JPS6131541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape tension control device, and in particular to a device for pulling a tape out of a cassette and running it along a tape path formed. To provide a tape tension control device which functions as a tension arm during tape running and performs tape tension control electrically, and which can perform tension control well when tape is running in both directions with a simple configuration. purpose.

In a conventional VTR device using a cassette, the mechanism that controls the tension of the tape that is pulled out of the cassette and runs along a predetermined tape path is based on the pressure force of the brake shoe against the reel disk depending on the rotational position of the tension arm. It was a mechanical tension control mechanism that controlled the back tension by changing the For this reason, it is virtually impossible to properly control the tension during tape bidirectional operation, resulting in a problem in that the functions of the VTR device are limited.

The present invention solves the above problems, makes it possible to electrically control the back tension with a simple configuration, and effectively improves the performance of the device, as shown in the drawings below. An example thereof will also be described.

First, a tape path drawing device to which the tape tension control device of the present invention is applied, which draws a tape out of a cassette to form a predetermined tape path, will be described.

Fig. 1 is a plan view of an embodiment of the tape drawing device in the tape drawing end state (the cassette, reel deck, guard plate, etc. are indicated by two-dot chain lines), and Fig. 2 is a partial joint of the device shown in Fig. 1. FIG.

First, the configuration will be explained. Figures 1 and 2
Referring to the figure, reel deck 4 is reference deck 1.
It is fixed by screws 3 to a plurality of studs 2 erected on the top of a reference deck 4. The supply side reel motor 6 and the take-up side reel motor 7 are connected to the reel deck 4 by four screws 5, respectively.
It is installed in a hanging state. A supply reel disk assembly 9 and a take-up reel disk assembly 11 are directly connected to each reel motor 6 and 7 by set screws 8 and 10, respectively, and are set at a predetermined height, respectively. Each reel disk assembly 9,1
1 includes three reel drive pins 14 that are biased upward via a pin holder 12 and a compression spring 13 so as to be slidable in the longitudinal direction. Further, the skirt portion of each reel disk has a slit-like shape. The photo coupler 16 is screwed and fixed at a predetermined position on the reel deck 4, and is provided opposite to the slit-like skirt portion to detect the rotational speed of the reel disk.

A pair of brake band arms 20 are rotatably arranged to correspond to the reel disk assemblies 9 and 11, respectively. The arm 20 is fixed to a pushing 19, which is fitted onto a stud 18 which is planted on the reel deck 4 and has a band guide plate 21 screwed to the top. Show 22
The brake band 23 lined with
The band holder 24 is fixed to a band holder 24 screwed by a screw 5, and is provided around each reel disk assembly 9,11. Further, each brake band arm 20 is biased by a spring 26 with a rotating force in a direction to tension each brake band 23, and when the solenoid 28 is deenergized, a braking force is applied to each reel disk assembly 9, 11. are doing. Furthermore, a solenoid 28 is screwed and fixed to the deck 4 in correspondence with each arm 20, and the tip of the arm 20 is connected to the plunger 2 of the solenoid 28.
It is loosely connected to a pin 27 set in the hole 9. When the solenoid 28 is activated, the braking force on the reel disk assemblies 9, 11 is released.

On the reel deck 4, there are two height position regulating pins 32a and 32b for securing the 3/4 inch video cassette 31 in the proper position, and the cassette 3.
Centering pins 33 and 34 are installed to determine the height position and horizontal position of 1. The band guide plate 21, which is screwed, has round holes placed on the stepped portions of the pins 32a, 32b, and 34, and on the upper end surface of the cylindrical spacer 37 fitted on the pin 33, and further fitted on the pin 34. E-washia worn 3
8 so that displacement in the thickness direction is restricted. In addition, the centering pin 34
also serves as a rotation center for the winding side tension control arm 36 which carries the tape guide roller assembly 35 at its tip end.

This tension control arm 36 is caulked to a pushing 40 which is rotatably supported on the pin 34, and is freely rotatable with respect to the pin 34. The pushing 40, ie, the vertical movement of the arm 36, is regulated by a stop ring 42 fixed to the pin 34 by a set screw 41. Note that this stop ring 42 also has the role of determining the mounting height position of the cassette.

The arm 36 is provided with a pivoting biasing and braking assembly. This assembly has the configuration shown in cross-section in FIG. The sliding pipe 45 has one end rotatably fitted into a pin 43 planted on the lower surface of the arm 36, and is prevented from coming off by an E washer 44. The sliding rod 49 has one end rotatably fitted into a pin 48 set on the upper surface of the holder 47, and is restricted from detachment by an E washer 50. The holder 47 is fixed to the band guide plate 21 with its position adjusted by screws 46. The rod 49 is slidably fitted into the fixed pipe 45, and its sliding surface is coated with silicone oil having high viscous resistance. This applied silicone oil functions as a damper. A compression coil spring 51 is inserted around the sliding pipe 45 between this collar and the collar of the sliding rod 49, and applies a clockwise rotational force to the arm 36.

The position detection differential transformer 55 is attached to the guard plate 52 with screws 54 via an L-shaped bracket 53. The detection rod 55a of the differential transformer 55 is biased toward the right in FIG. 1 by a built-in coil spring with a small spring constant, and is in contact with the side surface of the tension control arm 36 on the distal end side. Note that the arm 36 is supported by a spring 56 stretched between the base side and the folded piece of the guide plate 21.
As a result, the rotational force exerted by the detection rod 55a is canceled.

Next, the pinch roller arm mechanism will be explained. The pinch roller arm 62 is pivotally supported by a stud 58 set up on the loading ring 57 and stored by an E washer 59. A pinch roller 61 is rotatably held on the free end side of the arm 62. In addition, the pin 63 installed near the pinch roller 61 of the arm 62 has
A return roller 65 is provided so as to be prevented from coming off by an E washer. This return roller 65
When the loading ring 57 rotates, the tape 66 of the tape loop formed outside the cassette
It has the role of locking the loop from the inside and drawing it around the guide drum 64.

Next, the configuration of the tape pull-out mechanism will be explained with reference to FIGS. 5 to 12.

First, the tape pull-out mechanism provided on the take-up reel disk side will be explained. 5 and 6 are longitudinal cross-sectional views taken along lines - and - in FIG. 3, respectively, and FIG. 7 is a diagram showing the positions of the rotating members and arm members of the tape pull-out mechanism in correspondence with each other. It is.

