JPS6238779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects a moving member that moves to a plurality of positions in response to various operation modes such as stop, playback, and fast forwarding, and detects the position of the moving member and detects whether the moving member is in any operation mode. The present invention relates to a magnetic tape device such as a video tape recorder having a detecting means for detecting whether or not the magnetic tape is detected.

In recent years, in order to reduce the cost and weight of magnetic tape devices, a motor is used to rotate a cam without using a solenoid, and a sliding member that follows the cam and moves to multiple positions is used to generate magnetic tape. Magnetic tape devices have been developed that switch the operating mode of the tape device. The displacement of the sliding member is detected, for example, by detecting the conduction state between a movable terminal and a fixed terminal that are integrally displaced with the sliding member, thereby detecting the mode of operation. However, as will be described later, this method has a problem in that the moving member cannot be stopped with good positional accuracy.

The present invention provides a magnetic tape device that solves the above-mentioned problems.

Hereinafter, the present invention will be explained based on illustrated embodiments. In FIGS. 1 to 6, a supply reel stand 16 and a take-up reel stand 18 are rotatably supported on shafts 12 and 14 implanted on the upper surface of a substrate 10, respectively.
As in the prior art, when the cassette 20 is installed at a predetermined location on the main body of the apparatus, it engages with the supply reel hub 22 and the take-up reel hub 24 inside the cassette 20 and can rotate together. The magnetic tape 26 wound on the supply reel hub 22 is inserted into a pair of notches 28 provided at the front of the cassette 20.
30 and is wound onto the take-up reel hub 24. The pair of notches 28, 3
Two sets of guide posts 34, 36 and 38, 40 are provided in the inside of the magnetic tape 32 for pulling out and guiding the magnetic tape 32, respectively. On the other hand, substrate 1
A gear 48 rotated by a motor 50 via a belt 44 and a pulley 46 is supported on a shaft 42 installed on the back side of the
A cam 5 meshed with a gear portion 48 formed on the outer periphery
2 is rotatably supported on a shaft 58 implanted on the back surface of the substrate 10.

The cam 52 is as shown in FIGS. 7A and 7B.
It is a positive cam with two grooves 54 and 56 on both sides extending over 360 degrees, and its lift curve is such that the lift amount changes within a certain rotation angle range, as shown by curves a and b in Figure 8. It is set as. Note that in FIG. 8, a indicates a lift curve of the groove portion 54, and b indicates a lift curve of the groove portion 56.

A first cam follower, which will be described later, is fitted into one groove 54 of the cam 52, and the first cam follower moves only when the rotation angle of the cam 52 is between 50° and 360°, as shown by curve a in FIG. It is designed to do so. A shaft 60 is disposed on the back side of the substrate 10 , and a sector gear 64 having a first cam follower 62 that fits into one groove 54 of the cam 52 is rotatably supported on the shaft 60 . The teeth 66 are attached to the guide posts 34, 36, 38, 4.
0 from the non-operating position shown in FIG. 1 to the operating position shown in FIG. 3, or vice versa.
(see figure). That is, when the cam 52 starts rotating counterclockwise from the position shown in FIG.
For the first 50°, the sector gear 64 does not move at all,
From a rotation angle of 50 degrees, the sector gear 64 begins to rotate counterclockwise in FIG. 40 moves in the direction of arrow A in FIG. 1 and pulls the magnetic tape 32 out of the cassette 20. When the rotation angle of the cam 52 reaches 360 degrees, the sector gear 64 stops rotating at the position shown in FIG. As shown in FIG. 2, the pulled-out magnetic tape 68 comes into contact with a drum 70 having an internal rotating head (not shown) and a fixed head 72 for recording/reproducing audio signals.

On the other hand, when the rotation angle of the cam 52 is from 0° to -25°, the lift amount of the groove 54 does not change as is clear from the curve a in FIG. 8, and therefore the sector gear 64 also does not move. , guide posts 34, 36 and 38, 40 are stopped at the positions shown in FIG.

A capstan 74 rotatably disposed on the substrate 10 is rotated via a capstan belt 76 by a capstan motor 78 capable of forward and reverse rotation.

