JP2551801B2 - Magnetic recording / reproducing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a magnetic recording / reproducing apparatus, and an object of the present invention is to obtain a magnetic recording / reproducing apparatus in which a reproduction signal is not lost when a magnetic tape is reversely rotated. is there.

(Prior Art) In recent years, along with a remarkable increase in demand for magnetic recording / reproducing devices, there has been an increasing demand for price reduction of magnetic recording / reproducing devices. At the same time, there has been an increasing demand for multifunctional magnetic recording / reproducing devices. For example, in the still / forward / reverse slow motion mode and the forward / reverse fast-forward mode, special reproduction capable of obtaining a reproduced image with less noise is an indispensable additional function. In addition, as a usability of the magnetic recording / reproducing apparatus, it is required that the mode transition of each reproducing mode is quick.

In order to speed up the mode transition, it is necessary to switch the forward / reverse playback mode while the pinch roller is kept in pressure contact with the capstan.

In order to reduce the price of the magnetic recording / reproducing apparatus, it has been proposed to reduce the number of motors driving the magnetic recording / reproducing apparatus.

As a specific example, as shown in FIG. 5, there is a device that drives a capstan and a pair of a supply-side reel stand and a pair of take-up reel stand with one motor. In FIG. 5, 51
Is a first motor, and this motor is a direct current motor for driving a capstan, and is constructed integrally with the capstan 23. The first on the back of the chassis board 50
The power from the motor 51 is transmitted to the center pulley 25 by the rubber belt 24. A center pulley gear 25-b is attached to the center pulley 25 through a friction member such as a felt, coaxially with the center pulley 25 by pressure contact with an elastic member. And rotate. Center pulley gear 25-b
The rotational driving force of the first idler arm 27 and the first rolling gear 28 attached to the first idler arm 27 is applied to the pair of reel bases 31, 32 via the pair of first reel base relay gears 29, 30. To transmit power to drive these reel stands. FIG. 5 shows that the magnetic tape 54 in the tape cassette 17 is pulled out to the outside, the magnetic tape 54 is rollingly contacted with the cylinder 20 of the rotary head, and the pinch roller 45 is pressed onto the capstan 23. It is a figure at the time of moving in the normal direction (arrow a-1) and reproducing the signal in the normal direction.

FIG. 6 shows the state in which the tape is fed in the reverse direction by driving the first motor 51 in the reverse direction while the pinch roller 45 is pressed against the capstan 23 from the time of the normal direction reproduction in FIG. . By reversing the first motor 51 (direction of arrow b-2),
At the same time that the capstan 23 rotates in the reverse direction (indicated by the arrow b-2), the magnetic tape 54 is transferred in the reverse direction as indicated by the arrow b-1. On the other hand, when the center pulley 25 connected by the belt 24 from the first motor 51 reversely rotates, the center pulley gear 25-
The first rolling contact gear 28 rollingly contacted with b is reversely rotated, and the meshing between the first rolling contact gear 28 and the first reel stand relay gear 29 is disengaged. And the first rolling gear 28 is the first idler arm.
27 together with the center pulley 25 in the direction of arrow b-4.
Starts to rotate coaxially with the first reel stand relay gear 30, and the supply reel stand 32 is turned in the direction of arrow b-3. Then, the magnetic tape 54 transported by the reverse rotation of the capstan 23 is wound around the supply-side tape reel 18. During this time, the reverse rotation of the capstan 23 causes the first rolling gear 28 to mesh with the first reel stand relay gear 30 from the moment when the tape is transported in the reverse direction, and the tape reel 18 is reversely driven. A time delay occurs before the magnetic tape 54 is wound up. During that time, winding failure of the magnetic tape 54 occurs and the magnetic tape 54 sags, so that the magnetic tape 54 is momentarily released from contact with the rotary head cylinder 20.
At this time, the magnetic tape 54 becomes as shown in FIG. 6, and the signal recorded on the magnetic tape 54 cannot be read by the head cylinder 20. Therefore, the recorded signal in that section cannot be reproduced.

