JPH0411258A - Liquid level detector and photosensitive material processing device and method for adding water to this device - Google Patents

Abstract

PURPOSE:To surely detect a liquid level with good accuracy by using a cup in the state of directing the opening face downward, detecting the pressure on the inner side of the cup by means of a pressure sensor mounted on a bottom cap and deciding the liquid level in accordance with the detected value of the pressure sensor. CONSTITUTION:A level detector 100 is mounted on the upper part of a processing tank 10 and the cup on a blind cylinder is formed of a hard member. The one opening face 104 is formed of a cylindrical body 102 disposed to face the liquid surface and a thin wall member and has the cap 106 for closing the other opening face of the cylindrical body 102. The pressure 108 which is mounted on the bottom cap 106 of this cup and detects the pressure on the inner side of the cup and a deciding means which decides the liquid level in accordance with the pressure detected by this pressure sensor 108 are provided. Since there are no mechanical movable parts, there is no malfunction and since the liquid surface and the detecting part do not come into direct contact with each other and, therefore, the deposition of liquid to the detecting part, etc., do not arise. The liquid surface is detected with the good accuracy over a long period of time in this way.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid level detection device for detecting a liquid level, a photosensitive material processing device in which this liquid level detection device is arranged in correspondence with a processing liquid level, and the same. This invention relates to a method for adding water to an apparatus.

[Prior art]

Automatic processors, which are part of photosensitive material processing equipment, are equipped with a developing tank, a bleaching tank, a fixing tank, a washing tank, and a stabilizing tank. (hereinafter collectively referred to as processing liquid). The photographic material subjected to the printing process is sequentially immersed in each processing tank, subjected to development processing, and then delivered to a drying device where it is dried and taken out.

The processing liquid is carried out by the conveyance of the photosensitive material, and
Since the amount of liquid decreases due to evaporation, it is necessary to replenish the replenisher according to the amount of photosensitive material processed. The amount taken out by the photosensitive material can be easily calculated from the appropriate amount of the photosensitive material. On the other hand, when the amount of the processing liquid is reduced due to evaporation, only the water content in the processing liquid decreases, resulting in a change in the concentration of the processing liquid. Therefore, it is necessary to add evaporated water separately from the replenisher. However, the amount of evaporation cannot be uniquely determined by calculation because it varies depending on the surrounding environment, that is, temperature and humidity, and also varies depending on whether the device is in operation or not.

For this reason, it has been proposed to install a liquid level sensor such as a hydrometer in the processing liquid in each processing tank and add water based on the detected value from this liquid level sensor (for example, JP-A-1-28
(See Publication No. 1446). According to this, changes in the concentration of the processing liquid can be recognized by the liquid level sensor, and an appropriate amount of water can be added.

However, the liquid level sensor has low reliability and may make false detections, which may prevent water from being added properly. This also applies to concentration sensors, and these liquid level sensors are expensive and impractical. For this reason,
It has been proposed to provide a monitoring treatment tank separate from the actual treatment tank and add water to the actual treatment tank based on the degree of evaporation in this treatment tank (JP-A-1-254959, JP-A-1-254960). (see publication).

According to this, it is possible to obtain data equivalent to the actual amount of evaporation, thereby improving reliability.

[Problem B to be solved by the invention] However, in the above-mentioned water addition system, a monitoring treatment tank is required in addition to the actual treatment tank, which increases the size of the device and the number of parts. There is a problem. Another problem is that management and maintenance to maintain conditions equivalent to those of an actual treatment tank are complicated.

The present invention has been made in consideration of the above facts, and an object of the present invention is to obtain a liquid level detection device that can reliably and accurately detect the liquid level.

In addition to the above objectives, the present invention also provides a photosensitive material processing device that does not require equipment to obtain the amount of evaporation in the device itself, can obtain an appropriate amount of water with high reliability, and can improve management and maintainability. The purpose is to obtain a method for adding water to the device.

[Means to solve the problem]

The invention according to claim (1) comprises a cylinder made of a hard member with one opening facing the liquid level, and a lid formed of a thin-walled member for closing the other opening of the cylinder. a cylindrical cup with a bottom, a pressure sensor attached to the bottom lid of the cup to detect the pressure inside the cup, and a determining means to determine the liquid level based on the pressure detected by the pressure sensor; have.

