Abstract: To provide a development system for lithographic printing plate precursors using a neutral developer, capable of preventing the non-image area of the resulting printing plates from being stained. In developing a lithographic printing plate precursor with a neutral developer having a pH of from 5.8 to 8.6, ultrasonic waves and/or an electric current are imparted to the neutral developer.

Abstract: Developer is supplied to a first spray pipe disposed in a developing bath. The inside of the developing bath is provided with a heater. A liquid-flow generating unit comprises a liquid-flow generating head and a branch duct, which is connected to a branch pipe of the first spray pipe via a rubber hose. A part of the developer flowing in the first spray pipe is forwarded to the liquid-flow generating head. By a gap-forming ring, a gap is secured between an outer surface of the heater and an inner surface of the liquid-flow generating head so that the developer uniformly flows along the outer surface of the heater in a longitudinal direction thereof. A heater cover is attached to the liquid-flow generating head. An inner surface of the heater cover inclines in the longitudinal direction of the heater.

Abstract: A washing bath in a photographic paper processor has plural washing chambers for washing photographic paper with washing water by passage of the photographic paper. Plural cell units are coupled with one another vertically by a modular structure. Each of the cell units has one of the washing chambers. A sealing medium of silicone rubber keeps a cell connection portion between the cell units in a liquid-tight state. A blade mechanism is secured to a panel constituting the cell units, allows the photographic paper to pass between the washing chambers, and blocks passage of the washing water. A transporting rack transports the photographic paper serially to pass the washing chambers. The cell connection portion includes a connection surface, disposed to extend horizontally, and separable for removal of the cell units in the vertical direction. The sealing medium is secured to one of two cell units being coupled.

Abstract: A submerged processing device for a photosensitive material disposed at a partitioning wall which is provided within a processing tank main body and which is between processing chambers respectively storing a processing liquid, the submerged processing device includes: a housing at an interior of which is formed a processing space where the processing liquid is stored; a conveying path for conveying-in of the photosensitive material and which is formed in the housing so as to communicate with an interior of the processing space; a path for conveying-out of the photosensitive material and which is formed in the housing so as to communicate with the interior of the processing space; a processing liquid passage preventing mechanism disposed at the photosensitive material conveying path such that only the photosensitive material passes therethrough; and a processing liquid changing mechanism provided at the housing, for changing the processing liquid stored in the processing space.

Abstract: A digital film processing system and film processing solution cartridge are disclosed. The cartridge comprises a housing and a chamber for storing a film processing fluid. The processing solution may be contained within a flexible bladder within the chamber. The cartridge may also include an integral applicator for coating the processing solution onto undeveloped film. The cartridge is generally removeably attached to the film processing system, but may also be refillable.

Abstract: The invention relates to photographic processing and provides a photographic processing system, comprising one or more processing tanks for processing photographic material. The system also has at least one buffer tank for receiving concentrated replenisher solution from a replenisher solution cartridge. The at least one buffer tank has an outlet in communication with the photographic processing system for direct supply of concentrated replenisher solution to the one or more processing tanks.

Abstract: A dual X-ray film-processing device having developer and fixer liquid receptacles connected to film processing tanks by twin chemical pumps through piping having valves therein whereby X-ray film for dental or medical use is being processed continuously thereby speeding up production while at the same time improving the resultant X-ray film surface image.

Abstract: The invention relates to an arrangement for preparing a liquid treatment solution for treating photosensitive material, said arrangement including a storage container for storing fresh treating solution to be fed to a development compartment of a development apparatus, a supply portion for supplying a dry component or components and/or one or several mixtures of components for preparing the treatment solution and a reception container for receiving a solvent, wherein according to the invention a mixing tank is interposed between said supply portion, said reception container and said storage container.

Abstract: A processor for processing photosensitive material has a rotatable outer drum and an inner sprocket wheel which is independently rotatable from the outer drum. Two sets of sprocket teeth and, are provided on the sprocket wheel to engage with the material to be processed and to positively drive the material into and out of the processor.

Abstract: A photosensitive material processing apparatus according to the present invention includes a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising a filter for purifying the processing solution, and a conduit for circulating the processing solution from a lower region of the tank body to an upper region of the tank body. Further, a pleated cartridge filter for use in a photosensitive material processing comprises a cylindrical pleated filter body formed by folding a filtering sheet member; and a blocking member, including a hole that communicates between an interior of the filter body and the outside, for blocking at least one end of the filter body, wherein a portion of the blocking member contacting the fitting portion is compressed when the blocking member is fitted to the fitting portion to closely contact the same.

