JPH10143945A - Control slide driving mechanism for magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving mechanism of a control slide for controlling members to be controlled in each operating mode of a mechanism in a magnetic recording and reproducing device. SOLUTION: This mechanism is composed of a cam gear 1 having a cam gear 2 and capable of forward and reverse rotation, the control slide 9 capable of linearly reciprocating motion in accordance with each operating mode and a relay member 7, of which one end is equipped with a pin 8 to be engaged with and moved along the cam groove and the other end is linked with the control slide, and then the cam gear is formed integrally with a pinion gear 3, while the relay member is provided with a sector gear 7a, which is meshed with and separated from this pinion gear. Then, the cam groove is formed from a prescribed spot of the cam gear via the vicinity of the center toward an outer circumference of the cam gear again, so as to move the following pin 8 in a longer distance than a radius of the cam gear in terms of a linear conversion of the groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder (VTR) for controlling the driving of a member to be controlled in each operation mode, for example, a tape tension detecting lever, a reel base brake, a tape speed switching clutch, and the like. The present invention relates to a mechanism for increasing a moving distance of a control slide for performing the control.

[0002]

2. Description of the Related Art Conventionally, as a slide moving mechanism, FIG.
(A) As shown in FIG.
2 is engaged with the cam groove 54 of the cam gear 53 so that the cam gear 5
The slide 51 has been moved by the distance L1 in the direction of the arrow (right in the drawing) by the pin 52 that follows the rotation of No. 3. still,
Reference numeral 55a denotes a guide pin that engages with the elongated hole 51a of the slide 51.

FIG. 1B shows a cam gear 53 and a slide 51.
Between the rotation lever 5 pivotally supported on the shaft 55b.
6 and an elongated hole 56a formed at one end of the lever 56.
, The pin 52 of the slide 51 is engaged, and the pin 57 fixed at the other end is engaged with the cam groove 54. In this case, the moving distance of the slide 51 can be increased to L2 by the ratio of the distance P1 between the support shaft 55b and the pin 57 and the distance P2 between the support shaft 55b and the pin 52.

[0004]

However, in the case of the former, it is impossible to obtain a moving distance greater than the radius of the cam gear. Therefore, even if the movement path of the pin is simply shifted slightly from the straight line passing through the support shaft of the cam gear to attempt to increase the movement distance of the slide, the slide is moved from the relationship between the cam groove and the force vector acting on the pin. There are dead points that cannot be made.

In the latter case, the greater the ratio of the arm length from the fulcrum of the lever, that is, the value of P2 / P1, the smaller the force transmitted to the slide. As a countermeasure, a method of adopting a motor having a large torque as a driving source or increasing a reduction ratio is adopted, but all of these methods increase costs.

[0006]

Therefore, according to the present invention, there is provided a cam gear having a cam groove which can be rotated forward and backward by a driving force of a driving source, a control slide which can linearly reciprocate in accordance with each operation mode, and a chassis. One end comprises a follower pin engaged with the cam groove at one end, and the other end comprises a relay member connected to the control slide. The cam gear is integrally formed with a pinion gear and meshes with the pinion gear. A sector gear is provided on the relay member.

Further, the cam groove is formed from a predetermined position of the cam gear through the vicinity of the center and again toward the outer periphery of the cam gear, and the follower pin moves a distance equal to or larger than the radius of the cam gear in linear conversion. Further, in the sector gear, the follower pin follows the cam groove, meshes with the pinion gear near the center of the cam gear, and drives the control slide.

Further, a plurality of cam portions and at least one gear portion are formed on the control slide, and the movement of the control slide according to each operation mode causes a tape pull-out device, a tape tension detecting device, a reel base brake device, a tape running device. The drive control of the speed switching clutch means and the like is performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view during the control slide movement, FIG. 2 is a plan view of a main part when the pinion gear and the sector gear are engaged, FIG. 3 is a side view for explaining a clutch mechanism, and FIG. FIG. 5 is a plan view of the recording / reproducing mode, and FIG.
7 is a plan view in a review mode, FIG. 7 is a plan view in a main brake operation, and FIG. 8 is a plan view in a fast-forward / rewind mode.

