JPS6279455A - Automatic developing device and its automatic temperature control method - Google Patents

Abstract

PURPOSE:To hold temperature precisely within a control range by providing an automatic temperature control means which has at least two temperature detecting means installed nearby a heating source or cooling source and at a target place where the temperature is controlled. CONSTITUTION:Air sent in by an air blower 1 is heated by a heater 2 and blown out to a drying part 3 through a duct 3 to strike on a processed photosensitive material 6 which is conveyed from between conveyor roller 5, thereby drying it. Sensors 7 and 8 are installed nearby the heat source 2 and drying part 4 respectively and connected to a control part 9. The control part 9 incorporates a CPU for arithmetic which calculates the on/off temperature point of a heater 2 on the basis of installation temperature outputs from the sensors 7 and 8 and is equipped with a setting input part 10 for inputting set temperature, so that the heater 2 is turned on and off by a relay 1 according to the signal from the control part 10.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an automatic developing device equipped with an automatic control device that keeps the temperature of air, particularly the temperature of the air for drying processed photosensitive materials, at a predetermined temperature, and its automatic developing device. Related to temperature control method.

[Prior Art] In order to adjust the air temperature in the drying section of an automatic developing device that processes photographic film, photographic paper, etc. to a constant temperature, outside air is taken in by a blower, sent to the target space by a duct, and then The usual method is to adjust the temperature by placing a heating source or a cooling source (hereinafter referred to as a heat source), and to automatically control this, a temperature sensing means such as a thermistor (hereinafter simply referred to as a The temperature of the gas is kept constant by turning the heat source on and off based on a predetermined set temperature whose detected temperature is set in advance.

Sensors are generally installed near a heat source, and in some cases they are installed near a target location where the temperature should be kept at a predetermined value, but in both cases, the sensor only detects the temperature at a single location and is not able to control the temperature. It was configured to take control.

[Problem to be solved by the invention 1 When the sensor is placed near a heat source as described above, temperature control will be performed based on the detected temperature at a location far from the target point of temperature control. Due to fluctuations in external temperature due to climate changes, etc., the degree of heat dissipation or absorption to the outside along the heat propagation path is not always constant, making it difficult to accurately estimate the temperature at the target location. It was difficult to maintain the temperature. In addition, if it is placed near the target point for temperature control, there will be a delay in heat reaching the sensor from the heat source, overshoot from the set temperature due to residual heat, and the top and bottom of the temperature near the heat source and near the sensor will be out of phase. Therefore, highly accurate temperature control was difficult.

In automatic developing equipment for processing photosensitive materials, the density, gradation, etc. of the photographic image obtained may change depending on the drying conditions of the material that has been developed, and in some cases may cause malfunctions such as unevenness. Therefore, it is important to maintain an appropriate air temperature in the drying section, and it has been desired to develop a simple gutter temperature control device that can stably and accurately control the air temperature.

[Means for Solving Problem 1] As a result of various studies, the present inventors have found that at least two temperature detection means are installed near the heating source or the cold JJI source and at the target location where the temperature is to be controlled. An automatic developing apparatus equipped with an automatic temperature control means characterized in that the temperature detected by the temperature detection means installed near the heating source or the cooling source is TI, When the detected temperature is T2 and the set temperature is T, the T is the difference between T1 and T2 plus the set temperature T', that is, T'
It has been found that the above problem can be solved by an automatic temperature control method characterized in that the heating or cooling source is controlled so as to match =T+lT, -T21.

The present invention will be explained below with reference to the figures.

FIG. 1 is a schematic diagram showing a drying section of an automatic developing apparatus equipped with temperature control means according to the present invention. Processing tanks such as a developing tank, a fixing tank, and a washing tank are omitted from the figure. The air taken in by the blower 1 is heated by a heater 2 serving as a heat source, passes through a gasket 3, is blown out to a drying section 4, hits the processed photosensitive material 6 conveyed from between conveyance rollers 5, and dries it. Sensors 1.7 and 8 are installed near the heat source and near the drying section, that is, the target point of temperature control, respectively. [I, and is connected to the control unit 9. The control unit 9 determines the temperature of the heater from the output of each sensor and the set temperature.
Built-in CPU for calculating N/OFF temperature points,
It also includes a setting input section 10 for inputting a set temperature. Reference numeral 11 denotes a relay that turns on/off the heater 2 in response to a signal from the control g10.

FIG. 2 shows that the two sensors of the above device are activated to operate the device according to the present invention, the set temperature T is input, and the method of the present invention is used, that is, T' = T + l T, -T21 is calculated by the calculation unit. 3 is a graph showing the temperature state near the heat source and the drying section, and T' when T1 is controlled to match T'. Since T', which is the reference value for temperature control, is determined in advance based on the target set temperature T and the temperature drop that will occur between the vicinity of the heat source and the drying section, the temperature T2 of the drying section is within a narrow range around the set temperature T. It is stable and well controlled.

Further, T' may be controlled by calculating it sequentially from the detected values of T, , T2 as described above, but it may also be controlled using the average value of T' within a certain time, or it may be controlled using the average value of T' within a certain time. It is also possible to obtain the average value of each of T , , T 2 and calculate T' and use it for control.

Figure 3 shows the temperature near the heat source 1 (T,) over time when the operation is performed using only the detection value T1 of the sensor near the heat source and setting the set temperature to T according to the conventional method.
and a graph showing fluctuations in the temperature near the drying section (T2). As shown in the figure, the temperature T, and T.

The amount of temperature decrease Ts due to heat dissipation in the air path is
Therefore, the temperature T2 in the drying section is at a level lower than the set value.In order to match the average value of temperature T2, which is the actual drying condition of the photosensitive material, to the required temperature T, the set value must be predicted in advance each time. It is necessary to set the average value of the temperature decrease amount Ts higher, and adjustment is difficult because the value of Ts varies depending on various conditions as described above.

In addition, Figure 4 shows the temperature T2 of the drying section and the vicinity of the heat source when the device is operated at ff1lJIIIL so that the detected temperature T2 of the sensor ■ matches the set temperature T using only the sensor ■ placed near the drying section. It is a graph showing changes in temperature T2. As shown in the figure, the drying section temperature T2 matches the set value T on average, but because the temperature detection position is far from the heat source, T2 fluctuates greatly due to overshoot, making it difficult to perform stable control. .

[Effects of the Invention] As described above, according to the present invention, it is possible to stably control and maintain the temperature of the target space within a narrow range. Furthermore, the temperature to be maintained can be easily and accurately set by simple operations.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the drying section of the automatic developing device of the present invention, FIG. 2 is a graph showing temperature changes when temperature is controlled by the method of the present invention, and FIGS. 3 and 4. are graphs showing changes in temperature when temperature control is performed using only sensors installed near the heat source or near the drying section, respectively. Applicant: Konishiroku Photo Industry Co., Ltd. Figure 2 Figure 3 Time Figure 4

Claims (2)

[Claims] (1) In a temperature control device for an automatic developing device that uses a heating source or a cooling source to control the temperature of gas at a constant level, at least two An automatic developing device characterized in that it is equipped with automatic temperature control means having temperature detection means. (2) When the temperature detected by the temperature detecting means installed near the heating source or cooling source is T_1, the temperature detected by the temperature detecting means installed at the target location is T_2, and the set temperature is T, the above T_1 an automatic developing apparatus characterized in that the heating source or the cooling source is controlled so that T' corresponds to the difference between T_1 and T_2 plus the set temperature T, that is, T'=T+|T_1-T_2| Temperature control method.