JPH0255860B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves pulling out a magnetic tape from a cassette having a built-in reel hub wound with the magnetic tape to the outside of the cassette, and causing the tape to run attached to a magnetic head drum installed outside the cassette. The present invention relates to magnetic tape devices such as video tape recorders that record or reproduce signals.

Generally, in a magnetic tape device such as a cassette-type video tape recorder, a magnetic tape is pulled out from a cassette and wound around a magnetic head.
In order to mechanically simplify this magnetic tape drawing operation, a dedicated motor is often provided.

A conventional video tape recorder equipped with a motor for drawing out magnetic tape has a structure in which the rotation of the motor is directly transmitted, and the magnetic tape drawing member is placed between the first position where the magnetic tape in the cassette can be pulled out and the magnetic tape removed. It was moved back and forth between a second position where it could be drawn out of the cassette and wound around a magnetic head at a predetermined angle. Of the first position and the second position, a second position is used to accurately determine the winding angle of the magnetic tape with respect to the magnetic head in order to accurately record/reproduce signals between the magnetic tape and the magnetic head. In order to improve the stopping position accuracy and to stably fix the motor, a stopper is arranged at the second position, and a spring is interposed between the driving side and the driven side to press the driven side into contact with the stopper. was. However, in this structure, the amount of extension of the spring after contacting the stopper depends on the rotational stop position of the motor, so if the spring constant of the spring is particularly large, the pressing force against the stopper will vary widely, which poses a problem. Furthermore, the pressing force required to achieve stable fixing is generally quite large, and the required torque of the motor is also required to be quite large. Further, in order to reduce the load on the motor, it is not preferable to make the transmission reduction ratio of the rotation of the motor too large because this slows down the moving speed of the magnetic tape pull-out member.

In addition, in recent years, a method has been proposed that uses a magnetic tape drawer motor to switch the operating mode of the device (for example, Japanese Patent Application No. 15263/1982).
However, in this conventional method, when the magnetic tape pull-out member is pressed and fixed to the stopper in the second position, the reaction force of the pressing force becomes a load when switching the operation mode, and a large amount of current is required from the motor. There was a problem.

The present invention solves the problems of such conventional magnetic tape devices, allows the stop positioning of the magnetic tape pull-out member to be reliably and effortlessly performed with a simple structure, and allows the magnetic tape to be quickly and smoothly pulled out from the cassette. It is an object of the present invention to provide a magnetic tape device that can switch the operating mode of the device under a light load. Hereinafter, the present invention will be explained 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 is engaged with the take-up reel hub 14 and the supply reel hub 16 in the reel base 20, respectively, and can be rotated integrally by claws 8 provided on both the reel stands 10 and 12. FIG. 2 shows a cross-sectional view of the reel stand drive system.
2 have reel gears 30 and 40, respectively, and the reel gears 30 and 40 are attached to a shaft 5 that is installed on the substrate 2.
The winding reel idler gear unit 52 and the supply reel idler gear unit 62, which are loosely and rotatably fitted in the windings 0 and 60, respectively, are meshed with each other and driven to rotate. The take-up reel idler gear unit 52 and the supply reel idler gear unit 62, as shown in FIG. The power is transmitted to a take-up reel idler gear 54b meshing with the reel gears 30 and 40 and a supply reel idler gear 64b via a clutch means.

