JPH046934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film feeding method, and more particularly to a film feeding method for a film having a leader tape portion at the leading end of a film portion having an image.

[Conventional technology]

FIG. 1 shows an example of the end portion of microfilm F (hereinafter abbreviated as film F) at the start of feeding. 5 is the leader tape part, 5 is the film part 1 and the leader tape part 4.
This is a splicing tape for joining.

In the illustrated example, the width of the film section 1 is 16 mm, and the width of the leader tape section 4 is 20 mm.

FIG. 2 is a sectional view of a pair of reel flanges in the film cartridge on the film feeding side at the time of starting film feeding. A film portion 1 of a film F is wound inside the reel flange 15', and a leader tape portion 4 is wound several times around its outer periphery. In this example, l ₁ =16 mm and l ₂ =20 mm. Reference numeral 16 denotes a feed roller, which rotates in pressure contact with the leader tape section 4 when film feeding starts, pulls out the film F from a cartridge (not shown), guides it to a take-up reel on the film winding side, and starts film feeding. It is for. As a result, the film F is wound onto the take-up reel and the search is started. The shaft of a supply motor (not shown) for feeding and winding the film is fitted into the center hole 15'' of the reel flange 15'. Reel flange 1
5' as shown in the illustrated example. The state in which the film F is rewound onto the reel flange 15' is schematically shown in FIGS. 3 and 4. As shown in Figure 3, the reel flange 1
Leader tape section 4 having a width wider than the width of 5'
When it reaches the outer periphery of the reel flange 15',
The subsequent leader tape section 4 is the reel flange 1
5' to complete the unwinding into a cartridge (not shown).

[Problem that the invention seeks to solve]

However, due to the rotational resistance (resistance in the direction opposite to the rotational direction of the arrow on the reel flange 15') of various parts of the film running system, especially the take-up motor (not shown) whose shaft is fitted to the take-up reel on the film take-up side, Since the tension T is applied to the film F as shown in Fig. 4,
A force F' is generated in the direction in which the leader tape portion 4 is inserted between the pair of reel flanges 15'. Therefore, in reality, as shown in FIG. 4B, the leader tape section 4 may sink into the space between the pair of reel flanges 15', damaging the film F and making it impossible to feed the film thereafter. In addition, the total length of the film portion 1 is short, and the winding diameter is small at the reel flange 15'.
The smaller the outer diameter is, the higher the probability of this trouble occurring.

[Means to solve the problem]

The present invention has been made in view of the above points and to eliminate the above drawbacks.When rewinding a film into a cartridge, the present invention detects that the leader tape portion of the film has come to the cartridge, and uses this detected signal to To provide a film feeding method capable of rewinding a film into a cartridge without damaging a leader tape part of the film by reducing the rewinding speed of the film and applying as little force to the film as possible.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 5 is a perspective view showing the overall structure of a film feeding apparatus using an embodiment of the film feeding method according to the present invention. 11 is a lamp for lighting, 1
A condenser lens 2 condenses the light from the lamp 11 and illuminates the film F. This light that has passed through the surface image 2 of the film F forms an image 2 on a screen (not shown) via a projection lens 13, and at the same time, the presence or absence of blip marks 3 on the film F is detected by a blip sensor 14 using a phototransistor or the like. Detected. 15 is a cartridge for storing the film F, and the above-mentioned reel flange is stored in this cartridge. 16 is a feed roller used to pull out the leader tape portion of the film F;
Reference numerals 7 and 18 denote a supply motor and a take-up motor for feeding the film F in the rewinding and fast-forwarding directions, respectively; 19 an encoder disc for detecting the rotational speed of the supply motor 17; and 20 a light source. A photodetector is a pair of photosensors, and the supply side motor 1 is connected to the encoder disk 19 and the photodetector 20.
The motor rotation detector 31 outputs a pulse signal with a pulse number proportional to the number of rotations of the motor. Note that the film F is transferred from the cartridge 15 to the roller 2.
The take-up reel 2 is held flat via 2 and 23.
It is wound in 1. In addition, the supply side motor 17,
By controlling the rotation of the take-up motor 18, the film F is fed and a desired image is retrieved. 36 is a film feeding control circuit, which has a motor rotation detector 31 and a detector for detecting the leader tape section in response to pulses from the blip sensor 14, and is for controlling the rotational speed of the supply side motor 17. .

FIG. 6 is a more detailed block diagram of the film feeding control circuit 36 shown in FIG. 5. 33 is a counter constituting a detector for detecting the leader tape section, which inputs the clock pulse from the motor rotation detector 31 to count the number of pulses, and resets it by inputting the pulse from the blip sensor 14 to the clear terminal. be. When the count value of this counter 33 reaches a predetermined value, a leader tape detection signal is output, and this detection signal is given to the control circuit 35, and the output from the control circuit 35 is transmitted to the transistor Tr ₁
The base side of the transistor and the emitter are grounded.
Each is given to the base side of Tr ₂ .

