A method of water replenishment for an automatic developing apparatus and device therefor

Abstract: A water replenishing device is disclosed which makes it possible to supply the necessary volume of water in response to a decrease in the processing solution in the processing tank (1) due to evaporation. A water supply guide member (11) is attached to an upper part of a processing solution tank. A discharge opening (13) is formed at one end of the water supply guide member (11). Water supplied from a water replenishing pipe (7) is fed to the water supply guide member (11) and then it is supplied into the processing solution tank (1). When the processing solution level in the processing solution tank reaches an overflow opening (5a), the excess water supplied to the water supply guide member is discharged outside the processing solution tank through the discharge opening.

Description: The present invention relates to a method and a device to replenish water into an automatic developing apparatus to develop photosensitive materials such as film, printing paper and the like. DE-A-3005471 discloses a water replenishing device as defined in the preamble of claim 5. In an automatic developing apparatus various processing solutions for developing, leaching, fixing, stabilizing, etc., are filled in respective processing solution tanks and a photosensitive material is immersed in turn into those solutions for development. The solutions gradually decrease due to evaporation, so that when a solution level falls to a predetermined level, the water is replenished to keep the solution level constant. In some cases water is manually replenished but this requires a significant amount of labor and sometimes the operator forgets to replenish the system. Therefore, a system with an automatic water replenishment feature is becoming popular. One of the well know methods for automatic water replenishment is to use a device comprising a pipe for replenishing water. One end of the pipe is disposed above the processing solution tank or a sub-tank communicating with the tank and the other end of the pipe is connected to a tank for replenishing water. The device also includes a water pump incorporated with the pipe. The water pump is controlled by a level detector installed in the processing solution tank or the sub-tank so as to replenish water. Instead of a level detector, another method wherein data such as ambient temperature, humidity, temperature of the processing solution and time are detected has been known. This system calculates the evaporated volume based on the detected data and a water pump is controlled to replenish the water. In the water replenishing method using a level detector, if the level detector has a poor degree of accuracy, it is impossible to always replenish the optimum amount of water. When the volume of water replenished is insufficient, it causes a highly concentrated processing solution. Further, when the water is excessively replenished, the solution is diluted due to solution discharge through an overflow opening in the processing solution tank. Therefore, this method requires a level detector with a high degree of accuracy and this results in a high cost level detector. On the other hand, using a water replenishing method where a water pump is controlled based on the detected data requires an exact data collection and calculating device with a high degree of accuracy also resulting in a high cost. An object of the present invention is to provide a method and a device of an extremely simple construction to replenish the necessary volume of water into a processing solution tank of an automatic developing apparatus. To solve the problem described above, the water replenishing method of the present invention for an automatic developing apparatus is defined in claim 1. The water replenishing device for an automatic developing apparatus of the present invention is defined in claim 5. Further, the water replenishing device of the present invention can be provided with a vessel-shaped water supply guide member as defined in claim 9. As for the water supply guide member mentioned above, one end of the guide member may be located outside the processing solution tank so that the excess supplied water is discharged into a water replenishing tank installed outside the processing solution tank. Furthermore, instead of the water supply guide member mentioned above another construction may be adopted, wherein a spout-shaped water supply guide member is disposed in the processing solution tank as defined in claim 12. To add to those described above, the water supply guide member may be a funnel-shaped water supply guide member as defined in claim 13. Another water replenishing device of the present invention has a spout-shaped water supply guide member provided with a bottom plate as defined in claim 14. In those device constructions described above, water supply by the water supply means starts when the processing solution level in the processing solution tank falls to a predetermined level. The water volume to be supplied by the water supply means is specified to be an excessive volume, more than a predetermined level. For example, a volume which brings a higher water level than that for the overflow opening, so that the water supply continues even after the processing solution level has reached a predetermined level. The excess supplied water is guided by a guide member of supplied water and is discharged outside the processing solution tank, so that the processing solution is protected from being discharged outside the processing solution tank. The above and other objects and features of the present invention will be clearly understood from the following description with respect to preferred embodiments thereof when considered in conjunction with the accompanying drawings, wherein the same reference numerals have been used to denote the same or similar parts or elements, and in which: Fig. 1 is a schematic view of a processing solution tank, sub-tank and water replenishing tank