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 is pressed against the rotating roller part 74 by applying a predetermined pressing force. Main idler 7
The rotation is transmitted to 6. The main idler 76 includes a pulley portion 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.
A belt 84 is stretched between them, and its rotation is transmitted to the relay roller 82. A rotating arm 88 with a rotatable idler gear 86 supported at one end is loosely fitted to the shaft 80, and the rotating arm 88 is arranged so that a multi-pole magnet 90 on its outer periphery is substantially concentric with the shaft 80. It is placed all together on top. Further, on the inner periphery of the relay roller 82, a magnetic material 92 having a magnetic hysteresis characteristic is arranged so as to face the magnet 90 with a predetermined clearance.
is fixed, generates a predetermined attraction force between it and the magnet 90, and applies a rotational force in the same direction as the rotational direction of the relay roller 82 to the rotating arm 88. Further, the idler gear 86 is constantly connected to the relay roller 82.
It is configured to mesh with a gear portion 94 provided in the device, 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. , the rotation of the capstan 72 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 onto a shaft 18 that is set up on the substrate 2, and a pinch roller 192 is rotatably supported on a shaft 24 that is set up at one end of the pinch roller lever 22. ing. A crimping lever 32 having an elongated hole 28 is fitted loosely into 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 rotatably fitted to a shaft 26 that is erected on the substrate 2. The connecting arm 36 is loosely fitted, 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. Further, a spring hook 42 is formed at the other end of the crimp lever 32, and a tension spring 4
4 is stretched between the shaft 26 and the spring hook 42, and urges the crimp lever 32 upward in FIG. 1, so that the end of the elongated hole 28 and the shaft 26 are in contact. . That is, the pinch roller lever 22 and the connecting arm 3
6 and the crimp 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. . Therefore, in Figure 1, main rod 4
When 8 moves to the left to the position shown in Figure 3,
Since the bent portion 21 is in contact with the pin 46, the pressure lever 32 is rotated clockwise, and the pinch roller lever 22 is rotated counterclockwise until the pinch roller 192 comes into contact with the capstan 72. The pinch roller lever 22 is not rotated after that, but the crimping lever 32 continues to rotate clockwise, so the crimping lever 32 is guided into the elongated hole 28 against the biasing force of the tension spring 44. 3, and at the same time, the pinch roller 192 is pressed against the capstan 72 with a predetermined pressing force.

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 surface 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 rotary magnetic head 186 and a fixed head 188 for recording/reproducing audio signals and It is attached to a tape guide 190 fixed to the substrate 2. Furthermore, capstan 7
2 rotates clockwise in FIG. 3, the main idler 76 rotates counterclockwise in FIG. 3, and the belt 84 and relay roller 82 also rotate counterclockwise in FIG. 3. Therefore, the pivot arm 88 is connected to the shaft 8
The idler gear 86, which is applied with a rotational force in the counterclockwise direction in FIG. 3 about 0 and rotates clockwise in FIG. The take-up reel stand 10 rotates clockwise, and the pinch roller 1
92 and the capstan 72 cooperate to wind the magnetic tape 80 fed at a constant speed 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 rotatably supported by a shaft 134 mounted on the substrate 2, and meshes with a rotating body 142 having a gear portion 143 on the outer periphery. Further, the rotating body 142 similarly meshes with a cam 162 having a gear portion 170 on its outer periphery. The cam 162 is supported by a shaft 164 that stands upright on the base plate 2, and is a positive cam having a groove 166 extending over 360 degrees as shown in FIG. 10, and its lift curve has a lift amount as shown in FIG. A cam follower 146, which will be described later, moves only in the changing section. Further, on the back side of the substrate 2, the rotation shaft 4 of the take-up reel stand 10 and the rotation shaft 50 of the take-up reel idler gear unit 52 extend from the surface, and the guide shaft 132 and the rotation shaft 164 of the cam 162 are installed. and a cam follower 146 that engages with the groove 166 of the cam 162.
The main rod 48 has a
The guide grooves 35, 37, 39, and 41 are loosely fitted so that they can move back and forth.