The take-up side pull-out arm 67 has a guide roller 70 rotatably attached to a pin 68 on its tip side, and a lock ring 72 that is adjustable in position using a screw 71 approximately in the center. The base side of the arm 67 is fitted into a shaft 73 installed on the height deck 1,
It is fixed to an arm holder 76 which is rotatably supported by a pair of E washers 74 and 75 on its upper and lower surfaces. Arm holder 76 of arm 67
The fixation to 4 is carried out through a compression coil spring 77.
This is done by screws 78 and the guide roller 70
is adjusted so that it is parallel to the axis 73. 79
A pin is set on the arm holder 76 and protrudes downward, and is fitted into an arcuate long hole 80a of the tape drawer drive gear 80. This drive gear 8
0 is rotatably fitted into the lower small diameter portion of the arm holder 76 and is held by an E washer 82. The torsion coil spring 81 is inserted into the hole 80b of the drive gear 80 with its bent arm on one end, and the arm on the other side is locked with the pin 79, so that the torsion coil spring 81 is inserted into the arm holder 76 with the spring force stored. It is provided around the central small diameter part, and is attached to the arm holder 76 in a counterclockwise direction.
A clockwise rotational force is applied to the drive gear 80.

The drive arm 83 is fixed to a pushing 84 by caulking, and the pushing 84 is rotatably provided at the lower part of the shaft 73. Supply side drive gear 86
is rotatably fitted into the pushing 84 and prevented from coming off by an E washer 85. The pin 87 is planted on the upper surface of the drive arm 83, and the torsion coil spring 88, which is fitted into the arc-shaped elongated hole 86a of the drive gear 86, has one bent arm portion inserted into the hole 86b of the drive gear 86. Then, with the other side arm latched to the pin 87 and the spring force stored,
It is provided between the drive gear 86 and the arm 83,
A rotational force is applied to the drive gear 86 in a counterclockwise direction and the arm 83 in a clockwise direction.

The arm holder 76 also includes a cam 76 that cooperates with a roller 102 of a position holding arm 98, which will be described later.
A is formed.

The drive gear 80 is formed with an upper cam 80c and a lower cam 80d, and the former cooperates with a roller 101 of an end lock arm 97, which will be described later.
The latter cooperates with the roller 103 of the lock drive arm 99. Further, a gear portion 8 is provided on the lower cam 80d.
0e is carved over a predetermined angular range, and furthermore, a protrusion 80f is formed at a predetermined position. The supply side drive gear 86 has a gear portion 86c carved at a predetermined position at a predetermined angle, and further has a protrusion 86d formed at a predetermined position to abut against the protrusion 80f. The gear portions 86c and 80e are configured to be sequentially driven by a power gear 95, as will be described later.

The tape drawing mechanism with the above configuration is powered by a motor 89.
and a power unit 90 (a reduction gear consisting of a worm and a worm wheel). The holder 92 has two screws 93 and two shafts 9.
4, and the power unit 90 is fixed on the reference deck 1 by screws 9 to this holder 92.
1, the hanging is fixed. power unit 90
is provided with a power gear 95 that sequentially meshes with the gear portions 80e and 86c. The power gear 95 meshes with the gear portion 86c in the state shown in FIG. 3, and meshes with the gear portion 80e in the state shown in FIG. Note that the shaft 94 has the role of supporting the guard plate 52 in cooperation with the screw 96. Furthermore, the shaft 94 is provided with a spacer 1 as shown in FIG.
00 is fitted, and furthermore, the arms 97, 98, 9
9 are pivotally supported in a stacked state.

The end lock arm 97 at the uppermost position is biased by a spring 108 to rotate counterclockwise, and the end lock arm 97 is rotated by a counterclockwise rotation force by a spring 108.
01 faces the upper cam 80c of the drive gear 80.

Further, a locking hook portion 97a is formed at the upper bent portion of this arm 97.

The position holding arm 98 is located inside the arm 97 having a U-shaped cross section, is biased with a counterclockwise rotational force by a spring 107, and is rotated by a pin 10 on the tip side.
The roller 102 held by the arm holder 76
cam portion 76a.

The lock drive arm 99 in the lower position is connected to the spring 1
09, the roller 103 supported by the pin 106 on the tip side faces the lower cam 80d of the drive gear 80.

Furthermore, a pad 110 is attached to the bent portion of the guard plate 52, as shown in FIG. During the final rotation of the arm 67 in the tape store mode, which will be described later, the side end surface of the arm 67 comes into contact with the pad 110, suppressing the generation of impact noise. Furthermore, a tape guide pole 112 is provided on the upper surface of the guide plate 52.
is attached with its height adjusted by screws 111, and furthermore, a micro switch 113 for detecting the rotational position of end lock arm 97 is attached by screws 114.

115 is a connecting arm, and pins 116 and 118 are installed at both ends thereof. One pin 11
6 is fitted into the hole 83a of the drive arm 83 and held by the E washer 117, and the other pin 1
17 is the cam block 1 of the tape drawer mechanism on the supply side.
19 and is held by an E washer 120. That is, the connecting arm 115 is
The tape pull-out mechanism on the winding side and the supply side are connected.

Next, a description will be given of the configuration of the supply-side tape pull-out mechanism that operates as the tension control device according to the present invention after the tape is pulled out. FIG. 8 is a plan view of the supply side tape pull-out mechanism, FIG. 9 is a sectional view taken approximately along the line - in FIG. 8, and FIG. 10 is a diagram showing the relationship between the cam block and the pressure arm in the tape store state.

The cam block 119 is rotatably fitted into the lower large diameter portion of the shaft 121 mounted on the reference deck 1, with upward displacement being restricted by the E washer 122. A rotating arm plate 126 is fixed to the upper surface of the cam block 119 with four screws 127, and a spring holder 124 is fixed to the rotating arm plate 126 with its position adjusted using two screws 125. Spring holder 1
A pin 128 is planted on the upper surface of 24.