(Problems to be Solved by the Invention) As described above, in the conventional magnetic recording / reproducing apparatus shown in FIG. 5, the magnetic tape is moved in the forward direction while the pinch roller is pressed against the capstan. When the capstan is rotated in the reverse direction from the reproduction mode to transfer the magnetic tape in the reverse direction to shift to the reverse reproduction mode, the magnetic tape comes off the magnetic head and a reproduction signal is lost. In particular, during slow-motion playback and frame-by-frame playback, a phenomenon in which a playback signal of at least several fields is completely lost when reversing from the forward direction to the reverse direction occurs in the playback image, which is a major obstacle to tape editing work. was there.

In view of the above-mentioned problems, the present invention, in the conventional magnetic recording / reproducing apparatus shown in FIG. 5, mounts a second motor and a second reel base drive mechanism so that the magnetic tape is reproduced in the reverse direction from the normal direction reproduction mode. It is an object of the present invention to provide a magnetic recording / reproducing apparatus which completely eliminates the loss of a reproduction signal due to the slack of a magnetic tape which occurs when the reproduction mode is entered.

(Means for Solving the Problems) In order to solve the above problems, a magnetic recording reproducing apparatus according to the present invention includes a capstan that moves a magnetic tape at a constant speed in cooperation with a pinch roller, and the capstan. A first motor for driving to rotate, a supply-side reel stand and a take-up reel stand that engage with a pair of tape reels around which a magnetic tape in a tape cassette is wound, and are driven by the first motor, A first reel stand drive mechanism that drives the supply-side reel stand and the take-up reel stand, a second reel stand drive mechanism that drives only the supply-side reel stand, and a second reel stand drive mechanism. And a second motor for rotationally driving.

(Operation) According to the present invention, according to the above-described structure, in the forward direction reproduction mode in which the magnetic tape is forwardly transferred in the state where the pinch roller is pressed against the capstan, the first reel base drive mechanism drives the take-up side reel. Drive the platform. Then, before the capstan is reversed to shift to the reverse reproduction, the first motor is once stopped to stop the capstan, and the still mode is set. In the still mode, the second reel base drive mechanism drives the take-up reel base (the capstan is stopped at this time, so the magnetic tape is not fed out). Immediately after that, the capstan is rotated in the reverse direction to transfer the magnetic tape in the reverse direction. Then, after that, the winding drive source of the supply-side reel stand is switched from the second reel stand drive mechanism to the first reel stand drive mechanism. In this way, it is possible to eliminate the slack of the magnetic tape due to defective winding of the magnetic tape, which has occurred in the conventional apparatus, when the magnetic tape is transported from the forward direction to the reverse direction. Further, the transition time from the forward direction reproduction mode to the reverse direction reproduction mode, including the still transit time, can be instantaneously performed within 1 second.

(Example) Hereinafter, regarding a magnetic recording / reproducing apparatus of an example of the present invention,
This will be described with reference to the drawings.

FIG. 1 to FIG. 4 are plan views of operation explanatory views of one embodiment of the present invention. In FIGS. 1 to 4, reference numeral 51 denotes a first motor, which is a direct current motor for driving a capstan, and is a capstan 23.
It is configured integrally with. The power from the first motor 51 arranged on the back surface of the chassis substrate 50 is transmitted to the center pulley 25 by the rubber belt 24. The center pulley 25 has
The center pulley gear 25-b is mounted coaxially with the center pulley 25 by means of an elastic member via a friction member such as felt. The center pulley 25 and the center pulley gear 25-b form a tri-limiter, have a torque control function, and rotate integrally with the center pulley 25. The rotational driving force of the center pulley gear 25-b is generated by the first idler arm 27 and the first rolling contact gear 28 attached to the first idler arm 27.
As a result, power is transmitted to the pair of reel stands 31 and 32 via the first reel stand relay gears 29 and 30 to drive these reel stands. The center pulley 25, the center pulley gear 25-b,
The first idler arm 25-a, the first rolling gear 28, and the first reel stand relay gears 29, 30 constitute a first reel stand drive mechanism. Reference numeral 1 is a second motor, which is attached to the rear of the chassis via a mounting bracket 11. Warm 2
The rotational driving force decelerated by is transmitted to the second pulley 5 via the belt 4 arranged on the rear surface of the chassis. A second pulley gear 5-b is attached to the second pulley 5 coaxially with the second pulley 5 by an elastic member via a friction member such as felt. The second pulley 5 and the second pulley gear 5-b form a torque limiter, have a torque control function, and rotate integrally with the shaft 9 as a rotation center. The rotational driving force of the second pulley gear 5-b causes the second idler arm 6 and the second rolling contact gear 7 attached to the second idler arm 6 to cause the second reel base relay gear 8 to drive the supply side reel base 32. To drive. The second pulley 5, the second pulley gear 5-b, the second idler arm 6,
The second rolling gear 7 and the second reel stand relay gear 8 are
It constitutes a second reel base drive mechanism.

