US3507650A - Method of depositing viscous photographic reagents - Google Patents

Description

E. H. LAND 3,5Q7,65 .0 METHOD OF DEPOSITiNG VISCOUS PHO'IQGRAPHIC RELMZrEN'IS A ril 21, 1970 2 Sheets-Shet 1 Filed Jan. 11

FIG. I

FIG. 2

ATTOR N EYS April 1970 E. H. LAND 3,507,650

METHOD OF DEPOSITING VISCOUS PHOTOGRAPHIC REAGENTS Filed Jan. 11,1966 2 Sheets-Sheet 2 h ,I I

INVENTOR.

BY 640141 444 M ATTORNEYS United States Patent Int. Cl. G03c 5/54 US. Cl. 9629 22 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for applying a uniform layer of a viscous reagent to the surface of an element, e.g., applying a viscous photographic reagent, from a source of such reagent.

This invention relates to novel methods and apparatus for applying a viscous reagent to sheet materials and, in particular, to the application of viscous photographic reagents.

Various processes require applying a viscous reagent to a sheet material at some stage in the performance thereof. For example, in the photographic art, this viscous reagent vmay comprise a light-sensitive emulsion, a sensitizer, e.g., a silver halide optical sensitizer or hypersensitizer, a viscous processing composition for developing an exposed light-sensitive layer, or a coating composition for protecting a photographic print from abrasion, loss of image quality, etc.

In general, difiiculties inherently exist in applying a precise amount of this viscous reagent in the desired substantially uniform continuous layer on the sheet material without depositing an excess of the reagent. On the other hand, deposition of an excess of reagent inherently tends to produce so-called over-run or deposition of the viscous reagent on the processing apparatus and/or other surfaces onto which deposition of the reagent is neither contemplated nor desired. Problems of applying a precise amount of reagent and, in turn, over-run are compounded in procedures wherein it is desired to apply the viscous reagent successively to a plurality of sheet materials from a common applicator source containing more reagent than is required for any single sheet material. These problems are further compounded when it is desired to obtain a high application rate, for example, a rapid application of viscous reagent to a plurality of intermittent separate sheets.

For example, it may be desired to provide an applicator containing a viscous processing composition for successively developing a plurality of exposed photosensitive elements over a period of time.

In addition to the aforementioned problems, difficulties also exist in preserving the stability of the viscous reagent in the applicator over any length of time, i.e., if it is not contemplated that all of the reagent is to be applied over a relatively short period of time before oxidation and other degradative reactions can occur. In other words, the viscous reagent may be subject to the degradative effects of oxidation, hardening due to loss of moisture," etc., so that means should be provided for preserving the reagent at least over the period of time of contemplated usage.

It is to these and related problems that the present invention is directed.

A primary object of the invention, therefore, is to provide novel methods and apparatus for applying a viscous reagent to sheet materials.

Another object is to provide novel systems for applying a viscous photographic reagent to sheet materials.

Still another objectis to provide novel systems for ap plying a viscous photographic processing composition to develop an exposed photosensitive element containing a developable image.

Yet another object is to provide novel systems wherein a viscous reagent is applied to a sheet material by first depositing it in a predetermined pattern over at least a substantial portion of a surface of the sheet material to provide on the surface first continuous areas substantially free of the reagent and second discontinuous areas containing the reagent; and thereafter spreading the deposited viscous reagent to provide a substantially uniform continuous layer of the reagent upon the sheet material.

A further object is to provide a simple and efficient apparatus for rapidly applying a viscous reagent to a sheet material in a substantially uniform continuous layer of a predetermined desired thickness.

These and other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others and the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a partially schematic, partially sectional front view of a novel device of this invention;

FIG. 2 is an enlarged fragmentary view of a portion of the device of FIGURE 1 during operation thereof; and

FIG. 3 is a sectional elevational view illustrating the use of this invention in a photographic document-copying apparatus.

As was mentioned previously, the present invention is directed to novel methods and apparatus for applying a viscous reagent to sheet materials.

The invention will be more readily understood by reference to the accompanying drawings.