The arm holder 142 is attached to the upper narrow diameter portion of the shaft 121 via two upper and lower ball bearings 141 so as to be able to rotate smoothly. Arm holder 14
The vertical movement of the head 2 is adjusted by a washer 145 and restricted by a head mounting board 147 fixed to the top of the shaft 121 with a screw 146. Further, the supply side drawer arm 123 is on the upper surface of the flange of the arm holder 142, and the arm 1 is on the lower surface side.
33 is fixed with four screws 144.
In particular, the arm 123 is adjusted so that the shaft 140 on the distal end side is parallel to the shaft 121 by the action of a compression spring 143. In addition, arm 123
A tension roller 139 is rotatably provided on the shaft 140 to receive a downward thrust load from a lower roller bearing 138 and to suppress shaft loss as much as possible. Further, a pin 134 is installed on the lower surface of the distal end side of the arm 133.

Between pin 128 and pin 134 is a pivot biasing and braking assembly shown in FIG. This assembly includes a sliding pipe 137 fitted onto a pin 134 and held by an E washer 135, and a pin 128.
It is generally composed of a sliding rod 130 which is fitted into the E washer 129 and fitted into the sliding pipe 137 with silicone grease interposed therebetween, and a compression coil spring 136 provided around the pipe 137. .

Further, a lock pin 132 is attached to the plate 126 with its position adjusted using a screw 131.

As shown in FIG. 1, the pressure arm 151 is rotatably mounted on the reference deck 1 with a screw 149 via a pushing 148, and has a pressure pole 150 at its tip. This pawl 150 presses the inclined cam portion 119b of the cam block 119 to apply a clockwise rotational force to the inclined cam portion 119b when the tape is completely drawn out. Connection rod 152
is connected at one end to the tip of the lock drive arm 99 by two nuts 153 and 154,
The other end side is the hole 151 of the pressure arm 151.
c is fitted. As a result, arm 99,1
51 are interlocked via a rod 152.

Next, the mounting structure of the head mounting board 147 and the members attached to this board 147 will be explained. In addition to being fixed to the reference deck 1 by the shaft 121 and screws 146, the substrate 147 is also fixed to the reel deck 4 by studs 155 and screws 156 set on the reel deck 4, and further It is fixed to a drum base (not shown) by screws 164a and 164b, and is stably and firmly attached to the apparatus.

On this substrate 147 is an address head 180.
and a full width erase head 181 are mounted in alignment, both heads 180, 181 applying tape 66 between tape guides 170, 171 on the substrate.

The tape path adjustment arm 161 is rotatably supported by a screw 164, a guide pole 157 is erected at one end thereof, and a leaf spring 158 is attached to the other end by a screw 159. This arm 16
1 is biased with a counterclockwise rotational force by a spring 160, and the rotation in the same direction is prevented by a screw 164.
Stop plate 1 fixed by a, 164b
63 in the position shown in FIG.
Note that this arm 161 is used to change the tape path during fast forward and rewind modes. Further, the leaf spring 158 is locked and pressed by the pinch roller arm 62 during the final loading operation.

Further, a position detection differential transformer 165 is adjusted in position on the substrate 147 via a bracket 166 and fixed with a screw 167, and this detection rod 165a is attached to a bent portion 123a of one arm of the supply side drawer arm 123. is in contact with. This differential transformer 165 has a similar structure to the differential transformer 55 described above.

Further, a micro switch 168 is attached to a predetermined position on the substrate 147 with a screw 169. This micro switch 168
3 to detect the store end.

Furthermore, a lid opening member 172 is attached to a predetermined position on the board 147 by screws 173 for opening the front lid of the cassette when the cassette is installed.

Next, the operation of the tape drawer having the above structure will be explained.

First, to explain the meaning of the term "operation mode", "tape drawer" refers to the operation of pulling out the tape from the video cassette from the tape store end shown in FIG. 3 to the state shown in FIG. 1.
"Tape store" refers to the operation of sequentially winding and storing the tape in a video cassette from the tape drawer end shown in Figure 1 to the state shown in Figure 3. "Tape loading" refers to the rotation of the loading ring. This refers to the operation of pulling out the tape further than the state shown in FIG. 1 and drawing it around the guide drum 64 to form a tape path on which recording and reproduction can be performed.

In the recording and reproducing apparatus equipped with the above-mentioned tape drawer, the tape drawer end state shown in FIGS. It is done.

First, the state of each part at the end of tape draw-out will be briefly explained. The pair of solenoids 28 are deenergized, and the pair of brake band arms 2
0 is rotated by the spring 26, each brake band 23 is under tension, and the reel disc assemblies 9, 11 are in a braking state.

Regarding the supply side tape drawing mechanism side, the rotating arm plate 126 is pressed by the pressure pole 150 against the inclined cam portion 119b of the cam block 119, and is biased with a clockwise rotational force, and this rotation causes the lock pin 132 to rotate on the reel deck 4. It is in a restricted state by being fitted into the V-groove 4a. Note that the pressing force of the ball 150 itself is due to the cam 8 of the drive gear 80.
This is achieved by the action of 0d and the arm 99, especially the restoring force of the arm 99 which has been slightly elastically deformed. The supply side tape pull-out arm 123 is at a rotational position where the clockwise rotational force due to the elastic force of the compression coil spring 136 and the counterclockwise rotational force due to the tension of the tape 66 guided by the tension roller 139 are balanced.
If the tape tension increases, arm 1
23 rotates counterclockwise with the compression of the spring 136, and furthermore, the end surface 137a of the sliding pipe 137 in the assembly shown in FIG. is the rotating arm plate 1
26 and cam block 119 directly. Conversely, when the tape tension decreases, the arm 123
Rotates clockwise due to the elastic force of the spring 136,
In FIG. 1, the gap A becomes narrower and becomes approximately zero.

Regarding the tape take-out mechanism on the winding side, the arm 67 has a locking ring 72 fitted into the locking hook 97a of the arm 97, and a side surface abutting the bent portion 52a of the guard plate 52, so that the watch and the tape can be pulled out. Both are in a fixed state with limited rotation in the counterclockwise direction.

The tape path adjustment arm 161 rotates counterclockwise about the screw 164a as shown in FIG. The tape path near the guide pole is in the state shown by the two-dot chain line. This is to slightly correct the tape path during fast forwarding and rewinding, taking into consideration that the tape height position within the cassette 31 is somewhat different between the supply side and the take-up side.

