JPH0328742B2 - - 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, a method for switching the operating mode of a magnetic tape device has been developed as a low-cost, lightweight device that uses a motor to rotate a cam without using a solenoid, and a moving member that follows the cam and moves to multiple positions. (Japanese Unexamined Patent Publication No. 114154/1983).
Then, the displacement of the moving member is determined, for example, by
As shown in Publication No. 140540, the type of operation mode is detected by detecting the conduction state between a movable terminal that is integrally displaced with the movable member and a fixed terminal corresponding to each operation mode. . However, as pointed out in Japanese Unexamined Patent Publication No. 58-94152, this method directly detects the movement of a moving member that moves along the slope of the cam, so the moving member stops on the slope while it is moving. As a result, there was a problem in that the stopping position varied greatly due to changes in load due to temperature changes, changes over time, and the like. Furthermore, the cam has to increase its operating modes in response to the recent multifunctionality of magnetic tape devices, so it is often necessary to increase the rotation angle or increase the radius. However, increasing the size of the switch in accordance with this trend will affect the overall size of the device, so there has been a strong desire for measures to keep the size of the device as small as possible.

The present invention aims to solve the above problems and provide a magnetic tape device that can satisfy the above-mentioned needs.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments. 1 and 3 show top views of this embodiment. In the figure, a take-up reel stand 10 and a supply reel stand 12, which are rotatably loosely fitted to shafts 4 and 6 installed on the upper surface of a substrate 2, are arranged so that when a cassette 20 is installed at a predetermined location on the main body of the apparatus, the cassette It engages with the take-up reel hub 14 and the supply reel hub 16 in the reel 20, respectively, and can rotate integrally by claws 8 provided on both the reel stands 10 and 12. FIG. 2 shows a sectional view of the reel stand drive system, and the take-up reel stand 10 and the supply reel stand 12 have reel gears 30 and 40, respectively, and the reel gears 30 and 40 are planted on the substrate 2. It meshes with a take-up reel idler gear unit 52 and a supply reel idler gear unit 62, which are rotatably fitted loosely on the shafts 50 and 60, respectively, and is driven to rotate. The take-up reel idler gear unit 52
And the supply reel idler gear unit 62, as shown in FIG. 30 and 40, and a supply reel idler gear 64b.

On the other hand, the capstan 72, which is rotatably supported by a bearing member 70 fixed to the substrate 2, has a rotating roller part 74 in a part thereof, and the main body is pressed by applying a predetermined pressing force to the rotating roller part 74. idler 76
The rotation is transmitted to. The main idler 76 has a belt 84 stretched between a pulley part 78 that is integrally constructed and a relay roller 82 that is rotatably loosely fitted to a shaft 80 that is set on the base plate 2. 82. A rotating arm 88 having a rotatable idler gear 86 supported at one end is loosely fitted to the shaft 80, and a multi-pole magnet 90 is integrally attached to the shaft 80 so as to be substantially concentric with the shaft 80. It is placed. Furthermore, a magnetic material 92 having a magnetic hysteresis characteristic is fixed to the inner circumference of the relay roller 82 so as to face the magnet 90 with a predetermined clearance, and generates a predetermined attractive force between the relay roller 82 and the magnet 90. death,
A rotational force in the same direction as the rotational direction of the relay roller 82 is applied to the rotating arm 88. Further, the idler gear 86 is a gear portion 9 provided on the relay roller 82 at all times.
4, and is configured to mesh with either the take-up reel idler gear 54a or the supply reel idler gear 64a by rotation of the relay roller 82 depending on the operation mode of the device, and the capstan 72 The rotation is selectively transmitted to the take-up reel stand 10 or the supply reel stand 12 depending on the direction of rotation. A pinch roller lever 22 is rotatably fitted loosely into a shaft 18 that is set on the base plate 2.
A pinch roller 19 is attached to the shaft 24 installed at one end.
2 is rotatably supported. A crimp lever 32 having an elongated hole 28 is loosely fitted onto a shaft 26 that is rotatable and slidable in the longitudinal direction, and a pin 34 that is installed at one end of the lever 32 is rotatable. A connecting arm 36 is loosely fitted to the pin 38, and the other end of the connecting arm 36 is rotatably fitted to a pin 38 set up on the other end of the pinch roller lever 22. A spring hook 42 is formed at the other end of the crimp lever 32, and a tension spring 44 is stretched between the shaft 26 and the spring hook 42, and the crimp lever 32 is moved upward in FIG. energize the elongated hole 28
The end of the shaft 26 is in contact with the shaft 26. That is, the pinch roller lever 22, the connecting arm 36, and the pressure lever 32 constitute a so-called toggle mechanism. Further, at the other end of the crimp lever 32, a pin 46 is configured to pass through a hole (not shown) provided in the substrate 2, extend toward the rear surface of the device, and come into contact with a bent portion 21 provided in a main rod 48, which will be described later. ing. Therefore, when the main rod 48, which will be described later in FIG. The pinch roller 192 rotates until it comes into contact with the capstan 72. Pinch roller lever 22
is not rotated after that, but the crimping lever 32 continues to rotate clockwise to release the tension spring 4.
4, the pressure lever 32 is guided by the elongated hole 28 and moves downward in FIG.
2 will be crimped.

