JPS5894152A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To attain high reliability, by positioning the moving position of an operating plate switching the operating mode of a magnetic tape device with high accuracy, in moving to a plurality of positions. CONSTITUTION:A capstan motor 78 turns counterclockwise and turns a capstan 74 clockwise. A motor 50 starts turning counterclockwise. The rotation of the motor 50 is delivered to a cam 52 via a belt 44 and a gear 48, but even if the motor 50 starts turning, a sector gear 64 does not move immediately. When the rotary angle of a cam 52 exceeds 50 deg., since the 1st cam follower 62 inserted to one groove 54 of the cam 52 is shifted to the left, the gear 64 turns counterclockwise by taking a shaft 60 as a center. A gear 65 of a magnetic tape unloading means is turned, a guide post is moved and a magnetic tape is drawn out at the outside of a cassette.

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, magnetic tape devices have been developed by using a motor to rotate a cam without using a solenoid, and a sliding member that moves to multiple positions following the cam. A magnetic tape device has been developed in which the operating mode of the magnetic tape device can be switched. 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.

1 to 6, a supply reel stand 16 and a take-up reel stand 18, each of which is rotatably supported on a shaft 12.14 implanted on the upper surface of the substrate 1o, are used to carry a cassette 2o into a device as in the prior art. When attached to the specified location on the main unit, the cassette)
The supply reel hub 22 and the take-up reel hub 24 in the reel 20 are engaged with each other so that they can rotate together. ,
The magnetic tape 26 wound on the supply reel 22 is inserted into a pair of notches 28.3 provided at the front of the cassette 2o.
0 and is wound up on the winding hub 24. Two sets of guide posts 34, 36 and 38, 40 for pulling out and guiding the magnetic tape 32 are disposed within the pair of notches 28, 30, respectively. On the other hand, the shaft 42 implanted on the back side of the substrate 10 has
A gear 48 rotated by a motor 6o via a belt 44 and a pulley 46 is supported, and near the gear 48,
A cam 62 meshed with a gear portion 48 formed on the outer periphery is rotatably supported by a shaft 58 implanted on the back surface of the substrate 1o.

The cam 62 has three parts as shown in FIG.
It is a positive cam with two grooves 64 and 66 extending over 60 degrees on both sides, 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 Fig. 8. It's Nishide.

Note that in FIG. 8, a indicates a lift curve of the groove portion 64, and b indicates a lift curve of the groove portion 66.

The first cam follower is fitted in such a way that the first cam follower moves only within the rotation angle of 50'-'-3600 as shown by curve a in FIG. 8.

A shaft 6o is disposed on the back side of the substrate 1o, and a sector gear 64 having a first cam follower 62 that fits into one groove 64 of a cam 62 is rotatably supported on this shaft. The teeth 66 are attached to the guide posts 34, 3.
6, 38.

It meshes with a gear 65 (see FIG. 2) constituting a magnetic tape withdrawal means for moving the magnetic tape 4o from the inoperative position shown in FIG. 1 to the active position shown in FIG. 3, and vice versa. That is, when the cam 62 starts rotating counterclockwise from the position shown in FIG.
4 does not move at all, but from the rotation angle 6o0, the sector gear 64
begins to rotate counterclockwise in FIG. 2 about the axis 6o, thus rotating the gear 65 of the magnetic tape extraction means, and the guide posts 34, 36 and 38, 40 move in the direction of the arrow M in FIG. and move the magnetic tape 32 to cassette 2.
Pull out to the outside of 0. The rotation angle of the cam 62 is 36
00, the rotation of the sector gear 64 stops at the position shown in FIG. As shown in FIG. 2, the pulled-out magnetic tape 68 is connected to a drum To having a rotating head (not shown) inside and a fixed head 7 for recording/reproducing audio signals.
It becomes attached to 2.

On the other hand, when the rotation angle of the cam 52 is from 00 to 125 degrees, the lift amount of the groove 54 does not change as is clear from the curve 8 in FIG. 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.

A main rod 82 having a second cam follower 80 that fits into the other groove 66 of the cam 62 is attached to a guide shaft 84.
* Guided by guide grooves 88 and 90 formed in Be and the main rod 82, it can freely reciprocate linearly. The other groove portion 66 of the cam 62 also extends over 36o0, 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 begins to rotate counterclockwise from the position shown in FIG. The rod 82 is guided by the guide shaft 84.86 and the guide groove 88.90 and begins to move to the left in FIG. 2, and when the rotation angle reaches 426°, the main rod 82
is moved 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 60 is stopped.