The cam 162 has a partial gear 43 with some teeth removed on the end face where the groove 166 is not provided.
6 and is configured to have a constant angular relationship. Then, from the stopped position shown in FIG. 4, the cam 16
2 rotates by a certain angle clockwise in FIG. 4, it meshes with the first sector gear 45 having a gear portion, and moves the tape pull-out members 182 and 183. Here, with reference to FIGS. 4 to 9, the tape pull-out member 182 is moved from the position shown in FIG. 1 or FIG. 2
The operation of moving the parts 3 and 27 to the position where they come into contact and press together will be described in detail. FIG. 5 shows the positional relationship in the stopped mode. Reference numeral 45 denotes a first fan-shaped gear that can mesh with the partial gear 43, and a second fan-shaped gear that is rotatably loosely fitted onto a shaft 51 that is set on the base plate 2, and has a gear portion.
It is molded integrally with the sector gear 49. Reference numeral 55 denotes an arm integrally formed with the first sector gear 45 and the second sector gear 49, and has a pressing pin 53 planted at its tip. Reference numeral 57 denotes a third sector gear having a gear portion, which is rotatably fitted loosely onto a shaft 59 mounted on the base plate 2, and meshes with the second sector gear 49. 9
Reference numeral 8 denotes an arm having a hole 61 having a cam surface 63 which will be described later, and the press pin 53 is inserted into the hole 61 so as to be able to come into contact with the cam surface 63. 6
Reference numeral 5 denotes a fourth sector gear which is integral with the third sector gear and the arm 98 and has a gear portion rotatable around a shaft 59; 1 loading gear 69. Reference numeral 71 denotes a second loading gear, which is a gear that can rotate around a shaft 67 together with the first loading gear, and a shaft 73 mounted on the substrate 2.
The third gear is rotatably fitted loosely into the
It meshes with the loading gear 75 and rotates synchronously. 7
Reference numeral 7 denotes a left loading first arm which is rotatably fitted loosely on the shaft 67, and as shown in FIGS. 5 and 9, a spring hook 79 and a second loading gear 71 are provided on the left loading first arm 77. A tension spring 81 is stretched between the pin 83 and the pin 83, and the pin 83 is brought into contact with the stopper 85 provided on the left loading first arm 77, so that the left loading first arm 77 and the second It is configured to be integrated with the loading gear 71 and rotate together. A second left loading arm 87 is rotatably connected to one end of the first left loading arm 77 by a pin 89, and a hole 91 is bored in the other side of the second left loading arm 87, and a hole 91 is formed in the other side of the second left loading arm 87 to connect the tape drawer member. It is in an engagement relationship with a pin 93 planted in 182. Reference numeral 95 designates a right side loading first arm, and the third loading gear 75 has the same structure as that between the left side loading first arm 77 and the second loading gear 71, and the other end is similarly connected by a pin 97. A second right loading arm 99 is rotatably connected, and a hole 101 formed at the other end of the second right loading arm 99 is engaged with a pin 103 set in the tape pull-out member 183. be. 47 is the cam 16 as shown in FIG.
2 is a guide wall provided on the end face of the guide wall 4.
7 is the first sector gear 45 in the stopped state shown in FIG.
Since the first sector gear 45 is sandwiched between a first projection 105 and a second projection 107 provided in the first projection 105 and the second projection 107, the first sector gear 45 maintains the position shown in FIG.

Now, when the cam 162 starts to rotate clockwise from the position shown in FIG. 5, the rotation angle is 40 degrees in the cam diagram shown in FIG. The wall 47 and the first projection 105 and the second projection 107 are disengaged from each other, and the first sector gear 45 and the second sector gear 49 begin to rotate counterclockwise. Further, the third sector gear 57 and the fourth
Since the sector gear 65 rotates clockwise, the first loading gear 69, the second loading gear 71,
The first left loading arm 77 rotates counterclockwise and the third loading gear 75 rotates clockwise, so the first arm 95 and the second right loading arm 99 rotate clockwise, resulting in tape drawer. Members 182 and 183 are guide grooves 3
1 and 33. FIG. 6 shows the cam 162 rotated 105 degrees. At this time, from the partial gear 43 to the first loading gear 69, the second loading gear
Loading gear 71, third loading gear 7
All movements up to 5 are performed by a gear train. FIG. 7 shows a state in which the cam 162 has been rotated to 160 degrees. At this time, the second sector gear 49 and the third
The sector gear 57 is disengaged from the meshing relationship, and the pressing pin 53
has started contacting the cam surface 63 provided on the arm 98. Also, in this state, the left loading
Arm 77 and right loading first arm 95
The guide posts 23 and 27 connect the tape pulling members 182 and 183 to the fixing members 184 and 183, respectively.
It is moved to a position where it contacts 185. Further, when the cam 162 continues to rotate clockwise in FIG. 7 from the state shown in FIG. 7, the first sector gear 45 rotates counterclockwise in FIG. Although the gear 57 is disengaged, the cam surface 63 is pressed by the pressing pin 53 and continues to rotate clockwise.

As described above, since the tape guides 23, 27 are in contact with the fixing means 184, 185, the left loading first arm 77 and the right loading first arm 95 cannot rotate beyond the state shown in FIG. The first loading gear 69 and the third loading gear 75 continue to rotate counterclockwise and clockwise, respectively, against the biasing forces of the tension springs 81 and 109. Then, when the cam 162 rotates to a rotation angle of 180 degrees, the meshing relationship between the partial gear 43 and the first sector gear 45 is released, and the pressing pin 53 is moved to the cam surface 6.
It is configured to be located in the horizontal part of Figure 7 of 3,
Furthermore, the guide wall 47 has rotated to a position where it can come into contact with the second protrusion 107. The toothless portion 111 of the third sector gear 57 is connected to the second sector gear 49 and the third sector gear 57.
The sector gear 57 is disengaged from the meshing relationship, and the pressing pin 53 is released.
This is provided to prevent interference between the teeth of the second sector gear 49 and the third sector gear 57 when the cam surfaces 63 move into abutting relationship.