The main rod 82 has a second cam follower 80 that fits into the other groove 56 of the cam 52.
It is guided by guide shafts 84, 86 and guide grooves 88, 90 formed in the main rod 82, so that it can freely reciprocate linearly. The other groove portion 56 of the cam 52 also extends over 360° and is a positive cam. As shown by b in FIG. 8, the lift curve is such that the second cam follower 80 moves only in the section where the lift amount changes. That is, when the cam 52 starts to rotate counterclockwise from the position shown in FIG. 2, the main rod 82 does not move at all for the first 20 degrees, as is clear from the curve b in FIG. 82 is guided by the guide shafts 84, 86 and guide grooves 88, 90 and begins to move to the left in FIG. 2, and the rotation angle increases.
When the angle reaches 425 degrees, the main rod 82 moves to the position shown in FIG. 3, and a recording/reproducing position contact, which will be described later, is turned on and power supply to the motor 50 is stopped.

A pinch roller lever 94 is rotatably supported on a shaft 92 installed on the upper surface of the substrate 10.
A pinch roller 98 is rotatably supported on a shaft 96 implanted at one end of the pinch roller lever 94. A tension spring 100 is hung between the other end of the pinch roller lever 94 and the main rod 82. Furthermore, the locking portion 102 provided on the pinch roller lever 94 and the tip of the adjustment screw 104 held on the main rod 82 are arranged to be in a contact/separation relationship. Therefore, when the cam 52 starts rotating counterclockwise in FIG. 2, the main rod does not move at all for the first 20 degrees, so the pinch roller lever 94 and the pinch roller 98 also stop at the position shown in FIG. There is. When the rotation angle reaches 20 degrees, the main rod 82 moves to the left in FIG. 2, that is, to the right in FIG.
It begins to rotate counterclockwise as shown in the figure. Main rod 8
2 reaches the position shown in FIG. 4, the pinch roller 98 comes into contact with the capstan 74, and the anticlockwise rotation of the pinch roller lever 94 in FIG. When the main rod 82 moves to the position shown in FIG. 4 by separating the locking portion 102 of the pinch roller 94 and stretching the tension spring 100, a predetermined pressing force of the pinch roller 98 against the capstan 74 is obtained.

In FIG. 3, the pulled-out magnetic tape 66 is transported to the right in FIG. 3 by the cooperation of the capstan 74 and the pinch roller 98, and is wound onto the take-up reel hub 24 by known means. It is set as.

114 is a shaft 106 implanted on the back surface of the substrate 10
The idler lever is rotatably supported on the main rod 82, and has a pin 110 that engages and disengages with the protrusion 108 of the main rod 82, and is rotated counterclockwise in FIG. 2 by a tension spring 112. Forced. Further, one end of a support plate 124 is rotatably supported on a shaft 115 installed at one end of the idler lever 114, and the support plate 124
Near the other end of 4, there is a fast-winding pulley 1 which is rotationally driven by a capstan motor 78 via a capstan belt 76 and a fast-winding belt 116.
A fast-winding idler 120 that selectively intervenes and rolls between the reel stand 18 and one of the two reel stands 16, 18 is rotatably supported by a support shaft 122. When the rotation angle of the cam 52 is between 0° and 425°, as shown in FIGS. 2 and 4, the counterclockwise rotation in FIG. 2 due to the tensile force of the tension spring 112 of the idler lever 114 is as follows. The pin 110 installed in the idler lever 114 is the main rod 8.
2, the fast-winding idler 120 is regulated to the position shown in FIG.
are reel stands 16, 18 and quick-winding pulley 118
A guide (not shown) is provided so that the supply reel table 16 and the take-up reel table 18 are spaced apart from each other so that the distances from the supply reel table 16 and the take-up reel table 18 are approximately equal. As cam 52 rotates clockwise from the position shown in FIG. 2, main rod 82 begins to move to the right in FIG. cam 5
2 rotates to a rotation angle of −25°, the main rod 82 moves to the position shown in FIG. Rotate counterclockwise as shown in Figure 2, and idler 1
20 moves downward in FIG. 1 and comes into contact with the quick-winding pulley 118. At this time, the fast winding idler 120 is connected to the fast winding pulley 118 by a well-known means.
Depending on the direction of rotation of
18 to transmit the rotational force of the quick-winding pulley to the reel stand.