In FIG. 1, the magnetic tape 54 in the tape cassette 17 is pulled out to the outside of the tape cassette, the magnetic tape 54 is rollingly contacted with the rotary head cylinder 20, and the magnetic tape 54 is sandwiched between the capstan 23 and the pinch roller 45 is crimped. With the condition
FIG. 9 is a state diagram when the magnetic tape 54 is transported in the forward direction (arrow a-1) and the signal recorded on the magnetic tape 54 is reproduced in the forward direction. At the same time as the magnetic tape 54 is sent out by the capstan 23 (arrow a-1), the first rolling gear 28 moves to the first position.
By engaging with the reel stand relay gear 29, the take-up side tape reel stand 31 is driven and the magnetic tape 54 is taken up on the tape reel 19.

The transition of the operation mode from the forward transfer to the reverse transfer of the tape will be described below.

In FIG. 2, the capstan 23 is stopped by stopping the first motor 51, and the still mode is set. Next, in the still mode, the second motor 1 is rotationally driven to mesh the second rolling gear 7 with the second reel base relay gear 8 shown from the position shown in FIG. The second pulley gear 5-b is moved while rolling on the second pulley gear 5-b. Then, the second rolling contact gear 7 meshes with the second reel base relay gear 8 and, at the same time, the second reel base relay gear 8 is rotationally driven to feed the second reel base relay gear 8 with the second gear base relay gear 8. The side reel stand 32 is rotationally driven in the direction of arrow b-3. This causes the tape reel 18 engaged with the supply-side reel stand 32 to wind up the magnetic tape 54. At this time, Capstan 23 is stopped,
The magnetic tape 54 is not sent out. Therefore, magnetic tape
As the tension of 54 increases, the tension post 60 is rotated in the direction of arrow b-4 from the position shown in FIG. 1 and brought to a position balanced with the tape tension of the magnetic tape 54 of FIG. It The reduced amount of the tape path changed by the rotation of the tension post 60 is wound on the tape reel 18 without causing the tape slack. The winding torque for winding the tape reel 18 is set by the torque limiter value of the torque limiter portion formed between the second pulley 5 and the second pulley gear 5-b described above. If the winding torque required for winding the tape reel 19 becomes larger than the set torque limit value, the second
A slip occurs between the pulley 5 and the second pulley gear 5-b, and further winding cannot be performed.

Next, FIG. 3 shows a state immediately after the supply side reel base 32 is driven by the second reel base drive mechanism as shown in FIG. In FIG. 3, the first motor 51 is rotated in the reverse direction, the capstan 23 is rotated in the direction indicated by the arrow b-2, and the magnetic tape 54 is transferred in the opposite direction indicated by the arrow b-1.

At this time, the transferred magnetic tape 54 is transferred to the second motor 1
By the second reel base drive mechanism driven by the tape reel 18, the tape reel 18 is wound without slack.

Then, thereafter, the first motor 51 is reversely rotated. Simultaneously with the reverse rotation of the first motor 51, the first rolling contact gear 28 is disengaged from the first reel base relay gear 29 and starts rotating in the direction of arrow b-4.