FIG. 8 shows the state in which the cam 162 has rotated to a rotation angle of 205 degrees and is in a regenerating state. As mentioned above, the seventh
From the state shown in the figure, the left loading first arm 77,
Since the first loading gear 69 and the third loading gear 75 rotated counterclockwise and clockwise, respectively, while the right loading first arm 95 cannot rotate, there is a gap of Δl between the pin 83 and the stopper 85.
Similarly, a gap of Δl' is generated between the stopper provided on the right loading first arm 95 and the pin installed on the third loading gear 75. After all, these gaps Δl and Δl' are nothing but the elongation of the tension springs 81, 109, and the guide posts 23, 27 are pressed against the fixing members 184, 185 by a force corresponding to this elongation, and the magnetic tape 1
8 is attached to the rotating magnetic head 186 in a stable state. On the other hand, the tension spring 81,
It is obvious that the pressing force by 109 acts as a reaction force to rotate the first loading gear 69 and the third loading gear 75 clockwise and counterclockwise, respectively. Therefore, the fourth sector gear 65 and the arm 98 This rotational force is applied to the pressing pin 53 in the direction of arrow A in FIG. 8 because the pressing pin 53 is located on the horizontal portion of the cam surface in FIG. That will happen. However, since the direction of the arrow A is configured to match the direction in which the pressing pin 53 and the shaft 51 are connected, this rotational force cannot be an effective force for rotating the arm 55 and the first sector gear 45. , despite the existence of the reaction force of the pressing force, the first sector gear 45 can maintain the state shown in FIG.
2 can continue to rotate clockwise without being affected by the reaction force while being disengaged from the first sector gear 45.

Next, the main rod 48 is rotated by the rotation of the cam 162.
The relationship between the movement of the tape pull-out member and the movement of the tape drawing member will be explained. When the cam 162 rotates 60 degrees clockwise from the stopped state shown in FIG. 4, the main rod 48 moves 1.5 mm to the right in FIG. Since the pinch roller 192 is pressed, the capstan 7
Approaching 2. The cam 162 continues to rotate and the rotation angle
When rotated to 180 degrees, the main rod 48 moves further by about 2.5 mm, and the pinch roller 192 is not able to generate enough pressure to contact the capstan 72. When the cam 162 rotates from a rotation angle of 180° to 200°, the main rod 48 further moves about 2 mm to the right in FIG. 4, and the pinch roller 192 is pressed against the capstan 72 with a predetermined pressing force by the tension spring 44. That is, as is clear from the cam lift curve shown in FIG. This means that the rotational angle range of 160° to 180°, which requires a rotational force on the cam 162 in order to press the fixed members 184 and 185, does not overlap.

Next, the operation will be explained. When the playback button (not shown) is pressed from the stopped state shown in FIG. 1, the motor (not shown) rotates, causing the drive gear 160 and rotating body 142 to rotate clockwise and counterclockwise in FIG. 4, respectively. The cam 162 starts rotating clockwise in FIG. When the cam 162 rotates through a rotation angle of 40 degrees, the partial gear 43 and the first sector gear 45 begin to mesh, and the tape pull-out members 182 and 183 are moved at a substantially constant speed to begin to pull out the magnetic tape 180 to the outside of the cassette 20. At the same time, the main rod 48 also has groove 16.
6, the pinch roller 192 begins to move rightward in FIG. 4, and the pinch roller 192 begins to move toward the capstan 72. When the cam 162 continues to rotate and rotates to a rotation angle of 160 degrees, the meshing relationship between the second sector gear 49 and the third sector gear 57 is disengaged, and the press pin 53 enters into contact with the cam surface 63, and the guide pins 23, 27 are brought into contact with the cam surface 63. When the cam 162 comes into contact with the fixed members 184, 185 and continues to rotate up to a rotation angle of 180°, the press pin 53 slides on the cam surface 63, thereby moving the guide pins 23, 27 to the fixed members 184, 185. It will be crimped. At this time, the pressing pin 5 of the cam surface 63
If the pressure angle relative to 3 is made as small as possible, the guide pins 23 and 27 can be attached to the fixing member 1 with less force.
It is clear that 84,185 can be crimped.
At this time, since the cam 162 has rotated to a rotation angle of 180 degrees, the main rod 48 has moved approximately 4 mm to the right in FIG. 4, as shown in FIG. do.
Further, as the cam 162 continues to rotate up to a rotation angle of 200 degrees, the main rod 48 moves 6 mm to the right in FIG. 4, completing the predetermined pressure bonding of the pinch roller 192 to the capstan 72. During this crimping operation, the meshing relationship between the partial gear 43 of the cam 162 and the first sector gear 45 is disengaged, and the guide pins 23 and 27 are not subjected to the reaction force of the crimping against the fixing members 184 and 185. It is clear that cam 162 is rotating.