As mentioned above, the clutch mechanism does not transmit the driving force of the motor 50 to the magnetic tape pull-out means when the rotation angle of the cam is between 0° and -25°, but only to the main rod 82 that switches the operation of the device. , so that operation switching can be performed with a simple structure.

Next, the operation will be explained.

When the recording/playback switch (not shown) is pressed from the stopped state shown in FIG. 1, the capstan motor 78 rotates counterclockwise in FIG. Rotate in the direction.
Also, in FIG. 2, the motor 50 begins to rotate counterclockwise. The rotation of the motor 50 is transmitted to the cam 52 via the belt 44 and the gear 48, but as is clear from the curve a in FIG. 8, the sector gear 64 does not start moving immediately even when the motor 50 starts rotating. When the rotation angle of the cam 52 exceeds 50°, the cam 5
Since the first cam follower 62, which is fitted in one of the grooves 54 of 2, moves to the left in FIG.
The sector gear 64 rotates counterclockwise in FIG. 2 about the shaft 60 and rotates the gear 65 of the magnetic tape pulling means, so that the guide posts 34, 36 and 38, 40 move in the direction of arrow A in FIG. , and pull out the magnetic tape 32 to the outside of the cassette 20. When the rotation angle of the cam 52 reaches 360°, the guide post 3
4, 36 and 38, 40 are moved to the positions shown in FIG. As is clear from curve a in FIG. 8, the sector gear does not move when the rotation angle of the cam 52 exceeds 360 degrees, so the guide posts 34, 36 and 38, 40 are held at the positions shown in FIG. Ru.

On the other hand, when the record/playback switch is pressed from the stopped state shown in FIG. 1, the motor 50 begins to rotate counterclockwise in FIG. 2 as described above. This rotation is transmitted to the cam 52, but the curve b in FIG.
As is clear from this, the main rod 82 does not start moving immediately. Pinch roller 98 therefore remains in the position shown in FIG. When the rotation angle of the cam 52 exceeds 20 degrees, the cam 52
As the second cam follower 80 fitted into the other groove 56 moves to the left in FIG. 2, the main rod 82 is guided by the guide shafts 84 and 86 and moves to the left in FIG. As a result, the pinch roller lever 94 begins to rotate counterclockwise in FIG.
comes into contact with. Then, when the cam 52 continues to rotate and the rotation angle reaches 425 degrees, the main rod 82 moves to the fourth position.
When the motor 50 moves to the position shown in the figure, a recording/reproducing position contact, which will be described later, is turned on, and power supply to the motor 50 is stopped. As shown in FIG. 3, the pinch roller 98 is pressed against the capstan 74 by the elastic force of a tension spring 100, and in cooperation with the capstan 74 moves the magnetic tape 68 at a constant speed to the right in FIG. 24 winds it up by known means.

In this way, the magnetic tape 68 runs along the drum 70 and the fixed head 72, and signals are recorded/recorded.
will be played.

When a stop switch (not shown) is pressed, power to the capstan motor 78 is cut off and the capstan 74 is stopped. At the same time, the motor 50 is energized, and the motor 50 rotates counterclockwise in FIG.
8 returns to the position shown in FIG. At this time, the magnetic tape 68 that has been pulled out is stored in the cassette 20 by well-known means. Then, when a stop position contact, which will be described later, is turned on, the rotation of the motor 50 is stopped, and the motor 50 returns to the stopped state.

During the above operation, the pin 110 implanted in the idler lever 114 is locked by the protrusion 108 of the main rod 82, so that the fast winding idler 120 can move the supply reel stand 16, the take-up reel stand 18, and the fast winding idler 120. It is spaced apart from the winding pulley 118.