The take-up side tension control arm 36 is at a rotating position where the elastic force of the compression coil spring 51 and the tape tension are balanced, as in the case of the supply side arm 123 described above.

The video cassette 31 also has pins 32a, 32b, a centering 33,
The height and horizontal position are determined by 34, and it is mounted in a predetermined position. The reel disk assemblies 9 and 11 are fitted to the reel, and the pin 14 is fitted into the hole of the reel, and the reel disk assembly 9,
11 and the reel are in a state where they can rotate integrally.

Next, the tape pull-out operation that starts from the store end state will be explained.

At the end of the store, that is, when the video cassette 31 is loaded, the device is in the state shown in FIG. ing.

The cam block 119 and the rotating arm plate 126 are connected to the connecting arm 1 by the elastic force of the torsion coil spring 88.
15, it is biased with a counterclockwise rotational force. The arm 123 actively pushes the shaft 140 on the tip side toward the portion B of the head mounting board 147, with the arm 135 being locked by the bent portion of the spring holder 124 and similarly biased with a counterclockwise rotational force. It rests in contact with the target. Also, arm 12
3 operates the microswitch 168 by the action of the arm 123b at the rotational rest position, thereby sending a signal indicating the store end state to the control system of the apparatus.

The mechanism for applying a counterclockwise rotational force to the cam block 119 will now be described. The drive arm 83 and the supply drive gear 86 have a relationship as shown in FIG. 11. The pin 87 is located approximately at the center of the elongated hole 86a, and a torsion coil spring 88 stores spring force. Here, since the drive gear 86 is meshed with the power gear 95 of the power unit 90 (which cannot be rotated by force from the outside), it is stopped at a predetermined position, and a counterclockwise force acts on the drive arm 83. . The counterclockwise rotational force of the arm 83 is transmitted to the supply side cam block 1 via the connecting arm 115.
19, which applies a clockwise rotational force.

On the other hand, the arm 67, as shown in FIG.
The inclined cam portion 76b of the arm holder 76 is
02 is pressed by the force of the spring 107 to apply a clockwise rotational force, and is at rest at a position where the side surface is in contact with the butt 110.

Note that both arms 67, 123 may be configured such that a V-shaped notch is formed in the cam, and a roller is fitted into this V-shaped groove to hold the arm at the above-mentioned rotational position.

When the video cassette 31 is loaded in this state, the tension roller 139 and guide roller 70
is relatively fitted inside the tape loop in the cassette 31. Further, when the cassette loading operation is completed, a microswitch (not shown) is closed and a tape withdrawal command is issued to the control system of the apparatus. The tape loop within the video cassette 31 is designed to wind the tape when both the take-up and supply reels rotate counterclockwise.

The tape pull-out operation by the tape pull-out command is as follows:
First, the arm 123 on the supply side starts rotating clockwise, and when this arm 123 rotates halfway, the arm 67 on the winding side starts rotating counterclockwise, and the arms 123 and 67 It roughly operates so as to reach the final position one after another. In particular, the supply side drawer arm 123 functions as a tension arm as described later after the tape drawer operation is completed.

To explain in detail below, upon receipt of a tape pull-out command, the pair of solenoids 28 are operated, the arm 20 is rotated, the brake band 23 is relaxed, and the braking force on each reel disk assembly 9, 11 is released. It is now in a state where it can rotate freely. Further, substantially the same voltage is applied to the pair of reel motors 6 and 7,
The reel disk assemblies 9 and 11 are to be rotated counterclockwise, that is, in the tape winding direction, with substantially the same torque. As a result, as described below,
The tape 66 is drawn out of the cassette with the back tension acting on the tape automatically minimized.

In addition, due to the above-mentioned tape draw-out command, the motor 8
9 starts. Note that in the store end state, the power gear 95 fixed to the worm shaft of the power unit 90 meshes with the gear portion 86c of the supply side drive gear 86 as shown in FIG.
It does not mesh with the gear portion 80e of the winding side drive gear 80.

When the motor 89 is started, the power gear 95 of the power unit 90 rotates clockwise, and the supply drive gear 86 rotates counterclockwise over the range in which the gear portion 86c is formed. The drive gear 86 initially rotates independently of the drive arm 83 (approximately 15
13A, the pin 87 comes into contact with the end of the elongated hole 86a, and then rotates integrally with the drive arm 83.

The rotation of the drive arm 83 is transmitted to the supply side cam block 119 as a clockwise rotation via the connecting arm 115, and the rotation arm plate 126 rotates in the same direction. Due to the rotation of the rotation arm plate 126, the supply drawer arm 123 starts to rotate clockwise via the compression coil spring 136 of the rotation biasing and braking assembly, and the tension roller 139 locks the tape. The tape 66 is then moved outside the cassette and begins to be pulled out of the cassette 31.

When the drive gear 86 rotates by a predetermined angle (26 degrees) in this state, the supply arm 123 rotates to the position shown by the dashed line in FIG. 3, and the tape drawer drive mechanism returns to the state shown in the mode in FIG. 13A. Become. That is, the timing protrusion 86 of the supply side drive gear 86
d collides with the timing protrusion 80f on the lower surface side of the winding side drive gear 80, and subsequently the drive gear 80 has its protrusion 80f pushed by the protrusion 86d and rotates together with the drive gear 86 in the same direction. Start.

Due to the rotation of the drive gear 86, the torsion coil spring 8
1, the arm holder 76 and arm 67 start rotating clockwise. As the arm 67 rotates, the guide roller 70 locks the tape and moves out of the cassette, and the tape 66 starts to be pulled out of the cassette 31 on the tape winding side. Note that the arm holder 76 is rotated against the rotation force applied by the action of the roller 102.

Due to the rotation of both drive gears 86 and 80, the supply side arm 123 and the take-up side arm 67 perform the tape pull-out operation in parallel, and the supply side arm 123 reaches the final position, and the tape pull-out drive mechanism is activated as shown in FIG. 13A. The state will be as shown in medium mode.

When the tape drawer drive mechanism reaches a state slightly before reaching the mode state (a state in which the gear portion 86c is engaged with the power gear 95 at a position near its final position),
The roller 103 is guided by the cam 80d, the arm 99 rotates clockwise against the spring 109, and the pressure arm 151 further rotates clockwise via the connecting rod 152. At this time, the cam block 119 has reached a rotational position where the starting end of the inclined cam portion 119b faces the pawl 150. Therefore, as the arm 151 rotates in the clockwise direction, the cam block 119 and the rotating arm plate 126 are pushed by the pawl 150 on the inclined cam portion 119b and are biased with clockwise rotational force, causing them to rotate somewhat in the same direction. and locked as described below.