Abstract: A chemical delivery system and method for use in a photographic processor is disclosed. The chemical delivery system includes a heating assembly that comprises a heating chamber and a level detection sensor. The heating chamber receives a predetermined amount of processing solution from a storage tank based on the level of the level detection sensor, heats the predetermined amount of processing solution and supplies the same to an associated photograph processor.

Abstract: A device for processing a photosensitive material using processing solution includes, processing chambers for storing processing solution therein, at least one of the processing chambers being lower than another processing chamber, a bypass for placing each processing chamber that is downstream of another processing chamber relative to conveyance direction of the photosensitive material in fluid communication with the another processing chamber to pass the processing solution therethough, and a check valve disposed at each bypass for allowing the processing solution which flows from the processing chamber disposed downstream relative to conveyance direction of the photosensitive material to the another processing chamber, and for preventing the processing solution from flowing from the another processing chamber to the downstream processing chamber.

Abstract: A processing solution delivery system and method for a photographic processor includes a plurality of chambers that are adapted to hold a distinct processing solution therein. A manifold is fluidly connected to the chambers and includes an inclined solution passageway. The manifold provides a connection between the chambers and an associated processor. Provided in a spaced manner along the inclined solution passageway are manifold bores which introduce solution at different points along the inclined passageway. With the present invention, it is possible to introduce wash solution at the highest point of the inclined processing path at the end of a processing cycle so as to assure the removal of contaminants from previously supplied solutions. Further, it is possible to introduce a bleach or fixing solution at the lowermost point of the inclined path to effectively and uniformly quench a development reaction.

Abstract: A drum chamber in which photographic material is processed is provided with a section in which the walls overlap to form a narrow channel therebetween. The channel acts as the entrance to and exit from the chamber for the material being processed.

Abstract: This invention facilitates the development of Diazo papers in small applications where a hand held unit is desirable. An example is where children want to make a silhouette print of a leaf.

Abstract: There is disclosed a developing processing method and apparatus in which developing processing is carried out with a developing solution being jetted toward an emulsion surface of a photosensitive material from jetting holes of a blowoff chamber. Only one blowoff chamber is disposed in a developing tank and conveying roller sets are disposed at both sides of the blowoff chamber. The photosensitive material is horizontally conveyed above the blowoff chamber by the conveying roller sets. Due to the number of components of the developing processing tank being thus reduced, the apparatus can be made small in size. Positions where the photosensitive material is nipped by the roller sets are located within a processing solution, and therefore, there is no possibility of the photosensitive material being nipped and conveyed in a state in which outer peripheral surfaces of the rollers are wet non-uniformly with the processing solution. As a result, non-uniform processing is prevented.

Abstract: In a developing processing method and apparatus in which developing processing is carried out in such a manner that a processing solution is jetted from jetting holes to an emulsion surface of a photosensitive material, a hole diameter of the jetting holes is set to be 0.5 mm to 0.9 mm. In this case, clogging of the jetting holes does not easily occur and the processing solution can be jetted from the jetting holes stably for a long period of time. Accordingly, non-uniform processing is rarely caused. Intervals between the jetting holes in the transverse direction of the photosensitive material are each in a range of 3.0 mm to 4.5 mm. The jetting holes are disposed in such a manner that jetting holes of adjacent three rows in a direction in which the photosensitive material is conveyed are located at different positions to form a staggered arrangement, and the three rows of jetting holes are formed repeatedly.

Abstract: A method of processing photosensitive material which passes through at least two processing solutions in which the material is rinsed after passing through a first solution and prior to passing through the second solution. The mixture of rinse solution and recovered first solution is returned to the process cycle to replenish the first solution.

Abstract: A method of replenishing a processing solution by adding the replenisher directly to the surface of the emulsion side of the material to be processed. This accelerates the processing of the material and maintains the sensitometry of the processing solution.