In the reproduction mode, as shown in FIG. 3, the magnetic tape 180 wound on the supply reel hub 16 is moved to the tape drawer member 18 with guide posts 23, 25 and 27, 29 set up from the front of the cassette 20.
2 and 183 are guided by guide grooves 31 and 33, respectively, and moved to fixed members 184 and 185 to be pulled out, and a rotating magnetic head 186 and a fixed head 188 for recording/reproducing audio signals are
and attached to a tape guide 190 fixed to the substrate 2. Furthermore, since the capstan 72 is rotating clockwise in FIG. 3, the main idler 76 is rotating counterclockwise in FIG. 3, and the belt 84 and relay roller 82 are also rotating counterclockwise in FIG. 3. Therefore, the rotating arm 88 is given a rotational force in the counterclockwise direction in FIG. 3 about the shaft 80, and the idler gear 86, which is rotating clockwise in FIG. 3, meshes with the take-up reel idler gear 54a. Take-up reel stand 1
0 is rotated clockwise via the clutch means described above, and the pinch roller 192 and the capstan 7
2, the magnetic tape 180 fed at a constant speed is wound around the take-up reel hub 14 without slack.

On the other hand, a driving gear 160 driven by a motor (not shown) is provided on the back side of the substrate 2 shown in FIG.
is disposed, has a gear on its outer periphery, and meshes with a sub-cam 142 that is rotatably loosely fitted to a shaft 156 set on the base plate 2. Further, the sub-cam 142 is rotatably loosely fitted onto a shaft 164 set on the base plate 2, and has a gear on its outer periphery having the same number of teeth as the outer peripheral gear of the sub-cam 142, so that it rotates in synchronization with the same angle as the sub-cam 142. The main cam 162 has a groove 1 extending over 360°.
As shown in FIG. 9, the lift curve is such that a cam follower 165 (described later) moves only in a section where the lift amount changes. Further, the rotating shaft 4 of the take-up reel stand 10 extending from the front surface to the back surface of the board 2, the rotating shaft 50 of the take-up reel idler gear unit 52, the guide shaft 132 planted on the back surface of the board 2, and the main cam 162. The main cam 162 is attached to the rotation shaft 164.
A main rod 48 having a cam follower 165 that engages with a groove 166 is loosely fitted along guide grooves 35, 37, 39, 41 provided in the main rod 48 so as to be able to move back and forth. Furthermore, main rod 48
The bending portion 21 is provided on the crimp lever 3.
The pin 46 provided at the other end of the pin 2 contacts the pin 46 provided at the other end of the pin 46.