Next, in FIG. 4, the first rolling contact gear 28 meshes with the supply-side first reel base relay gear 30, and at the same time, the supply-side reel base 32 starts to be driven. Immediately after the second rolling gear 28 drives the supply-side reel base 32, this time the second motor 1 is reversely rotated. Then, the second rolling contact gear 28 moves from the position meshing with the second reel stand relay gear 8 shown in FIG.
As shown in the figure, it rotates to a position where the meshing relationship is released. Then, the reverse rotation of the second motor 1 is stopped. After that, the magnetic tape 54 can be transferred in the reverse direction by the reverse rotation of the first motor 51. By performing the operations shown in FIGS. 1 to 4, the magnetic tape 54 is moved from the forward direction to the reverse direction without causing the slack of the magnetic tape 54 while the pinch roller 45 is being pressed against the capstan 23. It can be switched. The time to transfer from the above forward direction mode to the reverse direction mode via the still mode is also
It can be done instantly within 1 second.

As described above, in the conventional magnetic recording / reproducing apparatus that drives the capstan and the pair of reel bases with one motor,
It is possible to completely eliminate the loss of the reproduction signal that occurs when the magnetic tape 54 is switched from the normal reproduction mode to the reverse reproduction mode while the pinch roller 45 is pressed against the capstan 23. According to the present invention, by attaching the first motor 1 and the second reel base drive mechanism to the conventional apparatus, a reproduced image without a reproduction signal loss can be obtained in forward / reverse slow motion, forward / reverse frame feed, and forward / reverse feed mode. It is possible to easily add a special playback function that can do this. Further, since the forward / reverse feed is switched while the pinch roller 45 is pressed against the capstan 23, it is possible to quickly shift the mode between the respective reproduction modes.

(Effects of the Invention) As described above, according to the present invention, a capstan that moves a magnetic tape at a constant speed in cooperation with a pinch roller, a first motor that rotationally drives the capstan, and a tape cassette A supply-side reel stand and a take-up reel stand that engage with a pair of tape reels wound with the magnetic tape, and the supply-side reel stand and the take-up reel stand driven by the first motor. At least a first reel base driving mechanism for driving, a second reel base driving mechanism for driving only the supply side reel base, and a second motor for rotationally driving the second reel base driving mechanism are provided. With this configuration, the loss of the reproduction signal due to the slack of the magnetic tape is completely eliminated when the normal reproduction mode by the forward transfer of the magnetic tape is changed to the reverse reproduction mode by the reverse transfer. It is possible to eliminate the problem, and it is possible to obtain a playback image without signal loss during special playback of forward / reverse fast-forward, forward / reverse slow-motion, and forward / reverse frame-feed, and at the same time, an excellent effect of speeding up the forward / reverse playback mode transition. Can be obtained.

[Brief description of drawings]

1 to 4 are plan views showing respective operating states of an embodiment of the present invention, and FIGS. 5 and 6 are plan views showing respective operating states of a conventional magnetic recording / reproducing apparatus. 1 ... second motor, 2 ... second idler arm, 5
...... Second pulley, 7 ...... Second rolling gear, 8 ...... Second
Reel stand relay gear, 17 ... tape cassette, 18,19 ...
… Tape reel, 23 …… Capstan, 27 …… First idler arm, 28 …… First rolling gear, 31,32 …… Reel stand, 51 …… First motor, 54 …… Magnetic tape .

Claims (1)

(57) [Claims] 1. A capstan for moving a magnetic tape at a constant speed in cooperation with a pinch roller, a first motor for driving the capstan to rotate, and a pair of tapes around which a magnetic tape in a tape cassette is wound. A supply-side reel stand and a take-up reel stand that engage with the reel; and a first reel first drive mechanism that is driven by the first motor to drive the supply-side reel stand and the take-up reel stand. A magnetic recording / reproducing apparatus comprising: a second reel base drive mechanism that drives only the supply-side reel base; and a second motor that rotationally drives the second reel base drive mechanism.