As shown in FIGURE 1, there is provided a drum-like container 1 for the viscous reagent 2. A portion 3 of the wall of the container has a plurality of minute openings constructed and arranged in a desired pattern, preferably in a geometrical configuration which may, for example, take the form of a plurality of generally circular holes aligned at predetermined spaced intervals; While the remaining portion 4 of the container wall is solid, i.e., substantially impervious to air and moisture. For reasons .which will be discussed with more particularity hereinafter, these minute openings are preferably of substantially uniform area, and are distributed uniformly in a regular pattern. The viscosity of the reagent with respect to the size of the openings in the container wall is such that the reagent will not normally pass therethrough in the absence of some mechanical force such as will be described subsequently.

By way of illustration. the container wall may be made of a suitable plastic such as Mylar, Teflon, etc., metal or ,,the like. For reasons to be discussed with more particupoint within container 1. This squeegee or paddle is shown to have an end portion 7 slidably engaging the container wall and a side arm 8 conforming in general with the Wall contour but spaced slightly therefrom. While container 1 is shown to he rotatable and squeegee 6 immovably mounted so that the two elements are relatively movable, it will be noted that in lieu thereof, the container may remain stationary and the squeegee be rotatable therein. Likewise, in lieu of being mounted in the manner shown, the squeegee may be centrally mounted on a collar or equivalent means on shaft 5.

An endless belt-cover 9 movable on rollers or pulleys 10 is shown to engage a portion of the wall of container 1. The linear dimension of the area of engagement of beltcover 9 with the container wall is slightly greater than the linear dimension of wall portion 3 for reasons to be described subsequently. In any event, belt-cover 9 is preferably made of a suitable material, e.g., a plastic such as Mylar, which is at least impervious to air. Drive means (not shown) may be employed to rotate one or more of element 10 and, in turn, cause rotation of contaner 1 on shaft 5 due to frictional engagement of the belt-cover to the container wall. In lieu thereof, rotation of the container may be caused by suitable drive means (not shown) connected to shaft 5. In the latter case, belt-cover 9 may obviously be eliminated, if desired.

Positioned outside of container 1 is a spreader surface, shown to be a web of a spreader material 16, e.g., Mylar, Teflon, etc., to which the viscous reagent has little or no adherence. This web may be carried as an andless belt (shown somewhat schematically) moving over rollers in the direction shown by the arrows. In lieu of employing web 16, equivalent spreader means such as a drum having a smooth surface may also be employed.

For purposes of further illustrating the present invention, the use of the above-described device to apply a viscous processing composition to an exposed photosensitive element containing a developable image in order to provide a visible image will be described hereinafter.

Container .1 is charged with the desired amount of a viscous photographic developing composition such as those heretofore employed in the art for such purposes.

In general, these compositions comprise at least a viscosity-providing material such as water-soluble cellulose ethers, e.g., sodium carboxymethyl cellulose, hydroxyethyl cellulose, sodium alginate, starches, etc., and an aqueous medium containing ingredients essential to the development process.

Where the light-sensitive material in the photosensitive element is a silver halide emulsion, this aqueous medium may for example include an alkaline material, e.g., sodium hydroxide, potassium hydroxide, etc.; and a silver halide developing agent, e.g., any of the dihydroxybenzenes or aminophenols commonly employed in the art. The viscous reagent may also contain other ingredients for performing specifically desired functions, e.g., a silver halide solvent such as sodium thiosulfate, silver precipitating nuclei, preservatives, etc.

In any event, the processing reagent preferably has a relatively high viscosity, for example, on the order of at least 5000 centipoises.

Processing compositions of the foregoing description are well known in the art and per se comprise no part of the present invention.

To effect the desired development, an exposed film unit 12 carried on a web or endless belt 11 from an exposure station, e.g., a conventional camera lens system, passes between rollers 13 in juxtaposition with the container wall, as shown.