Abstract: A method of developing a photosensitive resin plate comprising, in order to greatly prolonging the service life of a developing solution and increase the number of plates that can be developed using a specified amount of the developing solution, supplying under circulation a developing solution (2) stored in a developer tank (1) and containing a surfactant to the surface of the tank (1), characterized in that a porous sheet (6) impregnated with a defoamer is disposed on or in the vicinity of the liquid surface of the developer tank (1) so that the developing solution (2) dropped from the surface of the photosensitive resin plate (5) passes through the porous sheet (6).

Abstract: An apparatus for processing a photosensitive media. The apparatus having a processing path for passing of a photosensitive media through the apparatus, and a light-lock feed slot assembly for allowing the photosensitive media to be fed into the processing path. The light-lock feed slot assembly comprises of a conduit having an inlet port at one end and an outlet port at the other end. The conduit has a configuration which forms a substantially serpentine passageway between the inlet port and the outlet port such that stray light which may be adjacent the entrance port is prevented from reaching the outlet port.

Abstract: Apparatus for processing photographic material comprises a succession of processing regions formed by inclined planes extending between sets of rollers. As the material is driven up the planes with its emulsion side down, wash solution flows down beneath it. The length of each plane can be different so that the material is washed for different times in each region, achieving chemical equilibrium in the final region before passing on to the drying stage.

Abstract: A method of development is disclosed, wherein printing plate precursors capable of being exposed with an infrared laser can be developed over a prolonged period without causing image defects, etc. The method comprises conducting the development of a photosensitive lithographic printing plate precursor using an automatic developing apparatus having a substantially closed developing tank in which a developing solution is introduced and a conveying means for conveying the plate precursor disposed within the developing tank.

Abstract: An apparatus for the processing of photographic material, and in particular for the development of photographically exposed plates intended for printing plates in a printing operation, comprises an upwardly open tank (5) containing a bath of liquid, conveyor means for conveying the plates (2) along a path (4) in which they are descended obliquely down into the bath and withdrawn again, and at least one movable brush (9) for brushing the top face of the plate. According to the invention the brush is enclosed in a downwards open cavity (12) which has its lower edge immersed into the bath and which is evacuated in order that liquid is sucked thereinto. The invention also comprises a washing apparatus and a method for the processing of photographic material.

Abstract: Method and apparatus are disclosed for washing exposed photographic material in less time and with a reduced replenishment rate compared with conventional processing. Multi-stage counter-current washing is employed, in which the time that the material spends in each stage is such that equilibrium of chemical concentration between solution contained in the material and solution contained in the stages (a) is reached in the final stage, but (b) is reached in fewer than all the stages, and wherein the material resides in at least one stage for a time that is different from that in at least one other of the stages. Preferably the longest time is spent in the final stage. The time distribution throughout the stages can be optimized to produce a final tank concentration comparable to that obtained with conventional processing.

Abstract: An apparatus for the processing of photographic sheet material comprises a plurality of treatment cells (12.sup.1, 12.sup.2, 12.sup.3) mounted one beside another to define a substantially horizontal sheet material path (14). Each cell comprises a housing (16) having a sheet material inlet (18) and a sheet material outlet (20) each being closed by a rotatable path-defining roller (28) biased into contact with a reaction surface (26) to form a nip (30) there-between through which the sheet material path (14) extends. The apparatus is characterized by sealing means (33) to seal each path-defining roller (28) to the housing (16) and means (36) to define a static liquid level (S) above the nip plane (P).

Abstract: Apparatus for processing photographic material has a plurality of stages for carrying out different processing steps. At least one stage has a series of processing regions each defined by an inclined surface that extends between sets of rollers. The surfaces may be of different length to provide different residence times for the material. Processing solution flows down the surfaces whilst the photographic material is driven upwards in counter-current mode. All the stages may be uni-directionally inclined end-to-end, or they may be arranged in a U-shape so as to minimize cross-contamination between the stages.

Abstract: Black-and-white elements, such as radiographic films, can be processed in roomlight because they include certain light absorbing dyes and desensitizers. Processing of such elements can be achieved using a processing kit and a two-stage process carried out in the same light- and fluid-tight processing apparatus. In the first stage, development is initiated with a developing composition having a pH of from about 10 to about 12.5, and comprising an appropriate black-and-white developing agent and a sulfite. After an appropriate time, a non-sulfite fixing agent is introduced into the processing apparatus or container to provide a combined developing/fixing composition, and development and fixing are carried out simultaneously. The processing method is carried out quickly, usually within about 90 seconds. The presence of sulfite and high pH in both stages decolorizes or deactivates the particulate dyes.

