US3177793A

US3177793A - Processor for photographic paper

Info

Publication number: US3177793A
Application number: US147899A
Authority: US
Inventors: Paul H Stewart
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1961-10-26
Filing date: 1961-10-26
Publication date: 1965-04-13
Anticipated expiration: 1982-04-13
Also published as: GB1019014A; DE1422970B1

Description

April 13, 1965 P. H. STEWART PROCESSOR FOR PHOTOGRAPHIC PAPER Filed Oct. 26, 1961 Fig.

PAUL H. STEWART INVENTOR. 5 wa/m QM 7 ATTORNEYS Fig. 4

United States Patent 3,177,793 PRUCESSOR FOR PHOTOGRAPHIC PAPER Paul H. Stewart, Rochester, N.Y., assignor to- Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Oct. 26, 1961, Ser. No. 147,399 11 Claims. (Cl. 95-94) This invention relates to apparatus for processing photographic paper of the type which is developable upon the application of heat in a moist atmosphere.

Photographic papers of the type involved have been introduced relatively recently and are especially well fitted for use in conjunction with oscillograph recorders. As described in an article on pages 113 and 114 of the publication Photographic Science and Engineering, volume 5, No. 2, March-April 1961, of which article applicant was one of the co-authors, such papers contain all the chemicals necessary for development of a latent image therein. This article also shows and describes one type of processing apparatus which may be used to develop the exposed paper and wherein the paper is drawn over a heated plate forming one wall of a substantially closed chamber, the chamber being arranged to retain the vapors driven out of the paper by the heat so as to preserve the desired moist atmosphere without requiring a separate source of moisture. Other arrangements for preventing the moisture or vapor from being dissipated have also been proposed, such as by the use of a nonpermeable belt overlying the paper throughout its movement through the processing apparatus. However, while such apparatuses produce most satisfactory developing action, they are relatively bulky, complicated in construction, and inconvenient to use. Moreover the paper being processed is not visible from the time when it enters the processing unit until it emerges therefrom, fully developed. Particularly where the paper is to be utilized in conjunction with an oscillographic recording, it is desirable that the recording be visible as soon as is feasible.

It is an object of this invention to provide a processor for photographic paper of the above type which is so constructed and arranged that the sensitized surface of the paper is visible throughout its travel through the processing apparatus.

A further object is to provide such a processing apparatus which is of relatively simple construction and yet which is extremely effective for the intended purpose.

Further objects will become apparent from the following description and claims particularly when considered in the light of the accompanying drawing wherein:

FIG. 1 is a top plan view of one embodiment of my improved processor with a strip of paper to be processed thereon shown in phantom lines.

FIG. 2 is a longitudinal sectional view of the processor.

FIG. 3 is a fragmentary cross sectional view taken on the line 3-3 of FIG. 1.

FIG. 4 is a somewhat diagrammatic view showing the manner in which the processor might be associated with an oscillograph recording apparatus.

FIG. 5 is a front view of a slightly modified embodiment of my invention.

As best shown in FIGS. 1 and 2, my improved processing apparatus comprises a metal block or shoe 1 across the upper surface 2 of which a strip 3 of heat developable photographic paper is adapted to be drawn, emulsion-side up, as indicated by the arrow 4. As shown in the drawing, the upper surface 2 of block 1 is preferably convexly curved so as to facilitate maintaining close contact between the strip and the block throughout its travel thereacross. The block 1 is arranged to be heated 3,177,793 Patented Apr. 13, 1965 so that its surface 2 will be at a temperature somewhat above the boiling point of water, say from 225 F. to 400 F. To this end, electric heating elements 5, adapted to be connected to a suitable source of current (not shown), may be provided in an appropriate recess 6 formed in the upper surface of a plate 7 suitably secured to the under surface 8 of block 1.

The surface 2 across which the strip of paper 3 is to be drawn, is provided with a pair of laterally spaced, parallel, guiding surfaces 9 and 10 which are adapted to be in intimate face-to-face contact with the edge portions of the strip throughout its movement across block 1. It is understood, of course, that the above-mentioned edge portions of the strip 3 would not normally be exposed and that only those portions of the web between the guide surfaces 9 and It? would require developing. The surface of the block 1 between these guide surfaces 9 and 1% may be considered as being divided into two zones, a preconditioning zone A, and a processing zone B. As will later appear, the paper moving across block 1 will be moistened somewhat in the preconditioning zone A while actual development of the latent image thereon will be produced while it is traversing zone B.