With the container moving relative to the squeegee, the end 7 of the squeegee forces the viscous processing composition into successive openings in the wall passing therebeneath. Since this composition adheres readily to the surface of the film unit and the wall material defining these openings has little or no affinity for the viscous composition, it is possible to make a clean separation of reagent in these openings to the area of the sheet material in juxtaposition therewith (see FIG. 2). Side arm 8 tends to facilitate this clean separation by providing in the area between this arm and the wall an area substantially free of reagent. Moreover, the positive pressure created in this space between arm 8 and the openings containing the reagent tends to facilitate deposition. Further, the absence of reagent above that contained in the openings avoids a meniscus-shaped deposition, so that the shape and dimensions of the deposited reagents (see FIG. 2) conform substantially identically to that of the openings. As noted in FIG. 2, after deposition therefrom the respective openings are substantially clean and this absence of clogging reagent permits repeated usage of the container to apply viscous reagent successively to a plurality of sheet materials. The viscosity of the reagent is such that the reagent is substantially non-flowable, i.e., the individual deposits will not merge into a continuous layer by mere flow of the applied reagent.

It will be observed from what has been stated that the present invention permits one to obtain a very precise deposition of reagent in a discontinuous pattern, e.g., as a plurality of tiny individual depositions over a desired area of the sheet material. As the amount deposited is a direct function of the number, size, thickness and arrangement of the openings in the container wall, it follows therefore that the container Wall may be readily constructed by predetermined calculations to deposit a precise desired amount of reagent, the amount deposited being neither too little nor too much.

As the sheet material (in this case an exposed film unit) containing the minute depositions of reagent passes from beneath the container, it is rapidly fed between rollers 15 and spring loaded rollers or idlers 14 in superposition with spreader sheet 16 to cause the plurality of individual deposits of reagent to be spread in a substantially uniform continuous layer on the surface of the sheet material. The thickness of the uniform layer of reagent is a function of the amount of reagent deposited and is not dependent upon the provision of a gap between the rollers, as is true in certain prior systems. The fact that the thickness of the layer is controlled by the reagent deposited in the foregoing manner, rather than being a function of the gap between the rollers makes it possible to obtain significantly higher linear rates of processing, e.g., on the order of 72"/sec. or higher. In this manner very thin uniform layers, e.g., on the order of about 1 mil thick may be obtained by employing, for example, a wall no thicker than about 5 mils, the area of each of the openings in the wall being no greater than about 0.3".

In the case of development of an exposed film unit, in order to obtain uniform development, spreading of the deposited processing composition must be perfected before the individual depositions have permeated the surface of the film uhit to initiate development at least to any appreciable extent. Thus, the relationship of the spreading means to the deposition or applicator means and the speed at which the sheet material is fed through the respective means must be regulated accordingly. In

other words, at least in systems for applying a viscous processing reagent wherein the time lapse between deposition and spreading must be relatively short, e.g., one second, the point of deposition and that of spreading should preferably be as close as is feasible.

Following spreading of the viscous processing composition, development proceeds in customary fashion to provide a visible image of the original subject matter.

This image may be a positive or a negative image in black and white or .in color, depending upon the particular photographic system employed. For example, positive silver transfer images may be obtained upon development of the film unit by known techniques. In gen eral, such procedures for preparing positive transfer images in silver involve the steps of applying to an exposed silver halide emulsion a processing composition containing an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent; developing exposed areas of the emulsion while forming in terms of unexposed areas an imagewise distribution of a soluble silver complex; and transferring this complex, at least in part, by imbibition to a stratum where it is reduced to image silver. A useful filmunit for this purpose is one containing a light opacity-providing material of the nature described and claimed in the copending application of Edwin H. Land, Ser. No. 519,995, or in the copending application of Edwin H. Land and Leonard C. Farney, Ser. 519,884, both filed concurrently as continuations-in-part of applications Ser. No. 368,622 and 368,- 621, respectively, filed May 19, 1964 and now abandoned. In general, these film units contain a layer of light opacity-providing material sufficient to mask effectively the negative image formed by development of the emulsion and to provide a background for viewing the positive transfer image which is formed in a layer above the layer of opacifying material, so that a composite print is formed which contains both a negative and a positive image, but which is viewable by reflected light as a positive silver transfer image. In application Ser. No. 519,995, the light opacity-providing material is present in a layer above the emulsion layer; while in application Ser. No. 519,884, opacity-providing material is contained in the emulsion layer itself and, optionally, an additional layer of opacity-providing material may be provided over the emulsion layer as in the former application. In either case, silver precipitating nuclei are preferably provided to facilitate positive image formation. These nuclei may be present initially in a silver-receptive stratum, or they may be present initially in the processing composition itself, as heretofore mentioned.