The invention set forth in claim (2) provides that the liquid level detection device set forth in claim (1) is disposed corresponding to the processing liquid level of a processing tank in which processing liquid for processing photosensitive materials is stored. It is a feature.

The invention according to claim (3) is characterized in that the concentration of the processing liquid is kept constant by adding water to evaporate from the processing tank in which the processing liquid is stored, which is used in the photosensitive material processing apparatus according to claim (2). This method of adding water to a photosensitive material processing apparatus for maintaining the temperature of the photosensitive material processing apparatus is characterized in that water is added when the liquid level detecting device detects a decrease in the liquid level for a predetermined period of time.

[Effect]

According to the invention described in claim (1), the cup is used with the opening surface facing downward, that is, with the cup turned upside down.

If the opening surface is away from the liquid level, the pressure sensor attached to the bottom cover will detect atmospheric pressure. When the liquid level rises to the same level as the opening surface, the inside of the cup is sealed. As the liquid level rises from this point on, the pressure inside the cup becomes higher than the atmospheric pressure due to water pressure.Since the pressure inside the cup and the liquid level are in a proportional relationship, the detected value of the pressure sensor The liquid level can be determined based on.

In addition, if the inner space is sealed at atmospheric pressure with an appropriate amount of processing liquid in the cup, the pressure in the inner space will decrease when the level of processing liquid drops, and this pressure By detecting this, it is possible to determine the amount of weight loss of the processing liquid.

In this way, since there are no mechanically moving parts, there are no malfunctions. In addition, since the liquid surface does not come into direct contact with the detection part, there is no chance of liquid precipitation on the detection part (and there is no fluctuation in the detected value over time. Therefore, it can be used with high accuracy over a long period of time. Liquid level can be detected.

According to the invention set forth in claim (2), the liquid level detection device is attached to a processing tank of a photosensitive material processing apparatus. A processing liquid is stored in this processing tank, and the liquid level detection device is installed so that one opening surface of the liquid level detection device is located at a position at a proper level of the processing liquid. As a result, when the level of the processing liquid is low, the pressure remains constant (atmospheric pressure), and when the level of the processing liquid is within the appropriate level range, the pressure sensor detects a value corresponding to that level. changes, and the liquid level can be determined.

This serves as a liquid level sensor that stops replenishing the replenisher or adding water when the detected value of the pressure sensor of the liquid level detection device changes, and also detects the excess amount of processing liquid within the appropriate level range by detecting the detected value of the pressure sensor. It can be calculated based on

The invention according to claim (3) provides that, in the photosensitive material processing apparatus, when adding evaporated water from the processing tank, the liquid level detecting device detects a drop in the liquid level that does not reach the lower limit of the appropriate level. Water is added when pressure (atmospheric pressure) is detected continuously for a predetermined period of time. According to this method, compared to adding a fixed amount of water at regular intervals, unnecessary water addition can be suppressed and the appropriate amount of water can be added, so the concentration of the processing liquid can be kept almost constant. can do.

〔Example〕

FIG. 1 shows an automatic developing machine as a photosensitive material processing apparatus according to the present invention. In this automatic developing machine, developer tank 12
, bleach tank 14, bleach-fix tank 16, fix tank 18, washing tank 2
2.24, stabilizing tanks 26 are installed in series, each filled with a predetermined amount of each processing solution: developer, bleaching solution, bleach-fixing solution, washing water, and stabilizing solution, and the photosensitive material F is transported through a transport system (not shown). (hereinafter collectively referred to as the processing tank 10). This conveyance system is controlled by a control device 78. This control device 78
A signal line of a sensor 76 which is provided at the entrance of the developer tank 12 and detects passage of the photosensitive material F is connected to the control device 7.
8, the presence or absence of the photosensitive material F can be recognized.

As shown in FIG. 1, a water tank 36 is provided near the processing tank 10. This water tank 36 is communicated with the bleach tank 14 via piping 34. A pump 32 whose drive is controlled by a control device 78 is interposed in the middle of the pipe 34, and water is supplied to the bleaching tank 14 by driving the pump 32. Further, a replenisher tank 44 is disposed adjacent to the water tank 36 and communicates with the bleach tank 14 via piping 42 .