Next, press the fast forward switch (not shown).
Capstan motor 78 rotates counterclockwise in FIG. 2, and quick pulley 118 rotates clockwise in FIG. Motor 50 rotates counterclockwise in FIG. 2, cam 52 rotates clockwise in FIG. 2, main rod 82 moves rightward in FIG. 2, and idler lever 114 rotates counterclockwise in FIG. Rotate to. When the cam 52 rotates to a rotation angle of -25 DEG, the main rod 82 moves to the position shown in FIG. 6, a quick winding position contact to be described later is turned on, and the power supply to the motor 50 is cut off. The fast-winding idler 120 abuts the fast-winding pulley 118, but in this case, since the fast-winding pulley 118 is rotating clockwise in FIG. 1, the fast-winding idler 120 is rotated to the right in FIG. 5, the winding pulley 118 and the take-up reel stand 18 come into contact with each other as shown by solid lines in FIG. Since the take-up reel stand 18 is rotated clockwise in FIG. 5, the magnetic tape 26 wound around the supply reel hub 22 is wound onto the take-up reel hub, thereby performing a fast forwarding operation. In this case, the pinch roller 98 rotates to the position shown in FIG. When a stop switch (not shown) is pressed, power to the capstan motor 78 is cut off, the capstan 74 stops rotating, and therefore the fast winding pulley 118 also stops rotating. At the same time, the motor 50 is energized and rotates clockwise as shown in FIG.
20 returns along a guide (not shown) to the neutral position shown in FIG. 1, and the main rod 82 and pinch roller 98 also return to the positions shown in FIG.
When the stop position contact, which will be described later, turns on, the motor 5
0 is de-energized and returns to the stopped state.

During the above operation, the guide posts 34, 36 and 38, 40 are stopped at the positions shown in FIG. 1, and the main rod 82 is moved between the stop position and the fast winding position without driving the magnetic tape pull-out means. I am moving it back and forth.

Pressing the rewind switch (not shown) causes the capstan motor 78 to rotate counterclockwise in FIG. 1, causing the fast wind pulley 118 to also rotate counterclockwise. The motor 50 rotates counterclockwise in FIG. 2, and the main rod 82 moves to the position shown in FIG.
0 is in rolling contact with the fast winding pulley 118 and the supply reel stand 16, as shown by the dotted line in FIG. 5, and rotates the supply reel stand 16 counterclockwise in FIG.
Winding the magnetic tape 26 onto the supply reel hub 22,
Perform rewinding operation.

When the stop switch (not shown) is pressed, the fast wind idler 118, main rod 82 and pinch roller 98 return to the positions shown in FIG. Then, it becomes stopped.

By the way, the above-mentioned stop position, recording/playback position, and fast winding position of the main rod 82 are conventionally detected by engaging with a pin 200 implanted in the main rod 82 and integrated with the main rod 82, as shown in FIG. As the movable contact 202 moves on the movable contact 202 and the fixed plate 204 and corresponds to the stop position, recording/playback position, and fast winding position of the main rod 82, the fixed plate 204 is moved.
This is done by a slide type switch 214 comprising a recording/reproducing position contact 208, a stop position contact 210, and a fast winding position contact 212, which are electrically connected to the common terminal 206 formed above.

However, as can be seen from Fig. 8, each switch is always turned ON (or OFF) at the slope of the cam curve b when detecting the position using the slide switch 214.
Therefore, there was a problem that the main rod 82 stopped at the slope of the cam curve b, and the stopping position of the main rod varied due to variations in load due to temperature changes and the like.

Therefore, in the present invention, as illustrated in FIG. 10, the rotational phase of the cam 52 is directly detected by a rotary switch 216 that meshes with the outer gear portion of the cam 52. In FIG. 10, shaft 218
A small gear 220 that rotates integrally with the cam 52 is meshed with the outer peripheral gear portion of the cam 52, and rotates in synchronization with the rotation of the cam 52. The rotation of the small gear 220 is transmitted via a pinion 222 attached to the shaft 218 and an intermediate gear 224 to an internal gear of a rotor 228 having a movable contact 226. With such a gear transmission system, the rotation of the cam 52 of more than 360 degrees is transmitted to the rotor 228 at a reduced speed of less than 360 degrees.