When the cam 162 further rotates to a rotation angle of 205 degrees, the cam lift curve in FIG.
The rotation of 62 is stopped. Meanwhile, at this time, the capstan 72 is rotated clockwise in FIG. 3, and the main idler 76 is rotated counterclockwise in FIG. 3. 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. The take-up reel stand 10 is rotated clockwise in FIG. 3 by means of the pinch roller 19.
2 and the capstan 72, the magnetic tape 180 fed at a constant speed is wound around the take-up reel hub 14 without slack, resulting in a recycle mode.

Next, when a stop button (not shown) is pressed, the motor is reversed, the drive gear 160 and the rotating body 142 are rotated counterclockwise in FIG. 4 and clockwise, respectively, and the cam 162 is rotated in the counterclockwise direction in FIG. The pinch roller 192 and the capstan 72 are separated from each other, and the tape pull-out members 182 and 183 are moved toward the cassette 20. Also, the capstan 72 is the third
The idler gear 86 meshes with the supply reel idler gear 64a, rotates the supply reel stand 12 counterclockwise in FIG. 3, and winds the drawn-out magnetic tape around the supply reel hub 16 without slack. Turn. Thereafter, when the cam rotates to a rotation angle of 0°, the switch is activated, stopping the rotation of the motor and stopping the cam 162. Furthermore, 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 of the present invention, according to the present invention, the tape pulling means can be reciprocated at a substantially constant speed using the gear means until it comes into contact with the fixing member. prevents sagging and excessive tape tension,
It becomes possible to prevent damage to the tape and improve the quality and reliability of image and audio recording/playback. Furthermore, since the tape pull-out member is crimped to the fixing member through the cam from the gear, it is possible to significantly reduce the load on the motor, which is advantageous in terms of the lifespan of component parts and power saving.

[Brief explanation of the drawing]

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. Fig. 5, Fig. 6, Fig. 7, and Fig. 8 are explanatory diagrams of the operation of the drive section of the tape pull-out member, Fig. 9 is a schematic sectional view of the drive section, and Fig. 10 is a diagram of the cam. It is a lift curve diagram. 48...Main rod, 43...Partial gear, 4
5...First sector gear, 49...Second sector gear, 5
3...Press pin, 63...Cam surface, 65...Fourth
Sector gear, 69...first loading gear, 75
...Third loading gear, 162...Cam, 1
66... Groove, 182, 183... Tape drawer member.

Claims (1)

[Claims] 1. Using a tape cassette with a built-in reel hub wound with magnetic tape, the magnetic tape is pulled out from the cassette and run along a magnetic head installed outside the tape cassette to record or reproduce signals. a magnetic tape that is configured as shown in FIG. Withdrawal means 182, 18
3, capable of forward and reverse rotation for driving the magnetic tape pulling means from the first position to the second position by rotation in one direction, and from the second position to the first position by rotation in the other direction; a motor; gear means 43, 45, 49 for transmitting rotational force for moving the magnetic tape extracting means between the first position and the second position from the motor to the magnetic tape extracting means; 57, 65, 6
9, 71, 75, 142, 162; and an elastic member, when the magnetic tape pull-out means moves from the first position to the second position,
Pressure fixing means 77, 81 for pressing and fixing the magnetic tape drawing means by the elastic force of the elastic member by further rotating the gear means by a predetermined amount;
87, 95, 99, and 109 move in conjunction with the gear means, and when the magnetic tape pull-out means moves to the second position, the gear is switched to a cam to apply the elastic force of the elastic member to the gear means. Cam means 5 for rotating by a predetermined amount against
3, 55, 63, and 98, when the motor rotates, the gear means moves the magnetic tape pulling means from the first position to the second position, and then the cam means presses and fixes the magnetic tape. A magnetic tape device characterized in that it is configured to drive means.