JPH0345368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microfilm drive device, and particularly to a two-motor type microfilm drive device in which both a supply reel and a take-up reel are each provided with a drive motor.

In recent years, as the number of publications and documents has increased, microfilms that record large amounts of information in a reduced size have come into wide use. This microfilm is applied to a microfilm system such as a known microfilm reader, reader printer, or microfilm retrieval device, and the recorded information on the microfilm can be projected onto a screen for observation, or it can be printed and used. I try to do that. There are various types of microfilm such as rolled film and fixed film. Usually, long films are stored in a roll on a reel or magazine. The film is sent out from the film, the film is passed through a search section or a projection section, and then a desired portion (frame) in the film is searched for by winding the film onto a take-up reel or rewinding the film onto a supply reel. I try to project it. Such a microfilm system uses a motor to automatically feed the microfilm, and when a desired image on the microfilm is retrieved, the motor is stopped to stop the film.

FIG. 1 shows an example of a microfilm reader. In the figure, 1 is an illumination lamp, and 2 is a condenser lens. These constitute an illumination means, and the information recorded on the microfilm F by this illumination means is The part of the image that is located is illuminated. Film guide plates 4 and 5 are made of transparent glass plates, and are separated from the film movement path while the microfilm is being fed, and when the film stops, are brought close to the film movement path to hold the film at a fixed position (focal position) and flatten it. Hold. The film guide plate is moved by, for example, a known solenoid. 6 is a projection lens for enlarging and projecting the microfilm image; 7
shows a screen for observing an enlarged image. 8 is a supply reel for winding the roll microfilm F; 10 and 11 are film guide rollers;
Reference numeral 13 indicates a winding reel for winding up the film. 14 is a supply reel shaft 8 via a gear (not shown).
15 is a motor that rotationally drives the winding reel shaft 13a through a gear (not shown).

In such a device, the speed changes from the speed at which the film is scanned (2 m/m/sec) to the speed at which it is wound at high speed (1000 m/m/sec).
Speed control is difficult to achieve with a single motor by simply changing the applied voltage, so a feedback method is used to control the speed. Furthermore, the size of the motor that can be used is limited due to the size of the device, cost, etc., and the motor output is also limited accordingly.

On the other hand, considering the diameter of the film wound on the take-up reel 13, the diameter of the film changes three times between when the film is not wound and when it is fully wound, for example, 100 feet. Therefore, if the torque of the motor 14 or 15 is constant, the force for winding the film F onto the reel varies by 3:1 between the beginning and the end of winding the film. On the other hand, looking at the supply reel 8 that is being pulled, if the brake torque is constant, the force with which the film is drawn from the reel changes by 1:3 between the beginning and the end of being pulled. Therefore, the entire film cannot be wound unless the torque of the drive motor 14 of the take-up reel 13 is changed by nine times between the beginning and the end of winding. However, in the conventional microfilm reader described above, when the speed is set to a certain low speed level, there are cases where the film cannot be wound onto the take-up reel 13 because the change in the torque of the drive motor of the take-up reel is small. Further, the case of rewinding by the supply reel 8 is also similar to the above.

FIG. 2 shows an example of a drive control circuit diagram of the motors 14, 15. In Figure 2, R
1 to 18 are resistors, C1 to 3 are capacitors,
OPA1 and 2 are operational amplifiers, FETs are field effect transistors, Q1 to Q5 are transistors, IC is a timer integrated circuit, D1 to 3 are diodes,
DB is a diode bridge, T1 is a transformer, S
1-1 is a selector switch for motor 14 or 15, S
1-2 is a short circuit switch for motor 14 or 15, V
cc is a positive power supply, Vss is a negative power supply, and VR1 is a variable resistor.

With this circuit configuration, the motor speed command voltage from the variable resistor VR1 and the motor 14 or motor 15
The voltage depending on the motor speed of each resistor R
1, operated by operational amplifier OPA1 through R3,
The result is a timer integrated circuit IC, resistor R14,
The field effect transistor FET,
It is stored in the capacitor C2 of the sampling hold circuit consisting of the transistor Q1, resistors R5 and R6, and the capacitor C2, and is used as a buffer operational amplifier.
The transistors Q2 and Q3 are made conductive through OPA2 to operate the motor 14 or 15.

Now, turn on the changeover switch S1-1 to the motor 15 side and the short-circuit switch S1-2 to the motor 14 side. Then, the motor 15 is energized to reel the winding reel 1.
3, the motor 14 connected to the supply reel 8 driven by the film F wound on the take-up reel 13 is short-circuited by the short-circuit switch S1-2 as described above. For,
Generates brake torque. Although this brake torque has the effect of keeping the motion of the film F constant at low speeds and eliminating chatter, it has the disadvantage of reducing the tensile force of the film F by the drive motor 15 of the take-up reel 13.