Pressure arm 151 of cam block 119
Due to the clockwise rotation by the connecting arm 115,
A counterclockwise rotational force is applied to the drive gear 86 via the drive arm 87 and the torsion coil spring 88 .
Therefore, even though the gear portion 86c is disengaged from the power gear 95, the drive gear 86 further rotates clockwise due to the rotational force. Due to the rotation of the drive gear 86, the winding-side drive gear 80 is still pushed by the protrusion 80f and rotates in the same direction, and this gear part 8
0e meshes with the power gear 95 reliably. As a result, the tape drawer drive mechanism enters the above mode. Drive gear 8 between modes
6 rotates about 30 degrees.

The locking mechanism of the cam block body will now be explained. As shown in FIG. 10, the hole 151a of the bearing portion of the pressure arm 151 is not circular, but has a shape with a V-shaped notch 151b in a part of its outer periphery. Further, the hole 119c in the bearing portion of the cam block 119 is not circular, but has a V-shaped cutout groove 119d formed on a portion of its outer periphery.
Here, the V-shaped notches 151b and 119d are formed so as to coincide with the radial direction in which the bearing portions are pressed against the respective shafts in the tape drawing end state.

In the tape drawing end state, the cam block body 119 has its inclined cam portion 1
19b is locked by the pole 150 of the arm 151 rotated clockwise, and the rotating arm plate 12
6 lock pin 132 into the V groove 4 of reel deck 4.
a and is locked with limited rotation in the counterclockwise and clockwise directions. Further, at this time, since the arm 151 is subjected to a clockwise rotational force centering on the pressure contact portion of the pawl 150 to the inclined cam portion 119b, the arm 151 is rotated through the rotation center hole 151a as shown in the mode of FIG. 13A. V-shaped notch 151
b is pressed against the circumferential surface of the bushing 148 to reliably restrict movement in the longitudinal direction, that is, in the direction in which the rotational force of the cam block body is received. Further, regarding the cam block body 119, due to the pressing force of the pawl 150, a clockwise rotational force is applied around the lock pin 132 fitted in the V groove 4a.
This rotational force causes the V-groove 119d of the hole 119c to be positively pressed against the circumferential surface of the shaft 121, thereby reliably controlling play in the shaft bearing portion. As a result, the cam block body is reliably and stably locked at the pull-out end position shown in FIG. 1 without any risk of displacement. Therefore, the tension control operation using the arm 123 as a tension arm is stably performed as will be described later.

When the cam block body is locked, the supply side drawer arm 123 reaches the position shown in FIG. 1 and the position shown by the two-dot chain line in FIG. It comes into contact with the tip of the detection lock 165a.

The rotation of the power gear 95 is in turn transmitted to the drive gear 80, and the drive gear 80 continues to rotate in the counterclockwise direction, and the tape drawing operation on the winding side continues. When the drive gear 80 further rotates by a predetermined angle (approximately 60 degrees), the take-up side pull-out arm 67
reaches the final position where its side surface abuts against the bent portion 52a of the guard plate 52, and rotation in the counterclockwise direction is restricted. At this time, the tape drawer drive mechanism
The state shown in the mode in Figure 3B is reached. Further, the lock ring 72 of the arm 67 is located at a position opposite to the locking hook portion 97a of the end lock arm 97.

Power gear 95 rotates further (angle β _T ) and the mode advances. As the power gear 95 rotates, the drive gear 80 rotates counterclockwise as the torsion coil spring 81 is torsionally deflected. At this time, the pin 79 moves relatively along the long hole 80a. power gear 95
Due to the above rotation, the cam 80c pushes the roller 101, and the end lock arm 97 rotates clockwise against the spring 108.

As the end lock arm 97 rotates, its locking hook 97a bites into the lock ring 72 so as to restrict clockwise rotation of the arm 67. As a result, the take-up side drawer arm 67 is reliably fixed at the final rotational position by the bent portion 52a and the locking hook portion 97a.

Here, the tape pull-out arms 123 and 67 are locked in their final positions by the mechanism that drives the tape pull-out mechanism. Therefore, there is no need for a special drive source such as a solenoid, which simplifies the configuration and reduces the number of parts used.
Furthermore, the lock timing can be determined accurately.

Further, due to the above-mentioned rotation of the arm 97, the bent portion 97b on the other end side pushes the leaf of the micro switch 113 to put it into an operating state. As a result, the take-up side draw-out completion command is transmitted to the control system of the recording/reproducing apparatus, and the drive of the motor 89 is stopped. motor 8
9 rotates somewhat due to inertial energy and then stops, and the tape drawer drive mechanism enters the state shown in mode V in FIG. 13B. In this state, the angle α
(An angle at which the drive gear 80 can rotate counterclockwise independently of the arm holder 76) is an angle T (an angle at which the drive gear 80 can be rotated by the power gear 95, and a gear portion 80e is formed. (determined by the angle). Therefore, even if the power gear 95 continues to rotate due to some kind of failure,
When the drive gear 80 is further rotated by an angle γ _T without pushing the pin 79, the final tooth of the gear portion 80e will escape from the power gear 95, and the gear 80 will not be rotated and the device will be destroyed. It won't happen.
Further, since the driving gear 80 is biased with clockwise rotational force by the torsion coil spring 81, the final tooth of the gear portion 80e is connected to the rotating power gear 95.
This sound is generated as an abnormality alarm sound.

Further, in response to the take-up side draw-out completion command, the pair of solenoids 28 are de-energized and deenergized, the brake band 23 is tensed by the spring 26, and a braking force is applied to the reel disk assemblies 9, 11. Also, according to the above command, each reel motor 6, 7
The voltage supply to is also cut off.

