the cam surface), and the cam surface 6) is formed on the outer periphery of the disk α force described above. Here, the cam is flush with
As shown in Figures 4 to 6 and Figure 8, when the magnetic recording/reproducing device is set to fast forward/rewind mode and its tape guide (b) is set to a position corresponding to the unloading state. , the bulge m (46B) is the force J
・While it is compatible with the follower, as shown in Figures 1 to 3 and Figure 7, the tape guide (
e) When Qob) is set at a position corresponding to the loading state, its recessed portion (to) b) is configured to correspond to the cam follower).

In the following E, in the recording/reproducing mode, as is clear from FIGS. 1 to 3 and FIG. 7, the rotation of the disk 0'f) causes the tape guide
The magnetic tape is moved from the notch (a) of (c) to the position shown in the figure, whereby the magnetic tape is wound around the rotating drum.

The pinch rotor (A) is still pressed against the capstan ■ at the same time. Additionally, in this mode, the cam follower)
is made to follow the concave portion (g) b) flush with the cam surface, so the swinging arm ■ moves clockwise in the figure (the first
As a result, the loaf θ is disengaged from the pair of pulleys (2). That is, when the clutch mechanism is opened, the synchronous torque output shaft (7) and the slip torque output shaft θ(5) in the electric motor (1) are separated. Note that the second pulley (c) is in the neutral position as shown in FIG.

Therefore, when the electric motor (1) rotates in the forward direction in the recording/reproducing mode, its slip torque is taken out by the first pulley Ono, and as shown in FIG. (to the second pulley by arrow B) is swung to the right (arrow C), and the first belt (b) is brought into contact with the rotor 081)) of the take-up side reel stand (221)), and In this state, it rotates counterclockwise (arrow D), causing the take-up reel stand (4) b) to slip as described above).
It is rotated clockwise (arrow E) by the rotation. On the other hand, the synchronous torque of the electric motor (1) is taken out by the pulley (8), and this is applied to the second belt
Since the torque is transmitted to the capstan (2) by l10I, the capstan (2) is rotated in the direction of arrow F by this synchronous torque. Through this series of operations, υ and magnetic tape θ are run in the normal direction (arrow G: see FIG. 7).

In this state, synchronous torque is transmitted to the capstan (E), so sufficient driving torque is applied to the first magnetic tape for its running, while the take-up reel stand Q! Since the slip torque is transmitted to 2b+, an appropriate surface tension is applied to the magnetic tape at the beginning, and stable recording and reproduction can be performed.

Further, when the magnetic tape 07) is to be run in the rewinding direction in the recording/reproducing mode, the electric motor (1) is rotated in the reverse direction. As a result, as shown in Figure 3, the first boo! 7 (
Since l is rotated in the opposite direction (arrow H), the second pulley) moves to the left, and the first belt (a) comes into contact with the rotor (e) of the supply reel stand), and It rotates like an arrow craft. Therefore, the supply side reel stand) is rotated counterclockwise (arrow J).

Also, since the capstan ■ is rotated clockwise (arrow K), the magnetic tape (goods) is rotated in the rewinding direction (arrow L;
(see figure).

Next, in the fast forward/rewind mode, as is clear from Figures 4 to 6 and Figure 8, as the disk (17) rotates in the reverse direction, the tape guide (e) It is set in the notch (A) of the cassette (C). Suddenly, the pinch roller was separated from the capstan.

In addition, in this mode, the cam follower (to) follows the bulge structure of the cam surface, so it moves counterclockwise (towards the cam surface) against the bias of the swinging arm (3) or spring. ), whereby the rotor θ becomes in mesh with the pair of pulleys θ2@υ at the same time. That is, the Kufutsu mechanism is in a continuous state, and the electric power [(1) to the synchronous torque output shaft (7) and the slip /l/r output shaft)] is continuously connected. Note that the 21st position (to) is in the neutral position as shown in FIG.

Therefore, the third pulley of the synchronous torque output shaft (7) @η
The synchronous torque extracted by
The slip torque is transmitted from the pulley θ to the output shaft Q2a) in this order. Therefore, as shown in Fig. 5, the first pulley (which becomes the second pulley due to the positive rotation of the wheel) brings the first belt (b) into contact with the rotor b) of the take-up reel stand @'b). At times, the take-up reel stand (b) is rotated clockwise by the synchronous torque to ensure sufficient initial winding torque for the magnetic tape. The same is true when the first belt (B) is brought into contact with the rotor of the supply side reel stand (Q28) by the second gooley due to the reverse rotation of the first gooley θ, as shown in Fig. 6. .

