JPH0414654A - Tape tension detecting mechanism - Google Patents

Abstract

PURPOSE:To detect tape tension even during loading and unloading by always bringing a tape into contact with a tape tension detection guiding means. CONSTITUTION:A Hall sensor unit (composed of a Hall sensor 74, a Hall sensor board 66, a Hall sensor base 65) is disposed on the same member as a loading plate 63 provided with a leaf spring 68 and a loading mechanism (composed a loading lever 60, a cam slot 61, a shaft 62, a tensile spring 71 and a shaft 72) is provided so that the tape 5 is always brought into in contact with a tape tension detection roller 7 during loading. The loading mechanism uses integrally a tape tension detecting mechanism, that is, a tape tension detecting arm 70, a supporting mechanism for the leaf spring 68 and and the position detecting mechanism such as the Hall sensor 74 for loading the tape. The tension detecting mechanism always detects the tape tension as the movement of the tape tension 70.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape tension detection mechanism, and particularly to an arm-type tape tension detection mechanism in a magnetic tape running device such as a magnetic recording/reproducing device.

(Prior Art) As this type of device that runs a tape by controlling tape tension, there is a magnetic recording/reproducing device (hereinafter referred to as a VTR) having a rotating tram equipped with a magnetic head.

FIG. 9 shows a schematic plan view of essential parts of an example of a tape running system after tape loading in a conventional VTR. 101
is the main chassis, 102 is the cassette half, 103 is the supply side reel, 104 is the take-up side reel, 105 is the magnetic tape, 106°108.110,111,113,1
14゜116 119. 120, 121 are each tape guide for kiting the fidget tape 105, 107
is a tension detection roller for detecting tape tension, 109,115! Each fixed head. 112 is a rotating drum equipped with a magnetic head; 117 is a tape 1;
This is a capstan for conveying the 05 by pinching it with the pinch rollers 118.

In the VTR on the side, the tape 105 is pulled out from the supply reel 103, and is moved through a tape guide 106, a tension measuring roller 107, and so on. Tape guide 108. Fixed head 109. It wraps around the rotating drum 112 via tape guides 110, 111. Furthermore, the tape 105 is conveyed via each tape kite 113, 114, fixed head unit 115° tape guide 116, while being held between a capstan 117 and a pinch roller 118. Furthermore, the tape 105 is connected to each tape guide 119, 120, 1
21 to be taken up by the take-up reel 104.

The tape tension in this VTR is detected by the tension detection roller 107. An enlarged plan view of the main part of this mechanism is shown in FIG. 10, and an enlarged sectional view of the main part is shown in FIG.
As shown in the figure. 160 is a rope ink lever, the 11th
The loading plate 163 shown broken in the figure is the shaft 1.
62 and is rotatably supported. A mechanical limiter 164 (hereinafter abbreviated as mechanical limiter) limits the movement of the arm 170 by coming into contact with a spring support shaft 169 provided on the tension detection arm 170 (shown broken in the figure). Reference numeral 167 is a mechanical limiter shaft, which contacts the tension detection arm 170 and thereby
0 movement is restricted. 165 is a hall sensor stand,
It is screwed onto the main chassis 101, and a Hall sensor board 166 is screwed onto the top surface.

A spring 168 elastically supports the tension detection arm 170 via the spring support shaft 169. A magnet 173 is fixed to the tension detection arm 170 with a screw. 174 is a Hall sensor (Hall element) mounted on the Hall sensor board 166, and 175 is a leaf spring! A spring plate is provided with a 68° mechanical limiter 164 and is screwed onto a loading plate 163. 176 is a limiter plate on which a mechanical limiter shaft 167 is erected, which is similar to the loading plate 163 described above.
It is screwed on top.

177 is a rotation support shaft of the tension detection arm 170.

Here, a means for detecting the tape tension of the magnetic tape 105 will be explained. The tape tension is transmitted to the tension detection roller 107, giving the tension detection arm 170 a clockwise rotation moment in FIG. 9.10. On the other hand, a spring support shaft 169 provided on the tension detection arm 170 pushes a leaf spring 168 provided on the loading plate 163. Loading plate 163
is fixed by the loading lever 160, giving the tension detection arm 170 a counterclockwise rotation moment in FIG. 9.10. Eventually, the tension detection arm 170 moves until the tape tension and the force of the leaf spring 168 are balanced. That is, the tension detection arm 170 rotates by an amount corresponding to the tape tension at that time. This amount of rotation is measured by the Hall sensor (element) 174.
and McNet. Tension detection arm 17
A macnet 73 for this purpose is provided on the tension detection arm 170, and moves together with the tension detection arm 170. On the other hand, on the main chassis 101 is a Hall sensor stand 165.
Hall sensor 17 via and Hall sensor board 166
4 is fixed. The Hall sensor 174 is an element that generates a voltage in response to changes in the magnetic field, and can thereby detect the movement of the macnet 173 on the tension detection arm 170.