A pinch roller lever 94 is rotatably supported on a shaft 92 installed on the upper surface of the substrate 1o.

A shaft 96 implanted at one end of the pinch roller lever 94
A pinch roller 98 is rotatably supported.

Pinch roller lever? -The other end of 94 and main rod 8
A tension spring 100 is hung between the two. The locking portion 102 provided on the pinch roller rail/C-94 and the tip of the adjustment screw 104 held by the main rod 82 are still in contact with and separating from each other. Therefore, when the cam 52 starts rotating counterclockwise in FIG. 2, the main rod does not move at all for the first 200 minutes, so the pinch roller lever 94 and the pinch roller 98 also stop at the positions shown in FIG. There is. When the rotation angle reaches 200, the main rod 8
2 moves to the left in FIG. 2, that is, to the right in FIG. 1, and the pinch roller C-94 begins to rotate counterclockwise in FIG. When the main rod 82 reaches the position shown in FIG. 4, the pinch roller 98 comes into contact with the capstan 74, causing a hiatus.

The counterclockwise rotation of the pinch roller lever 94 in FIG.
When the main rod 82 moves to the position shown in FIG. 4 by separating from the locking portion 102 and stretching the tension spring 10o, a predetermined pressing force of the pinch roller 98 against the capstan 74 is obtained, as shown in FIG. , pulled out magnetic tape 6
6 is moved to the right in FIG. 3 by the cooperation of capstan 74 and pinch roller 98, and is wound onto take-up reel 24 by known means.

Reference numeral 114 denotes an idler lever rotatably supported by a shaft 106 implanted on the back surface of the board 1Q, and this is connected to the pin 11 which engages and disengages from the protrusion 10B of the main rod 82.
0, and is biased to rotate counterclockwise in FIG. 2 by a tension spring 112. There is a support plate 124 on the shaft 115 installed at one end of the idler lever 114.
One end is rotatably supported, and its support plate 12
Near the other end of 4, a fast-winding pulley 118, which is rotationally driven by a capstan motor 78 via a capstan belt 76 and a fast-winding belt 116, and one of the two reel stands 16.1. A fast-winding idler 120 that selectively intervenes and rolls into contact is rotatably supported by a support shaft 122. The rotation angle of the cam 62 is 00 to 42β
In the 0 position, as shown in FIGS. 2 and 4, the rotation of the idler lever 114 in the counterclockwise direction in FIG.
The bottle 110 to be implanted in the protrusion 10 of the main rod 82
B, the fast-winding idler 120 is spaced apart from the reel stand 16.18 and the fast-winding pulley 118, and is regulated to the position shown in FIG.
A guide (not shown) is provided so that the distance from the take-up reel stand 18 is approximately the same as the distance from the take-up reel stand 18. Cam 62 is the second
Main rod 8 is rotated clockwise from the position shown in the figure.
2 begins to move to the right in Figure 2. When the cam 52 rotates to a rotation angle of −26°, the main rod 82 moves to the position shown in FIG.
As the idler lever 114 moves, the idler lever 114 rotates counterclockwise in FIG. 2 due to the biasing force of the tension spring 112.
Idler 120 moves downward in FIG. 1 and abuts quick pulley 118. At this time, the fast winding idler 120 is biased toward the left or right in FIG. and the fast winding pulley IJ-118, so that the rotational force of the fast winding pulley is transmitted to the reel stand.

As mentioned above, the clutch does not transmit the driving force of the motor 5o to the magnetic tape pulling means when the rotation angle of the cam is from 0° to -25°, but only to the main rod 82 that switches the operation of the device. Since the mechanism is configured, operation switching can be performed with a simple structure.

Next, the operation will be explained.

When the record/playback switch (not shown) is pressed from the stopped state shown in FIG. 1, the capstan motor 78 rotates counterclockwise in FIG. 2, and the capstan 74 rotates clockwise in FIG. direction.