according to a first embodiment of the present invention. Fig. 2 is a cross sectional view of a water supply guide member according to the first embodiment of the present invention. Fig. 3 is a cross sectional view of the water supply guide member of Fig. 2 discharging excess water into the overflow pipe of the first embodiment. Fig. 4 is a cross sectional view of a second embodiment of a water supply guide member of the present invention. Fig. 5 is a cross sectional view of a third embodiment of a water supply guide member of the present invention. Fig. 6 is a cross sectional view of a fourth embodiment of a water supply guide member of the present invention. Fig. 7 is a perspective view of a main part of a water supply guide member according to a fifth embodiment of the present invention. Fig. 8 is a perspective view of a main part of a water supply guide member according to a sixth embodiment not part of the present invention. Several embodiments of the present invention will now be described with reference to the drawings. Figs. 1, 2 and 3 show the first embodiment of the present invention. Outside a processing solution tank 1, a sub-tank 2 communicating with the upper part of the processing solution tank 1 is provided as illustrated. The lower part of the sub-tank 2 and the lower part of the processing solution tank 1 are connected with each other through a circulation channel 3 in which a circulating pump 4 is installed. The developing solution filled in the processing solution tank 1 and sub-tank 2 is circulated through both tanks 1 and 2 by the circulating pump 4, so as to make the temperature and the concentration of the developing solution uniform. An overflow pipe 5 and a level detector 6 to detect the solution level are installed in the processing solution tank 1. The lower part of the overflow pipe 5 protrudes outside through the side wall of the processing solution tank 1. At the outside of the processing solution tank 1 is a water supplying device 7 to replenish water into the tank. The water supply device 7 incorporates a water replenishing pump 10 in a water replenishing pipe 9. One end of the pipe 9 overhangs the processing solution tank 1 and the other end of the pipe 9 is connected to a water replenishing tank 8. The water replenishing pump 10 is controlled by the level detector 6. The level detector 6 uses switches such as a float switch in which a ring float is mounted outside its supporting cylinder so as to go up or down according to the rise or fall of the processing solution level. A magnet is attached to the inner surface of the float and operates a pair of proximity switches installed respectively in the upper and lower portions inside of the supporting cylinder. An electrode switch comprising lower and upper limit detecting electrodes can also be used in place of the magnet. Namely, the level detector 6 has two level detecting portions 6a and 6b to detect the upper and lower limit levels of the processing solution. The upper limit level detecting portion 6a of the level detector 6 is located a little bit lower than the overflow opening 5a of the overflow pipe 5. The level detector 6 starts to drive the water replenishing pump 10 when the processing solution level in the processing solution tank 1 falls to the lower limit level detecting portion 6b. The upper limit level detecting portion 6a detects when the processing solution level rises nearly up to the overflow opening 5a. Then, after a specified period after detection, the water replenishing pump 10 is stopped. The reason for the specified wait period is that a level detector 6 has a certain degree of accuracy. The level detector with a poor degree of accuracy might result in the water replenishing pump 10 stopping earlier or later than determined causing an insufficient or excessive amount of replenished water. In those cases where the upper limit level detecting portion 6a of the level detector 6 is set equal to the level of the overflow opening 5a, a predetermined level of the processing solution might not be retained because the processing solution level might fall below the overflow opening 5a when the replenished water volume is insufficient. To solve those problems described above, the upper level detecting portion 6a is set a little bit lower than the level of the overflow opening 5a. Further, the water replenishing pump 10 is stopped a specified period after the moment when the upper level detecting portion 6a has detected the processing solution level. Therefore, the water volume supplied by driving the water replenishing pump 10 exceeds the necessary volume required to raise the processing solution level from the lower limit level to that of the overflow opening 5a. In the upper portion of the processing solution tank 1, a vessel-shaped water supply guide member 11 is installed. The water supply guide member 11 has a pivot axis 12. The pivot axis 12 of the water supply guide member 11 is located above the overflow opening 5a of the overflow pipe 5 and is supported rotatably around the pivot axis 12. A water discharge opening 13 is formed on the end of a pivot axis side of the water supply guide member 11 so as to face the overflow opening 5a and located above the other end of the water supply guide member 11 is an end of the water replenishing pipe 9. In a water replenishing device constructed as above, if the level of the processing solution in the processing solution tank 1 falls due to evaporation, the other end of the water supply guide member 11 tilts downward. When the processing solution level falls to the lower limit level detecting portion 6b of the level detector 6, the water replenishing pump 10 starts to operate and the water in the water replenishing tank 8 is supplied through the water replenishing pipe 9 onto the water supply guide member 11 and subsequently overflows into the processing solution tank 1. As the processing solution level in the processing solution tank 1 rises, the water supply guide member 11 rotates upward due to the buoyant force of the float 11a. When