This mechanism is configured to be able to detect tape tension. Furthermore, in the VTR, tape tension is controlled based on this information. Its block diagram is shown in FIG. Tension detection mechanism 18
The tape tension detected by 0 is converted into a voltage signal by a Hall sensor 174, amplified by an amplifier 182, compared with a target tension voltage 183 by a comparator 184, and an error voltage is output. Furthermore, the motor driver 18
5 outputs a motor voltage corresponding to the error voltage, and the reel motor 186 applies back torque to the supply reel 187 to control tape tension.

Here, the VTR of the tension detection mechanism 180
The funnel and unloading operations will be explained with reference to FIG. FIG. 12 is a plan view of the VTR after unloading is completed.

130, 431, 132, and 138 are respective gears driven by loading motors (not shown), and 133 is an entrance side loading ring, the outer periphery of which meshes with the gear 132 and drives the ring. Moreover, the loading ring 133 is
A skate 136 provided with a tape guide on the drum artificial side is pulled along a guide groove 137 via a charging mechanism 134 and a lever 135. Reference numeral 139 denotes an exit side loading ring, the outer periphery of which meshes with the gear 138 to drive it.

Further, this rotating ring 139 is connected to the charging mechanism 140. A skate 142 provided with a tape guide on the drum outlet side is pulled along a guide groove 143 via a lever 141. 147 is the loading lever, gear 14
6 via a charging mechanism (not shown). This rope ink lever 147 is connected to the skate 14 provided by a pinch roller and a tape guide via a lever 148.
9 along the guide groove 150. The gear 146 is driven by the rotating ring 139 through gears 144 and 145. Reference numeral 160 denotes the already mentioned rope ink lever, which is rotatably supported on the gear 146 and the rope ink plate 163. Also, 170 is
The tension detection arm mentioned above! 74 is a Hall sensor.

Next, the loading operation of the tension detection mechanism will be explained. In FIG. 12, a loading motor (not shown) connects the mouth to the ding ring 133 via each gear 130, 131132, and each gear 130, 131, 1.
A loading ring 139 is also driven via 32,138.

At the same time, loading levers 147 and 160 are driven via gears 144, 145, and 146, respectively. At this time,
Each of the loading links 133139 drives each skate 136 and 142 via a charging mechanism 134 and a lever 135 and 141, respectively. Also,
Loading lever 147 drives skate 149 via lever 148. Furthermore, the rope ink plate 163 is rotationally driven by the loading lever 160. As a result of the above, each skate 136, 142, 1
49 and a tape kite provided on the tension detection arm 170 to pull out the tape 105 and perform a loading operation. Here, the tension detection mechanism is rope-inked by the loading plate 163, and after the loading is completed, the movement detection mechanism of the tension detection arm 170 by the Hall sensor 174 is activated to detect the tension.

By the way, the Hall sensor 174 that detects the movement of the tension detection arm 170 has conventionally been installed via the Hall sensor stand 165 on the main chassis 101 which is fixed separately from the loading plate 163 and does not move. I hit it.

The Hall element voltage output with respect to the movement amount of the Hall sensor 174 and the magnet 173 is shown in the 14th diagram showing an example of its characteristic diagram.
The relationship is as shown by the dotted line in the figure. That is, the relationship has an extreme value when the north pole or south pole of the macnet 173 approaches.

Therefore, the movement of the tension detection arm 170 is limited to the area indicated by X in FIG. 14 by the mechanical limiters 164 and 167 shown in FIGS. 10 and 11. Furthermore, electrically, the Hall element voltage used for tension control is limited to vc to avoid malfunction of tension control due to false detection by sensor 174.

[Problem to be solved by the invention]

However, in the conventional example as described above, the Hall sensor 174 is fixed on a separate member from the load ink plate 163, and the tape 105 is constantly in contact with the tension detection roller 107 during loading. Not yet. For these reasons, the tension detection mechanism cannot be activated until loading is complete and a complete tape bus is formed, making it impossible to detect abnormal tension during loading/unloading. there were.

The present invention has been made in view of the problems of the prior art as described above, and an object of the present invention is to provide means that can constantly detect tape tension even during tape loading and unloading.