The sliding surface of the movable contact 226 attached to the rotor 228 of the case 230 has a common contact 232 serving as a fixed contact as shown in FIG. 10A, a stop position contact 234, a recording/playback position contact 236, and a fast winding A position contact 238 is provided and the rotor 228
When the movable contact 226 is rotated and the movable contact 226 is placed on each contact, the common contact 232 and each position contact become electrically connected, and the operating mode of the magnetic tape device can be detected.

As can be seen from FIG. 8, the relationship between the position of each position contact and the rotational phase of the cam 52 can be configured such that the common contact 232 and each position contact are electrically connected at the flat part of the cam curve b. Therefore, the stopping position of the main rod 82 can always be determined with high precision regardless of load conditions or environmental conditions.

As described above, the magnetic tape device of the present invention includes a cam that is rotatably driven by a motor, and moves to multiple positions such as a recording/playback position, a stop position, and a fast-winding position following this cam, and operates the device. an actuating plate for switching the mode to a mode corresponding to each position; and an actuating plate that rotates in synchronization with the cam to obtain signals corresponding to multiple positions of the actuating plate, such as a recording/playback position, a stop position, and a fast winding position. and a rotary switch capable of operating the rotary switch, and each of the recording/playback position, stop position, and fast-winding position of the actuating plate corresponds to the recording/playback position, stop position, and fast-winding position of the rotary switch. Since each of the plurality of fixed contacts is associated with an angular range where the amount of movement is zero on the change curve of the amount of movement of the actuating plate with respect to the rotation angle of the cam, the rotary switch is in the recording/playback mode. , stop mode, and fast winding mode, the multiple positions of the actuating plate can be detected with high precision, and the multiple moving positions of the actuating plate can be determined with high precision, achieving unprecedented high reliability. It is possible to obtain it. Since the rotary switch is connected to the cam via a rotation reduction mechanism, even if the rotation angle of the cam is set to 360 degrees or more, the rotary switch can be set within 360 degrees, and the Signals from the rotary switch can be effectively used, and the movement stroke of the actuating plate operated by the cam can be increased, increasing the degree of freedom in design.

[Brief explanation of the drawing]

1 and 2 are a top view and a back view of essential parts in a stopped mode of an embodiment of the present invention, and FIGS. 3 and 4 are top views of essential parts in a recording/reproducing mode of the same embodiment. 5 and 6 are a top view and a back view of the main part in the fast winding mode of the same embodiment, FIGS. 7A and B are a top view and a back view of the cam in the same embodiment, Figure 8 shows the lift curve of the cam along with the contact position of the switch, Figures 9A and B are explanatory diagrams of the main parts of the slide switch, and Figure 1
Figures A and B are explanatory views of the main parts of the rotary switch. 16... Supply reel stand, 18... Take-up reel stand, 32, 69... Magnetic tape, 34, 36, 3
8, 40...Guide post, 50...Motor, 5
2...Cam, 54, 56...Groove, 65...First
Cam follower, 64... sector gear, 65... gear, 70... drum, 72... fixed head, 74
... Capstan, 78 ... Capstan motor, 80 ... Second cam follower, 82 ... Main rod, 98 ... Pinch roller, 118 ...
Quick-winding pulley, 120... Quick-winding idler,
216...Rotary switch.

Claims (1)

[Claims] 1. A cam that is rotationally driven by a motor and moves to multiple positions such as recording/playback position, stop position, and fast-winding position following this cam, and switches the operating mode of the device to a mode corresponding to each position. a rotary switch that rotates in synchronization with the cam and can obtain signals corresponding to a plurality of positions of the operating plate, including the recording/playback position, stop position, and fast winding position; and a rotation deceleration mechanism that decelerates and transmits the rotation of the cam to a rotor carrying a movable contact of the type switch, and the amount of movement on a change curve of the amount of movement of the actuating plate with respect to the rotation angle of the cam is zero. The recording/reproducing position, stop position, and fast winding position of the actuating plate, and the recording/reproducing position of the rotary switch are shown in a certain angular range.
A magnetic tape device characterized in that a plurality of fixed contacts corresponding to a playback position, a stop position, and a fast-winding position are associated with each other.