A pump 38 that is driven and controlled by a control device 78 is interposed in the middle of this piping 42, and similarly to the water supply described above,
The bleaching tank 14 is replenished with the bleaching replenisher by driving the pump 38.

Note that a branch pipe 35 is provided in the pipe 34 for replenishing water to the bleaching tank 14 on the upstream side of the pump 32. This branch pipe 35 extends to the developer tank 12. Branch piping 3
A pump 33 whose drive is controlled by a control device 78 is interposed in the middle part of the developer tank 1.
Water is supplied to 2.

The developing tank 12, the fixing tank 18, and the stabilizing tank 26, which are processing tanks other than the bleaching tank 14, are each provided with piping 56, 58, and 62 for supplying replenishing processing liquid. Further, a water supply pipe 64 is arranged to the washing tank 24 for replenishing washing water. Rinsing water is sent from the washing tank 24 to the washing tank 22 by an overflow 66, and fixing liquid is sent from the fixing tank 18 to the bleach-fixing tank 16 by an overflow 67. The rinsing water in the rinsing tank 22 is sent to the fixing tank 18 by a pump 72 and piping 73. Note that the driving of these pumps is also controlled by the control device 78.

As shown in FIG. 2(A), above the processing tank 10,
A liquid level detection device 100 is attached.

The liquid level detection device 100 includes a cylindrical body 102 in the shape of a truncated cone. The cylindrical body 102 is made of a hard material, such as plastic, and has an opening surface 104 at its lower end in FIG. Further, a lid 106 is attached to the upper end of the cylinder 102 in FIG. The lid 106 is made of a soft material, such as elastic synthetic resin or plastic, or a thin metal film. Therefore, 1106 is recessed toward the lower pressure side due to the pressure difference applied to both end faces thereof.

A pressure sensor 10 is attached to the outer end surface of the lid 106. This pressure sensor 108 is made of a piezoelectric material that outputs an electrical signal in response to the pressure generated on the lid 106. As piezoelectric materials, ■piezoelectric polymer materials, ■synthetic polymer electret materials, and ■piezoelectric ceramic materials can be used.As piezoelectric materials, commercially available piezoelectric ceramics (trade name, manufactured by Flevite Co., Ltd.) and PZT can be used.
-4, PZT-5, PZT-6, PZT-8, etc. can be used.

A flange 1 protruding in the radial direction is provided on the outer periphery of the cylindrical body 102.
10 is integrally formed and fixed to the partition wall 10A of the processing tank 10 via bolts 111.

Here, the opening surface 104 of the cylindrical body 102 is set at the lower limit position of the appropriate level of the processing liquid in the processing tank 10, as shown in FIGS. If the appropriate level lower limit position has not been reached, the pressure sensor 108
The detected value corresponds to the atmospheric pressure, and when the processing liquid reaches the liquid level, the inside of the cylindrical body 102 is sealed. As the liquid level further rises, the detected value of the pressure sensor 108 will output a value corresponding to a pressure higher than atmospheric pressure in accordance with this liquid level. In addition,
The upper limit position of the appropriate level is the level at which the water flows into an overflow tank (not shown).

As shown in FIG. 1, the control device 78 includes a microcomputer 80. The microcomputer 80 is composed of a CPU 82, a RAM 84, a ROM 86, an input/output board 88, and a bus 90 such as a data bus or a control bus that connects these. The pumps 32, 33, 38, and 72 are connected to the input/output port 88 via drivers 32A, 33A, 38A, and 72A, respectively. Also, the sensor 76 and the pressure sensor 108 are connected to the input/output port 88. It is connected. Furthermore, this input/output port 88 has a signal line 92 to the transport system.
is also connected.

A map (see FIG. 4) showing the relationship between the signal from the pressure sensor 108 and the liquid level is stored in the RAM 84 of the microcomputer 80, and the CPU 82 determines the liquid level according to the input signal. It is supposed to be done. Further, in the cpus 2, when the obtained liquid level continues to be below the appropriate level for a predetermined period of time, the pump 32 is activated to supply water to the processing tank 10.

Next, the operation of this embodiment will be explained.

The photosensitive material F is sequentially guided from the developing tank 12 to the bleaching tank 14 and the bleach-fixing tank 16, where it is subjected to processing such as development and bleaching, and after being pulled out from the stabilizing tank 26, it is dried.

