JPH1153796A - Tape threading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a sensing tape from being wound round a rotary drum. SOLUTION: The device is provided with a cassette 10 wherein a tape 18 for detecting the tape ends is adhered to the both ends of a magnetic tape 16. When this cassette is mounted to the device, a sensor 34 is fronted inside an opening recessed part 10a of the cassette. The sensor detects whether the end detecting tape is positioned at the place confronted with this sensor, or not. When the end detecting tape is confronted with the sensor, the tape threading is carried out after the end detecting tape is taken up. By such an operation, the end detecting tape does not be wound round the rotary drum in any cases since the threading operation is started after the detecting tape is taken up. Thus, such accidents as the magnetic head is damaged by the end detecting tape or the head clogging is generated by an adhesive, are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape threading (tape loading) apparatus suitable for use in a recording / reproducing apparatus having a rotating drum. Specifically, when winding the magnetic tape around the rotating drum using a tape cassette having both ends of the magnetic tape stuck to the end detection tape, the end detection tape is not sufficiently wound. When there is a possibility that a part of the tape may be wrapped around the rotating drum, the tape for detecting the end of the tape is once wound into a cassette and then tape threading is started so that the tape for detecting the end of the tape is not wrapped around the rotating drum. Things.

[0002]

2. Description of the Related Art Video cameras for reporting (handy cameras)
For example, a digital recording / reproducing apparatus capable of digitally recording recorded contents and reproducing the recorded contents is provided. When a magnetic tape is used as a recording medium, a recording / reproducing device using a rotating drum is built in.

FIG. 6 shows a tape threading device of this type of recording / reproducing device. 6, a pair of reels (a supply reel 12S and a take-up reel 12T) are provided in a cassette 10, and a magnetic tape 16 is provided between the reels 12S and 12T via internal guide pins 14 and 14. It is wound.

The cassette 10 is mounted so as to face the rotary drum 20, and the magnetic tape 16 in the cassette 10 is pulled out by a pair of sliding guide pins 22a and 22b shown in the directions shown by curves La and Lb. 20
Over an angular range of approximately 280 °.

The tape path from the cassette 10 to the rotary drum 20 (shown by a two-dot chain line) is a pin 24 as shown in FIG.
a, 24b, 26, 28. here,
The pins 24a and 24b are moving pins that move in the directions of the arrows Lc and Ld. The pin 26 is a pin for a tension regulator. The pin 28 is a fixed pin.

The sliding guide pins 22a and 22b and the moving pins 24a and 24b face the opening recess 10a provided at the center front of the cassette 10, and are located inside the magnetic tape 16 (indicated by a dashed line) in the unthreaded state. positioned. In addition, a sensor 34 for detecting an end detection tape (sensing tape) to be described later is arranged in the opening concave portion 10a.

[0007] Sensing tapes are attached to both ends of the magnetic tape 16 in order to detect both ends. FIG. 7 shows the sensing tape 18 (18a) attached to the end of the magnetic tape on the take-up reel 12T side. As the sensing tape 18, an opaque tape or a transparent tape on which a metal film is deposited is used. In the example shown in the figure, an opaque tape is used.

[0008]

By the way, in a business-use video camera or the like, when rewinding the magnetic tape of the cassette 10 used for this purpose, a dedicated rewinder (tape winding device) is usually used. . In this case, since the magnetic tape is wound up at a high speed, the sensing tape 18a has a leading end portion as shown in FIG.
It may be wound up to the 2S side.

When tape threading is performed again using the cassette 10 in a state where the tip of the sensing tape 18a is wound up to the supply reel 12S side, as shown in FIG. A portion may be wrapped around the rotating drum 20.

When a part of the sensing tape 18a is wound around the rotating drum 20, a magnetic head (not shown) provided on the rotating drum 20 scans while contacting the sensing tape 18a. In many cases, the magnetic tape 16 and the sensing tape 18a are joined by an adhesive 19 or the like as shown in FIG. When an opaque tape is used for the sensing tape 18a, a metal film such as aluminum is often deposited on the surface of the tape.

The sensing tape 18a made of such a material
If the magnetic head rotates and scans the magnetic head at a high speed, the magnetic head may be considerably damaged. Also, if even a part of the adhesive connecting the magnetic tape 16 and the sensing tape 18a adheres to the magnetic head, a head clog is quickly generated, and the magnetic head is seriously damaged. Then, good recording and reproduction cannot be realized.

In view of the above, the present invention has solved such a conventional problem, and has devised tape threading so that the sensing tape does not wind around the rotating drum in any case. The magnetic head can be reliably protected.

