EP0158595B1 - Method and device for treating flexible photographic paper with a photograhic emulsion on one side - Google Patents

Description

The invention relates to a processing device for photographic material in sheet form and a method for treating such material.

Amateur and professional photographers have used trays for the various baths required to make their own copies, which copies have had to be moved continuously or from time to time in such a tray to ensure even processing of the copies. Development processes often take one to two minutes or more, and fixing can sometimes take just as much time. Photographic institutions that produce hundreds of copies per hour use very long processing tanks through which the copies are continuously passed for development or fixing for the required time, with fresh solution being constantly brought into contact with the copy surface during transport through the solution. However, amateur and professional photographers who want to process their own copies cannot afford such large processing systems, the size of which depends on the duration of the processing time and the number of copies to be made per unit of time.

In a number of known treatment devices described in patents, photographic material is directed by the device onto a drum rotating in the treatment liquid, the material adhering to the outer surface of the liquid for a fraction of a full revolution of the drum. Such processing devices are such. B. described in DE-Al 1 497 496 and DE-AI 2 615 932. However, the material in these devices does not remain in contact with the treatment liquid long enough to complete the processing.

Now, however, DE-AI-2 414 824 describes a device in which a photographic film is caused to adhere to the surface of a drum rotating in a bath of treatment liquid and to rotate with the drum long enough to complete the treatment complete. At the end of the treatment period, knife-like liquid jet lifters are used to detach the photographic material from the drum surface. A simpler method for removing a sheet of photographic material from the drum in a similar treatment device is described in our European patent application EP 78 770. However, both in the device of DE-Al 2 414 824 and in that of EP 78 770 the sheet of photographic material in contact with the surface of the central rotary drum is rotated with the emulsion surface facing outward, the sheet of material on the drum by a system of rollers arranged around the circumference of the drum. Here, given the tendency of the piece of photographic material to curl with the emulsion surface inward, a number of rollers around the drum circumference are required to ensure that the material closely follows the drum.

It has now been found that when such treatment devices are used, the quality of the emulsion surface tends to be impaired both by physical contact with the row of peripheral rollers and by uneven treatment; as a result, the photographic material often has streaks after treatment.

Another device for developing photographic material is described in DE-AI 3 209 262 and consists of a number of baths which are arranged one after the other, so that in each bath part of the process for the complete color development of an image takes place. In each of these baths, the photographic material is circulated through a number of transport roller pairs arranged in a circle with fixedly mounted guide combs so as to guide the photographic material that has passed between one pair of rollers into the nip between the next pair of rollers. The photographic material can be passed through the rollers and guide combs to follow a circular path with the emulsion surface either on the inside or the outside, or two sheets can be passed simultaneously with their two backs against each other. In any case, however, the guide combs are arranged in such a way that, in order to guide the photographic material in the desired manner, the moist emulsion surface comes into contact with the stationary guide combs to a greater or lesser extent and can be damaged.

An object of the present invention is to provide a method and an apparatus for the liquid treatment of sheets or sheets of flexible photographic material coated on one side with a photographic emulsion, in particular for amateur photographers, in which it is possible to add the photographic material develop without being damaged as a result of contact with stationary parts of the device or excessive pressing on rollers.

The invention can also be designed in such a way that it permits adequate development using relatively small amounts of treatment liquid and is therefore particularly economical when used by amateur photographers.

According to a first aspect of the present invention, this is achieved by a method for the liquid treatment of sheets or sheets of a flexible photo- coated on one side with a photographic emulsion. graphic material achieved, which has the features listed in the characterizing part of claim 1. According to another aspect of the present invention, this is achieved by a device for liquid treatment of said sheets or sheets, which has the features listed in the characterizing part of claim 3.

In practicing the process of the present invention, a sheet of pliable photographic material coated on one side with a photographic emulsion is placed in a treatment vessel above the level of the liquid therein with the side coated with the emulsion down into the nip between a pair of rollers introduced, which moves the sheet along the inner wall of the vessel so that the side coated with emulsion points towards the center of the vessel, where it cannot come into contact with any stationary part of the vessel. The sheet is then moved in a circle in the vessel for a sufficiently long time until the treatment has been carried out completely, whereupon it is ejected from the vessel by a swiveling part of the guide system above the liquid level.