In FIG. 1, reference numeral 1 denotes a cam gear having a cam groove 2 and a pinion gear 3 and rotatable about a shaft 4a of a chassis 4. The cam gear 1 rotates reversibly in forward and reverse directions via a motor (not shown) as a drive source and a reduction gear 6.
The cam groove 2 is located at a predetermined position (in the drawing, approximately 1
/ 3 from the middle position closer to the center), through the center of the cam gear 1, that is, a position close to the pinion gear 3, and again extends approximately 360 ° toward the outer periphery. Reference numeral 7 denotes a sector gear portion 7 pivotally supported by a shaft 4 b on the chassis 4 and engaged with a follower pin 8 engaged with the cam groove 2 and the pinion gear 3.
This is a rotatable relay member having a at one end and having an engagement pin 10 at the other end.

Reference numeral 9 denotes a control slide having an elongated hole 9b at one end into which an engaging pin 10 is inserted, and a guide shaft 4c, 4c engaged with the elongated holes 9a, 9a to be able to reciprocate obliquely in the drawing. The control slide 9 includes cam units 11 and 12 for controlling a reel base, which will be described later, a gear unit 13 for driving and controlling a tape drawing unit, cam units 14a and 14b for controlling a tape tension detecting unit, and a tape speed switching clutch unit. Are integrally formed with the cam portion 15 for actuating the lever, a bent piece 16 for a stopper of a reel base drive idler gear shaft, and the like.

In FIG. 4, 17 is a take-up reel stand, 18 is a supply reel stand, 19 is a clutch switching mechanism, 20 is a tape pulling means having a pair of leading guide blocks 21 and 21, and 22 is a tape tension detecting means. , 23 is a cylinder, 24 is a stopper, 25 is a main brake on a take-up side rotatable around a shaft 4d on the chassis,
26 is a soft brake which is pivotally supported by the main brake 25 and is urged in the counterclockwise direction (CCW) by a spring 27; 28 is a supply-side main brake rotatable about a shaft 4d on a chassis; 29 is a main brake 28 to 28
The soft brake 29 is urged clockwise (CW) by a spring 30. As will be described later, the main brake and the soft brake are engaged and separated from each other and
Is configured to individually apply a braking force.
31 is a capstan motor pulley and 32 is a belt.

In FIG. 3, reference numeral 33 denotes a belt pulley;
Is a switching gear that is movable in the direction of the shaft 4e and that rotates synchronously with the belt pulley 33;
Is urged downward as shown. 36 is a transmission gear, 37 is a slip gear, 38 is a slip felt 3
9, a limiter gear to which torque is transmitted via the gear 3
8 meshes with the transmission gear 36. A swing lever 41 is rotatably supported by a shaft 4e via a felt 40, and a relay gear 42 is rotatably supported by the lever 41.

Next, the operation will be described. In FIG.
By the rotation of the motor (not shown), the reduction gear 6
, The cam gear 1 rotates to CW. The relationship between the position of the following pin 8 in the cam groove 2 in FIG. 1 and the operation mode of the apparatus is as shown in Table 1. The rotation of the cam gear 1 causes the follower pin 8 of the relay member 7 to move in the cam groove 2 from A to H. Accordingly, the control slide 9 moves the distance L
Move 3 By the movement of the control slide 9, the controlled projections 25b and 28b of the main brakes 25 and 28 move to A to H of the cam portions 11 and 12 of the control slide 9. Actually, the main brakes 25 and 28 only rotate about the shaft 4d. However, in FIG. 1, the cam gear 1 and the control slide 9 are fixed and the tracking pin 8 and the main brakes 25 and 28 are moved for convenience of explanation. This is illustrated in FIG.

[0015]

[Table 1]

When a cassette (not shown) is loaded, the motor starts and the cam gear 1 rotates to CW via the reduction gear 6 to move the cassette to the mounting completion position B (Cassette IN) (see FIG. 4). At this time, the following pin 8 is
, The control slide 9 does not move. In this state, as shown in Table 1, both reel bases 1
With respect to the main brakes 7 and 18, the main brakes 25 and 28 are separated from the reel bases 17 and 18 and the braking force is released, and the braking force by the soft brakes 26 and 29 is applied.
In Table 1, ○ indicates that braking force was applied, and X indicates that braking force was released.