Abstract: A sheet material processing apparatus comprises at least one treatment cell in which a pair of rotatable path-defining rollers (28, 30) define a sheet material path (20) through the cell. The path-defining rollers have a closed position in which the path-defining rollers are biased into contact with each other to form a nip (36) through which the seat material path extends, and an open position in which the path-defining rollers are spaced from each other. The path-defining rollers can be separated from one another, for the purpose of cleaning the apparatus, by a simple and convenient construction in which the rollers (28, 30) are supported by bearings (70, 72) carried by eccentric sleeves (68) which are stationary in the closed position. Means (76) are provided for partly rotating the sleeves (68) thereby to withdraw the path-defining rollers (28, 30) from each other into the open position.

Abstract: A machine part (24) is provided with a resilient seal (28) having an in-use condition in which the seal (28) protrudes beyond a sealing face (32) of the machine part (24). The seal (28) has an alternative condition in which it is accommodated in a cut-out portion (52) in the sealing face (32) of the machine part (24). The arrangement can be used in an apparatus comprising a number of machine parts, a first machine part (24) being provided with the resilient seal (28) which protrudes beyond a sealing face (32) of the first machine part (24) to seal the first machine part (24) to a second machine part (30). The arrangement enables such an apparatus to be dis-assembled with reduced risk of damaging the seal or tearing it from its mounting.

Abstract: An apparatus, having relatively low capital cost, for the processing of photographic sheet material (22) comprises a plurality of closed treatment cells (12.sup.1, 12.sup.2, 12.sup.3, 12.sup.4) and a sheet material path (20) extending through the cells in sequence. A following cell (12.sup.3) has a treatment liquid inlet (40) and a treatment liquid outlet (42). The treatment liquid outlet (42) is connected to a treatment liquid inlet (44) of a preceding cell (12.sup.2) by way of a connecting passage (46). A single pump (48) is sufficient to transfer treatment liquid through the cells.

Abstract: The roller (20) comprises a main body member (31), a shaft (46) fixed to the main body member (31) and extending from one end thereof, and an end member (34) in contact with the main body member (31), characterised in that the end member (34) is mounted on the shaft (46) in a replaceable manner.

Abstract: Exposed photographic film is washed in a multi-stage arrangement in which the film is guided through a container of solution and transferred from one stage to the next via air bubbles. The surface of solution that is exposed to the ambient atmosphere is minimized so that oxidation of the solution and the quantity needed is minimized.

Abstract: The apparatus comprises at least one treatment vessel (12) comprising a housing (14) having a sheet material inlet opening (17) and a sheet material outlet opening (18) defining a sheet material path (20) through said vessel (12). Each opening (17, 18) is closed by a path-defining rotatable roller (28) biased towards a reaction surface (30) to form a nip (36) there-between through which said sheet material path (20) extends. The path-defining roller (28) is in contact along its length, with a plurality of rotatable intermediate rollers (38) carried in fixed bearings (40) mounted on said housing (14).

Abstract: There is provided a light-sensitive material processing apparatus comprising a development section having processing baths including a development bath, a fixing bath and washing baths, a drying section and a sorter section, wherein at least one of the processing baths is a pan-shaped horizontal processing bath with its upper surface opened that is disposed at a horizontal position, transports light-sensitive materials in processing solutions in the processing baths in a horizontal direction and can be drawn out in a horizontal direction which is parallel with or normal to the transport direction of the light-sensitive materials. The processing baths can be handled at ease and a space occupied by the apparatus can be reduced. Maintenance such as the cleaning, repair, replacement of the respective processing baths and the transport mechanism racks becomes also unnecessary. As a result, prints of high quality can be finished at all times.

Abstract: An apparatus for processing a silver halide photographic light-sensitive material, the apparatus having plural processes of at least a developing process, a bleaching process and a fixing process, comprises a supplying device to supply a processing solution to a silver halide photographic light-sensitive material in at least one process of the plural processes, whereby a point of the silver halide photographic light-sensitive material is supplied with the processing solution during a supplying time, wherein the point of the silver halide photographic light-sensitive material is processed during a processing time in the process and the supplying time is not longer than 70% of the processing time; and a heater to heat the silver halide photographic light-sensitive material in such a manner that a surface temperature of the silver halide photographic light-sensitive material when the silver halide photographic light-sensitive material is supplied with the processing solution by the supplying device is 40.degree.