Positive image formation may also be obtained by advancing the film unit between rollers 14-15 in superposition with a separate element containing an image-receiving layer. To this end, spreader sheet 16 may be eliminated (spreading being effected by the respective superposed elements passing between rollers 14-15), or spreader sheet 16 may itself contain the image-receiving layer.

In the foregoing description of the use of the present invention in the development of an exposed film unit, it will be appreciated that all steps are performed in the absence of actinic light. Thus, the device of FIG. 1 may, if desired, be contained in a lighttight box. This lighttight box may take the form of a separate processing unit, or, in lieu thereof, it may also include an exposure station, e.g., a conventional camera lens system.

The length of the are formed by wall portion 3 con taining the openings is correlated with respect to the distance between the feed end and trailing end of the sheet material so that viscous reagent is deposited only on desired portions of the sheet material. In like manner, the length of the container itself is so correlated as to preclude undesired deposition. Thus, while wall portion 3 is shown to be greater than solid wall portion 4 for purposes of illustration, the converse may in fact be conterriplated, depending upon the dimensions of the sheet material to which the reagent is to be applied.

When not in use, e.g., at completion of operation, container 1 has preferably rotated so that solid wall portion 4 is in down position. In this manner, cover 9 cooperates with the solid wall portion to provide an effective protection against oxidative changes, loss of moisture, etc., thereby preserving the shelf life of the viscous reagent over the contemplated period of usage thereof.

The following examples show'by way of illustration and not by way of limitation the application of a viscous processing composition to develop an exposed film unit in accordance with this invention. 1 1

6 EXAMPLE 1 A photosensitive element comprising a paper base support containing a layer including a silver iodobrornidegelatin emulsion as the light-sensitive material and titanium dioxide as light opacity-providing material was prepared in the manner described in Example 1 of the aforementioned application Ser. No. 368,621. This photosensitive element was then photoexposed and a viscous processing composition comprising the following proportions of ingredients:

Water 8400.0 cc.

Sodium carboxymethyl cellulose (medium viscosity type)600.0 g.

Sodium sulfite675.0 g. 7

Sodium hydroxide180.0 g.

Potassium thiosulfate207.0 g.

4-amino-2,6-dimethylphenol-180.0 g.

Aqueous solution of sodium sulfide (.0156 g. Na S/ cc.)-9.0 c-c.

Aqueous solution of lead acetate and cadmium acetate (8.7 g. of lead acetate and 6.3 g. of cadmium acetate/ 300 cc.)192.0 cc.

was applied thereto by depositing it as a plurality of tiny dots in a uniform pattern over the surface thereof.

- This deposition was ,elfected by forcing the viscous reagent through a material of the character described above having a plurality of substantially round openings of approximately of an inch in diameter arranged in alignment in staggered rows with the centers of the openings about of an inch apart. The material was about 3.5 mils thick. The exposed element containing these individual dots of viscous composition corresponding substantially identically to the thickness and diameter of the openings was then pulled through a pair of rollers in superposition with a Mylar spreader sheet at a rate of about 10l2"/sec. (elapsed time from deposition to spreading was within one second) to press the individual dots into a substantially uniform continuous layer of developing composition. After about two seconds dark time a composite print viewable as a positive print exhibiting excellent resolution was obtained. Following processing, the applicator material, including the openings therein, was observed to be clear of processing composition.

Repetition of the foregoing procedure with speeds as fast as 72"/ sec. gave comparably good results.

