US3641911A

US3641911A - Photographic processing apparatus

Info

Publication number: US3641911A
Application number: US882681A
Authority: US
Inventors: Marcel Frans Aelterman; Emile Frans Stievenart
Original assignee: Agfa Gevaert NV
Current assignee: Agfa Gevaert NV
Priority date: 1968-12-06
Filing date: 1969-12-05
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15
Also published as: DE1961026B2; FR2025505A1; GB1296037A; BE742767A; DE1961026C3; DE1961026A1

Abstract

Processing apparatus for the rapid processing of film, which comprises a tank, an open-ended processing chamber which is composed of two symmetrical sections, which defines a substantially horizontal path for the material to be processed and which is located above the level of the liquid in the tank, an transport roller pair at the entry and at the outlet opening of said chamber, and means for directing streams of processing liquid towards the plane of said path in the processing chamber. The exposing of the liquid to which emerges from the inlet and outlet opening of the chamber is reduced by receiving said liquid in narrow vertical channels which dip in the body of liquid in the processing tank.

Description

United States Patent Aelterrnan et al. 1 Feb. 15, 197 2 [54] PHOTOGRAPHIC PROCESSING 3,192,846 7/1965 Wright ..95/89 X APPARATUS 3,372,630 3/1968 Schmidt ..95/94 [72] Inventors: Mnreel 'Fram Aelterrnan, Mortsel; Emile Primary Emminer-lohn Hora" M su m, H n, f g. Assistant Examiner-Alan Mathews um Attomey--William J. Daniel [73] Assignee: Gevaert-Agta N.v., MOIISCI, Belgium 57 ABSTRACT [22] Filed: M 1969 Processing apparatus for the rapid processing of film, which comprises a tank, an open-ended processing chamber which is [21] AppI' 882,68 composed of two symmetrical sections, which defines a substantially horizontal path for the material to be processed and [30] Foreign Application Priority Data which is located above the level of the liquid in the tank, an transport roller pair at the entry and at the outlet opening of Dec. 6, 1968 Great Bntarn ..58,l5l/68 said chamber and means for directing streams of processing A liquid towards the plane of said path in the processing [52] U.S.CL ..9 5/94 R, 95/89 R h b The xposing of the liquid to which emerges from [51] lnt.Cl. G03d 5/04 the inlet and outlet opening of the chamber is reduced by [581 FieldofSearch ..95/89, 94, 96; 118/419, 429 receiving said liquid in narrow vertical channels which dip in v the body of liquid in the processing tank.

[56] References Cited UNITED TATES PATENTS v 6 Claims, 4 Drawing Figures 3,027,82l I 4/1962 Wright .95/ 89 i w a, 1

I l I 35 It! I\ a 43 4 7 I a 5 7 5s 56 r 62 63 f ,-19

6, I .58 I 7 5? ii 52 GO 5 30- IF ll 5 r I'll-ll PHOTOGRAPHIC PROCESSING APPARATUS The present invention relates to a photographic processing apparatus for the fluid treatment of Strip or sheet material, and more particularly to an apparatus for rapidly processing image-wise exposed photographic film, wherein layers of agitated processing liquid contact the film surfaces to process Processing apparatus for the rapid processing of film are known which comprise a tank, an open-ended processing chamber which'is composed of two symmetrical sections which defines a substantially horizontal path for the material to be processed and which is located above the.level of the liquid in the tank, a transport roller pair at the entry and at the outlet opening of said chamber, and means for directing streams of processing liquid towards the plane of said path in the processing chamber. I In the mentioned apparatus only a minor part of the processing liquid which is fed to the processing chamber is carried along by the film as it passes to the next processing station whereas the main part of the liquid emerges from the inlet and/or the outlet opening of the processing chamber in the form of a curtainto the lower located body of liquid in the processing tank. I

As a consequence of the surface area of the liquid curtain, the processing liquid becomes intensively exposed to the atmospheric oxygen, whereby an increased exhaustion of the processing liquid results. Moreover, owing to the strong evaporation of the fixing composition sulphur dioxide is introduced into the air, so that a corrosive atmosphere is produced in the apparatus.

The present invention aims at providing an improved processing apparatus of the kind described, wherein the processing liquid is but little exposed to the air as it flows from the processing chamber to the liquid bath in the tank.

According to the present invention, improved processing apparatus for fluid processing of photographic strip or sheet material is provided wherein there is a processing tank, at least one open-ended processing chamber situated in said tank and defining a substantially horizontal path above the level of the liquid in'the tank for the material to be processed, a pair of transport rollers at the entry and the outlet opening of said chamber, means arranged within said chamber for directing streams of processing liquid towards the plane of said path, and means defining a narrow channel or channels located to receive liquid which leaves said processing chamber through its entry or outlet opening and descends from between said chamber and the adjacent pair of transport rollers, 'andto conduct such liquid downwardly into the body of liquid in the processing tank.