In the simplest embodiment of the device according to the present invention, this comprises a vessel to which the sheet can be fed in order to get into the nip between two rotating rollers, one of which is a central or main roller and the other a peripheral or pressure roller, which cooperates with the main roller and whose axis is arranged above that of the main roller. The guide system formed by the guide members in the vessel is arranged and shaped such that the guide edge of the photographic material, after exiting the pair of holding rollers, forms a loop which leads back to this pair of holding rollers, one or both of the pair of rollers being driven, and one part of the guiding system, which is above the level of the liquid in the vessel, is pivotally mounted to allow the sheet of photographic material to be led out of the vessel when this part of the guiding system is in the open position.

With this embodiment, however, only sheet material of limited downward length can be treated satisfactorily, since a part of the length of the sheet material must always be gripped by the pair of holding rollers in order to enable the continuous circular movement of the sheet material in the vessel.

The lower roller of the pair of holding rollers preferably has a soft surface covering and the upper roller has a hard surface covering.

In each embodiment, the guide system is advantageously shaped so that the inner wall contour of the vessel, and thus the self-contained curved circulation path, run essentially in a circle.

In a preferred embodiment of the device according to the invention, a central or main roller is provided in the vessel, with which a number of peripheral rollers are in contact, each of which forms a nip together with the main roller. In this embodiment, each of the guide members approaches and moves away from the main roll in the area of each of the nips, so as to form pockets for receiving liquid. Therefore, in this embodiment, the sheet is conveyed to enter the nip between the rotatable main roller and one of the peripheral rollers mounted around it. The guide members are arranged and shaped such that the sheet of photographic material in one of the pockets, after leaving the first pair of holding rollers, forms a loop moving away from the surface of the main roller, but then again to the main roller in the next, between the main roller and the subsequent one Circumferential roller formed nip is steered through which it passes in its circulation around the main roller. The main roller may be a driven roller and / or each of the peripheral rollers may be driven, again with a guide member which is above the level of liquid in the vessel pivotally mounted so that when this guide member is in the open position, the sheet of photographic material must be led out of the vessel. Preferably two, three or four circumferential rollers are arranged around the circumference of the main roller having a larger diameter than the circumferential rollers.

Each of the rollers in the vessel is preferably driven. The rollers are advantageously connected via a gear so that only one drive shaft is required.

The main roller preferably has a soft coating, it is best composed of a covering made of soft foam plastic with a closed cell surface, so that the coating is soft but does not absorb any liquid. Plastic and rubber, which can be hard or soft, come into consideration as further materials for forming the surface of the main roller.

The peripheral rollers advantageously consist of solid polyvinyl chloride or other plastic, or of a metal such as e.g. stainless steel that is not attacked by the treatment liquid. Each roller can also consist of a metal rod that carries a sleeve made of plastic or rubber. Preferably the surface of the or each peripheral roller is hard.

The angular arc distance between two circumferential rollers on the circumference of the main roller depends on the smallest length of the photographic sheets to be treated.

It is important that the peripheral rollers are not grouped too closely together, otherwise the photographic sheet will not be able to loop out from the main roller, and it is an important feature of this embodiment of the apparatus according to the invention that When using the device, the treated photographic sheet stands out from the main roller with a loop so that the emulsion layer side of the sheet is exposed to the greatest possible extent to the action of the treatment liquid, since the sheet is introduced into the device in such a way that the emulsion layer side faces the main roller and is carried around it, but only comes into contact with the main roller there, where it forms a nip with one of the peripheral rollers.

The continuous formation of a loop causes the sheet to wave from and back to the main roll surface and this causes some bath movement in the processing liquid which causes fresh bath solution to constantly come into contact with the emulsion layer side of the sheet. Together with the squeezing action of the holding rollers, this leads to very uniform treatment conditions of the photographic sheet.

In all embodiments of the device according to the invention, the sheet of photographic material is circulated in and out of the liquid for a sufficient time in the vessel, so that the treatment, e.g. B. Developing or fixing, or washing can take place, whereupon the pivotable guide part is opened and the leading end edge of the sheet is guided past this guide part past the device at the next revolution.

Thus, during operation of the device, the sheet of photographic material is fed into the vessel containing the treatment solution or wash water above the liquid and into the uppermost pair of holding rollers with the emulsion layer side down. The driven rollers are then held in rotation for a sufficient period of time so that the treatment step or washing operation to be performed in the vessel is completed. In one embodiment, the number of revolutions of the driven rollers required for that period of time is previously set on a revolution counter, and the rollers then continue to rotate in the vessel with the sheet of photographic paper along the inner wall of the vessel. As soon as the number of revolutions previously set on the revolution counter connected to the driven rollers has been carried out, the revolution counter causes the pivotable guide part in the vessel to open via a mechanism and the sheet is guided out of the vessel.