As a result, the recording/reproducing apparatus enters the state in which the ``tape drawing'' is completed as shown in FIG. 1, and the tape 66 is drawn out of the cassette and attached to the addressing head 180 located at a predetermined position outside the cassette. That is, the tape 66 pulled out from the tape roll on the supply side is guided by the tape guide 171, and then transferred to the full-width erasing head 181 and the address head 18.
0, and is guided by the tape guide 170, tension roller 140, and tape guide 175 on the drum base, and is further guided by the inclined guide ball 157 between the supply side tape roll and the take-up side tape roll. The tension in the width direction of the tape due to the height position step is adjusted, and the tape is guided by a guide roller 70 attached to a part of the guide drum 64 and further stably held at a fixed position on the winding side, and the tape guide roller assembly is assembled. 35 and reaches the tape roll on the take-up side inside the cassette.

As described above, in the tape pull-out operation, the supply-side pull-out arm 123 and the take-up-side pull-out arm 67 start rotating at different times and continue to operate while maintaining a predetermined relationship with each other. The above predetermined relationship means that the length of the tape path formed outside the cassette after being pulled out of the cassette during the tape pull-out operation is as shown by the graph line in FIG. It is set to increase at a certain rate. That is, the speed at which the tape is drawn out from the cassette at each point in time during the tape drawing operation process is always approximately constant, so that no excessive back tension is applied to the tape being drawn out, and there is no variation in the load on the tape drawing mechanism. , the tape drawing operation is performed stably.

Note that when the two systems of drawer arms 67 and 123 are operated simultaneously, the length of the tape path formed outside the cassette during the tape drawer operation process changes as shown by the graph line in FIG. .
That is, there is a large variation in the speed at which the tape is drawn out of the cassette during the tape drawing process, and this causes an unreasonable force to be applied to the tape.

In order to achieve the above object, contrary to the case of this embodiment, the drawer arm on the tape winding side is first rotated, and then the drawer arm on the supply side is rotated. You can also do it. Also,
In the above embodiment, both drawer arms 12
Since the operation timings of the arms 3 and 67 are determined by the protrusions 80f and 80d formed on the gears that rotate each arm, the timings can be determined accurately with a simple configuration.

Next, the tape drawn out from the cassette in the tape drawing mode will be explained.

In tape draw mode, reel motors 6 and 7
have approximately equal torque in the tape winding direction (approximately
150g _r −cm) is given. For this reason, the tape is naturally pulled out from the tape winding body with the smaller tape pull-out drag to form a tape path. Especially when there is a large difference in the diameter of both tape winding bodies, the tape winding diameter It is wound up into a small winding body and drawn out of the cassette while traveling.

Specifically, it is as follows.

When most of the tape is in the supply tape roll, and there is very little or no tape in the take-up tape roll: When the tape is pulled out, the tape is pulled out from the supply tape roll, and the tape is not taken up. It is wound up on the side tape winding body and transferred to the winding side.

When the diameter of the tape roll on the supply side is larger than the diameter of the tape roll on the take-up side: When withdrawing the tape, the take-up reel remains stationary and the tape is pulled out from the tape roll on the supply side. It will be pulled out of the cassette.

When the diameter of the tape winding on the supply side is approximately the same as the diameter of the tape winding on the take-up side: When drawing out the tape, the tape is pulled out from both tape windings and out of the cassette.

When the diameter of the tape winding on the take-up side is relatively larger than the diameter of the tape winding on the supply side: When withdrawing the tape, the supply reel remains stationary and the tape is pulled out from the tape winding on the winding side. It will be pulled out of the cassette.

When most of the tape is in the take-up tape roll, and there is very little or no tape in the supply tape roll: When the tape is pulled out, the tape runs from the take-up side to the supply side, i.e., when the tape is drawn out, the tape runs from the take-up side to the supply side. The tape is taken up on the side reel and pulled out of the cassette from the tape winding body on the take-up side.

Thereby, when the tape is drawn out, the tape is drawn out from the wound body on the side that is easily drawn out, that is, the tape is drawn out smoothly with the minimum tension. This is highly desirable in terms of tape protection. Furthermore, when the tape is pulled out, it is possible to reliably avoid applying excessive force to the tape itself due to the tape being pulled out to the end. Accidents such as damage to the rotating magnetic head etc. due to contact with the drum 64 and damage to other fixed heads for the same reason are prevented.

In this state, the recording/reproducing apparatus is placed in fast forward or rewind mode, and when the tape is running at high speed, a control signal or an address signal is reproduced by the address head 180, and a random access operation for quickly detecting a predetermined position on the tape 66 is performed. In addition,
Fast forward and rewind mode (or search mode)
This is done by releasing the braking force on both reel disc assemblies 9 and 11 and driving the take-up reel motor 7 or the supply reel motor 6, and the tape 66 is rolled while the tape tension is controlled. To run smoothly at high speed without causing creases on widthwise edges.

Here, the tape tension control mechanism and operation will be explained. First, the principle of the tension control mechanism will be explained with reference to FIG. 15. The tension arm 185 is pivotally supported by a shaft 186, and has a tension pole 187 erected at one end thereof, and a tape 188 is wound and guided around this pole 187. The tape 188 has tape tensions T ₁ and T ₂
This applies a rotational force to the tape 185 in the counterclockwise direction. A compression coil spring 189 is provided at the other end of the arm 185, and this spring 189 imparts clockwise rotational force to the arm 185. The rotational position of the arm 185 is a position where the rotational force exerted by the tape tension and the rotational force exerted by the spring 189 are balanced, that is, a position representing the magnitude of the tape tension. The rotational position of the arm 185 is detected by a differential transformer 190, and the back tension of the tape is controlled by this output voltage. Note that the detection terminal 19 of the differential transformer 190
0a is constantly in contact with the tension arm 185 by a spring with a very small spring constant.

In this apparatus, the tension control mechanism is provided at the supply side tape outlet section and the take-up side tape outlet section. The tension control mechanism of the supply side tape exit section, which is the main part of the present invention, is based on the tension roller 13.
9, an arm 123, a compression coil spring 136, a position detection differential transformer 165, etc. Here,
The compression coil spring 136 is kept in a fixed position by the rotating arm plate 126 which is stably locked, and the differential transformer 165 is screwed to the board 147, so that the positional relationship between the two is reliably kept constant.
Tension detection and control are performed accurately. Furthermore, since the differential transformer 165 is fixedly provided, the wires drawn out from it can be wired easily. Note that the differential transformer 165 can also be attached to the rotating arm plate 125, but in this case, it is necessary to give the wire a predetermined slack depending on the rotational movement range of the transformer 165.