[0013]

According to a first aspect of the present invention, there is provided a tape threading apparatus according to the present invention, comprising: a cassette in which a tape for detecting a tape end is attached to both ends of a magnetic tape; When the cassette is mounted on the apparatus, the sensor is arranged so as to face the concave portion of the opening of the cassette, and it is detected by the sensor whether the end detection tape is positioned at a position facing the sensor. When the end detection tape is opposed to the sensor, tape threading is performed after winding the end detection tape.

According to the present invention, when the tape is pulled out and wound around the rotary drum while the cassette is mounted, the sensor detects a case where a part of the end detection tape is applied to the rotary drum. When this state is detected by the sensor, the end detection tape is wound on the reel side, and then the tape is pulled out to perform tape threading.

By doing so, the end detecting tape does not wrap around the rotating drum in any case, so that the magnetic head is damaged by the end detecting tape or the head clog is caused by the adhesive. Can be prevented beforehand.

[0016]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example in which a tape threading device (mechanism) according to the present invention is applied to a recording / reproducing means (VTR) mounted on a video camera for recording. A tape threading device 40 for winding the magnetic tape 16 around the rotating drum 20 is disposed between the loaded cassette 10 and the rotating drum 20.

In FIGS. 1 to 5, the sensing tape 18 is thick and exaggerated so that the relationship between the sensing tape 18 and the magnetic tape 16 can be easily distinguished. A plurality of gears used are also shown only at the meshing portion. FIG. 1 shows a state in which guide means 42A and 42B described later are provided, but the guide means 42A and 42B are omitted from FIG. 2 and thereafter. This is to clarify the relationship between the other members.

FIG. 1 shows a state in which the cassette 10 is mounted, and shows an unthreading state. FIG. 5 shows a threading completed state. In the state of FIG. 5, the pinch roller 4 comes into contact with the capstan 2 so that the magnetic tape 16 runs in the direction of the arrow. The full erase head HE and the control head HC abut against the magnetic tape 16 on the tape entry side to the rotating drum 20, and the time code head HT abuts on the tape exit side to control at a predetermined position on the tape. Recording and reproduction of signals and time codes are performed. In addition, the entire width including the recording signal is erased as necessary.

The pin 26 provided in the tape running system is a pin for adjusting the tape tension. As shown in FIGS. 4 and 1, the pin 26 of the L-shaped tension arm 90 which rotates around the fulcrum is used. It is planted at the tip. A spring 92 for applying a clockwise elastic force is attached to one end of a tension arm 90 to apply a constant tension (back tension) to the magnetic tape 16.

The tension arm 90 further includes a brake band (brake shoe) 9 for the supply reel 12S.
4, one end of the brake band 9
4 is connected to one end of the V-shaped lever 96 by making approximately 2/3 rotation of the supply reel 12S.

The V-shaped lever 96 is rotatably fixed to the chassis of the apparatus. As shown in FIG. 2, a pin 104 mounted on the other end 96b of the V-shaped lever 96 is formed on the spur gear 100. Ω-shaped cam groove 102. Spur gear 1
00 is transmitted from a left spur gear 50 described later.

When the cassette 10 is mounted and the operation mode is not in the stopped state, the brake band 94 acts on the supply reel 12S to apply a braking force as shown in FIG. Thus, the magnetic tape 16 does not sag even when the video camera is moved while the cassette is mounted.

When the magnetic tape 16 is threaded on the rotary drum 20, the magnetic tape 16 can be pulled out from the cassette 20 by loosening the brake band 94. However, the tape shown in FIG. In this state, the supply reel 12S is slightly tightened by the brake band 94. Thus, an appropriate back tension is applied to the magnetic tape 16.

As shown in FIG. 5, a stopper 106 for regulating the rotation angle of the tension arm 90 and the tape path is provided near the pin 26, and a stopper 108 is similarly provided for the right pin 28. I have.

The tape threading device 40 will be described in more detail. First, as shown in FIG.
Is pulled out of the cassette 10 and is
Sliding guide pins 22a, 22b threaded to a position where they can be wound over a predetermined angular range of
Guide means 42 (42A, 4A) for guiding
2B) is provided.

The pair of guide means 42A and 42B has a shape in which the question mark (?) Is turned upside down, and the guide means 42A located on the left side is further turned upside down. A pair of guide plates 4 having an overall shape that is reversed left and right.
4a and 44b. And each guide plate 44
a and 44b are attached to an apparatus body (chassis) (not shown) in a state where they are opposed to each other such that a guide groove 46 having a width large enough to receive the end of the sliding guide pin 22a is formed. Fixed.

As shown in FIG. 2, a flat gear 50 is disposed at the center of the large curved portion (lower portion) of each of the guide plates 44a and 44b, and a sliding force is applied to the sliding guide pin 22a from the rotating shaft 50a. Is done. Therefore, the sliding guide pin 22
a and a plurality of link plates 52a between the rotary shaft 50a
The link mechanism 52 constituted by... Is connected.