On the other hand, the swiveling part in the vessel can also be opened by hand in order to cause the sheet to be ejected after the previously set treatment time.

If desired, an electronic timer can be provided which actuates a solenoid device which moves the pivotable guide member into the open position, whereby the sheet is ejected after the set time has elapsed.

The present device can be designed in the form of a treatment module and a feed module for feeding the photographic sheet material and a sheet ejection module for receiving the treated sheet material from the treatment module can be provided. With this arrangement of the device, a treatment system can be created in which a number of treatment modules are provided in series between a feed module and a sheet ejection module. Thus, the photographic processing system can comprise four such treatment modules, of which e.g. B. the first contains a photographic developer and a copy therein requires a treatment time of one minute, while the second contains an acid stop bath in which a treatment of 20 minutes is required, the third may contain a fixing solution in which a minute treatment time is required , and the fourth can be a washing device in which one minute is required for complete washing.

This embodiment of the present apparatus can also be used for color copying where three treatment baths are required in a well known color process and the dwell time in each bath is three minutes.

• Fig. 1 ein seitlicher Aufriß im Querschnitt eines Behandlungsgeräts nach der Erfindung, welches einen Zuführungsmodul, einen Behandlungsmodul und einen Blattauswerfmodul umfaßt;
• Fig. 2 ein seitlicher Querschnittaufriß eines Behandlungssystems, welches drei der in Fig. 1 gezeigten Behandlungsmodule umfaßt;
• Fig. 3 ein Querschnitt-Seitenriß eines abgeänderten Behandlungsmoduls dargestellt ist.

In order to facilitate an understanding of the invention, reference is now made to the accompanying drawings, which illustrate schematically and only by way of example only some embodiments thereof and in which

• Figure 1 is a side elevation in cross section of a treatment device according to the invention, which comprises a feed module, a treatment module and a sheet ejection module.
• FIG. 2 is a side cross-sectional elevation of a treatment system that includes three of the treatment modules shown in FIG. 1;
• Fig. 3 is a cross-sectional side elevation of a modified treatment module is shown.

Referring to Fig. 1, there is shown a processor for use in developing an exposed, flexible photographic material by treating with a fixing and developing liquid. The device shown in Fig. 1 comprises a feed module 1, a treatment module 2, and a sheet ejection module 3. The modules 1, 2 and 3 are held together by a suitable coupling mechanism (not shown).

The feed module 1 consists of a stand 4 which carries a tray 5 which is in the raised position and in which a sheet S of photographic paper rests before it is introduced into the treatment module 2 through a slot 6 which is normally covered by a pivotable light trap 7.

The treatment module 2 comprises a raised light-tight vessel 8 in which a central main roller 9 is mounted, which has a covering layer 10 made of soft foam material closed cell surface is covered. Around the circumference of the roller 9 three driven rollers 12, 13 and 14 made of PVC are arranged. The four rollers are interconnected by a gear (not shown) such that the peripheral speeds of the rollers at the nips are the same. All rollers are driven by a single drive shaft and rotate in the directions indicated by arrows.

The rollers 12, 13 and 14 are mounted with respect to the roller 9 so that their surfaces press into the soft shell of the roller 9.

A series of curved guide wall parts 16a, 16b and 16c are attached to the side walls of the vessel 8. A pivotable guide member 17 with a handle 18, which protrudes from the head wall 20 of the module 2, is mounted above the guide wall part 16a and can be pivoted in the direction indicated by an arrow from the closed position shown in FIG. 1 to an open position.

As can be seen, the guide wall parts have a smaller distance from the main roller 9 in the areas of the nips and a greater distance to the same in the areas lying therebetween, so that they form pockets for holding liquid. The pockets can of course be of the desired size so that the device is able to process both a larger amount of sheet material and a smaller one.

On the inside of the head wall 20, two further guide members 21a and 21b are attached. The guide member 21a forms, together with the end of the guide wall part 16c, an entry opening 22 which is connected to the slot 6. An outlet opening 23 on the opposite side of the vessel 8 is not covered when the guide member 17 is pivoted into the open position.

The sheet ejection module 3 comprises a pair of driven holding rollers 25 and a pivotable light trap 26 which is mounted so that it covers the outlet opening 23 in the closed position.

