JPS6128985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In developing photographic film, photographic paper, printing plates, etc., the temperature of the processing solution greatly affects the development results, so automatic processors usually use a constant temperature device. The temperature of the processing liquid is maintained at a predetermined temperature.

Figure 1 schematically shows the method of keeping the temperature of the developer and fixer that is generally carried out in automatic processors. 1 is the power supply line, 2 is the developer heated at the appropriate location in the developer tank. A temperature controller such as a heater or a cooler (hereinafter collectively referred to as a heater); 3 is a commonly used magnetic switch that controls power supply to the heater 2; 4 is a
This thermostat is installed at a suitable location in the developing tank and is activated by the temperature of the developing solution to open and close the magnetic switch 3.

In this constant temperature device, when the developer temperature falls below a predetermined temperature, the thermostat 4 closes, the excitation coil 3a of the magnet switch 3 is energized, the magnet switch 3 is closed, the heater 2 is supplied with power, and the developer is discharged. When the developing solution temperature reaches a predetermined temperature, the thermostat 4 is opened, the magnetic switch 3 is opened, and the power supply to the heater 2 is stopped.

The fixing tank is also provided with a constant temperature device consisting of a heater 5, a magnetic switch 6, and a thermostat 7 similar to those described above.
1 in parallel.

Therefore, in the constant temperature method described above, power is often supplied to both heaters 2 and 5 at the same time, so the power supply lines 1 and 1 must have a capacity that can withstand the sum of the rated currents of both heaters 2 and 5. It is.

Generally, in film development processing, the tolerance range for the developer temperature is narrow and must be kept close to the prescribed temperature with high precision, but the fixer temperature has a wide tolerance range and may vary slightly above or below the prescribed temperature. However, there is no practical problem.

The present invention takes advantage of this fact and connects the power supply line to either of the two constant temperature devices while keeping the temperature of both processing solutions within the allowable range so as not to impair the finished development result. This method relates to a constant temperature method that allows a larger current capacity, that is, about half the capacity of the conventional method, and will be explained in detail below with reference to FIG.

Figure 2 shows a constant temperature device for developing solution and fixing solution to which the method of the present invention is applied.
14 are the same power supply lines, first heater, and first magnetic switch as in 1, 2, and 3 above, respectively.
is a first thermostat as described below corresponding to 4 above, and 15, 16, and 17 are a second heater, a second magnet switch, and a second thermostat similar to 5, 6, and 7 above, respectively. be.

The first thermostat 14 has two contacts 14
b, 14b. It has a changeover switch structure, and when the developer temperature is lower than a predetermined temperature, the contact piece 14a is in pressure contact with the first contact point 14b on the left side in FIG.
Pressed into contact with the second contact 14c on the right side of the figure, contact 14b,
14c are the first magnetic switches 1 and 14c, respectively.
3 excitation coil 13a and the second thermostat 1
7 is connected.

That is, the first contact 14b of the first thermostat 14 and the excitation coil 13a of the first magnet switch 13 are connected in series, and the second contact 14c of the first thermostat 14 and the second thermostat 17 are connected in series. The excitation coil 16a of the second magnet switch 16 is connected in series.

FIG. 2 shows a situation where both the developer and the fixer have reached a predetermined temperature and the power supply to both heaters 12 and 15 is cut off, and the contact piece 14a of the first thermostat 14 is connected to the second contact. It is in pressure contact with 14c.

In this state, when the developer temperature falls below a predetermined temperature, the thermostat 14 is activated and its contact piece 14a comes into pressure contact with the first contact point 14b.
The magnetic switch 13 is closed and the first heater 1
2 and heats the developer to a predetermined temperature.

Furthermore, when the temperature of the fixing liquid drops below a predetermined temperature, the second thermostat 17 closes, so the second magnet switch 16 closes, supplying power only to the second heater 15, and heating the fixing liquid to a predetermined temperature.

However, even if the developing solution temperature drops and the fixing solution temperature also drops while power is being supplied to the first heater 12 and the second thermostat 17 closes, the contact piece 14a of the first thermostat 14 and the second contact 14c Since the second magnetic switch 16 is located far away from the
No power is supplied to the heater 15.

Additionally, if the developer temperature drops while power is being supplied to the second heater 15, the contact piece 14 of the first thermostat 14
Since the contact point a swings toward the first contact point 14b and moves away from the second contact point 14c, the power supply to the second heater 15 is cut off, and during that time, the temperature of the fixing fluid further decreases.

When the developer temperature reaches a predetermined temperature, the first
The contact piece 14a of the thermostat 14 is the second contact 14
c, power supply to the second heater 15 is started, and the fixing liquid is heated.

In the above description, 13 and 16 are described as magnetic switches, but it goes without saying that thyristors may be used, and the thermostat 14 can also be integrated into an IC by using a flip-flop circuit.

In this way, according to the method of the present invention, both heaters 1
2 and 15 at the same time, and the constant temperature device consumes most of the power in the heater 12 or 15. Therefore, the power supply lines 11, 11 are connected to the passing current of whichever of the two constant temperature devices has a larger capacity. It only needs to be durable, and it can be about half the capacity of the conventional method.

Furthermore, in the method of the present invention, it is not possible to heat the developer and fixer at the same time, and the developer is prioritized and heated individually, so the meandering of the fixer's temperature is greater than in the conventional method. As mentioned above, since the fixer temperature has a wide allowable range, it does not adversely affect the finished film development result, and there is no problem in practical use.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram for explaining a conventional constant temperature method, and FIG. 2 is a wiring diagram for explaining an example of the constant temperature method of the present invention. DESCRIPTION OF SYMBOLS 1... Power supply line, 2... Heater, 3... Magnetic switch, 3a... Excitation coil, 4... Thermostat, 5... Heater, 6... Magnetic switch, 7... Thermostat, 11... ...power line,
12...First heater, 13...First magnet switch, 13a...Excitation coil, 14...First thermostat, 14a...Touch piece, 14b...First
Contact, 14c...Second contact, 15...Second heater, 16...Second magnetic switch, 16a...
...excitation coil, 17...second thermostat.

Claims (1)

[Scope of Claims] 1. A constant temperature method in which the temperature of the developing solution and fixing solution of an automatic developing machine is controlled by a thermostat with a device that opens and closes a switch connected in series with the temperature regulator, The developer thermostat has a changeover switch structure having two contacts that switch at a predetermined temperature, and one of the two contacts is the one that is connected when the developer temperature is lower than the predetermined temperature. By connecting in series the and the developer temperature control switch, and by connecting the other contact in series with the fixer thermostat and the temperature control switch,
A method for constant temperature of a developer and a fixer in an automatic processor, characterized in that power is supplied to both temperature regulators individually and at different times, giving priority to a temperature control switch for the developer.