JPH0753150Y2 - Reel drive gear dead center canceling device in magnetic recording / reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> This invention is used for a magnetic recording / reproducing apparatus such as a rotary head type digital audio tape recorder, and can be used for fast-forwarding and rewinding a mounted cassette. The present invention relates to a device for canceling a dead center state between a reel gear and an intermediate gear that occurs when stopped or finished.

<Prior Art> In a magnetic recording / reproducing apparatus, generally, the reel is rotationally driven by rotational driving of a reel gear and a drive gear meshed with the reel gear via an intermediate gear. When shifting, at the end of the rewinding operation, the rotation of the drive motor connected to the drive gear is electrically stopped, so the intermediate gear is stopped,
Since the teeth of the reel gear that try to continue to rotate collide with each other from the rear, the engagement between the reel gear and the intermediate gear is in a dead center state.

In such a dead center state, the next operation, for example, when immediately shifting to the play operation after the rewind operation, in the desired play operation direction, even if the drive gear or the intermediate gear is rotated, the dead center state cannot be released, Regeneration, of course, is an obstacle to the drive motor, etc., and means for releasing this is required. Therefore, in the past, this has generally been solved in a purely mechanical manner. For example, an appropriate operating lever is attached to the shaft of the intermediate gear. Incidentally, there is known a structure in which this lever can be moved after the rewinding operation.

<Problems to be solved by the device> However, according to such a conventional configuration, the dead point state is released purely mechanically, so there is dissatisfaction in terms of operability and also in terms of certainty now. There was a feeling of one step.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a drive circuit for a drive motor connected to a drive gear that meshes with a reel gear and an intermediate gear, in which one operation is reversed. When the operation is shifted to the above operation, the release pulse supply means capable of supplying the reverse rotation drive pulse opposite to the rotation direction by the other operation is provided.

<Operation> For example, when the rewinding operation is completed, a dead center state is established between the reel gear and the intermediate gear as described above. Immediately after the reproduction operation, the drive motor connected to the drive gear is given a reverse pulse for rotating it in the direction opposite to the reproduction direction, causing the drive gear to rotate a little in the direction opposite to the reproduction direction, which causes the drive gear to rotate. The connected intermediate gear rotates in the direction opposite to the reproduction direction and moves away from the teeth of the reel gear, and the dead point state of meshing between the intermediate gear and the reel gear is released.

<Embodiment> FIG. 1 shows an embodiment of a rotary head type digital audio tape recorder according to the present invention. In the figure, reference numeral 1 is a fixed base.
Is provided with a cylinder 2 having a magnetic head mounted thereon, and a pair of V-shaped stoppers 3 and 4 are fixed to both sides of the cylinder 2. Guide grooves 5 and 6 extend in the respective V-shaped stoppers 3 and 4, and the tips of the grooves 5 and 6 face a position slightly inserted in the tape exposed portion side of the mounted cassette C. Has been done. Further, guide posts 7 and 8 are provided near the two guide grooves 5 and 6, respectively, and a capstan shaft 9 is provided near one guide post 8. In addition, both guide grooves 5 and 6 are provided with the supply-side base 1
0, a winding-side base 11 is slidably attached, and guide rollers 12, 14 and inclined posts 13, 15 are arranged on the bases 10, 11, respectively.

On the other hand, at the mounting position of the cassette C, the reel shaft 17 of the supply reel 16 and the reel shaft 19 of the take-up reel 18 are connected to the reels 1.
The shafts are axially mounted at 6 and 18 axes. Reel gears 20 and 21 are rotatably supported on the reel shafts 17 and 19, respectively, and an intermediate space between the reel gears 20 and 21 that can selectively mesh with either one of the gears 20 and 21. A gear 22 is arranged. The intermediate gear 22 has a support shaft 23 that can move freely. Furthermore, the intermediate gear 22 is a drive gear.
The support shaft 25 of the drive gear 24 is attached to the fixed base 1 so as to mesh with 24. Also, the intermediate gear 22
The support shaft 23 and the drive shaft of the drive gear 24 are connected by a swing arm 26. Further, the drive gear 24 is adapted to mesh with a drive connection gear 28 mounted coaxially with the drive pulley 27, and the drive pulley 27 is connected with the main drive shaft 30 of the drive motor 29 via the drive belt 31. Has been done.

The fixed base 1 is provided with a coil spring 33 whose one end is locked by a locking pin 32, and the other end of the coil spring 33 is a brake plate 34 pivotally supported by the fixed base 1. The brake plate 34 is locked at one end, and the other end of the brake plate 34 can come into contact with a contact member 36 fixed to a brake shoe 35 that rotates integrally with the reel shaft 19 as described later. (See Figure 2). Further, 37 is a loading motor which operates at the time of loading, 40 is a rotary mounting plate rotatably mounted on the fixed base 1, and the rotary mounting plate 40 includes a pinch roller 41 and a guide pin.
42 is fixed.