SUMMARY OF THE INVENTION An object of the present invention is to provide a microfilm drive device that can smoothly wind up a film to the end even when the film is being fed at a low speed such as when the film is being scanned.

That is, the present invention is a microfilm driving device characterized by the following configuration.

A first motor coupled to the take-up reel, a second motor coupled to the supply reel, a power supply for the first motor, and motor speed command voltage variable means for adjusting a drive voltage corresponding to the command voltage by the means. 1st from power supply
a drive control circuit that supplies the motor; and a first motor that feeds back a voltage corresponding to the motor speed of the first motor to the input side of the drive control circuit.
a feedback system; a detection means for detecting the generated voltage of a second motor rotating in accordance with the rotation of the supply reel while the film is being fed from the supply reel to the take-up reel by the drive of the first motor; and the detection means and a second feedback system that feeds back the output of the drive control circuit to the input side of the drive control circuit, and changes the drive voltage of the first motor in accordance with the generated voltage of the second motor in order to feed the film at a constant speed. A microfilm drive device characterized in that the drive control circuit is controlled by the output of the detection means.

The drawings will be explained below. FIG. 3 is a circuit configuration diagram showing an embodiment of the present invention in which the same parts as in FIG. 2 are given the same reference numerals.
A generated voltage detection resistor R31 is connected in series with the resistor R31, the terminal voltage of the resistor R31 is supplied to the operational amplifier OPA3 via the resistor R32, and the output of the operational amplifier OPA3 is fed back to the operational amplifier OPA1 via the resistor R34. It is the composition. The above resistance R3
1 uses a resistance value (experimentally 5Ω or less) that does not impair the braking characteristics of the motor 14 or 15.

Now, as shown in the illustrated example, switch S1-1 is set to the motor 15 side, and short switch S1-2 is set to the motor 15 side.
When the film F is fed to the 4 side, the motor 15 drives the take-up reel 13 to wind up the film F as described above.
At this time, the supply reel 8 is driven by the moving force of the film F, and in accordance with this driven movement, the motor 14 rotates as a generator to generate brake torque.
Then, the motor 1 generated at both ends of the resistor R31
The generated voltage of No. 4 is generated by resistor R32, operational amplifier OPA3,
The signal is fed back to the operational amplifier OPA1 via a feedback system of resistor R34. In addition, the operational amplifier OPA1 includes a resistor R3, a capacitor C1,
The motor 15 is controlled by the feedback system of resistor R4.
The motor 15 performs its own feedback and is controlled so that the drive voltage of the motor 15 does not fluctuate with respect to fluctuations in the power supply voltage. Further, the generated voltage of the motor 14, which rotates as the supply reel 8 rotates, is fed back to the take-up motor 15, and the drive voltage of the motor 15 is controlled to increase as the generated voltage decreases. That is, as the amount of film on the take-up reel increases and the film winding speed decreases, the voltage generated by the motor 15 decreases. I try to send it at high speed. As a result, the film can be smoothly wound to the end even at low speed feeding. Note that the same parts as those in FIG. 2 operate in the same manner as described above, so their explanation will be omitted.

Since the present invention has the above configuration, the film speed can be easily changed from a low speed for skimming to a high speed for simply winding, and the film can be smoothly wound even at low speeds. This is extremely effective for a two-motor type microfilm drive device in which both the supply reel and the take-up reel are provided with drive motors, respectively.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an outline of a microfilm reader, FIG. 2 is a circuit diagram of a conventional microfilm driving device, and FIG. 3 is a circuit diagram of a microfilm driving device of the present invention. F is microfilm, 8 is supply reel, 13
is a winding reel, and 14 and 15 are motors.

Claims (1)

[Claims] 1. A first motor coupled to a take-up reel, a second motor coupled to a supply reel, a power source for the first motor, and a motor speed command voltage variable means, including a means for varying the command voltage by the means. from the power supply to the first drive voltage corresponding to
a drive control circuit that supplies the motor; and a first motor that feeds back a voltage corresponding to the motor speed of the first motor to the input side of the drive control circuit.
a feedback system; a detection means for detecting the generated voltage of a second motor rotating in accordance with the rotation of the supply reel while the film is being fed from the supply reel to the take-up reel by the drive of the first motor; and the detection means and a second feedback system that feeds back the output of the drive control circuit to the input side of the drive control circuit, and changes the drive voltage of the first motor in accordance with the voltage generated by the second motor in order to feed the film at a constant speed. A microfilm drive device characterized in that the drive control circuit is controlled by the output of the detection means.