During the operation of the device described in the foregoing, the vessel 8 is filled with liquid to the level L-L and the rollers 9, 12, 13 and 14 are set in rotation. A sheet S of photographic material is then placed with the emulsion-coated side down on the tray 5 and inserted by hand through the slot 6 past the light trap 7 into the inlet opening 22 of the vessel 8, making contact with the guide wall part 21a which is in contact with the emulsion-free back of the photographic material comes into the nip between the rollers 9 and 12 is guided. These rotating rollers grasp the sheet, pull it down from the tray 5 and move it forward so that its leading edge contacts the guides 21b and 17 which continue to form a loop through the liquid in the pocket between the surface the main roller 9 and the guide wall portion 16a is moved therethrough. The guide wall portion 16a then directs the loop back to the main roller 9 so that the leading edge of the sheet S is inserted into the nip formed between the rollers 9 and 13. This pair of rollers then grips the sheet and moves it forward so that it closely follows the guide wall portion 16b to form a loop, the leading edge of which is passed through the bottom pocket to the nip formed between the rollers 9 and 14. This is the position of sheet S shown in Fig. 1. Rollers 9 and 14 then move the sheet first along guide wall portion 16c and finally out of the liquid so that its leading edge meets guide wall portion 21a and in between the rollers 9 and 12 formed nip is steered. In this nip, most of the surface liquid is squeezed from the emulsion layer side of the sheet, so that it dips back into the liquid quite dry and takes up completely fresh solution.

The sheet S is moved around the roller through the nips formed between the roller 9 and the rollers 12, 13 and 14 and thus essentially follows the inner wall of the vessel 8 with its emulsion layer side facing inwards so that these are not fixed in any way Part of the vessel can come into contact. The sheet is moved several times around the roller 9 into and out of the liquid.

When passing through each of the nips, liquid is squeezed off the surface of the emulsion layer so that fresh solution is constantly applied to the side of the emulsion layer. As can be seen, the path along which the sheet is moved does not follow the surface of the roller 9, and in fact such a course of the path would be disadvantageous since the emulsion layer side remains in contact with the surface of the roller 9 over its entire circumference and would therefore not come into sufficient contact with the liquid. Instead, this path includes loops that move away from and approach the roller 9, while the path that the sheet follows is through one of the pockets. This causes some agitation in the liquid and also on the emulsion layer surface of the sheet S.

After the sheet S has been treated in the vessel 8 for a certain time, the handle 18 is pulled in the direction indicated. As a result, the guide member 17 is moved into the open position and the light trap 26 can also be opened. As a result, the sheet S, the next time it has passed the nip formed between the rollers 9 and 12, instead of being guided by the guide member 17 into a downward curvature towards the guide wall part 16a, rather by the open guide member is guided past the light trap 26 into the outlet opening 23 and further between the conveyor roller pair 25, whose rollers rotate in opposite directions and eject the sheet from the device. The sheet is then practically dry since it has passed the gap between rollers 9 and 12 shortly before.

FIG. 2 shows a treatment system which comprises a sheet insertion module 1, three treatment modules 2a, 2b and 2c and a sheet ejection module 3, these modules having already been described above.

There is color processing solution in each of the treatment modules and the residence time of the photographic material may e.g. B. 3 minutes. After every 3 minutes, the handle 18 is pulled in order to open the guide member 17 connected to it and to cause a sheet S to either leave the system or be transferred to the next treatment module. The handles 18 are then depressed so that each of the guide members 17 is closed, whereupon the treatment of sheets can be continued.

FIG. 2 shows how a sheet S is moved around within the treatment module 2a, while another sheet S is being transferred from the treatment module 2b into the treatment module 2c.

In the process module 2, as shown in FIG. 1 or 2, there is an open space 27 below the vessel 8, in which hot water or hot air can circulate, in order to thereby keep the liquid L at a uniformly elevated temperature. On the other hand, a diving heater in contact with the liquid can also be provided in the bottom of the vessel 8.

In a specific embodiment of the treatment module shown in FIG. 1, the pressure gauge of the main roller 9 is 80 mm and its length is 440 mm; the speed of the roller is 12 r.p.m. A device of this type is suitable for processing photographic material with a sheet size of 13 x 10 cm to 30 x 40 cm.

3 now shows a modified treatment module compared to that shown in FIGS. 1 and 2. In this embodiment, the roller 9 and the circumferential rollers 12, 13 and 14 are replaced by a foam-covered roller 30 and a hard-coated counter roller 31, the axis of which is arranged above that of the roller 30. A sheet S of photographic material which is inserted into the module through the entry slot 34 is looped along a circular rail 32 as shown. After the photographic material has been treated for a predetermined time, a pivotable guide member 33 is pivoted upward in the direction of the arrow and the material can be transferred to the sheet ejection module.