As shown in FIG. 2, one end of the reel shaft 19 on the winding side is pivotally supported by an auxiliary base 43 provided below the fixed base 1. As described above, the reel shaft 19 has a reel gear. 21 is mounted coaxially. A coil spring 39 is interposed between the brake shoe 35 integrated with the reel gear 21 and the collar 38 fitted at the tip of the reel shaft 19. Further, a coil spring 39 is interposed between the holding plate 23a and the intermediate gear 22 on the support shaft 23 of the intermediate gear 22 that meshes with the reel gear 21.

A support shaft 25 of a drive gear 24 meshing with the intermediate gear 22 is pivotally supported by the fixed base 1.

The operation of the device configured as described above is as follows. First, at the beginning of tape loading,
As shown in the figure, the cassette C is mounted at the tape loading position, and the guide rollers 12, 14 of the bases 10, 11 and the inclined posts 13, 15, the pinch rollers 41, etc. are placed inside the exposed magnetic tape T of the cassette C. Faced. Then, when the loading motor 37 starts operating, the bases 10 and 11 move toward the V-shaped stoppers 3 and 4 along the guide grooves 5 and 6, respectively, and the rotary mounting plate 40 rotates, so that the magnetic tape T is moved. Is drawn from the supply reel 16 according to the movement of the.

In this case, the supply reel 16 needs to keep its rotation free, but the take-up reel 18 needs to stop its movement as described in the section of the prior art, so that the brake plate 34 is brought into contact with the contact member. Keep it in contact with 36. Therefore, until the magnetic tape T is pulled out and loading is completed,
The rotation of the take-up reel 18 is blocked. By the way, when loading is completed and, for example, predetermined rewinding is performed and then a play operation is to be started, at the end of rewinding, the intermediate gear 22 and the reel gear 20 mesh with each other as shown in FIG. This meshing state is strong because the teeth of the reel gear 20 that is going to continue to rotate after the intermediate gear 22 first stops as described in the prior art are meshed from the rear. The strong meshing state is the dead center state. From this state, when performing a play operation in which the direction of rotation is opposite to the previous one, the operation button shown in FIG.
By operating 50, the dead center release pulse supply circuit 51
4 generates a pulse P shown in FIG. 4 and supplies the pulse P to the drive circuit 52 of the drive motor to rotate the drive motor in the direction opposite to the play direction.
Also rotates in the opposite direction to the play direction (right in the figure). That is, the dead center state between the intermediate gear 22 and the reel gear 20, which has been generated by the extra rotation of the reel gear 20 that is the cause of the dead center state, is a direction that is reversed from the rotation direction that is the cause. In addition, the intermediate gear 22 is released by rotating the reel gear 20 by the extra rotation of the reel gear 20. Then, a smooth transition to the subsequent play operation can be performed. Note that the pulse P need only be supplied when the dead center is released, and thus the electric signal immediately before that may be used.

It should be noted that FIG. 5 is for explaining the start of tape loading. In this case, the take-up reel 18 is the brake plate.
Although the drive is stopped by 34, the supply-side reel 16 is rotatable because the reel gear 20 is meshed with the intermediate gear 22, and the pinch roller 42 and the like move according to the rotation, and the magnetic tape. The T is wound on the supply reel 16. Then, when the tape loading is completed, the reel gear 20
Since the meshing between the and the intermediate gear 22 is maintained as it is,
This meshing works as a rotation brake of the supply reel 16 and prevents the slack of the wound magnetic tape T.

<Effect of Device> As described above, according to this device, the pulse for releasing the dead center state between the reel gear and the intermediate gear can be supplied to the drive motor at the time of operation. The operability is superior to the solution, and the reliability is significantly improved.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a block diagram showing a dead center release pulse supply means. FIG. 4 is a time chart for explaining the driving state of the motor, and FIG. 5 is a plan view of the magnetic recording / reproducing apparatus at the time of tape unloading. 1 ... Fixed base, 18 ... Take-up reel, 20, 21 ... Reel gear, 22 ... Intermediate gear, 23 ... Intermediate gear support shaft, 26
...... Swinging arm, 24 ...... Drive gear, 52 ...... Drive motor drive circuit, 54 ...... Dead point release pulse supply circuit.

Claims (1)

[Scope of utility model registration request] 1. A reel gear rotatably supported about a rotation center of a reel, an intermediate gear meshing with the reel gear, and a drive gear meshing with the intermediate gear and axially mounted on a fixed base. A swing arm that connects the support shaft of the drive gear and the support shaft of the intermediate gear and rotates about the support shaft of the drive gear; and a drive motor that drives the drive gear, In the drive circuit of the drive motor, when the traveling direction is reversed from the direction of the previous operation command, the drive gear is rotated in the direction opposite to the desired operation direction so as to separate the reel gear from the intermediate gear. A drive gear dead center canceling device for a reel in a magnetic recording and reproducing device, characterized in that a dead center canceling pulse supplying means for supplying a drive pulse is provided.