In this embodiment, the link mechanism 52 is constituted by five link plates 52a to 52e, and the link plate 52 at the tip end is provided.
a is a slider 53 on which a sliding guide pin 22a is erected.
Are connected, and the end link plate 52d is connected to the rotating shaft 50a. One end of each of the connecting pins 54a to 54d for connecting the link plates 52a to 52e is loosely inserted into the guide groove 46 shown in FIG. 1, and the link plates 52a to 52e are also connected to this guide plate. It is adapted to move back and forth along the means 42A.

The guide means 42B located on the right side of the rotary drum 20 has the same structure as the guide means 42A, and as shown in FIG. 1, a pair of guide plates arranged with the question marks inverted upside down as shown in FIG. 64
The guide groove 66 is formed by a and 64b. A flat gear 68 is disposed at the center of the large curved portion of the pair of guide plates 64a and 64b so that a sliding force on the sliding guide pin 22b engaged with the guide groove 66 is obtained from the flat gear 68. I have.

Therefore, as shown in FIG. 2, a link mechanism 70 composed of a plurality of curved link plates 70a to 70d in this example is provided between the sliding guide pin 22b and the rotating shaft 68a of the spur gear 68. Are disposed, and the curved link plate 70 at the tip
a, a slider 71 having a sliding guide pin 22b planted thereon is attached, and a rotating shaft 68 is attached to a distal curved link plate 70d.
a are connected. The connection pins 74a to 74c connecting the curved link plates 70a to 70d slide in the guide grooves 66 so that the slide guide pins 22b can slide to a predetermined position.

A drive motor 76 is provided to transmit the rotational driving force to the above-described spur gears 50 and 68, and the rotational force from the drive motor 76 is transmitted through a plurality of gear trains (not shown) to the first stage. The power is transmitted to the spur gear 80, and the right spur gear 68 described above meshes with the spur gear 80. An intermediate spur gear 8 provided for reversing the rotation direction is provided on the spur gear 80.
2 is meshed with the left spur gear 50 described above.

Therefore, when the first-stage spur gear 80 rotates counterclockwise, the left-side spur gear 50 is transmitted with counterclockwise rotation, and the right-side spur gear 68 is transmitted with clockwise rotation. Become.

The vertical relationship of the plurality of members constituting the tape threading device 40 has been described ignoring this, but in practice, the plurality of spur gears 50, 68, 8
0, 82, and 100 are disposed on the lower surface side of the front part of the cassette 10, and link mechanisms 52, 70
Is attached. Then, a cam groove 102 is cut on the upper surface of the spur gear 100, and the pin 104 of the V-shaped lever 96 is engaged here. A brake band 94 is provided on the upper surface of the V-shaped lever 96.

Now, the opening recess 1 of the cassette 10 described above.
0a, a pair of sliding guide pins 22a, 2
2b, sensing tape 18 (18a, 18b)
Is disposed. When an end detection tape on which a metal film is deposited as shown in FIG. 10 is used as the sensing tape 18, for example, as the sensor 34, an inductance element constituting an LC tank circuit is used as the sensor 34 and the magnetic tape 16 and It is arranged at a position facing the sensing tape 18.

When the magnetic tape 16 is opposed to the sensor 34, the Q is high, so that the LC element oscillates, and when the facing interval with the sensor 34 is widened, or when a tape other than the magnetic tape 16, for example, the sensing tape 18 is approached. , L
Oscillation stops because the Q of the C circuit decreases.
Therefore, by detecting the continuation and stop of the oscillation state, it is possible to detect whether the magnetic tape 16 or the sensing tape 18 is facing the sensor 34.

FIG. 2 shows a state in which the sensing tape 18 is not sufficiently wound on the take-up reel 12T, and the leading end of the sensing tape 18a remains on the supply reel 12S.

Since the magnetic tape 16 is pulled out from the cassette mounted state as shown in FIG. 2 and tape threading is performed as shown in FIG. 5, the output from the sensor 34 is used as a judgment material in the present invention. In the example of FIG. 2, the sensor 34 is opposed to the sensing tape 18a, so that the oscillation of the tank circuit is stopped.

When the oscillation is stopped, the drive motor 76 (see FIG. 1) is first rotated by a command from a mechanical control unit (not shown) constituted by a microcomputer, assuming that the sensing tape 18 is opposed. Thus, the driving force is transmitted to the spur gear 100. Since the spur gear 100 rotates clockwise, the brake band 96 is loosened to reach the state shown in FIG.