the processing solution level rises up to the overflow opening 5a, the water inside the water supply guide member 11 starts to flow into the discharge opening 13. Since the water replenishing pump 10 is designed to stop after replenishing a larger volume of water than necessary, water supply continues even after the processing solution level rises up to the level of overflow opening 5a. The excessive water is discharged through the discharge opening 13 into the overflow opening 5a. As described above, the discharge of excessive water from the overflow opening 5a before being mixed with the processing solution always secures the proper volume of water supply to the processing solution tank 1 so that the processing solution is not diluted. The processing solution level in the processing solution tank 1 rises up to the upper level detecting portion 6a of the level detector 6 and the water replenishing pump 10 is stopped after a specified wait period following detection of this rise by the level detector 6. Since there is not a demand for a high degree of accuracy, it is possible to use a comparably inexpensive level detector 6 with a lower degree of accuracy. Fig. 4 shows a second embodiment of the present invention. In this embodiment, some middle portion of the water supply guide member 11 is supported swingably around a pivotal axis 12, and one end of the water supply guide member 11 is formed as a discharge opening 13 and located outside the processing solution tank 1, passing through a window 14 formed on the side wall of the processing solution tank 1. At the other end of the water supply guide member 11 is attached a float 18 which goes up and down according to the processing solution level change in the processing solution tank 1. Located above this end of the water supply guide member 11 is one end of a water replenishing pipe 9. The other parts of the second embodiment are constructed the same as the first embodiment so that the same symbols will be used for the same components to avoid further explanation. In the second embodiment described above, the water supplied from the water replenishing pipe 9 is fed onto the water supply guide member 11 and overflows from the other end of the water supply guide member 11 to replenish the processing solution tank 1. Further, as the processing solution tank level rises, the water supply guide member 11 swings. After the processing solution level rises up to the overflow opening 5a, the excessive water supplied to the water supply guide member 11 is discharged through the discharge opening 13 into a water replenishing tank 8. The second embodiment enables an effective use of water as the excess water supplied to the water supply guide member 11 is sent back to the water replenishing tank 8. Fig. 5 shows a third embodiment of the present invention. In this embodiment, one end of a spout-shaped water supply guide member 15 is disposed passing though a window 14 formed in the side wall of the processing solution tank 1. The water supply guide member 15 is slanted downward to one end. A pin 16 is provided at the other end of the water supply guide member 15 and is inserted so as to slide in a slanted oblong guide hole 17 formed on the side wall of the processing solution tank 1. At the other end of the water supply guide member 15, a float 18 is attached which goes up and down according to the processing solution level in the processing solution tank 1. As the float 18 moves up and down, the water supply guide member 15 moves along the oblong guide hole 17, so that when the processing solution level rises up to the level of overflow opening 5a, the other end of the water supply guide member 15 comes to face one end of the water replenishing pipe 9. In the third embodiment described above, the water supply guide member 15 moves obliquely downward as the processing solution level in the processing solution tank 1 falls. Further, the other end of the water supply guide member 15 moves out of position from facing the end of the water replenishing pipe 9. Therefore, the water supplied through the water replenishing pipe 9 goes directly to replenish the processing solution tank 1. As the processing solution level rises, the water supply guide member 15 moves upward obliquely. When the solution level rises up to the level of overflow opening 5a, one end of the water supply guide member 15 comes to face one end of the water replenishing pipe 9. The excess water supplied through the water replenishing pipe 9 is received by the water supply guide member 15 and flows along the slope of the water supply guide member 15 to be sent back to the water replenishing tank 8. Fig. 6 shows a fourth embodiment of the present invention. In this embodiment, a funnel-shaped water supply guide member 19 is attached at the upper end of the overflow pipe 5 so that it can slide freely up and down. The water supplied from the water replenishing pipe 9 is fed onto the outer circumferential part of the water supply guide member 19. The other parts of the fourth embodiment are constructed the same as the first embodiment, so that the same reference numerals will be used for the same components to avoid further explanation. In the fourth embodiment described above, the water supplied from the water replenishing pipe 9 is fed onto the water supply guide member 19 and overflows from the outer circumference of the water supply guide member 19 to replenish the processing solution tank 1. The water supply guide member 19 which is made of a formed material covered with an outer skin is raised as the processing solution level rises until the level of water stored in the water supply guide member 19 reaches to that of the overflow opening 5a. Then the excess water is supplied from the water replenishing pipe 9 onto the water supply guide member 19 and is discharged from the overflow opening into the overflow pipe 5. Also in the fourth embodiment described above, no dilution of the processing solution takes place at all as the excessive water supplied is discharged outside the