While the follower pin 8 moves the cam groove 2 from B to C (see FIG. 1), the control slide 9 moves through the relay member 7 to pull out the tape from the cassette and wind the tape around the cylinder 23. . That is, when the control slide 9 is moved from the state shown in FIG. 4, the gear portion 13 of the control slide 9 and the special cam portion 20a of the tape pull-out means 20 are engaged with each other, and the tape pull-out means 20 is driven. This cam groove 2 is close to the center axis of the cam gear 1 between B and C,
The sector gear portion 7a is designed at a position where it can mesh with the pinion gear 3. Therefore, the two members mesh with each other, and the tape pull-out means 20 is driven by the control slide 9 via the relay member 7 with a sufficient driving force (see FIG. 2). Following the movement of the leading guide block 21, the tape tension detecting means 22 rotates to CCW by the urging force of the spring,
The tape tension can be detected at the position shown in FIG. Each operation mode such as recording / reproducing and tape fast-forward / rewind in this apparatus is performed in a state where the tape is wound around the cylinder 23.

By the Play operation, the follower pin 8 moves from C to D of the cam groove 2 to be in the state shown in FIG. . FIG.
In the recording / reproducing mode shown in FIG. 7, the movement of the control slide 9 causes the controlled protrusion 2 of the main brake 25 on the winding side to move.
5b pivots slightly to CW while slidingly contacting the cam portion 11, contacts the concave portion 11a in the figure, depresses the soft brake 26 and pivots slightly to CCW to release the braking on the take-up reel base 17. Controlled protrusion 28 of supply side main brake 28
The b rotates slightly to the CCW, abuts against the stepped cam portion 12a of the cam portion 12, presses the soft brake 29, rotates the brake 29 slightly to the CCW, and releases the braking to the reel base 18. Therefore, both the main brake and the soft brake are released for both reel stands 17 and 18.
At this time, the tape tension detecting means comes into contact with the tape and is in a tension detectable state.

FIG. 6 is a plan view showing the REview mode, in which the follower pin 8 is located at the position E shown in FIG. By the movement of the control slide 9, the projection 25b of the main brake 25 comes into contact with the peak 11b of the cam portion 11, and the main brake 2
5 is slightly rotated to CCW. Following this, the soft brake 26 also rotates to the CCW, and applies a light braking force to the take-up reel base 17. On the other hand, the controlled projection 28b of the supply side main brake 28 only slides on the stepped cam portion 12a and does not rotate. Therefore, soft brake 2
9 also does not rotate. That is, in the Review mode, only the braking force of the soft brake 26 is applied to the take-up reel base 17.

FIG. 8 is a plan view showing the FF / Rew mode. By the FF or Rew operation, the cam gear 1 rotates to CW to the maximum. Therefore, the follower pin 8 is
In the position. At this time, the controlled projections 25b and 28b of the main brakes 25 and 28 are
2 is in contact with the leftmost end. Main brake 25, 28
The state of the soft brakes 26 and 29 is indicated by R in FIG.
In the same state as in the ec / Play mode, all brakes are released. At this time, the cam portion 15 of the control slide 9 is engaged with the tongue piece 19a of the clutch switching means 19 to operate the clutch switching means 19, and FIG.
From the state shown in (a), the switching gear 34 is moved upward in the direction of the shaft 4e as shown in FIG. Thereby, the switching gear 34 and the transmission gear 36 rotate integrally. Therefore, the capstan motor pulley 31, the belt 3
2, belt pulley 33, switching gear 34, transmission gear 3
The torque is transmitted to the reel base 17 (18) via the sixth relay gear 42, and the tape is fast-forwarded or rewound. The protruding piece 22a of the tape tension detecting means 22 is bent at the bent piece 9b of the control slide 9 and held at the position shown in the figure.