Further, the sub-cam 142 is also a positive cam having a groove 144, and its lift curve is such that the groove 144 is formed only in the section where the lift amount changes as shown in FIG.
The sub-rod 13, which has a cam follower 146 that engages with the main rod 48 and is partially indicated by a dashed line, is configured to reciprocate in the same manner as the main rod 48.

Further, as shown in FIG. 4 and FIG.
Detection switch 4 capable of detecting a predetermined rotation angle of 42
3 is attached with screws. The detection switch 4
The structure of No. 3 will be explained with reference to FIGS. 5 to 9. 45
is a rotating gear that meshes with the outer gear of the sub-cam 142, but it has fewer teeth than the outer gear and therefore has a smaller diameter than the sub-cam 142. It is rotatably supported by a case 47.
Further, a pinion 55 is integrally formed with the shaft 49. Reference numeral 51 denotes a fixing member that is held and fixed to the case 47. On one side of the fixing member 51, six first fixed contacts 65a, 65 are provided on the outer periphery as shown in FIG.
b, 65c, 65d, 65e, 65f, and a second fixed contact 67 is arranged on the inner periphery.

Reference numeral 53 denotes a movable contact portion which is rotatably loosely fitted onto the shaft 49 and has an internal gear 57 on its inner periphery. A transmission gear 61 rotatably loosely fitted into a protrusion 59 provided on the case 47 meshes with the pinion 55 and the internal gear 57, and transmits the rotation of the pinion 55 to the movable contact portion 53 at a reduced speed. Further, the brush 63 is connected to the first fixed contacts 65a, 65b, 65c, 65d, 65 as shown by the dashed line in FIG.
e, 65f and the second fixed contact 67 so that the movable contact part 53 can slide by rotating. The brush 63 is connected to the first fixed contacts 65a, 65b, 65
c, 65d, 65e, 65f, the brush 63 and the first fixed contacts 65a, 65
b, 65c, 65d, 65e, and 65f and between the brush 63 and the second fixed contact 67 are electrically conductive, and as a result, the fixed terminals 69a and 69b are electrically conductive. The rotation angles of the sub cam 142 and the main cam 162 are detected by detecting this electrically conductive state.

In FIG. 9, the lift curve of the main cam 162 or the sub cam 142 shows angular positions at -85°, -35°, where the lift amount shows no change.
0°, 205°, and 300° are angles corresponding to each operating mode of the device. Here, it is not the purpose of the present invention to explain everything about each operation mode, but for example, as described later, a rotation angle of 0° corresponds to a stopping mode, and a rotation angle of 205° corresponds to a reproduction mode.
Then, the main cam 162 and the sub cam 142 rotate at the aforementioned angular positions of -85°, -35°, 0°,
When the brush 63 rotates by 205 degrees, 250 degrees, and 300 degrees, the first fixed contacts 65a, 65b, 65c, and 65 are located at the sliding positions of the brush 63 that slides and rotates accordingly.
d, 65e, and 65f are arranged. However, in this embodiment, the first fixed contacts 65a, 65
Since independent terminals are not provided for b, 65c, 65d, 65e, and 65f, they are connected to a common fixed terminal 69a as shown in FIG.
No matter which of the first fixed contacts 65 the brush 63 comes into contact with, a similar state of electrical continuity is only obtained between the fixed terminals 69a and 69b. Therefore, for example, as shown in FIG. 9, the first
Main cam 162 based on fixed contact 65c,
When the sub cam 142 is rotated clockwise and counterclockwise in FIG. 4, that is, when it is rotated in the forward direction in FIG. 9, the fixed terminals 69a and 69 are
If electrical continuity is obtained between terminals b, it is determined that the rotation angle of 205° has been achieved, and the second fixed terminal 69
If there is electrical continuity between a and 69b, the rotation angle
Fixed terminal 69 that determines that it has rotated by 250°
Needless to say, an electric circuit means (not shown) is required to count the number of times that electrical conduction occurs between a and 69b.