(Means for Solving the Problems) Therefore, in the present invention, a control device for controlling tape tension and running the tape includes a tape guide means for detecting the tape tension, and one end of which is rotatably supported. and a tape tension detection arm having a tape tension detection kite means at the other end thereof, elastic support means for biasing the arm in a rotational direction, and position detection means for detecting movement of the arm. Tape tension detection means for pulling out a tape from a cassette half, the elastic support means and the position detection means being disposed on the same loading plate, and during loading and unloading of the tape, the tape tension detection means The above object is achieved by configuring the tape tension detection mechanism so that the loading plate is provided with elastic means for constantly contacting the tape tension detection guide means.

[Effect]

With the configuration of the tape tension detection mechanism as described above,
Since the tape is always in contact with the tape tension detection guide means, it is possible to detect the tape tension even during loading and unloading.

〔Example〕

The present invention will be explained below based on examples.

1 and 2 are a plan view and an enlarged cross-sectional view of essential parts of an embodiment of the tape tension detection mechanism according to the present invention, and FIG. 3 is a V
A schematic plan view of the tape running system upon completion of loading of the TR is shown, and the same (equivalent) components as in the conventional example shown in FIGS. 9 to 13 are represented by corresponding symbols excluding 100-digit numbers.

(Configuration) 1 is the main chassis, 2 is the cassette half, 3 is the supply side reel, 4 is the take-up side reel, 5 is the magnetic tape, 6, 8,
10, 11, 13, 14° 16.19, 20.21 are
each tape guide for respectively guiding the tape 5;
7 is a tension detection roller as a tension detection guide means, 9.15 is each fixed head, 12 is a rotating tram equipped with a magnetic head, and 17 is a pinch roller 1 for the tape 5.
This is a capstan that is used to hold and transport items. The tape 5 is pulled out from the supply reel 3, and the tape kite 6
, tension detection roller 7, tape kite 8. Fixed head9. Rotating drum 1 through each tape guide 10.11
Wrap around 2. Further, the tape 5 is connected to each tape guide 13.
゜14, fixed head unit 15. The tape is conveyed through a tape guide 16 while being held between a capstan 17 and a pinch roller 18 . And each tape kite 19.2
0.21, and is wound onto the winding reel 4.

(Tension Detection Mechanism) Next, regarding the tension detection mechanism implementing the present invention,
This will be explained using FIG. 1, which is an enlarged plan view that best shows the characteristics, and FIG. 2, which is an enlarged sectional view.

60 is a loading lever, and above it is a cam groove 6.
1 is formed. 62 is the loading plate 6
There is a shaft provided on the lower surface of the cam 3, which is pulled by a tension spring 71 and is brought into contact with the side surface of the cam 61. 64
The mechanical limiter limits the movement of the arm 70 by coming into contact with a spring support shaft 69 provided on the tension detection arm 70. 67 is the mechanical limiter axis,
By coming into contact with the tension detection arm 70, the movement of the arm 70 is restricted. Reference numeral 65 denotes a Hall sensor stand, which is screwed onto the rope ink plate 63, and a Hall sensor board 66 is screwed onto the top surface. A plate spring 68 elastically supports the tension detection arm 70 via the spring support shaft 69 described above. 72 is a shaft provided on the main chassis 1, and the above-mentioned tension spring 7
This is the fixed end of 1. A magnet 73 is fixed to the tension detection arm 70 with a screw.

74 is a Hall sensor (Hall element) mounted on the home sensor board 66, and 75 is the leaf spring 68. With a spring plate that is fixed by a mechanical limit 64,
It is arranged on the loading plate 63. A limiter plate 76 is provided with a mechanical limiter shaft 67 and is disposed on the loading plate 63. 7
7 is a rotation support shaft of the tension detection arm 70.

The operating principle of the tension detection mechanism is the same as that of the conventional example described above, and therefore, repeated explanation will be omitted here. The features of this embodiment are that the Hall sensor unit, that is, the Hall sensor 74, the Hall sensor board 66, and the Hall sensor stand 65 are disposed on the same member as the rope ink plate 63 provided with the leaf spring 68, and that The loading mechanism, ie, the loading lever 60, the cam groove 61. Axis 62. This is because a tension spring 71 and a shaft 72 are provided.

By the former mechanism, the tension detection mechanism, that is, the tension detection arm 70. It becomes possible to integrate and load the leaf spring 68 support mechanism, the position detection mechanism such as the Hall sensor 74, etc.

Furthermore, the latter mechanism allows tape tension to be constantly detected as movement of the tension detection arm 70.