A said channel or channels at the or each side of the processing chamber and extending transversely of the apparatus between the adjacent pair of transport rollers and the adjacent entry or outlet opening as the case may be, of the processing chamber, may be defined by wall means and the upper opening of such channel or channels may extend close.

to the gap between the lower roller and the processing chamber whereas, the lower opening(s) of the channel or channels extend below the level of the liquid contained in said tank.

According to a preferred embodiment of the invention, one longitudinal wall of the or each narrow channel fits to the lower part of the processing chamber and the upper end portion of the opposite longitudinal channel wall diverges from said one wall to providea widened inlet opening for the channel:

The invention has been particularly developed in connection withthe rapid processing of X-ray film coated on both sides, and used for medical purposes. In automatic film processing apparatus for treating the mentioned type of film the requirements are critical, since the processing must occur rapidly and the development must be very even for densities up to 2.8, since subtilities of light and shade play an important part in the interpretation of the radiographs.

It should be understood, however, that the apparatus according to theinvention is not limited to the treatment of photographic material of the mentioned type, and thus other materials, such as industrial X-ray film, continuous tone film for graphic purposes, color film, photographic film for air photography, for data-storage, and for other purposes, may be processed as well in the apparatus according to the invention.

In the application of the invention each distinct processing composition may be applied to the film by one or more processing chambers, but it will be apparent that the application of one processing liquid, e.g., the developer, could occur by a processing chamber whereas the performance of the other wet processing steps could occur in other ways, e.g., by dip or lick-roller application of the liquid.

Finally, the application of the processing liquid in a processing chamber may also occur to one side of the film only, if such treatment is sufficient for the processing of the material.

The invention will be described hereinafterby way of embodiment with reference to the accompanying drawings wherein:

FIG. 1 is a sectional elevationthrough a processing apparatus according to the invention.

FIG. 2 is a sectional elevation of a processing tank.

FIG. 3 is a front view of a processing chamber, and

FIG. 4 is a plan. view of a processing chamber, the upper section of which isremoved.

Referring to FIG. 1, the processing apparatus comprises a developing station 10, a fixing station 11, a rinsing station 12 and a drier 13 which are located in a housing 14. A film to be processed is introduced into the apparatus over the supporting surface 40 and follows a horizontal path through the apparatus indicated by the dash and dot line 41. The stations comprise the tanks 15, 1 6 and 17, which are removably supported at each lateral side by an elongate lateral support 18, and which contain processing liquid, the level of which is indicated by the dash and dot line l9. The level of the liquid in each tank is controlled by overflow openings 20, 21 and 22 which are connected by suitable pipes to a drain conduct.

Each tank is provided with at least one open-ended processing chamber located above the level of the liquid and intended for applying processing liquid to a film passing through the chamber.

The circulation of the processing liquid in a station occurs in a closed circuit and, as shown in particular for the fixing station 11, occurs through a pump 23 which draws liquid from the tank through a filter 39 and feeds the liquid through a conduct 24 to the

inlet connections

25 and 26 which are represented diagrammatically. The inlet 25 is connected with the upper section of the processing chamber and the inlet 26 with the lower section thereof.

Regeneration liquid which is stored in containers 27 and 28 may be fed by means, not shown, to the developing and the fixing tank through

openings

29 and 30. The rinsing station 12 is continuously .supplied with tap water through inlet opening 31. Heating means, not shown, which are thermostatically controlled, are arranged in the circuits of the different processing solutions in order to keep the temperature conditions to a constant value.

The drier 13 comprises a plurality of blower tubes 32 which are provided with a longitudinal slot. The tubes are fed at their extremities with air pressurized by a blower 33 and heated by a thermostatically controlled electric heater 34 so that sheets of air are produced which are directed towards the path of a film as shown by the small arrows. The circulation of the air in the drier 13 occurs mainly in a closed circuit whereas a minor part of the air is vented and replaced by fresh environment air.

Further details about appropriate drier devices may be found in US. Pat1. No. 3,435,539 relating to drier for wetprocessed photographic film.

The transport of a film through the apparatus occurs by a plurality of pairs of rollers, such as the

pairs

35 and 36 located in the fixing station 11 which are provided with a resilient 7 3 covering and which are urged towards each other under a certain amount of spring loading, e.g., by means of an endless coil spring arranged around the bearings of the two rollers. All the pairs of rollers are connected to a common drive means by way of a worm shaft extending the length of the apparatus and engaging worm wheels which are provided at one extremity of the shaft of each upper roller.