EXAMPLE 2 Polacolor Type 108 Land Film (a commercially available fihn sold by Polaroid Corporation, Cambridge, Massachusetts which includes a photosensitive element and an image-receiving element for obtaining positive color reproductions) was photoexposed. To the thus-exposed photosensitive element was applied, as a plurality of individual dots in the manner described in Example 1, a viscous processing composition comprising the following proportions of ingredients:

Sodium carboxymethyl cellulose (high viscosity type)60.0 g. Benzotriazole70.0 g. Potassium thiosulfate-10.0 g. Zinc nitrate10=.0 g. Potassium hydroxide200.0 g. N-benzyl-a-picolinium bromide40.0 g.

Water to make 2000.0 cc.

material was observed to be visibly clear of processing composition.

The present invention is also particularly adaptable for use in document duplication systems for preparing one or more visible images of an original.

Apparatus useful for such procedures in accordance with this invention is illustrated in FIG. 3.

This aspect of the invention is illustrated in FIG. 3 as comprising means for exposing successive areas of a lightsensitive sheet to light from an original (document), cutting the sheet into sections each approximately equal in size to the original and including an exposed area, and then treating the sections with a viscous processing agent, in the manner heretofore described, to form a positive image of the original. The operation of the apparatus may be substantially automatic and the construction may be such as to permit the apparatus to be loaded with sulficient materials including the light-sensitive sheet and viscous processing agent to produce a large number of prints in the form of document copies.

The apparatus includes an exposure system of the type incorporating means for supporting a document or other two-dimensional surface in position for exposure, means for illuminating the surface to be photographed, an optical system including an objective lens for forming an image of the original at a plane, and means for positioning successive areas of the light-sensitive sheet material for exposure at this plane. This exposure system includes a generally horizontal transparent window comprising the upper wall of a chamber in which are mounted lamps 21 and reflectors 22 for illuminating an original document to be positioned for exposure on the upper surface of window 20. The chamber is defined by walls comprising the housing of the apparatus including a lower wall 23 provided with a centrally located opening 24 in which is mounted an objective lens and shutter assembly 25 of a conventional type employed in photography.

The means for positioning successive areas of a lightsensitive image-recording sheet, designated 26, include a support plate 27 disposed in a plane parallel with the axis of lens 25 substantially at the focal surface of the lens. A mirror 28 arranged substantially at a 45 angle with respect to both the lens axis and support plate 27 is provided for redirecting light from the lens toward the support plate. A frame 29 is mounted between the support plate' and the mirror closely adjacent the support plate for holding sections of sheet 26 against the support plate. Sheet 26 is supplied coiled on a spool 30 mounted behind and beneath mirror 28 and extends from the spool around a feed roll 31 between the latter and a second feed roll 32 located in juxtaposition with roll 31 closely adjacent the lower edges of support plate 27 and frame 29,

-with the bite of the rolls located substantially in the same plane as the support plate. Feed rolls 31 and 32 function to advance sheet 26 from spool 30 upwardly between the support plate and frame into position for exposure by light transmitted by lens and shutter assembly 25 and reflected from mirror 28.

Mounted above the support plate and frame are a second pair of juxtaposed feed rolls 33 and 34 for advancing the sheet material upwardly from between the frame and support plate into the section of the apparatus in which treatment with the viscous processing agent is effected. A rotary knife 35 and an opposed anvil 36 are located between feed rolls 33 and 34 and the upper edges of the support plate and frame for severing each exposed section of the image-recording sheet from the next succeeding section of the image-recording sheet located in position for exposure.

In the operation of the apparatus, a section of sheet 26 is advanced upward between the support plate and frame by feed rolls 31 and 32 into the bite of feed rolls 33 and 34. Movement of the sheet is then arrested, the section of the sheet between the support plate and frame is exposed, and then feed rolls 33 and 34 are rotated to advance the exposed section of the image-recording sheet upwardly from between the frame and plate while, at the same time,

advancing another section of the image-recording sheet into position for exposure. The trailing edge of the exposed section of the image-recording sheet passes between knife 34 and anvil 36, the knife is rotated, severing the section at its trailing edge. Following the next exposure, rolls 31 and 32 are driven, at least during the initial rotary cycle of rolls 33 and 34, to advance the upper leading edge of the image-recording sheet from adjacent anvil 36 into the bite of rolls 33 and 34.