(Loading mechanism) Based on the plan views shown in FIGS. 3 to 8 showing changes in the loading state of the tape running system of the VTR,
The rope ink mechanism of this embodiment will be explained. FIG. 4 is a front view of the VTR running system of this embodiment in an unloaded state. Numerals 30, 31, 32, and 38 are gears driven by a loading motor (not shown), and 33 is a loading ring on the artificial side, the outer periphery of which meshes with the gear 32 and is driven. Further, this loading link 33 is connected to a charging mechanism 34. A skate 36 provided with a tape guide on the drum entrance side is pulled along the guide groove 37 via the lever 35. 39 is the exit side loading link, and the outer periphery is the gear 38
It engages and drives. Also, this rhodein ring 3
9 is a charging mechanism 40. The skate 42 provided with the tram exit tape guide is pulled along the guide groove 43 via the lever 41. A loading lever 47 is provided to the gear 46 via a charging mechanism (not shown). This loading lever 47 is connected via a lever 48 to a skate 49 equipped with a pinch roller and a tape kite.
is pulled along the guide groove 50. The gears 46 are driven by the loading ring 39 via respective gears 44,45. 60 is a loading lever, which is driven by the gear 38 in the vertical direction. A cam groove 61 is formed on the rotin lever 60, and guides a shaft 62 provided on the lower surface of the rope ink plate 63 with the help of a tension spring 71.

(Loading Operation) Next, the loading operation will be explained. A loading motor (not shown) drives each gear 30.31.3.
2 through the loading link 33 or each gear 30
, 31, 32, and 38, the loading link 39 and the loading lever 60 are driven. At the same time, the loading lever 47.degree. 60 is driven through each gear 44.degree. 45.46. At this time, the loading link 3
3.39 or fidget charging mechanism 34°40, lever 3
5.41 also drives each skate 36.42. Further, the rope ink lever 47 drives the skate 49 via the lever 48.

On the other hand, loading of the tape tension mechanism is as follows. the loading lever 60 that moves in the vertical direction;
A cam groove 61 is formed on the top, and this cam groove 61
along the shaft 6 provided on the rope ink plate 63
2 will be guided. Here, the tension detection arm 70 is loaded via a spring support mechanism provided on the rope ink plate 63. By the way, as mentioned above, the Hall sensor 7 is mounted on the loading plate 63.
4 is also provided, and the movement of the tension detection arm 70 can be detected even during loading and unloading. Further, plan views showing various states during this loading are shown in FIGS. 4 to 8. That is,
When the tape 5 is pulled out from the cassette half 2, it first comes into contact with the tension detection roller luff, and the tape 5 is always in contact with the tension detection roller 7 during rope ink. Therefore, the tape tension in each of the above states can be detected as the movement of the tension detection arm 70.

Furthermore, in this embodiment, since the width of the cam groove 61 is made larger than the diameter of the guide groove 62 after rope inking is completed, even if excessive tension is applied to the tape 5 at times, the tension detection arm 70 and rope ink plate 6
It can be buffered by moving as one.

(Other Examples) Note that in this example, the tension detection arm 70
The same effect can be obtained even if the position detection is performed using the Macnet 73 and the Hall element 74, or if the position is detected by a Macnet/MR element.

〔Effect of the invention〕

As described above, according to the present invention, the spring support means and the position detection means of the arm-type tape tension detection means are provided on one loading plate, and the tension detection guide By providing the loading means of the tension detection mechanism configured such that the tape is always in contact with the means, the tape tension can be detected even during tape loading and unloading.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the tension detection mechanism of the present invention, FIG. 2 is a cross-sectional view of the main part of FIG. 1, and FIG.
FIG. 4 is a schematic plan view of the tape running system at the time of completion of loading of the VTR of this embodiment, and FIGS. 5 and 6 are front views of the same in the unloaded state. 7 and 8 are plan views showing various states during the rope ink as above, respectively. FIG. 9 is a plan view of an example of a conventional VTR running system, and FIG. 10 is the main part of FIG. 9. FIG. 11 is an enlarged sectional view of the main part of FIG. 10, FIG. 12 is a plan view of FIG. 9 after unloading is completed, and FIG.
The figure is a tape tension control block diagram, and FIG.
It is an example of a Hall element voltage characteristic diagram. 5------Magnetic tape 7...Tension detection roller (detection guide means) 60...Loading lever 63...Rope ink plate 68...
- Leaf spring 69...Spring support shaft 70...Tension detection arm 71...
・Tension coil spring

Claims (1)

[Claims] A control device for running a tape by controlling tape tension, comprising: a tape guide means for detecting the tape tension; and a tape tension detection arm having one end rotatably supported and a tape tension detection guide means at the other end. , a tape tension detection means for pulling out the tape from the cassette half, comprising an elastic support means for biasing the arm in one rotation direction, and a position detection means for detecting the movement of the arm,
The elastic support means and the position detection means are disposed on the same loading plate, and the elastic means is arranged to keep the tape in constant contact with the tape tension detection guide means during loading and unloading of the tape. A tape tension detection mechanism featuring a loading plate.