JPS6127739B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for replenishing a processing solution for an automatic film developing machine.

Various methods of this type have been proposed in the past, but none of them have been satisfactory.

For example, the processing liquid replenishment method described in Japanese Patent Application Laid-Open No. 49-115547 utilizes an integrating circuit, inputs a reverse polarity reference voltage to the integrating circuit, integrates it, and replenishes the replenishing liquid during this time. However, this method may be affected by noise due to disturbances such as voltage fluctuations and temperature changes.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for replenishing a processing solution for an automatic film developing machine, which enables precise processing solution replenishment and always obtains photographic images of constant density.

The present invention will be explained below with reference to Examples.

In FIG. 1, reference numeral 2 denotes a developed film. A light source 1 irradiates the film 2, and a photoelectric detection element 3 receives transmitted light. 4 is a photoelectric detection element that directly receives the light from the light source 1 and outputs a reference output.

The outputs of the photoelectric detection elements 3 and 4 are amplified by amplifiers 5 and 6, respectively, and input to a differential amplifier 7. In this case, the output of the differential amplifier 7 is adjusted in advance so that the output is 0 when there is no passing film, and the output of the differential amplifier 7 is adjusted so that the maximum output is produced when the blackened area ratio on the film is maximum. If the circuit is configured, this differential amplifier 7 will output an output proportional to the blackened area ratio of the passing film.

The output of the differential amplifier 7 is input to an integrator 8, where the output of the differential amplifier 7 is integrated over a certain period of time as described later.

The output of the integrator is sent to a voltage-frequency converter 9 (hereinafter referred to as
VFC). VFC9 is integrator 8
oscillates at a frequency that corresponds to the output voltage.

The output of the VFC 9 is input to a counter 11 through a gate 10 which is open for a time T _A (for example 50 milliseconds) given by a timer 17. At that time, the gate 10 is operated at a time T _B as shown in FIG.
(for example, 30 seconds) to open by the time T _A.
You should be careful.

When the counter 11 has counted the time T _A , the gate 10 closes and at the same time the gate 12 opens.
The counter 11 remains open until the added pulse becomes zero, and the pulse from the timing pulse generator 13 is input to the counter 11.

The timing pulse generator 13 outputs pulses having a constant time interval T _C as shown in FIG. 2g.

Note that this time interval T _C can be arbitrarily changed by a known method.

At this time, the integrator 8 is reset within a short time by a signal from the control circuit 14 and is ready for integration of the next signal.

The counter 11 is an up-down counter, and operates as a subtraction counter by a signal from the control circuit 14 when the gate 10 is closed. A signal from the control circuit 14 issued at the same time causes the drive circuit 15 to start operating, and the pump 16 to start replenishing the liquid. The control circuit 14 outputs a signal when the counted pulses in the counter 11 become zero due to subtraction, stops the drive circuit 15, and stops the pump 16.
At the same time, the gate 12 is closed.

The operation of the automatic liquid replenishment system described above will be explained with reference to the time chart shown in FIG. In the chart, the horizontal axis represents time. Differential amplifier 7
produces an output as shown in a when the blackened film passes through it.

Since the integrator 8 is reset at every time determined by the timer 17, it outputs periodic outputs as shown in b.

Since the VFC 9 outputs a pulse with a frequency corresponding to the output of the integrator 8, during the time T _B at the end of the operation of the integrator 8 given by the timer 17, the differential increase integrated by the integrator 8 is A pulse output with a frequency corresponding to the output of the width filter 7 is output.

The counter 11 functions as a subtraction counter when the gate 10 is closed by the control circuit 14.
At every time interval T _C given by the timing pulse generator 13, the counted pulses are decremented.

The subtraction count continues while the gate 12 indicated by h is open, and when the counted pulses in the counter 11 reach zero, the control circuit 14 outputs a signal to stop the drive circuit 15 and at the same time open the gate 12. close. As already mentioned, the pump 16 operates only while the drive circuit 15 is operating to replenish the liquid.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the method of the invention, FIG.
The figure is a time chart of FIG. 1. DESCRIPTION OF SYMBOLS 1... Light source, 2... Film, 3, 4... Photoelectric detection element, 8... Integrator, 9... Voltage-frequency converter, 11... Counter, 15... Drive circuit. 〓〓〓〓〓

Claims (1)

[Claims] 1. During the development process, the blackened area ratio of the developed film obtained by the photoelectric detection unit is integrated at regular intervals and within a certain time, the integrated value is frequency-converted and oscillated, and this oscillation signal is counted. , processing solution replenishment for an automatic film developing machine, characterized in that after the measurement time ends, replenishment of the developer is started at the same time, a subtraction pulse is generated, and the count number is subtracted and replenishment is performed until the count becomes zero. Method.