Abstract: A photograph developing apparatus includes a main processing tank and a sub-tank which is connected to the main processing tank. The sub-tank is provided with a filter, a sensor, and the like in order to filter processing solution and feed the filtered processing solution back to the main processing tank. The sub-tank has a lid for covering the top of the sub-tank. The lid has an evaporation prevention block which is extended to a point below the surface of the processing solution. Cavity portions are formed in the evaporation prevention block at least at positions corresponding to the filter and the sensor. Alternatively, evaporation of the processing solution is suppressed through employment of an evaporation prevention block which floats on the surface of the processing solution. In this case as well, cavity portions are formed in the block at least at positions corresponding to the filter and the sensor.

Abstract: A processing apparatus and method for processing photosensitive material includes processing paths which comprise downwardly inclined and upwardly inclined portions with respect to a conveying direction of photosensitive material. The processing paths are thin channel paths and are oriented so as to provide for a compact processor. Also, the processing apparatus includes several processing sections which are structured to permit an easy assembly and disassembly of the apparatus and thereby facilitate maintenance. The processing apparatus combines the concept of cascading solution flow and nozzle delivery of processing solution for recirculation and replenishment.

Abstract: A housing (10) defines a liquid treatment chamber (12). The chamber (12) has entrance and exit openings (16, 18) each closed by a pair of co-operating path defining rollers (20), rotatable about a horizontal axis (26) and in contact with each other to form a nip (22) through which a material transport path segment (24) extends. Sealing means (28) seal the path defining rollers (20) to the housing (10). A drip tray (30) is so shaped and positioned as to collect treatment liquid dripping from the roller (20), both when the material path segment (24) is vertical and when it is horizontal. The vessel may be connected in a closed manner to one or more further treatment vessels to constitute a apparatus for processing photographic material. The vessel can be successfully used in either orientation.

Abstract: The vessel (10) comprises a housing (12) having openings (14, 16) closed by pairs of rotatable path-defining rollers (18, 20, 22, 24) through which a sheet material path (30) extends. Liquid level control means (38) define a dynamic liquid level (L) in the treatment chamber (32) above the sheet material path (30). A buffer comprises one or more drip chambers (34, 36) positioned to receive liquid escaping from the treatment chamber (32) through the nips (26, 28) and between the rotatable path-defining rollers (18, 20, 22, 24) and the housing (12). The buffer has a maximum total volume such that a static liquid level (S) is established below the sheet material path (30), without the buffer overflowing. In a non-operative condition, treatment liquid, which escapes through the nips and between the path-defining rollers and the housing, is all retained in the buffer, for later re-use as desired.

Abstract: A rack for use in a low volume thin tank of a photosensitive web processing apparatus. The rack comprises a plurality of fluid circulation ports in a face of the rack for applying fluid to a photosensitive web during processing. The fluid circulation ports are arranged, in use, to discharge fluid into and withdraw fluid from the tank in which the rack is situated. The rack has a textured surface structure over which the fluid passes in use to provide agitation of the fluid in the tank. Improved processing of the photosensitive web can result, thereby also reducing the time taken to process the web. Additionally, the rack may be modular in construction, thereby facilitating the installation of the rack into the tank of the processing apparatus.

Abstract: A compact integrated system for film and print processing has chemical processing trays, sink, water filter and faucet, chemical storage, and drying screens integrated into a single multi-purpose unit. The processing trays are vertically stacked and rolled or slid in tray paths traversing the length of the sink. A print under development is directly transferred vertically between chemical processing trays across a print sponge with a print gripper. Each print is uniformly processed in a chemical processing tray by rolling or sliding the tray, ensuring uniform distribution of the processing chemical without manually agitating the print. The water rinse step of the print development process is accomplished in an oscillating wash bath wherein the water is continuously circulated over and between the prints being rinsed. Each of the processing chemical trays may be angled downward for emptying into a basin which can also provide a sink as well as safe recycling/disposal following print processing.