Also, in FIG. 2, the motor 6o begins to rotate counterclockwise. The rotation of this motor 50 is controlled by the belt 44 and the gear 48.
However, as is clear from the curve a in FIG.
4 doesn't start moving right away. The rotation angle of the cam 62 is so
After passing O, the first cam follower 62 fitted in one groove 54 of the cam 52 moves to the left in FIG.
The guide posts 34, 36 and 38, 40 move in the direction of the arrow in FIG. 1 to move the magnetic tape 32 into the cassette 20. Pull it out to the outside. When the cam 620 rotation angle reaches 3600, the guide posts 34, 36 and 3
8.40 moves to the position shown in FIG. As is clear from the curve a in FIG. 8, when the rotation angle of the cam 52 is 3600 degrees or more, the sector gear does not move, and therefore the guide post) 3
4.36 and 38.40 are held in the position shown in FIG.

On the other hand, when the record/playback switch is pressed from the stopped state shown in FIG. 1, the motor 6o begins to rotate counterclockwise in FIG. 2 as described above. Although this rotation is transmitted to the cam 52, the curve shown in FIG. 8 does not come out. Therefore, pinch roller 98 remains in the position shown in FIG.

When the rotation angle of the cam 62 exceeds 200 degrees, the second cam follower 80 fitted into the other groove 56 of the cam 62 moves to the left in FIG. 86 and moves to the left in FIG. As a result, the pinch roller lever 94
begins to rotate counterclockwise in Figure 1, and the pinch roller 9
8 abuts against the capstan 74. And Naorim 5
2 rotates and the rotation angle reaches 425°, the main rod 82 moves to the position shown in FIG. 4, the rear recording/reproduction position contact is turned on, and the power supply to the motor 6o 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 4 moves the magnetic tape 68 at a constant speed to the right in FIG. , winding-up 24 winds it up by known means.

In this manner, the magnetic tape 68 runs along the drum 70 and the fixed head 72, and signals are recorded/reproduced.

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 60 is energized, causing the motor 60 to rotate counterclockwise in FIG. 4, reversing the operation previously described, and moving the guide posts 34, 36, 38, 40, . The pinch roller 98 returns to the position shown in FIG. At this time, the magnetic tape 68 that has been pulled out is stored in the cassette 2o by well-known means. Then, when a stop position contact, which will be described later, is turned on, the rotation of the motor 6o is stopped, and the motor 6o returns to the stopped state.

During the above operation, since the pin 11o implanted in the idler lever 114 is locked by the protrusion 108 of the main rod 82, the half-winding idler 120 is connected to the supply reel stand 16, take-up reel stand 18', and It is spaced apart from the quick winding pulley 118.

Next, pressing the fast forward switch (not shown) causes the capstan motor 8 to rotate counterclockwise in FIG. 2 and the fast winding boot IJ-118 to rotate clockwise in FIG. The motor 6o rotates counterclockwise in FIG. 2, the cam 62 rotates clockwise in FIG. 2, the main rod 82 moves rightward in FIG. 2, and the idler lever 114 rotates counterclockwise in FIG. rotate in the direction. When the cam 62 rotates to a rotation angle of −25°, the main rod 82 moves to the position shown in FIG.
The power supply to 0 is cut off. The fast-winding idler 120 comes into contact with the fast-winding boot 1)-11s, but in this case, since the fast-winding boot IJ-11a is rotating clockwise in FIG. It receives a biasing force in the direction by a well-known means, and comes into rolling contact with the fast winding pulley 118 and the take-up reel stand 18, as shown by solid lines in FIG. Since the take-up reel stand 18 is rotated clockwise in FIG. 6, the magnetic tape 26 wound around the supply reel hub 22 is wound onto the take-up reel hub to perform a fast forwarding operation. In this case, the first pinch roller 98 rotates to the position shown in FIG. When a stop switch (not shown) is pressed, the power to the capstan motor 78 is cut off, the capstan 4 stops rotating, and therefore the fast winding pulley 118 also stops rotating. At the same time, the motor 60 is energized and rotates clockwise in FIG. 6, the reverse operation described above, and the fast winding idler 120 is moved along a guide (not shown) to the neutral position shown in FIG. The main rod 82 and the pinch roller 98 also return to the positions shown in FIG. When the stop position contact (described later) turns on,
The motor 6o is de-energized and returns to the stopped mode.

During the above operations, guide posts) 34.36 and 38.
40 is stopped at the position shown in FIG. 1, and the main rod 82 is reciprocated between the stop position and the fast winding position without driving the magnetic tape pull-out means.

When a rewind switch (not shown) is pressed, the capstan motor 78 rotates counterclockwise in FIG. 1, causing the fast winding pulley 118 to also rotate counterclockwise.