The thus-exposed element moves from rollers 33 and 34 into the processing chamber of the apparatus where application of a viscous developing composition is effected in the described manner.

Following application of the developing composition, means are provided for guiding each element 26 within a light-free environment and thereafter delivering the developed element now containing a visible image from the apparatus. These means are shown to comprise guide wires 37 to control the path of movement following movement through rollers 14 and 15 to spread the viscous processing reagent. Wire guides are provided in order to reduce the area of contact between the sheets and the guide means so as not to interfere with the processing of the sheet and to reduce friction between the sheet and the guide means. Each sheet 26 is permitted to fall under the force of gravity downwardly through a chute defined by guide wires 37 and from the apparatus through an opening 38 in the housing thereof where the developed sheet 26 containing a visible record of the original subject matter may be collected in a suitable tray or the like (not shown).

Means such as microswitches (not shown) may be provided along the path of movement of the sheets in position to be engaged and actuated by the sheets so as to control the operation of the apparatus including the rotation of the various feed rolls, the processing device, etc. Also, adjacent the path of movement of the sheets there may be provided means such as a source of infrared radiation and/ or hot air for drying each sheet 26 before it emerges from the apparatus. In any event, it will be appreciated that the path which the sheet means must follow from the application of the processing reagent until it passes through opening 38 should be of a length suflicient to insure retention of the sheet in a light-free environment for the requisite processing time. To this end, feed rolls, guide wires and the like may, if desired, be employed to define a tortuous path of movement of each sheet 26 to provide the requisite time in a light-free environment.

It will be appreciated that various changes may be made in the apparatus shown in the illustrative drawings without departing from the scope of the invention.

For example, belt 11 may be eliminated and feed rollers or other such drive means may be employed for advancement of the sheet material to be treated.

Likewise, the web of spreader material 16 may, if desired, be eliminated and spreading accomplished merely by means of rollers 14-15. However, particularly satisfactory results have been obtained with this spreader material in terms of the smooth uniform character of the layer of viscous reagent after spreading. Moreover, since the viscous reagent does not contact the rollers when the spreader material is employed, steel rollers or the like to which some of the reagent may tend to adhere can be employed.

The particular form or shape of element *6 may also be varied according to individual wishes or needs, and various types of paddles, doctor blades, etc., may be employed in lieu thereof.

The novel devices of this invention may be fully or partially automated by means of appropriate timing devices, microswitches, etc., or they may be designed for manual operation.

Other changes, modifications, and additions will be readily apparent to those skilled in the art in the light of the foregoing description.

In view of the specification and illustrative drawings, it Will be seen that the present invention provides a simple and efiicient' means for-applying a viscous reagent in a substantially uniform continuous layer upon a surface of a sheet material. The essence of the invention is the provision of a method and apparatus for applying a predetermined precise amount of reagent from a source normally containing more reagent than is contemplated to be applied to any single sheet material, without clogging of the apparatus, over-run and/or unwanted deposition of excess reagent either on the sheet material itself or upon other surfaces. In addition to these significant advantages, the present invention permits very rapid application of reagent, e.g., very rapid treatment of exposed photosensitive elements, as noted by the excellent results obtained at speeds on the order of 72"/ sec. in the procedure described in the Example 1. This rapid processing of exposed photosensitive elements is of particular importance in document copying systems such as illustrated in FIG. 3.

Since certain changes may be made in the above method and apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A process of applying a viscous photographic reagent to a sheet material which comprises pressing said sheet material against an applicator containing a plurality of minute openings; forcing said viscous reagent through said openings while in juxtaposition therewith to deposit on a surface of saidsheet material a predetermined amount of said reagent in a pattern corresponding to said openings, and to provide on said surface first continuous areas substantially free of said reagent and sec: ond discontinuous areas containing said reagent; and thereafter spreading said viscous reagent to provide a substantially uniform continuous layer of said reagent upon said sheet material.