The input side of the supply motor 17 is connected to a power supply V via a resistor R, and both ends of this resistor R are connected to the collector side and emitter side of the transistor _Tr1 . Further, the output side of the supply side motor 17 is connected to the collector side of the transistor _Tr2 . Note that 36 is the aforementioned film feeding control circuit;
34 is a drive circuit for the supply motor 17.

Next, the procedure according to this embodiment will be explained with reference to FIGS. 5 and 6.

When an operator (not shown) issues a command to rewind the film F, the control circuit 35 turns on the transistor
A "high" level signal is output to the base sides of Tr ₁ and Tr ₂ , and transistors Tr ₁ and Tr ₂ are switched on. As a result, the power supply V causes transistor Tr ₁ → supply side motor 17 → transistor Tr ₂
→The supply side motor 17 is energized through the path of grounding, and the supply side motor 17 rotates at high speed in the direction of the arrow shown in the figure.The reel flange inside the cartridge 15 also rotates at high speed in the direction of the arrow, and rewinding of the film F is started. Ru. When the supply side motor 17 rotates, a pulse is generated from the motor rotation detector 31, and the counter 33
However, since the film F moves at the same time, the blip sensor 14 detects blip marks 3 on the image 2 of the film F one after another and generates pulses.
Since the counter 33 is reset, the counter 33 is cleared every time this pulse is input and does not count up. Most of the film F is rewound into the cartridge 15 and the leading edge of the image 2 on the film F passes the blip sensor 14;
When the leader tape section 4 shown in FIG. The counter 33 to which the pulse is input counts up and reaches a low point, outputs a detection signal, and this signal is given to the control circuit 35. As a result, the control circuit 35 does not apply a signal to the base side of the transistor Tr ₁ and switches off the transistor Tr ₁ .
However, since the transistor Tr ₂ is still switched on, the resistor R →
The supply side motor 17 continues to be energized through the supply side motor 17 → transistor Tr ₂ → ground, but
The current flowing through the supply motor 17 decreases due to the resistance R, and the rotation speed of the supply motor 17 slows down.
The rewinding speed changes to low speed. Then, since there is inertia in the rotational force of the take-up reel 21, which was freely rotating as the film F is unwinded, its rotational speed does not decrease in response to changes in the rewinding speed, and therefore the supply side Immediately after the motor 17 is switched to low speed, the film F is slightly slack and almost no tension is applied to the film F. In this state, as shown in FIG. 2 (at this point, the feed roller 16 is not in contact with the film F).
Since the leader tape portion 4 of the film F is wound without applying strong force to the outer circumference of the reel flange 15' in the cartridge cartridge 15, the film F
is completely wound into the cartridge 15 without being damaged.

The means for detecting the leader tape portion is not limited to the embodiment, and a wide leader tape portion may be detected using, for example, a micro switch. In addition, a timer is provided that operates for a time longer than the time interval of pulses generated for each blip mark, and if a pulse is generated before the set time elapses, the timer is reset, and a pulse must be generated before the set time elapses. For example, the leader tape detection signal may be generated from a timer.

Further, the timing at which the film winding speed is reduced after the leader tape portion is detected is appropriately set in consideration of the winding speed and the like.

〔Effect of the invention〕

As explained above, the present invention uses a detector to detect when the leader tape approaches the cartridge while rewinding the film onto the supply reel at high speed, and detects the rotational speed of the supply reel using a signal output from the detector. This reduces the tension of the film between the supply reel and take-up reel, and then winds the leader tape around the outer periphery of the pair of reel flanges at a low speed. The leader tape is properly wound and stored in the cartridge without being sunk in, and can be easily sent out the next time the film is sent out.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the unwinding end of the microfilm, Figure 2 is a sectional view showing the state of the film wound around the reel flange, and Figure 3 is a diagram of the film wound around the reel flange before the end of unwinding. FIG. 4 is a simplified diagram of the state of a film wound around a conventional reel flange. FIG. 5 is a perspective view showing the configuration of a film feeding device using an embodiment of the present invention. FIG. 5 is a block diagram for explaining the operation of the film feeding control device shown in FIG. 5. FIG. 1...Film section, 3...Blip mark, 4
... Leader tape section, 14 ... Blip sensor, 15 ... Cartridge, 15' ... Reel flange, 17 ... Supply side motor, 21 ... Take-up reel, 31 ... Motor rotation detector, 33 ... Counter, 35...Control circuit, 36...Film feeding control circuit, _Tr1 , _Tr2 ...Transistor, R...
resistance.

Claims (1)

[Claims] 1. After winding the film onto the take-up reel from the supply reel, which has a leader tape at its end that has a leader tape wider than the gap between the flanges of a pair of flanges on the supply reel in the cartridge, the supply reel is rotated at high speed. When rewinding the film onto the supply reel,
A detector detects when the leader tape approaches the cartridge, and the output signal of this detector reduces the rotational speed of the supply reel to reduce the tension of the film between the supply reel and take-up reel. A film feeding method characterized in that the tape is wound around the outer periphery of the pair of flanges at a low speed.