Considering first zone A, the surface of block 1 between the guiding surfaces 9 and 10 is depressed somewhat below these guiding surfaces so as to form a relatively large, shallow recess 11 extending throughout the length and width of the preconditioning zone A. Therefore, throughout this preconditioning zone, only the unexposed, lateral edges of the strip of paper 3 will be in actual contact with the surface of block 1.

The surface 2 of block 1 in the processing zone B is formed to provide a plurality of spaced depressions or pockets 12 with intervening walls 13, the outermost surfaces 14 of the walls 13 being coplanar with the guiding surfaces 9 and 10. Suitable shallow slots or grooves 15 are provided in the walls 13 so as to provide fluid communication between the various pockets and between the pockets and the recess 11 of zone A below the plane of the guide surfaces 9 and 10. While, in the drawing, we have shown the pockets 12 in the form of parallel, transverse grooves extending over the entire width of the processing area, this is merely one example of the many possible configurations which could be employed. The primary requirement is to provide, along any straight line extending lengthwise of the path of movement of the strip, an alternating series of raised 14 and depressed areas 12 with the depressed areas or pockets 12 in fluid communication with one another and with the recessed area 11. As best shown in FIG. 1 it is preferable that the interconnecting grooves 15 be located in a random, nonrepeating, non-symmetrical arrangement thereby avoiding any tendency to cause streaking of the developed image.

It will be noted in FIGS. 1 and 2 that the grooved portion of the processing zone B does not extend clear to the right-hand end of the block 1. To avoid the necessity of supplying a separate source of moisture, applicant utilizes the moisture driven from the portion of the paper in zone B to dampen that portion of the paper traveling through zone A. It is for this reason that the pockets or depressions 1-2 and the interconnecting grooves 15 are provided. In operation, moisture is driven out of the paper as it is heated by contact with the surf-aces 1-4 in zone B and tends to collect as vapor in the pockets 12 building up a slight pressure therein. Thus the vapor driven into pockets 12 will be forced to travel through the slots 15 into the preconditioning chamber 11 where, due to the fact that the strip is still relatively cool at this point, the vapor will be condensed onto the surface thereof and absorbed thereby. It is 9 found that substantially all of the moisture which can thus be driven out of the paper will have been removed therefrom by the time that the paper has reached the last groove or pocket 12. The last wall 13' therefore forms, in effect, a vapor barrier, preventing passage of vapor to the right beyond this point and therefore of fectively limiting the volume into which the vapor can expand. This insures that the maximum possible amount of vapor will be forced to the left into the preconditioning recess or chamber ll.

It is obvious that my improved processor could be mounted in any desirable Way. I have shown in FIG. 4, purely as an example, the processor mount-ed in conjunction with an o-scillographic recorder 16 so that the web 3 of exposed paper will be guided by

suitable guide rollers

17 and 18 so as to pass over the processing block 1 immediately asit is drawn from the recorder, by a take-up reel 19. With such an arrangement the recorded information will become visible almost immediately after it has been recorded. 1

In operationthe web'of exposed paper will be drawn across the processing apparatus at a uniform steady rate, sufficient moisture being present in the first portion of the strip to precondition succeeding portions thereof so that they will be developed. In practice it is found that the image will begin to appear almost as soon as it reaches the leading edge of the processing zone B, the density of the image increasing as it traverses the remainder of this zone. Thus the operator may view the recorded information almost immediately and without inconvenience since it is always in direct view.

Certain photographic papers of the heat developable type are exceptionally difficult to process without the use of additional moisture. Even on an apparatus'such as is described above where the pockets 12 provide space beneath the web for the vapor to collect, some vapor will escape through the paper web if the web is at all porous. It is therefore highly desirable in the case of such hard-to-develop papers to provide additional means to prevent this loss of available moisture.

In such cases improved devloping action can be 0btained by training a flexible belt 20 around

guide rollers

17 and 18 as clearly shown in FIG. so that the belt overlies the surface of the web 3 being processed as it traverses the shoe 1. To retain the advantage of being able to observe the developed image as soon as it appears, belt 20 is preferably made of a heat-resistant transparent material such as polyester tape material. The apparent thickness of both the belt 20 and web 3 have necessarily been considerably exaggerated in FIG. 5. Operation of the FIG. 5 embodiment will be exactly like that previously described except that the belt 20 will, of course, bepulled about

rollers

17 and 18 by virtue of its frictional engagement with the upper surface of web 3 and will prevent escape of moisture therethrough.