When shifting from the FF / Rew mode to another operation mode, the device of the present invention is designed so as to reach the relevant operation mode after passing through the main brake mode G and the soft brake mode F as shown in FIG. doing. That is, when the tape is rapidly shifted from the high-speed feeding state to the low-speed tape or stop mode, tape slack occurs, and there is a concern that the tape may run or the reproduction screen may be disturbed. Therefore, FIG.
As shown in FIG. 1, first, the braking force by the main brakes 25 and 28 is applied to both the reel bases 17 and 18, and once the reel base 1
7 and 18 are suddenly braked and then released, and then a soft brake 29 is applied to the supply-side reel base 18 so that the slack of the tape from the tape feed-out side is taken up by the winding-side reel base 1.
7. Note that the brake mode F,
At the position G, the tape tension detecting means 22 is held at the position shown in the drawing in contact with the bent piece 9b of the control slide 9.

As in the configuration of the present invention, the control slide is moved only by the relation of the operation direction of the follower pin 8 without engaging the sector gear portion 7a provided on the relay member 7 with the pinion gear 3 of the cam gear 1. However, in consideration of the coefficient of friction and the like, there is a portion that cannot actually operate. Therefore, when the locus of the follower pin 8 engaging with the cam groove 2 is in the vicinity of the support shaft 4a of the cam gear 1, the control slide is driven by meshing between the pinion gear and the sector gear.
The follower pin 8 can be operated with a stroke greater than the radius of the cam gear 1, the movable range of the control slide is expanded, and each controlled member is controlled, thereby streamlining the design.

[0023]

According to the above-described structure, the trajectory of the following pin moves from the vicinity of the outer periphery of the cam gear to the center axis and moves to the outer periphery again. At first, the trajectory follows the cam groove with the rotation of the cam gear. When the cam groove approaches the center axis, the sector gear meshes with the pinion gear to drive the relay member, and then the relay member moves following the cam groove by a stroke larger than the radius. And the control slide is largely driven. With such a configuration, an operation stroke larger than the radius by the cam gear can be obtained without lowering the operation force of the control slide, and a rational design is possible.

[Brief description of the drawings]

FIG. 1 is a plan view during a control slide movement.

FIG. 2 is a plan view of a main part when a pinion gear and a sector gear mesh with each other.

FIG. 3 is a side view of a main part of a clutch mechanism.

FIG. 4 is a plan view when the cassette is completely mounted.

FIG. 5 is a plan view in a recording / reproducing mode.

FIG. 6 is a plan view in a review mode.

FIG. 7 is a plan view when a main brake is operated.

FIG. 8 is a plan view in a fast-forward / rewind mode.

FIG. 9 is a plan view of a main part of a conventional slide moving mechanism.

[Description of Signs] 1 Cam gear 3 Pinion gear 7 Relay member 7a Sector gear 8 Tracking pin 9 Control slide 19 Clutch switching mechanism 20 Tape pull-out means 22 Tape tension detection means 26, 29 Main brake 25, 28 Soft brake

Claims (4)

[Claims] 1. A cam gear having a cam groove rotatable forward and backward by a driving force of a driving source, a control slide capable of linearly reciprocating in accordance with each operation mode, and a cam supported at one end by a chassis. A relay member having a follower pin engaged with the groove and having the other end connected to the control slide, a pinion gear is integrally formed with the cam gear, and a sector gear meshing with the pinion gear is formed on the relay member. A control slide drive mechanism for a magnetic recording / reproducing apparatus, wherein: 2. The cam groove is formed from a predetermined portion of the cam gear through the vicinity of the center and again toward the outer periphery of the cam gear, and the following pin moves a distance equal to or larger than the radius of the cam gear in linear conversion. The control slide drive mechanism of the magnetic recording / reproducing apparatus according to claim 1, wherein: 3. The sector gear according to claim 1, wherein the follower pin moves following the cam groove, meshes with the pinion gear near the center of the cam gear, and drives the control slide. A control slide drive mechanism of the magnetic recording / reproducing apparatus described in the above. 4. The control slide has a plurality of cams and at least one gear formed thereon, and the control slide is moved in accordance with each operation mode so that a tape pull-out means is provided.
2. A control slide drive mechanism for a magnetic recording / reproducing apparatus according to claim 1, wherein drive control of a tape tension detecting means, a reel base brake means, a tape running speed switching clutch means and the like is performed.