As shown in Figures 1 and 4, the first and second pulleys (to) are in the neutral position in the stop mode, that is, the tape cassette (c) attachment/detachment mode. In order to strengthen the force for swinging between the neutral position and the connected position in
What is necessary is to apply a frictional force between the lift and its support shaft, or to provide a hook mechanism.

In addition, in the above embodiment, the first pulley. The belt and the second pulley (g) are constructed as binions, and the first belt) is constructed as a timing belt that meshes with them.
Reliable torque transmission is possible. In addition, it is also possible to use gears in the rollers θ and the rotor 08b) so that the outer surface of the first belt (b) meshes with them. Furthermore, the first belt (b) > , 1: (J
The second belt (■) may be a flat belt or a square belt with a triangular or square cross section.
(8a) (Support) b) is made according to the shape of the belt.

As described above, according to the present invention, the capstan and the reel stand can be rotated by one forward/reverse rotation drive mechanism, and in that case, the rotation of the reel stand can be controlled in the recording/reproducing mode. Since the slip torque is used in the fast forward/rewind mode, and the synchronous torque is used in the fast forward/rewind mode, the operation in each of the above modes is reliable and stable. In addition, since the torque is mainly generated electromagnetically, it has superior humidity characteristics and is more economical than conventional methods that use, for example, frictional force from felt.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams of the operation of the recording and reproducing mode in the magnetic recording and reproducing apparatus according to the embodiment of the present invention, and FIGS.
Fig. 6 is an explanatory diagram of the operation in the fast forward and rewind modes, Fig. 7 is a plan view of the tape guide drive unit corresponding to Figs. 1 to 3, and Fig. 8 is a diagram corresponding to Figs. A plan view of the corresponding drive unit, FIG. 9 is a front view when the tape cassette is attached, FIG. 10 is a vertical side view of the electric motor, and FIG. 11 is a
12 is a sectional view taken along the line ■-■ in FIG. 10, and FIG. 13 is a diagram showing the relationship between slip torque and relative rotation speed of the electric motor. (1)... Forward/reverse rotation drive mechanism, (7)... Synchronous torque output shaft, Q oscillation... 1st pulley, 02a)... Slip torque output shaft, 0υ... Capstan, ( B)·
...Inlet side tape guide, @b)...Outlet side tape guide, (c)...Tape cassette, (b)...2nd pulley, (b)...1st belt, ■... 2nd bet,
θ1)...3rd pulley, GI...loaf, @η・
...Magnetic tape 0 In the figures, the same reference numerals indicate the same or corresponding parts. Agent Makoto Kuzuno - (1 other person) Figure 1 Figure 2-3 Figure 4 44 42 Figure 5 44 42 Figure 6 Figure 7 Figure 9 Figure 10 I-11 Part 12 13th M ------>R, P, M

Claims (5)

[Claims] (1) On the outer periphery of the rotating drum containing the rotating magnetic head,
In a magnetic recording and reproducing device that winds a magnetic tape in a tape cassette pulled out by a tape guide, a forward/reverse rotation drive mechanism equipped with a slip torque output shaft and a synchronous torque output shaft, and a slit torque output shaft are used. A first pulley provided and a second pulley corresponding to the first pulley.
a pulley, a first belt wound between the first pulley and the second pulley, a capstan located outside the tape cassette when the tape cassette is attached and for causing the magnetic tape to run steadily; A clutch mechanism for selectively setting the synchronous torque output shaft and the slip torque output shaft between a continuous state and a disconnected state, and a second belt for interlocking the capstan and the synchronous torque output shaft, The second pulley is connected to a connecting position where the first belt is selectively connected to the supply side reel stand or the take-up side reel stand according to the forward and reverse rotation of the first pulley, The table is also configured to be able to swing forward and backward between a neutral position where the first belt is not connected, and the clutch mechanism is in the above-mentioned continuous state in the fast forward and rewind modes, and in the edge disconnected state in the recording and reproducing mode. A magnetic recording/reproducing device characterized in that it is configured as follows. (2) The magnetic recording and reproducing apparatus according to claim 1, further comprising a cam mechanism for controlling the clutch mechanism, and the cam mechanism is configured to operate in conjunction with a tape guide. (3) The clutch mechanism includes a first belt, a third pulley provided on the synchronous torque output shaft, and a roller that is simultaneously engaged and disengaged from the first belt and the third pulley. A magnetic recording and reproducing device according to claim 1 or 2. (4) The first pulley and the second pulley are gears,
4. A magnetic recording and reproducing apparatus according to claim 1, wherein the belt is a timing belt that meshes with these belts. (5) The magnetic recording and reproducing apparatus according to claim 4, wherein the rotor is a gear, and the first belt is a timing belt meshing with the gear.