In this state, since the rotation of the drive motor 76 is also transmitted to the left spur gear 50 and the right spur gear 68,
The sliding guide pins 22a and 22b are slightly
Side, a pair of sliding guide pins 22a, 22
b contacts the sensing tape 18a. As the sliding guide pins 22a and 22b slightly move toward the rotary drum 20 in this manner, the opposing distance between the sensor 34 and the sensing tape 18a slightly increases, thereby oscillating the tank circuit. When the tank circuit goes into oscillation,
This state is fed back to the drive motor 76 to control the drive motor 76 to stop. Thereafter, at the stage where the take-up reel 12T rotates and the sensing tape 18a is sufficiently wound on the take-up reel 12T side (therefore, even if the tape is pulled out, the sensing tape 18a does not contact the rotating drum 20), and the reel rotates. Stop.

When the rotation of the take-up reel 12T stops, the drive motor 76 starts to rotate again. As a result, the pair of sliding guide pins 22a and 22b further advance in the guide grooves 46 and 66 as compared with the case of FIG.
The magnetic tape 16 is pulled out toward the rotating drum 20 from the inside.

When the drive motor 76 is further rotated, the pair of sliding guide pins 22a and 22b slide to the final stop position, whereby the pair of sliding guide pins 22a and 22b are wound around the rotary drum 20 with a tape path as shown in FIG. . Since the sensing tape 18a is wound on the take-up reel 12T, the sensing tape 18a does not wind even slightly on the rotating drum 20 during the tape pulling process.

Since the above-described cam groove 102 is formed in an Ω shape, the brake band 94 is wound around the supply reel 12S in the state shown in FIG.
The braking force on S becomes slightly stronger. This is the back tension in the operation mode, and the tightening state of the brake band 94 changes in conjunction with the tension arm 90 so that the back tension on the magnetic tape 16 becomes constant.

When the cassette 10 is mounted such that the magnetic tape 16 is wound on the take-up reel 12T and a part of the sensing tape 18b is stopped at a position facing the sensor 34, In this case, the magnetic tape 16 may be wound around the rotating drum 20 by the reverse operation, or the tape may be wound without shifting to the tape threading mode as shown in FIG.

The cassette 10 in which the sensing tape 18a is completely wound on the take-up reel 12T side
Is mounted, the sensor 34 on the side of the opening recess 10a
In this case, the normal tape threading mode in which the magnetic tape 16 is pulled out is executed in this case.

In the above-described example, the sensing tape 18 on which a metal film is deposited is used as the end detection tape, and the sensor 34 also uses the inductance element of the tank circuit. As the sensor, a transmission type or reflection type sensor may be used.

The present invention is very suitable for application to a recording / reproducing section using a magnetic tape mounted on a video camera or the like, but its application range is not limited to a video camera for news gathering or the like.

[0048]

As described above, according to the present invention, when the tape is pulled out and wound around the rotating drum while the cassette is mounted, a case where a part of the end detection tape is applied to the rotating drum is detected. In this case, the end detection tape is wound on the reel side, and then the tape is pulled out to perform tape threading.
According to this method, the end detection tape does not wrap around the rotating drum in any case, so that the end detection tape may damage the magnetic head or cause an adhesive to cause head clogging. Has features that can be prevented. Therefore, the present invention is extremely suitable for application to a recording / reproducing section using a magnetic tape mounted on a video camera or the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an outline of an embodiment of a tape threading device according to the present invention.

FIG. 2 is a configuration diagram similar to FIG. 1 except for a guide unit.

FIG. 3 is a diagram showing a state immediately after winding a sensing tape.

FIG. 4 is a diagram illustrating a state where winding of a sensing tape is completed.

FIG. 5 is a diagram showing a tape threading completed state.

FIG. 6 is a diagram showing a conventional outline of a tape threading device.

FIG. 7 is a diagram (part 1) illustrating a state where the sensing tape is wound on the take-up reel side.

FIG. 8 is a diagram (part 2) illustrating a state where the sensing tape is wound on the take-up reel side.

FIG. 9 is a diagram illustrating a tape threading state of the tape threading device.

FIG. 10 is a cross-sectional view illustrating a configuration of a sensing tape.

[Description of Signs] 10 cassette 16 magnetic tape 18 (18a, 18b) sensing tape (end detection tape) 20 rotating drum 22a, 22b sliding guide pin 34 ..Sensors 42A, 42B ... Guide means 46, 66 ... Guide grooves 50, 68, 80, 82, 100 ... Spur gear

Claims (3)

[Claims] 1. A cassette having a tape for detecting the end of a tape attached to both ends of a magnetic tape, and when the cassette is mounted on an apparatus, a sensor faces a recessed portion of the cassette. At the same time, whether or not the end detection tape is positioned at a position facing the sensor is detected by the sensor. When the end detection tape is facing the sensor, the end detection tape is wound and then tape threading is performed. Tape threading device, wherein the tape threading is performed. 2. The winding device according to claim 1, wherein when the end detection tape is opposed to the sensor, winding of the end detection tape is started after a brake on a supply reel is released. The tape threading device as described in the above. 3. The tape threading device according to claim 1, wherein an inductance element of an oscillation tank circuit is used as said sensor.