On the other hand, the tension control mechanism at the tape exit section on the winding side includes the tape guide roller assembly 35 and the arm 3.
6, a compression coil spring 51, a position detection differential transformer 55, etc.

In the fast-forward mode, the supply side mechanism cooperates with the reel motor 6, and in the take-up mode, the take-up side mechanism cooperates with the reel motor 7.

In the fast feed mode, the take-up reel motor 7 rotates counterclockwise at a constant speed in cooperation with the rotation speed detection mechanism at the bottom of the reel assembly, and the supply reel motor 6 applies voltage from the differential transformer 165. A braking force is applied to the tape 66, and a back tension is applied to the tape 66. This back tension is detected by the tension roller 139 on the supply side, and the arm 123 rotates according to the magnitude of the tape tension due to the action of the compression coil spring 136, and the output voltage from the differential transformer 165 changes. . As the tension increases, the braking force of the reel motor 6 decreases, and conversely, as the tension decreases, the braking force of the motor 6 increases, and the tape tension is controlled to a predetermined value.

In addition, in the winding mode, the supply reel motor 6 rotates counterclockwise at a constant speed in cooperation with the rotational speed detection mechanism, and the winding side reel motor 7 receives voltage from the differential transformer 53. A braking force is applied and back tension is applied to the tape 66. In this mode, the tape tension is detected by the tape guide roller assembly 35, and as in the case described above, the braking force of the reel motor 7 is varied depending on the magnitude of the detected tape tension. The tension is controlled to a predetermined value.

Note that each of the tension control mechanisms described above is constructed so as not to cause resonance during operation.

Furthermore, since the tape tension can be controlled in the fast forward mode and the rewind mode as described above, the following effects are achieved.

The attachment of the tape 66 to the address head 180 becomes stable, and the address head 180 reads and reproduces address signals without error, thereby allowing accurate random access.

No uneven winding or fluctuations in winding height occur on the tape roll.

Since the tension roller 139 is always stably attached to the tape, it is possible to stably rotate the roller as the tape runs without causing any slip between the roller and the tape.
The actual running length of the tape can be accurately measured by counting the number of revolutions of the tape.

The reason for providing separate tension control mechanisms on the supply side and take-up side is to perform tape tension control on both the tape supply side and the tape take-up side during recording/playback mode, which will be described later. It is. Also, the reason why the tension control mechanism on the supply side is selectively operated in the fast-forward mode and the tension control mechanism on the take-up side in the rewind mode is that the tape tension and winding at the position of the tension roller 139 in the fast-forward mode are Since the tape tension at the position of the tape guide roller assembly 35 in the return mode has approximately the same value as the tape tension in the recording/playback mode, the tape tension recording in the fast forward mode and the rewind mode is This is because the output voltage of the differential transformer 165 or 55 can be used as is for controlling the tape tension in the reproduction mode, and there is no need to provide a special electric circuit.

If the address signal, etc. reproduced by the address head 180 during high-speed tape running matches the preset value, the recording/reproducing apparatus stops running the tape at high speed and enters tape loading mode, tape store mode, or the like.

The tape loading operation is carried out by rotating the loading ring 57 clockwise to a predetermined position, and the tape 66 is stopped by the return roller 65 and pulled out from the tape winding body on the winding side to be placed on the drum 64. It is routed around the drum and loaded into a predetermined path that extends approximately 180 degrees to the drum. Note that when the ring 67 reaches the final position, the tape path adjustment arm 161 rotates the leaf spring 158 clockwise against the spring 160 by being pushed by the shaft support of the pinch roller arm 62, and the guide pole 157 rotates. The tape retreats from the tape path and leaves the tape 66 and is guided by the tape guide 175 directly onto the guide drum 6 as shown by the dashed line.
Reach 4. That is, since adjustment of the tape path by the guide ball 157 is required only in the fast forward and rewind modes, the guide pole 157 is in a retracted position away from the tape 66 in the recording/reproducing mode. After loading is completed, the device enters the recording or playback mode, in which both the supply and take-up tape tension control mechanisms operate.

Note that in the fast forward mode, rewind mode, and recording/reproducing mode, the winding angle of the tape 66 with respect to the tension roller 139 on the supply side is relatively large;
rotates as the tape runs with almost no slippage between the tape and the tape. Therefore, by detecting the rotation of the tension roller 139 by optical means or the like and counting the number of rotations, the actual tape running length in each of the above modes can be determined from the counted value.

Furthermore, when a store command enters the control system of the apparatus, the pair of solenoids 28 are energized, the braking force on each reel disk assembly 9, 11 is released, and the supply side reel motor 6 is activated for tape winding. A voltage is applied.

Subsequently, the motor 89 reverses, and the tape drawer mechanism operates in the reverse order (13th
Mode in Figure B and Figure 13A→→→→
), and the winding-side drawer arm 67 and the supply-side drawer arm 123 sequentially rotate clockwise and counterclockwise. Here, the arms 67, 12
As shown by the graph line in FIG. 14, the rate at which the length of the tape path formed by No. 3 decreases is approximately constant over the entire tape store operation process.
Therefore, as the arms 67 and 123 sequentially move, the tape 66 outside the cassette is wound onto the supply reel by the motor 6 and stored in the cassette 31 without loosening.

When the arm 123 on the supply side rotates to the final position shown in FIG. 3, the micro switch 169 is pushed by the arm portion 123b and turned on, and a store end command is sent to the control system. As a result, the solenoid 26 is demagnetized and each reel disk assembly 6 is
A braking force is applied to motors 7 and 7, and the motor 89 is de-energized, rotates somewhat due to inertia, and then stops. In addition,
The rotation angle of the drive gear 80 due to the inertial rotation of the motor 89 is δ _s in FIG. Here, the long hole 86a
drive gear 86 until the end of the drive gear 86 contacts the pin 87.
The rotation angle α _S (that is, the angle at which the drive gear 86 can rotate clockwise independently of the drive arm 83 with the deflection of the torsion coil spring 88) is the angle at which the drive gear 86 is rotated by the power gear 95. It is assumed that the angle γ S is larger than the curve angle γ _S. Therefore, even if the motor 89 continues to rotate due to some kind of failure, the drive gear 86 will only be rotated by an angle γ _S , and at this time, the end of the elongated hole 86a will not abut against the pin 87. .
Therefore, as in the case of the tape pull-out mode, no excessive force is applied to the device, and no inconvenience such as destruction of the device occurs. Further, when the power gear 95 continuously rotates, the gear 95 rotates through the gear portion 86c.
The last tooth of the machine will open, and the sound at this time will be generated as an abnormality alarm sound.