2. A continuous process for applying a viscous photographic reagent to a sheet material which comprises advancing said sheet material to an applicator station in juxtaposition with an applicator member having a plurality of uniformly distributed small openings of substantially uniform size; depositing said reagent from a source thereof through said openings to a surface of said sheet material to provide on said surface a pattern of reagent corresponding to said openings, said pattern containing first continuous areas substantially free of said reagent and second discontinuous areas containing said reagent, said openings in said applicator member being constructed and arranged whereby to provide a predetermined amount of reagent on said surface; continuously advancing said sheet material to a spreader station; and spreading said viscous reagent to provide a substantially uniform continuous layer of said reagent upon said sheet material.

3. A process as defined in claim 2 wherein said spreading step is effected by sandwiching said reagent between said surface of said sheet material and a spreader having substantially less afiinity for said reagent than said surface to spread said deposited reagent and to form said uniform layer having a predetermined desired thickness, said thickness being a function of the shape and dimensions of said openings and the relationship of said openings with respect to one another; and thereafter separating said sheet material containing said layer of reagent from said spreader sheet.

4. In a process for developing an exposed photosensitive element containing a developable image wherein a surface of said elementis contacted with a viscous processing composition which permeates said surface to develop said image; the steps which comprise applying said viscous processing composition as a multiplicity of relatively small separate deposits over a portion of surface; and before the processing reagents in said deposits have initiated development at least to .any appreciable extent, spreading said viscous composition to provide a substantially uniform continuous layer of said viscous composition upon said surface to develop said image.

5. A process as defined in claim 4 wheren said deposits are of a substantially uniform shape and configuration.

6. A process as defined in claim 4 wherein said deposits are arranged in a geometric pattern over at least a substantial area of said surface.

7. A process as defined in claim 4 wherein said deposits are of a size and relationship with respect to one another so as to be capable, upon spreading, of providing said substantially uniform layer having a predetermined desired thickness.

8. A process as defined in claim 4 wherein said photosensitive element includes a light-sensitive silver halide emulsion layer and said viscous processing composition includes an aqueous alkaline solution of a silver halide developing agent.

9. A process as defined in claim 8 wherein said solution further contains a silver halide solvent; said processing composition permeates said surface to develop said emulsion layer to form a negative image and a positive silver transfer image.

10. A process as defined in claim 9 wherein said processing com-position further includes silver precipitating nuclei for facilitating formation of said transfer image.

11. In a process wherein a viscous processing composition is applied to the surface of a film unit including an exposed light-sensitive silver halide emulsion layer to develop said emulsion and to form a silver transfer image, the steps which comprise placing said film unit juxtaposition with an applicator containing a plurality of minute openings; forcing a viscous processing composition through said openings while in juxtaposition to deposit on a surface of said sheet material a predetermined amount of said viscous composition in a pattern corresponding to said openings, whereby to provide on said surface first continuous areas substantially free of said composition and second discontinuous areas containing said composition, said openings in said applicator being constructed and arranged to provide a predetermined amount of said composition on said surface; and before said viscous composition in said second areas has initiated development at least to any appreciable extent, spreading said viscous composition to provide a substantially uniform layer of said reagent upon said sheet material to develop said emulsion and to form said transfer image.

12. A process as defined in claim 11 wherein said film unit includes an opacifying material and said transfer image is formed on said surface, said opacifying material being present in' an amount sufficient to mask effectively said negative image while at the same time providing a background for viewing said transfer image as a positive silver reflection print.

13. A process as defined in claim 11 wherein said opacifying material is present in said emulsion layer.

14. A process for forming silver transfer images which comprises advancing a film unit including an exposed silver halide emulsion layer to an applicator station including a source of a viscous processing composition; applying a predetermined metered amount of said processing composition from said source as a multiplicity of relatively small separate deposits on a surface of said film unit to provide on said surface first continuous areas substantially free of said composition and second discontinuous areas containing said composition; substantially immediately thereafter and before said composition has initiated development, at least to any appreciable extent, advancing said film unit from said applicator station to a spreader station where said composition is spread to form a substantially uniform continuous layer on said surface; and allowing said composition to permeate said surface to develop said emulsion layer and to form said transfer image.