The narrow channels .by which the exposure of the processing liquid to the atmosphere is reduced and which are represented diagrammatically in FIG. 1, will now be described in detail with reference to FIGS. 2 to 4, and in particular for the fixing station 11. I -'lhe processing chamber is composed of an upper section 42 and slower section 43 which form hollow elongate structures running transversally. of the. apparatus and into which processing liquid may b efed through

inlet connections

25 and 26. The walls of both sections which face each other have a corrugated surface, whilst the lateral end walls of the upper and lower sections respectively project below and above the lowestand highest points of their corrugated walls by about 1 mm. When the two sections are superimposed to form a processing chamber, the said end walls abut and thus act as stops, and there remains a gap of about 2 mm. at the narrowest points between the peaks of opposite corrugations. In addition, ribs are provided at the innerside of the corrugated walls to reinforce said walls in the longitudinal direction (transversally with respect to the film path 41) and to ensure a uniform distribution of the liquid fed into the sections before the liquid flows away through elongate apertures and towards the film path in a direction obliquely opposite to the direction of film travel. The apertures are determined by the longitudinal edges of the corrugated walls and by the folded ends of

stainless steel strips

46 and 47 which are fitted to the upper and lower sections by screws 48, and are supported by resilient joint strips 49.

At the underside of the section 43 there is provided a boxlike structure, open at the underside, which is formed by

vertical walls

52 and 53, and lateral walls 54 fitted at both sides to the

walls

52 and 53. Small bores 55 near the top of wall 52 permit the establishment of atmospheric pressure within said structure.

The narrow channel under the entry and the outlet opening of the processing chamber are formed by

plates

56 and 57, the upper parts of which are bent over about 45, and which are fitted in parallel to the

walls

52 and 53 by means of

spacers

58 and 59 at the lateral ends and at the middle, to define a channel with a width ofabout l mm. The tank is finally provided with floats6l, 62 and 63 which further reduce the surface of the processing liquid which is in contact with the atmosphere.

The lateral positioning of both sections of the processing chamber occurs through the engagement of

notches

50 and 51 provided in the lateral walls of the sections, with vertical ribs, not shown, provided on the innerside of the walls of the tanks.

The vertical positioning of the processing chamber is realized in that the lateral walls 54 rest with the underside on an elongate rim 60 which is formed by a projection on the innerside of the lateral walls of the tank.

In the operation of the apparatus, fixing solution is continuously supplied by pump 23 to the upper and the lower section of the processing chamber of the fixing station. The streams of fluid emerge symmetrically to the plane of the photographic material from the elongate apertures and they are opposed to the direction of movement of the photographic material. In the absence of film material in the processing chamber, all of the liquid pumped into the chamber flows away through the inlet opening of the processing chamber. When a film sheet or web is moving through the chamber, a minor part of the liquid flows away through the outlet opening of the chamber. To this minor amount of liquid becomes added the liquid which is squeezed off the film by the pair of outlet rollers. The stream or streams of liquid emerging from the processing chamber are subjected to a very intensive contact with air as they return to the liquid bath in the tank 16. The mentioned contact is directly proportional to the height over which the liquid must drop before reaching the level 19 of the liquid in the tank. The

said height is considerably reduced in the improved arrange la: 1 D 2 2; (s)

wherein h is the rise of the liquid in respect of the liquid level in the tank 7 g is the gravitational acceleration d is the flow per time unit sis the cross section of the channel The fonnula 1) is calculated from the known formulas:

v Vfi giving the outstream velocity at the level of the liquid in the tank, and

D=v.S giving the flow per time unit.

Since the parameters g and D, as well as the desired rise h are known, the cross section S of the channel may be calculated from formula l In the present example, a rise of about 25 mm. was obtained 'for a channel with a cross section of 1.5X340 mm. and a flow rate of 400 ccs./sec., whereby the height over which the emerging liquid was subjected to air contact was reduced by half.

This numerical example counts for the channel located at the entry opening of the processing chamber. At the outlet opening the rise of the liquid was less on account of the smaller volume of liquid flowing at this place.

An increased rise of the liquid at the outlet channel may be obtained by using a channel with reduced cross section in respect of the channel at the entry opening of the processing chamber but, as said already hereinbefore, on account of changing conditions during the operation of the apparatus according to the presence or absence of a film in the processing chamber, an optimum rise of the processing liquid in the channels will not be obtained.

In the operation of the apparatus, it has been noticed that the arrangement according to the invention reduced the oxidation of the processing liquid, and in particular the oxidation of the developer by a factor 4 at a temperature of 40 C., so that the oxidation of the developer amounts only to about 0.8 times that of conventional processing apparatus with dip tanks.

From the diagrammatic representation of the apparatus in FIG. 1 it can be seen that the processing chamber of the rinsing station is also provided with narrow channels. Although the channels at this place do not serve the purpose of reducing the oxidation, they considerably reduce the evaporation of the rinsing water which is supplied at a relatively great flow rate, so that the moistening of the atmosphere is maintained at an acceptable degree.