In addition, as shown in FIG. 9, the main cam 162,
The sub cam 142 rotates over 360 degrees from a rotation angle of -85 degrees to 300 degrees, and the number of teeth of the rotating gear 45 that meshes with the sub cam 142 is smaller than the number of teeth of the outer peripheral gear of the sub cam 142.
The amount of rotation of the movable contact portion 53 of the detection switch 43 is suppressed to less than 360°, and as shown in FIG. ,6
5e and 65f are arranged around the outer periphery of the fixed member 51 within a range of 360 degrees or less, and connections to the fixed terminals 69a and 69b are also made with sufficient space. When transmitting rotation from the rotary gear 45 to the movable contact portion 53, the pinion 55, the transmission gear 61, and the internal gear 5
This is realized by configuring a gear train consisting of 7 gears.

Although detailed explanation will be omitted since this can be realized by well-known means, the tape pull-out members 182 and 183 are configured to move in accordance with the rotation of the main cam 162, as shown in FIG. The tape pull-out members 182, 183 are moved in a rotation angle range from 40° to 180° clockwise from the stopped state shown in FIG. 4.

Next, the operation of an embodiment of the present invention will be explained.

When the playback button (not shown) is pressed from the stop state shown in FIGS. 1 and 4, the drive gear 160 driven by a motor (not shown) starts rotating clockwise in FIG. The sub cam 142 and the main cam 162 are rotated counterclockwise and clockwise, respectively, in FIG. When the main cam 162 rotates to a rotation angle of 40 degrees, the tape pulling members 182, 18
3 begins to move, and the magnetic tape 180 begins to be pulled out from the cassette 20. At the same time, the main rod 48 follows the groove 166 and begins to move rightward in FIG. 4, and the pinch roller lever 22 begins to rotate. Subsequently, when the cam 162 rotates to a rotation angle of 180 degrees, the movement of the tape pull-out members 182 and 183 is completed, resulting in the state shown in FIG. 3. At this time, as shown in FIG. 9, the main rod 48 has moved approximately 4 mm to the right in FIG. 4, and the pinch roller 192 begins to come into contact with the capstan 72. Furthermore, cam 162
As the main rod 48 continues to rotate up to a rotation angle of 200°, the main rod 48 moves 6 mm to the right in FIG.

Even if the main cam 162 and the sub-cam 142 further rotate from a rotation angle of 200 degrees, the cam lift curve enters the horizontal portion in FIG. The part 53 continues to rotate, and at a rotation angle of 205°, the brush 63 and the first fixed contact 65d come into contact as shown by the dashed line in FIG. The rotation of the sub cam 142 and the main cam 162 is stopped. At this time, the capstan 72 is rotated clockwise in FIG. 3, and the main idler 76 is rotated counterclockwise in FIG.
Therefore, the belt 84, the relay roller 82, and the rotating arm 88 also rotate counterclockwise in FIG. 3, and the idler gear 86 rotating clockwise in FIG. 3 meshes with the take-up reel idler gear 54a. The take-up reel stand 10 is rotated clockwise in FIG. 3 via the clutch means described above, and the pinch roller 192 and capstan 72 cooperate to keep the magnetic tape 180 fed at a constant speed from slacking. It is wound around the take-up reel hub 14 and reproduced.

Next, when a stop button (not shown) is pressed, the motor reverses, and the sub cam 142 and main cam 16
2 start rotating clockwise and counterclockwise in FIG. 4, respectively, and the pinch roller 192 and capstan 7
2 apart, and the tape pull-out members 182, 183
is moved in the direction of the cassette 20. In addition, the capstan 72 rotates counterclockwise in FIG.
Idler gear 86 is supply reel idler gear 64
a, the supply reel stand 12 is rotated counterclockwise in FIG. 3, and the magnetic tape that has been pulled out is wound around the supply reel hub 16 without slack. As shown in Fig. 9, when the main rod 48 is rotated to a rotation angle of 40°, it has already stopped moving, and the rotation angle is further increased.
When it rotates to 7 degrees, the sub rod 130 also stops moving. However, from this state, the sub cam 14
2. The main cam 162 continues to rotate, and when the rotation angle reaches 0°, the brush 63 of the detection switch 43 and the first fixed contact 65c come into contact, the fixed terminals 69a and 69b become electrically connected, the motor stops, and the sub cam 142 , the main cam 162 also stops rotating.
Further, the rotation of the capstan 72 is also stopped, resulting in the stopped state shown in FIG.