processing solution tank 1 before being mixed with the processing solution. Fig. 7 shows a fifth embodiment of the present invention. In this embodiment, the upper end of the overflow pipe 5 penetrates through a bottom plate 7a of a spout-shaped water supply guide member 7 provided at the upper portion of the processing solution tank 1. The overflow pipe 5 protrudes a bit out of the bottom plate 7a. Reference numeral 5a designates the upper overflow opening of the overflow pipe 5. The water supplied from the water replenishing pipe 8 onto the water supply guide member 7 does not flow into the overflow opening 5a but flows along the water supply guide member 7 and into the processing solution tank 1, because the upper end of the overflow pipe 5 protrudes a bit higher out of the bottom plate 7a of the water supply guide member 7. When the processing solution level in the processing solution tank 1 rises up to the level of the overflow opening 5a, a processing solution stream flows to the overflow opening 5a and the excess water additionally supplied after this moment is discharged out through the overflow opening 5a because it is fed into the stream and flows along with the stream over the water supply guide member 7 without flowing out of the water supply guide member 7. As described above, the discharge of excess water through the overflow opening 5a before being mixed with processing solution always allows the best volume of water to be replenished into the processing solution tank 1 and no dilution of processing solution takes place. In the embodiment shown in Fig. 7, the excessive water is discharged outside the processing solution tank 1 through the overflow pipe 5 which penetrates the bottom plate 7a of the water supply guide member 7. The excessive water may also be discharged through an overflow opening 5a which is formed in a side wall of the processing solution tank 1 above the bottom plate 7a of the water supply guide member 7, as shown in Fig. 8. The embodiments described above are so constructed that a solution level detector 6 is provided to control a water replenishing pump 10, but they allow a larger volume of water than necessary to be replenished. Therefore, a predetermined volume of water may be replenished at a specified time without providing any particular solution level detector. Regarding the embodiments described above, the explanations have been made about how to replenish water into a processing solution tank, but the invention is also applicable to replenishing water into a sub-tank. The present invention secures a necessary volume of water to be replenished into a processing solution tank by replenishing water into the processing solution tank by a water supply means, and discharging the excess water supplied by the means outside the processing solution tank through a water supply guide member after the processing solution level in the processing solution tank has reached a predetermined level. Therefore, the concentration of the processing solution can be controlled so that it is neither too thick nor diluted and is otherwise kept constant. The present invention provides an inexpensive water replenishing device because of its simple construction with a water supply guide member installed in a processing solution tank. It is to be understood that although the present invention has been described with regard to preferred embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope of the invention, and such other embodiments and variants are intended to be covered by the following claims.

Claims: A water replenishing method for an automatic developing apparatus having a processing solution tank (1) and a water supply means (7) to replenish water into the processing solution tank (1), comprising the steps of: providing a movable water supply guide member (11) installed in the processing solution tank (1) for automatically switching the replenishing water from the water supply means (7) so as to guide the replenishing water to the processing solution tank (1) or outside the processing solution tank (1), in response to the level change of processing solution in the processing solution tank (1); and discharging the excess replenishing water, supplied from the water supply means (7), outside the processing solution tank (1) by means of the water supply guide member (11) when the level of the processing solution goes up by the water replenished from the water supply means (7) and reaches a predetermined level. A water replenishing method as defined in claim 1, further comprising the step of: switching the replenishing water in response to a buoyant force from the processing solution. A water replenishing method as defined in claim 1 or 2, further comprising the step of: supplying water from the water supply means (7) onto the water supply guide member (11). A water replenishing method as defined in claim 1, 2 or 3, further comprising the step of: starting the supply of replenishing water from the water supply means (7) when the volume of processing solution has decreased to a predetermined level, and stopping the supply of water after having replenished a sufficient volume of water so that the solution level reaches a predetermined level. A water replenishing device for an automatic developing apparatus having a processing solution tank (1); the water replenishing device comprising: a water supply means (7) to replenish water into said processing solution tank (1); characterized by : a movable water supply guide member (11) installed in the processing solution tank (1) to automatically switch, a channel (5) for the replenishing water from said water supply means (7, 8, 9) so as to guide the replenishing water to said processing solution tank (1) or outside said processing solution tank (1) to discharge the water in response to the level change of the processing solution in said processing solution tank (1) so that excess replenishing water supplied from said water supply means (7, 8, 9) is discharged outside the processing solution tank (1) by said water