First, a description will be given based on the operating control routine shown in FIG. 3(A). In step 150, it is determined whether or not it is time to add water, such as at the start of operation, and if the determination is affirmative, the process proceeds to step 152, where it is determined whether flag F is set (1). This flag F is a flag for determining whether or not it is necessary to add water, and will be described later. If an affirmative determination is made in step 152, that is, if it is determined that it is necessary to add water, the process proceeds to step 154, where the pump is activated to start adding water. Next, in step 156, the liquid level detection device 10
It is determined whether the detected value of 0 has changed, and if it has changed, it is determined that the liquid level has reached the opening surface of the cylinder 102 of the liquid level detection device 100, and the process moves to step 157 to stop the pump. . If the determination in step 156 is negative, the detected pressure indicates atmospheric pressure, and it is determined that there is a gap between the opening surface and the liquid level, and step 156 is repeated.

In the next step 158, the flag F is reset (to 0) and then the process moves to step 160. Here, step 150
Or, if a negative determination is made in step 152, that is, it is not time to add water or there is no need to add water, directly proceed to step 16.
Transition to 0.

In step 160, it is determined whether or not it is time to replenish. If it is time to replenish, the process moves to step 162 and the memory is stored in the RAM 84.
The amount of replenishment is taken in from , and then replenishment is performed in step 164 , after which the process moves to step 150 . Also, step 1
If it is determined in step 60 that it is not time for replenishment, steps 162 and 164 are skipped and the process proceeds to step 150.

The above is the control during operation, and in this embodiment, in addition to this control routine during operation, a water addition necessity determination routine shown in FIG. 3(B) is operated regardless of whether the apparatus is in operation or at rest. This water addition necessity determination routine will be explained in detail below.

In step 200, it is determined whether flag F has been reset (0), and if the determination is negative, it has already been determined that water needs to be added, so step 200 is repeated until the water addition is completed. If an affirmative determination is made in step 200, the process proceeds to step 202, where the timer is reset and started, and the process proceeds to step 204.

In step 204, the pressure sensor 108 causes the lid 10 to
6 is detected and taken into the control device 78.

Next, in step 206, the liquid level is obtained from the detected value-liquid level map (see FIG. 4) stored in the RAM 84 of the control device 78.

In the next step 208, this read liquid level is compared with a pre-stored appropriate level lower limit value, and if a positive determination is made, that is, the liquid level is within the appropriate level range (outside the atmospheric pressure range), processing is performed. Since the processing liquid in the tank 10 is sufficiently drained, there is no need to add water (Proceed to step 202 and reset and start the timer again.

If a negative determination is made in step 208, that is, if the liquid level has not reached the lower limit of the appropriate level (within the atmospheric pressure range), the process proceeds to step 210, and whether a predetermined period of time (3 hours in the experimental example described below) has elapsed. If it is determined whether or not the predetermined time has elapsed, the process moves to step 204, and steps 204, 206, and 208 are repeated.

When it is determined in step 210 that the predetermined time has elapsed,
The process proceeds to step 212, where a flag F indicating that water needs to be added is set (1), and the process proceeds to step 200.

In this way, by constantly detecting the presence or absence of overflow whether operating or not, it is possible to deal with not only the large amount of evaporated water during nighttime suspension, but also the amount of evaporated water during operation, and to control the concentration of the processing liquid. can be held almost constant. Therefore, stable development processing etc. can be performed.

Here, as an experimental example, when the liquid level detection device 100 according to this embodiment is attached to the water washing tank 22 and water is added when the atmospheric pressure time continues for 3 hours, the temperature is adjusted for 10 hours/day, and the treatment is performed. Even after one month of running with A4.1 sheet/day, no staining was observed.

In addition, as another experimental example, the liquid level detection device 10 of this embodiment
0 and the liquid level of the conventional floater method, it was found that the conventional floater method had malfunctions three times in five months, but the liquid level detection device 100 of this embodiment
was working well. The cause of the failure is thought to be the occurrence of precipitates in the movable parts of the floater.