The same processing chamber arrangements are used in the developing station but it can be seen there that two such chambers are provided in order to obtain the necessary developing time. The deflected ends of the opposite walls of the two adjacent narrow channels loosely support a folded cross over strip 65 consisting of a piece of stainless steel.

The narrow channels which have been described hereinbefore have a uniform cross section. It will be apparent that a rise of the liquid level may also be obtained by channels or channellike structures which slightly converge from the inlet opening towards the lower outlet opening, or which have a uniform wider cross section over the full height which is only tapered near the outlet. It isevident that for such embodiments, the smallest value of the cross section of the channel must be considered for formula (1). It should be noted, however, that the increased surface area of the liquid in each channel may give rise to a less good reduction of the oxidation effects.

The width, or occasionally the narrowest section-of the channels may be adjustable. The adjustment may occur by displacement of one wall in respect of the other. Such displacement may be done by -a parallel or angular displacement of one longitudinal wall of the channel in respect of the other, but it may also be done by deformation of one wall in respect of the other, e.g., by pinching together the longitudinal wall ends defining the outlet opening. The adjustment may also occur by the introduction of space filling members such as small rods, plates, etc., in the channel, or by partially closing the outlet opening. 1

The walls defining the channel may be provided with ribs or the like to reduce frictional contact with the floats.

Finally, the opposite walls of the channels, e.g., the

walls

56 and 57 of the channels in the fixing station, may form part of,

or be constituted by other members. For instance, the

walls

56 and 57 may form part of the longitudinal walls of the tank which are so formed that they run closely parallel with the

walls

52 and 53, or the

walls

56 and 57 may be formed by the side walls of vertically extending floats.

In the embodiment shown, the upper end portions of the

opposite channel walls

56 and 57 were deflected over about 45 to bring the upper edge of each wall next to the vertical plane passing through the axes of the adjacent pair of rollers. The upper portion of one or each wall may be deflected over other angles, and may occasionally have a flexible extremity acting as a scraper on the appertaining roller, so as to additionally remove liquid from the roller periphery. The widened inlet opening of the vertical channels may be closed at the lateral ends thereof and the wall means forming such lateral closing may extend upwardly to lie flush with part of the ends of the rollers extending between the shafts of the rollers and the processing chamber.

In the described apparatus, the direction of the streams of processing liquid was opposite to the travel of the film sheets through the apparatus. It should be understood that the present invention is not limited to a processing chamber wherein the processing liquid is applied in the described way, and thus the invention includes also apparatus wherein the layers or streams of processing liquid flow onto the film path in the same direction as the film sheets. Furthermore, said streams of processing liquid may be produced by several narrow openings arranged at each side of the film path, rather than by one opening as shown in the Figures and said narrow opening may also be in the form of a plurality of adjacent circular or elongate small openings and reference may be taken to various patents and other publications in this field for further details.

We claim:

1. A processing apparatus for fluid processing of moving photographic strip or sheet material comprising a tank for processing liquid including at least one processing chamber disposed above the liquid level in said tank and defining a generally horizontal path for the passage therethrough of said material, a pair of transport rollers at each of the inlet and outlet openings of said chamber, means in said chamber for projecting streams of processing liquid toward said path, and collecting means for said liquid comprising a downwardly directed narrow channel provided at at least one of the openings of said chamber, and defined by a pair of spaced apart longitudinal walls, the wall nearer said chamber terminating at said opening and the other wall diverging from said nearer wall adjacent its upper end to form an enlarged mouth for said channel and terminating in close proximity to the periphery of said lower roller, said channel emptying into said tank.

2. Processing apparatus according to claim 1 including one of said narrow channels at each of the entry and outlet openings of the processing chamber, and wherein the two nearer longitudinal walls are connected by vertical sidewalls which extend to the bottom of the processing chamber to constitute with said nearer walls a boxlike structure which is open at the underside and extends at its lower end into the processing liquid in the tank,

3. Processing apparatus according to claim 2, wherein an opening is provided in said boxlike structure at a point above the level of the liquid in the tank to expose the interior of said structure to atmospheric pressure.

4. Processing apparatus according to claim 1, wherein at least two processing chambers are arranged in said tank, each adjacent pair of such chambers being separated from each other by a pair of transport rollers.

5. Processing apparatus according to claim 1 wherein each such channel extends substantially the full width of said chamber.

6. Processing apparatus according to claim 1 wherein said processing chamber comprises a passageway defined by two spaced apart sinuously curved walls, the peaks and valleys, respectively, of said curved walls being in registration along said processing path.

Claims

2. Processing apparatus according to claim 1 including one of said narrow channels at each of the entry and outlet openings of the processing chamber, and wherein the two nearer longitudinal walls are connected by vertical sidewalls which extend to the bottom of the processing chamber to constitute with said nearer walls a boxlike structure which is open at the underside and extends at its lower end into the processing liquid in the tank.