Abstract: A processing apparatus and method combines thin channel and nozzle technology, as well as cascading processing solution flow. The processing apparatus includes a base member that defines at least one opening which has a longitudinal axis that extends at an angle with respect to a horizontal axis, and at least one rack member which is removably insertable in the at least one opening. When inserted in the at least one opening, a processing path is defined between an inner surface of the opening and an outer surface of the rack member. The openings are configured so as to provided for a compact arrangement and the rack members are removable in a manner which facilitates maintenance and repair.

Abstract: Black-and-white elements, such as radiographic films, can be processed in roomlight because they include certain light absorbing dyes and desensitizers. Processing of such elements can be achieved using a processing kit and a two-stage process carried out in the same light- and fluid-tight processing apparatus. In the first stage, development is initiated with a developing composition having a pH of from about 10 to about 12.5, and comprising an appropriate black-and-white developing agent and a sulfite. After an appropriate time, a non-sulfite fixing agent is introduced into the processing apparatus or container to provide a combined developing/fixing composition, and development and fixing are carried out simultaneously. The processing method is carried out quickly, usually within about 90 seconds. The presence of sulfite and high pH in both stages decolorizes or deactivates the particulate dyes.

Abstract: A developing processor is constructed of a chassis block 300 with a developer reservoir, a fixer reservoir and a washing solution reservoir arranged on a chassis, a base plate block 200 detachably mounted on the chassis block 300, and a roller block 100 detachably mounted on the base plate block 200. The roller block 100 is constructed of roller pairs which form processing spaces for development, fixing and washing, respectively. Parts, each of which is likely to develop a trouble or is not very likely to develop a trouble, are all fixed on a base plate 201 of the base block 200. Included as these parts are a control box 210, a drive motor for driving the rollers, a warm-air fan 213, a pump motor, and the like. Upon development of a trouble, the base plate block 200 is replaced.

Abstract: A processing apparatus for processing photosensitive material combines thin channel technology with nozzles, and an inclined processing path. Processing solution can be introduced into the inclined processing path so as to cause the solution to flow along the inclined processing path in a direction which is opposite to a direction of travel of the photosensitive material in the inclined processing path. With the arrangement of the present invention, photosensitive material can be processed in the first processing path by way of the nozzle spray arrangement and can be subjected to further processing along the inclined processing path.

Abstract: A nozzle assembly includes a channel or tubular member that has openings or slots along its length to permit a passage of solution flowing within the channel or tubular member therethrough. A partition or splitter member is positioned within the channel or tubular member and has a cross-section that outwardly diverges in a direction from an inlet of the channel or tubular member to an end of the channel or tubular member downstream of the inlet. This serves to equalize a pressure of the solution along the length of the channel or tubular member as the solution exits the channel or tubular member through the openings. The nozzle assembly can supply processing solution to a processing path of a processing tank that processes photosensitive material and is structured so as to provide a uniform processing of the photosensitive material within the processing path.

Abstract: A feed rack in which a substantially U-shaped film passage is formed, and disposed in a processing tank such that the processing solution level of the processing tank is located below the top surface of a block by a predetermined dimension so as to reduce the area of contact between the processing solution and outside air. The processing tank is equipped with a solution level regulation tank or replenisher tank in which air-isolating member is floated on a contained solution. Between the replenisher tank and the processing tank are provided a transport mechanism for transporting a replenisher from the replenisher tank to the processing tank and a prevention mechanism for preventing the air-isolating member from entering the processing tank.

Abstract: A light-sensitive material processing apparatus comprises a circulating path through which processing solution in a processing tank is circulated; a pump for circulating the processing solution through the circulating path; and an oxidation promoting section provided to at least one of a part of the processing tank and a part of the circulating path, the oxidation promoting section having a depth shallower than that of the processing tank and a upper portion open to atmosphere, wherein a flow speed of the processing solution at the oxidation promoting section is not slower than 1.times.10.sup.3 mm/min.

Abstract: The present invention relates to a replaceable coating cartridge and a method of coating at least one surface of a photosensitive material using the replaceable coating cartridge. The method and apparatus can be used in a photographic processing device, and the apparatus can be built into an existing or new photographic processor or added on as an accessory. The method and apparatus are utilized to apply a viscous solution to at least one surface of processed photosensitive materials prior to drying in a manner that allows the solution to be uniformly applied to the at least one surface at a specific thickness. The viscous solution after drying functions as a protective coating which can protect the processed photosensitive material against scratches and moisture.