supply guide member (11) when the level of the processing solution increase by replenished water from said water supply means (7, 8, 9) and reaches a predetermined level. A water replenishing device as defined in claim 5, wherein said processing solution tank (1) is provided with an overflow opening (5a) to discharge processing solution outside said processing solution tank (1) when the processing solution level rises above a certain level. A water replenishing device as defined in claim 5 or 6, wherein said water supply guide member (11) is constructed to guide excess replenished water supplied from said water supply means (7) into the overflow 30 opening (5a). A water replenishing device as defined in claim 5, 6 or 7, wherein said processing solution tank (1) comprises a level detector (6) to detect a water level of processing solution; and said level detector (6) sends a signal when the processing solution level falls below a predetermined level so that said water supply means (7) starts to supply water in response to said signal. A water replenishing device as defined in claim 6 wherein the movable water supply guide member is a vessel-shaped water supply guide member (11) located in an upper portion of said processing solution tank (1) to move and to tilt about a pivotal axis (12) according to the level change of the processing solution in said processing solution tank (1) and to tilt so that the water stored inside said vessel-shaped water supply guide member (11) flows toward the overflow opening (5a) when the processing solution level has reached the overflow opening (5a); a discharge opening (13) is provided on a first end of said water supply guide member (11) opposing the overflow opening (5a); water supplied by said water supply means (7) is fed onto the second end of said water supply guide member (11); so that the amount of replenishing water from said water supply means (7) is discharged out through said discharge opening when the level of processing solution reaches the overflow opening (5a). A water replenishing device as defined in clam 6, wherein said water supply guide member (11) is provided with a float (18). A water replenishing device as defined in claim 10, wherein one end of said water supply guide member (11) is located outside said processing solution tank (1) to discharge the excess water in a water replenishing tank (8) of said water supply means (7). A water replenishing device as defined in claim 6 wherein inside said processing solution tank (1) there is an overflow pipe (5) provided with an overflow opening (5a) and an opening (14) is formed in a side wall; the movable supply guide member is a spout-shaped water supply guide member (15) disposed to be obliquely slanted in said processing solution tank, a first end of said water supply guide member (15) passing through the opening (14) in said side wall so as to locate a portion of said water supply guide member (15) outside said processing solution tank (1), said water supply guide member (15) being supported so as to slide obliquely in said opening (14); a pin (16) is provided at the second end of said water supply guide member (15), the pin is inserted so as to slide in a slanted oblong guide hole (17) formed on another side wall of the processing solution tank (1); a float (18) is attached to said water supply guide member (15) so that said water supply guide member (15) slides up and down in said opening (14) according to the level change of the processing solution; a water supply outlet (9) of said water supply means (7) is disposed facing above the second end of said water supply guide member (15) so that when said water supply guide member (15) is in an upper limit standstill slanted position corresponding to when the level of processing solution reaches the overflow opening (5a) the amount of replenished water from said water supply means (7) is discharged outside said processing solution tank. A water replenishing device as defined in claim 6 wherein inside said processing solution tank (1) there is an overflow pipe (5) which has said overflow opening (5a) on one end; and wherein the movable supply guide member is a funnel-shaped water supply guide member (19) attached on an upper end of said overflow pipe (5) so as to slide up and down along said overflow pipe (5) as the level of the processing solution in said processing solution tank (1) changes; a water supply outlet (9) of said water supply means (7) is disposed so as to face an outer circumferential part of said water supply guide member (19); and an amount of replenished water from said water supply means (7) is discharged through said overflow opening (5a) and said overflow pipe (5) when the funnel-shaped water supply guide member and the level of water stored in said water supply guide member (19) reach the overflow opening (5a) on the one end of said overflow pipe (5). A water replenishing device as defined in claim 6 wherein inside said processing tank (1) there is an overflow pipe (5) which has an overflow opening (5a) on one end, and the movable water supply member is spout-shaped water supply guide member (7) having a bottom plate (7a) to be provided inside of said processing solution tank (1) the overflow pipe (5) protruding above said bottom plate rises along the overflow pipe due to the rising of th processing solution in said processing tank, and said spout-shaped water supply guide member directs the water supplied by said water supply means (8) over the processing solution in said processing tank (1) and forms a processing solution stream toward the overflow opening (5a) when a processing solution overflow takes place, so that the amount of replenishing water from said water supply means (8) is discharged out through said overflow opening (5a) when the level of processing solution reaches the overflow opening (5a).

Inventors: KINOSHITA TOGO, MATSUMOTO RYOSUKE, KINOSHITA, TOGO, MATSUMOTO, RYOSUKE
Applicants: NORITSU KOKI CO LTD, NORITSU KOKI CO., LTD.
Application year: 1997
Main classification: G03D3
IPC codes: G03D3