If an abnormal alarm sound is generated in the tape drawer mode or store mode, the operator can simply turn off the power of the apparatus. Note that since damage to the mechanical system of the device is prevented, the device can operate normally by simply repairing the electrical system of the motor 89.

In the above embodiment, the driving force is transmitted from the motor to the tape drawing mechanism using a gear, but the present invention is not limited to this, and the driving force may be transmitted using friction rollers that press against each other. . In this case, the drive gear 8
0.86 By forming the friction transmission part only in the part where the middle gear part is not formed, and making the other parts small in diameter so that they do not come into pressure contact with the power friction wheel, the rotation of the power friction wheel can be prevented due to a failure in the same way as above. Even if the system does not stop, destruction of the device can be prevented.

By the way, by stopping the motor 89, the apparatus enters the tape store completion state shown in FIG.

As described above, according to the tape tension control device of the present invention, in a device that draws a tape out of a cassette and runs it along a formed tape path, the tape tension control device moves the tape from a position inside the cassette to an operating position outside the cassette in the tape draw-out mode. A tape drawer rotating arm mechanism that locks the tape and moves to pull out the tape; and a reference value in the tape drawer direction on the rotating arm having a tape drawer guide member at one end of the tape drawer arm mechanism in the operating position. A spring means for applying a rotational force and a detection rod integrally formed with the core are always brought into positive contact with a part of the rotation arm, and the rotation position of the rotation arm is detected at the above-mentioned operation position. It consists of a differential transformer that outputs a control voltage according to the moving position, and a reel motor to which the control voltage from the differential transformer is applied and a rotational load according to the control voltage is electrically applied,
The tape pull-out arm mechanism is rotatably supported by positively fitting the rotating arm and a V-shaped groove formed on the side surface of the rotating center hole into the fixed center shaft,
Since the structure consists of the rotating arm and a driving rotating arm that is connected via the spring means and rotates the rotating arm to the operating position, the tension arm is separate from the tape drawer arm. Since there is no need for a special provision, not only can the configuration be simplified, but also tape tension control can be performed well when the tape is running in both directions, and when the tape is running while the tape speed is significantly changed. The high performance of the device can be achieved, and furthermore, the V-shaped groove of the drive rotating arm actively engages with the fixed center shaft, completely preventing play at the shaft support at the final rotation position. Because it is held stably in a
It has an excellent feature that the tape tension control operation can be performed accurately and stably even when the device itself is being transported or when an external shock is applied to the device.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of a tape drawing device to which the tape tension control device of the present invention is applied, in the tape drawing end state, and Fig. 2 is a partially longitudinal front view of the device shown in Fig. 1. Figure 3 is the first
The figure shows the state of the tape drawer system at the end of the tape store, Figure 4 is a sectional view of the rotary biasing-brake assembly, and Figures 5 and 6 are the tape pullout mechanism on the winding side. Fig. 3 is a sectional view taken along lines - and - in Fig. 3 showing the structure, and Fig. 7 shows the rotating members and arm members of the take-up side tape pull-out mechanism corresponding to their respective positions in the store end state. Exploded view, FIG. 8 is a plan view of the supply side tape pull-out mechanism that functions as a tension control device according to the present invention;
FIG. 9 is a sectional view of the supply-side tape pull-out mechanism taken along the line - in FIG. A diagram showing the relationship between the drive arm and the supply side drive gear (mechanism that applies a counterclockwise rotational force to the supply side drawer arm 123) in the store end state. Diagram 13A showing a mechanism that applies clockwise rotational force to the arm
13B and 13B are diagrams showing the states of the supply side and take-up side drawer mechanisms at different times in the tape drawer mode, and FIG. 14 is a diagram showing the relationship between the tape drawer operation stroke and the tape path length formed. The graph diagram, FIG. 15, is a diagram showing the operating principle of the tension control mechanism. 1... Reference deck, 6... Supply side reel motor, 7... Take-up side reel motor, 9, 11... Reel disk assembly, 31... Video cassette,
57...Loading ring, 66...Tape,
70... Guide roller, 80... Drive gear, 86
... Supply side drive gear, 89 ... Motor, 90 ...
Power unit, 95... Power gear, 115...
Connection arm, 119...cam block, 119d
... V-shaped notch, 121 ... shaft, 123 ... supply side drawer arm, 123a ... bending part, 124
... Spring holder, 126 ... Rotating arm plate, 130 ... Sliding rod, 136 ... Compression coil spring, 137 ... Sliding pipe, 138 ... Ball bearing, 139 ... Tension roller, 140 ...
...shaft, 141 ... ball bearing, 150 ... pressure pole, 151 ... pressure arm, 15
2... Connection rod, 165... Differential transformer for position detection, 165a... Detection rod, 166... Bracket, 180... Address head.

Claims (1)

[Claims] 1 In a device that pulls out a tape outside a cassette and runs it along a formed tape path, a tape pull-out circuit that locks the tape from a position inside the cassette to an operating position outside the cassette and pulls out the tape in the tape pull-out mode. Detection integrated with a core, including a moving arm mechanism, a spring means for applying a rotational force serving as a reference value in a tape drawing direction to a rotating arm having a tape drawing guide member at one end of the tape drawing arm mechanism at the operating position; The rod is always actively brought into contact with a part of the rotating arm,
A differential transformer that detects the rotating position of the rotating arm at the operating position and outputs a control voltage according to the rotating position, and a rotating load that is applied with a control voltage from the differential transformer and that responds to the control voltage. and a reel motor to which the tape pull-out arm mechanism is electrically applied, and the rotating arm and the V-shaped groove formed on the side surface of the rotating center hole are positively fitted to the fixed center shaft. A tape tensioner characterized in that the tape tensioner is rotatably supported, and is configured to include the rotary arm and a driving rotary arm connected via the spring means to rotate the rotary arm to an operating position. Control device.