The module shown in Fig. 3 has a simple roller arrangement and is used in the same way as that shown in Fig. 1. However, it can only be used for sheets of downward limited size photographic material since part of the sheet must always be gripped by rollers 30 and 31 to ensure that the sheet travel is continuous.

Claims (13)

1. A method of treating with a liquid sheets of flexible photographic material coated with a photographic emulsion on one face thereof, in which a sheet (S) of photographic material is introduced into a processing vessel (2) from above the liquid (1) in the vessel and then into the liquid, driving the sheet (S) along a curved endless path within the vessel and in so doing passing the sheet through the nip(s) between a main roller (9, 30) and at least one holding roller (12, 13, 14, 19), guiding the sheet around the main roller substantially following the inside wall of the vessel (8) during its passage through the liquid, so that the emulsion surface does not come into contact with a stationary part (16, 17,_21) of the vessel (8), the driving and guiding of the sheet being carried out for sufficient time for the treatment to be completed, whereupon the sheet (S) is removed from the vessel (8) so that the emulsion surface does not come into contact with a stationary part (16,17, 21) of the vessel (8), characterised in that the guiding of the sheet takes place in such a way that the sheet (S) leaves the main roller (9, 30) while forming a loop after its guide edge has emerged from the nip, in order to come closer to said roller in the region of the next roller nip, which displaces the sheet (S) in a wave-like movement which leads to agitation of the processing liquid, and that the emulsion surface of the sheet (S) is facing the main roller (9, 30).

2. A method according to Claim 1, characterised in that the sheet (S) of photographic material is passed in turn through a plurality of said processing vessels (8) arranged in series.

3. An apparatus for treating with a liquid sheets of flexible photographic material coated with a photographic emulsion on one face thereof, with a vessel (8) for holding the liquid, an inlet (22) to said vessel (8) for introducing a sheet (S) of photographic material and along a curved endless path around a main roller (9, 30), an outlet (23) from said vessel for treated sheets, said outlet comprising a pivotably mounted guide member (17) and at least one holding roller (12, 13, 14, 19) which with the main roller (9, 30) provides at least one roller nip and means for driving at least one of the rollers, characterised in that the inner wall of the vessel (8) is provided with guide members (16a, 16b and 16c) which are shaped to define the curved endless path within the vessel, the guide members of the main roller (9, 30) each being closer in the region of the roller nip(s) and each further away in the intermediate regions, so that they form a widened area in the form of a pocket for receiving the agitated processing liquid in said intermediate regions.

4. An apparatus according to Claim 3, characterised in that the central main roller (30) cooperates in the vessel (8) with only one holding roller (31), the axis of which is located above that of the main roller (30), said rollers (30, 31) providing a roller nip, that guide members (32) are spaced around the periphery of said main roller (30) at a distance therefrom and that the length of said path is at most approximately the length of a sheet (S) of photographic material which is to be treated in the apparatus.

5. An apparatus according to Claim 3, characterised in that the central main roller (9) cooperates in the vessel (8) with a plurality of holding rollers (12, 13, 14) all providing together with the main roller (9) a respective roller nip.

6. An apparatus according to Claim 5, characterised in that there are three holding rollers (12, 13, 14) of smaller diameter than the diameter of the main roller (9).

7. An apparatus according to one of Claims 3 to 6, characterised in that the main or inner roller (9; 41, 43, 45) has a soft surface.

8. An apparatus according to Claim 7, characterised in that the soft surface is provided by a closed cell foam plastic.

9. An apparatus according to one of Claims 3 to 6, characterised in that the holding or outer roller (12, 13, 14; 40, 42, 44) has a hard surface.

10. An apparatus according to Claim 9, characterised in that each roller is arranged to be driven by said driving means.

11. An apparatus according to Claim 10, characterised in that all the rollers are connected by gearing to a single driving shaft.

12. An apparatus according to one of Claims 3 to 6, characterised in that it comprises at least one process module (2), and that a sheet feed module (1) and sheet ejection module (3) are connected to the process module (2) for feeding photographic sheet material to and receiving it from the process module.

13. An apparatus according to Claim 12, characterised in that a plurality of process modules (2a, 2b, 2c) is connected in series between a sheet feed module (1) and a sheet ejection module (3) so that a sheet (S) can pass in turn through each module.

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