The motor 6o rotates counterclockwise in FIG.
The door 82 moves to the position shown in FIG. 6 with the same movement as during fast forwarding, and the fast winding idler 120 moves to the fast winding boot IJ-118 and the supply reel stand 16 as shown by the dotted line in FIG.
The supply reel stand 16 is rotated counterclockwise in FIG. 6, the magnetic tape 26 is wound onto the supply reel 22, and a rewinding operation is performed.

When the stop switch (not shown) is pressed, the fast winding idler 118, main rod 82 and pinch roller 98 are moved to the positions shown in FIG. It returns to the stopped mode.

By the way, conventionally, as shown in FIG. 9, the stop position, recording/playback position, and fast winding position of the main rod 82 are detected by engaging a bottle 200 implanted in the main rod 82, Movable contact 202 that is integrally displaced
and on the fixed plate 204.

The common terminal 20 formed on the fixed plate 204 is moved by the movable contact 202 corresponding to the stop position, recording/playback position, and fast winding position of the main rod 82.
6 and the recording/reproducing position contact 2o8, which are in conductive state respectively.
, a stop position contact 210 , and a fast winding position contact 212 .

However, as can be seen from FIG. 8, position detection using the slide switch 214 is always turned ON (still OFF) at the slope of the cam curve, so the main rod 82 is located at the slope of the cam curve. There was a problem in that the stopping position of the main rod varied due to changes in load due to temperature changes, etc. Therefore, in the present invention, as illustrated in FIG.
The rotational phase of the cam 62 is directly detected by a rotary switch 216 that meshes with the outer peripheral gear portion of the cam 62. In FIG. 10, the pinion 2 rotates integrally with the shaft 218.
20 meshes with the outer peripheral gear portion of the force/muro 2, and rotates in synchronization with the rotation of the cam 62. The small gear 220 above
The rotation of the rotor 22 having a movable contact 226 is performed via a pinion 222 attached to a shaft 218 and an intermediate gear 224.
The signal is transmitted to the internal gear No. 8. With such a gear transmission system, the rotation of the cam 62 over 3,600 degrees is caused by the rotation of the rotor 228 by three rotations.
It is designed to be transmitted at a speed of 600 rpm or less.

Movable contact 2 attached to the rotor 228 of the case 230
A common contact 232 serving as a fixed contact, a stop position contact 234, a recording/reproducing position contact 236, and a fast winding position contact 238 are arranged on the sliding surface of 26 as shown in FIG. When the rotor 228 rotates and the movable contact 226 comes over the respective contacts, 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 520 can be constructed so that the common contact 232 and each position contact are electrically connected at the flat part of the cam curve. The stopping position of the main rod 82 can always be positioned with high precision regardless of load conditions or environmental conditions.

As described above, the magnetic tape device of the present invention can highly accurately determine the movement position of the operating plate that changes the operating mode of the magnetic tape device by moving to a plurality of positions, thereby achieving unprecedented high reliability. is possible.

[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. 6 and 6 are a top view and a back view of the main parts in the half-roll mode of the same embodiment, and FIGS. 7(A) and 7(B) are top views of the cam in the same embodiment. 8 is a diagram showing the lift curve of the cam along with the contact position of the switch, and FIG. 9 (A). (B) is an explanatory diagram of the main parts of the slide switch, Figure 1o (
(B) is an explanatory diagram of the main parts of a rotary switch. 16... Supply reel stand, 18... Take-up reel stand, 32.69... Magnetic tape, 34
, 36 , 38 . 40...Guide post, 6o...Motor, 52...Follower, 64...Group/sector gear, 6
6...Mark/Gear, 70...Drum, 72...
... fixed head, 74... river capstan, 78.
...Capstan motor, 8o...2nd
Cam follower, 82...Main rod, 98
... Pinch roller - 1118 ... Fast winding pulley, 120 River... Fast winding idler, 216
...Rotary switch.

Claims (1)

[Claims] A cam that is rotationally driven by a motor, and a cam that follows the cam and moves to multiple positions such as recording/reproducing total amount, stop position, and fast winding position, and switches the operating mode of the device to a mode corresponding to each position. It is characterized by comprising an actuating plate and a rotary switch that rotates in synchronization with the cam and can obtain signals corresponding to the recording/reproducing position, stop position, and fast winding position of the actuating plate. magnetic tape device.