15. A process as defined in claim 14 wherein said film unit includes an opacifying material and said transfer image is formed on said surface, said opacifying material being present in an amount sufiicient to mask effectively said negative image while at the same time providing a background for viewing said transfer image as a positive silver reflection print.

16. A continuous system for preparing transfer images in silver which comprises the steps of advancing a photosensitive element including a silver halide emulsion layer to an exposure station; exposing said element to actinic light at said exposure station to form a developable image; at some time subsequent to exposure advancing said exposed element to an applicator station including a source of a viscous processing composition comprising a viscous reagent and an aqueous alkaline processing solution; depositing a predetermined metered amount of said processing composition from said source in a predetermined pattern over at least a substantial surface of said exposed element to provide on said surface first continuous areas substantially free of said composition and second discontinuous areas containing said composition; substantially immediately thereafter and, before said composition has initiated development to any appreciable extent, advancing said film unit from said applicator station to a spreader station; at said spreader station, spreading said deposited processing composition to substantially uniform continuous layer on said surface; and permeating said emulsion layer with said layer of processing composition to develop said exposed emulsion layer and to form said transfer image.

17. A device for obtaining visible images which comprises an exposure station including means for exposing a photosensitive element; means for advancing a phtosensitive element to said exposure station; an applicator station for depositing a viscous photograph processing composition to said photosensitive element after exposure thereof, said applicator station including means comprising a non-porous material having a plurality of minute openings arranged in geometric configuration over at least a portion thereof, said openings being of a predetermined size and configuration whereby to permit deposition of a predetermined amount of said composition in a discontinuous pattern on a surface of said exposed photo sensitive element, said applicator station further including pressure means for forcing said reagent through said openings to said element; means for advancing said element from said exposure station to said applicator station; a spreader station including means for spreading said deposited viscous composition to provide a substantially uniform continuous layer of said processing composition on said element to develop said exposed element and to form said visible image; and means for advancing 12 said element from said applicator station to said spreader station.

18. A device as defined in claim 17 wherein said applicator station comprises Wall means defining a container for said composition, at least a portion of said wall means having a plurality of small openings constructed and arranged so as to be adaptable for depositing a predetermined desired amount of said reagent in said discontinuous pattern and pressure-providing means within said container for forcing said composition through said openings to said element, said Wall means having said openings and said pressure-providing means being relatively movable.

19. A device as defined in claim 18 including means for releasably engaging said sheet-material in'juxtaposition with said wall means having said openings.

20. A device as defined in claim 18 wherein the surface area of said portion of said wall means having said openings is slightly less than the surface area of said sheet material, the area of each of saidopenings is no greater than about 0.3 inch and said portion is not thicker than 5 mils.

21. A device as defined in claim 18 wherein said container is rotatably mounted, said device including means for rotating said container.

22. A device as defined in claim 21 wherein said pressure-providing means comprises at least one doctor-like member fixedly mounted at a point within said container and extending toward said wall means, whereby to force viscous reagent between the free end of said element and said 'wall means adjacent thereto into said openings as said container is rotated.

References Cited UNITED STATES PATENTS 2,543,181 2/1951 Land 9629 XR 2,662,882 12/1953 Land 9629 2,893,314 7/1959 Gore 117--38 XR 2,893,315 7/1959 Reynolds et a1. 117--38 XR 3,036,927 5/1962 Jerothe 118-212 3,086,879 4/1963 Lassiter 118-2l2 3,313,270 4/1967 Labombarde ct a1. 1l82l2 3,179,517 4/1965 Tregillus et al. 9676 XR FOREIGN PATENTS 511,281 8/1939 Great Britain.

634,169 3/ 1950 Great Britain.

746,948 3/ 1956 Great Britain.

874,046 8/ 1964 Great Britain.

NORMAN G. TORCHIN, Primary Examiner I. R. HIGHTOWER, Assistant Examiner US. Cl. X.R. -89; ll8--246

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