As described above in detail based on the embodiments, the present invention includes a cam that is rotationally driven by a motor, and that moves to a plurality of positions following the rotation of the cam to control various operating modes of the device. a moving member for switching to a mode corresponding to the position, a rotating member that rotates in synchronization with the rotation of the cam, a fixed member provided with fixed contacts corresponding to the plurality of positions, and a fixed member on the fixed member. The movable contact portion has a movable contact that is slidable and can be electrically connected to the fixed contact, and deceleration transmission means that decelerates the rotation of the rotating member and transmits the deceleration to the movable contact portion. , the movable contact portion rotates due to the rotation of the cam,
When the movable contact contacts one of the plurality of fixed contacts, the movable contact and the fixed contact become electrically conductive, thereby detecting the position of the movable member. Since the rotation angle of the movable contact part is set to 360 degrees or less relative to the cam's operating angle range, it is possible to prevent the cam from rotating more than 360 degrees or reducing the pressure angle of the cam as magnetic tape devices become more multifunctional. Increase in rotation angle due to
Furthermore, in response to the demand for smaller detection switches due to the miniaturization of devices, it is now possible to provide multiple contacts on the same circumference of the fixed member without overlapping, and furthermore, it is possible to take out the output of the contacts. There is no need for the terminals to have a complicated structure such as using a multi-layer system to connect to the contacts, and a simple structure can be used, which increases the degree of freedom in design and can be expected to have a great effect on miniaturizing the device.

Furthermore, the cam can be reliably stopped only after the movable member is located at the horizontal portion of the cam's lift curve and its movement has stopped and the corresponding operating mode has been reached, and the load changes due to environmental changes or aging. The effects are extremely large, such as enabling highly accurate positioning that is less affected by

[Brief explanation of drawings]

Fig. 1 is a surface view of the main parts of an embodiment of the present invention in a stopped state, Fig. 2 is a schematic sectional view of the reel drive system, Fig. 3 is a surface view of the main parts in a reproducing state, and Fig. 4 is a stopped state. 5 is a partial sectional view showing the mounting state of the detection switch, FIG. 6 is a plan view of the main part of the movable contact, FIG. 7 is a sectional view of the main part of the detection switch, and FIG. FIG. 9 is a plan view of the fixed contact portion and a lift curve diagram of the cam. 43...Detection switch, 45...Rotating gear, 51...
Fixed member, 53... Movable contact portion, 57... Internal gear,
63... Brush, 65... First fixed contact, 48... Main rod, 130... Sub rod, 142... Sub cam, 162... Main cam.

Claims (1)

[Claims] 1. A cam rotationally driven by a motor, a moving member that moves to multiple positions following the rotation of the cam and switches various operating modes of the magnetic tape device to modes corresponding to each position, and the cam. a rotating member that rotates in synchronization with the rotation of the rotating member, and a fixed member provided with fixed contacts corresponding to the plurality of positions, respectively;
a movable contact portion having a movable contact that is slidable relative to the fixed member and capable of electrically conducting with the fixed contact; and a deceleration transmission means that decelerates the rotation of the rotating member and transmits it to the movable contact portion. The movable contact portion rotates as the cam rotates, and when the movable contact contacts one of the plurality of fixed contacts, the movable contact and the fixed contact are electrically connected. The magnetic tape is configured to detect the position of the movable member by being in a conductive state, and the rotation angle of the movable contact portion is set to 360° or less with respect to the operational rotation angle range of the cam. Device.