In addition, in this embodiment, the cylinder body 1 in the liquid level detection device 100
Although the opening surface 104 of 02 was installed so as to match the lower limit of the appropriate level, as shown in FIGS. The space may be sealed. That is, Fig. 5 (A
), when the liquid level falls below the lower limit of the appropriate level, the pressure in the inner space of the cylinder 102 becomes low and the lid 128 is recessed downward. Moreover, as shown in FIG. 5(B),
When the liquid level reaches the appropriate level, the lid 108 becomes flat, and when the liquid level exceeds the appropriate level, the lid 10B protrudes upward, as shown in FIG. 5(C).

Therefore, with this arrangement, a pressure drop in the inner space (a value lower than atmospheric pressure) can be detected. Thereby, the amount of reduction from the lower limit of the appropriate level of the processing liquid can be determined by calculation. Therefore, it is sufficient to supply this reduced amount when adding water.

In this embodiment, the cylinder of the liquid level detection device 100 is shaped like a truncated cone, and the pressure applied to the opening surface 104 is applied to the lid 106.
Although the cylinder body may have a cylindrical shape, if the pressure sensor 108 has good responsiveness, pressure fluctuations in the inner space of the cylinder body can be reliably detected.

Further, in this embodiment, only water was added to the processing tank 10, but during evaporation, the preservative pre-filled in the processing liquid also evaporates along with the water. This preservative has a function of suppressing oxidation of the processing solution, and as the preservative decreases, the degree of oxidation will accelerate.

Therefore, if the water supplied to the treatment tank 10 contains this preservative, the oxidation of the treatment liquid can be kept suppressed. By using the liquid level detection device W100 of this embodiment, water can be added appropriately, and an appropriate amount of preservative can also be replenished.

Furthermore, in this embodiment, water is supplied directly from the piping port to the processing tank by operating a pump, but a processing rack (not shown) disposed in the processing tank 10 and directly facing the photosensitive material F (not shown)
If water is added through parts that are in direct contact with air and easily dry, such as the rollers at the top of the rollers or the rollers of a crossover rack (not shown) that transfers the photosensitive material F to the adjacent processing tank 10, the rollers etc. can be prevented from drying out, and precipitation, staining, etc. can be prevented.

[Effects of the Invention] As explained above, the liquid level detection device according to the present invention has the excellent effect of being able to reliably and accurately detect the liquid level.

In addition to the above-mentioned effects, the photosensitive material processing apparatus and the method for adding water to the apparatus according to the present invention do not require equipment for obtaining the amount of evaporation in the apparatus itself, and can obtain a highly reliable and appropriate amount of water. , and has the excellent effect of improving management and maintainability.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an automatic developing machine to which the present invention is applied, FIG. ) is an explanatory diagram showing the relative position between the liquid level detection device and the liquid level, FIG. 3(A) is a flowchart showing the operation control routine according to this embodiment, and FIG. 3(B) is according to this embodiment. Flowchart showing the routine for determining whether or not water is required. Fig. 4 is a characteristic diagram showing the relationship between the detected value of the liquid contact surface sensor and the liquid level. Figs. 5 (A) to (C)
FIG. 3 is an explanatory diagram showing the relative position of a liquid level sensor and a liquid level according to a modified example. F...Photosensitive material, 10...Processing tank, 32.38.46...Pump, 36...Water tank, 44...Replenisher tank, 7B...Control device, 100... Liquid level detection device, 102... Cylindrical body, 104... Opening surface, 106... Lid, 108... Pressure sensor.

Claims (3)

[Claims] (1) A cylindrical cup with a bottom, which includes a cylindrical body made of a hard member with one opening facing the liquid level, and a lid that is made of a thin-walled member and closes the other opening of the cylindrical body; A liquid level detection device comprising: a pressure sensor attached to a bottom lid of the cup to detect pressure inside the cup; and determining means for determining a liquid level based on the pressure detected by the pressure sensor. (2) A photosensitive material processing apparatus characterized in that the liquid level detection device according to claim 1 is disposed corresponding to the processing liquid level of a processing tank in which a processing liquid for processing a photosensitive material is stored. (3) Photosensitive material processing for maintaining the concentration of the processing liquid at a constant level by adding water to evaporate from the processing tank in which the processing liquid is stored, which is used in the photosensitive material processing apparatus according to claim (2). 1. A method for adding water to a photosensitive material processing apparatus, characterized in that water is added when the liquid level detecting device detects a decrease in the liquid level for a predetermined period of time.