While I have shown but two forms of the invention, it will be obvious from the preceding description that many other variations and modifications could be made without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. Processing apparatus for a web of heat-developable photographic material comprising a body member of relatively high thermal conductivity having a web-guiding surface across which said web is to be drawn in a predetermined path in intimate contact therewith, and means for supplying heat to said body member, said web guiding surface of said body member being provided with a plurality of spaced depressions in fluid communication with one another and extending over substantially the entire width of said surface but terminating short of the lateral edges of said path.

2. Processing apparatus as in claim '1, wherein said web guiding surface is further provided with a recess positioned along said path ahead of said depressions and in fluid communication therewith, the dimension of said recess lengthwise of said path being considerably greater than that of the individual depressions and the width of said recess being substantially coextensive with that of said plurality of depressions.

3. Processing apparatus as in claim 2 wherein said surface is provided with grooves interconnecting at least certain of said depressions with said recess to provide said fluid communication therebetween.

4. Processing apparatus for a strip of heat-devel'opable photographic material comprising a body member providing a guide surface over which said strip is to be moved along a predetermined path and means for heat ing said body member whereby to apply heat to said strip, said guide surface being provided with a plurality of depressions in the area traversed by said path but terminating short of the lateral edges of said path and adapted to form pockets facing the adjacent surface of a strip moving over said guide member, and with grooves interconnecting at least certain of said pockets.

5. Processing apparatus as in claim 4 wherein one of said depressions which is located in that portion of said guide surface which is first traversed by paper moving along said path is considerably larger in area than the others, said one depression extending across substantially the entire width of said path and a substantial distance lengthwise thereof.

6. Processing apparatus as in claim 5 wherein said grooves interconnect saidone depression with at least those other depressions positioned along said path immediately following said one depression in the direction of intended movement of said strip.

7. Processing apparatus for a web of heat-developable photographic material comprising a guide shoe over the surface of which said web is to be moved along a predetermined path, and means for heating said guide shoe, said guide :shoeproviding a preliminary web-conditioning zone at the beginning of said path and a processing zone following-said conditioning zone, the surface of said. guide shoe in said conditioning zone being arranged to provide a relatively large, outwardly facing recess extending substantially across but terminating short of the width of said path and throughout the entire length of said conditioning zone, and the surface of said guide shoe in said processing zone inwardly of the edges of said path being provided with a plurality of spaced depressions at least some of which are in fluid communication with said recess, said depressions having wall portions therebetween so positioned that every portion of the inner face of a web moving along said path and traversing said depressions and recess will, during such movement successively between said guiding surfaces providing, sequentially arranged along said path, a web preconditioning zone followed by a processing zone, the surface of said shoe throughout the length and width of said preconditioning zone being depressed below theoplane of the adjacent portion of said guiding surfaces to form an outwardlyfacing recess, and thesurface of said shoe in said processing zone being formed to provide a plurality of raised and depressed areas, alternately arranged lengthwise of said path, and the outermost surfaces of said raised areas being coplanar with the adjacent portions of said guiding surfaces, said depressed areas and raised areas being so arranged as to conjointly form a network of fluid conducting passageways below the plane of said guiding surfaces and connecting at least certain of said depressed areas in said treatment zone with said recess.

9. Processing apparatus for a web of heat-developable photographic material comprising a guide shoe over the surface of which a web to be processed is adapted to be moved along a predetermined path, and means for heating said guide shoe, said guide shoe providing a pair of laterally spaced, coplanar, guiding surfaces conjointly defining said path of movement and adapted to engage, in intimate face-to-face contact therewith, the edge portions of a web moving along said path, the surface of said shoe along said path being formed to provide, in sequence, a preconditioning Zone and a processing zone, said shoe surface between said guiding surfaces throughout said preconditioning zone being depressed below the plane of said guiding surfaces to form an outwardly facing recess, and the shoe surface between said guiding surfaces in said processing zone being provided with a plurality of transversely extending grooves having outwardly extending walls therebetween, the outermost surfaces of which walls are coplanar with said guiding surfaces, and with additional grooves provided in at least certain of said outwardly extending walls, said additional grooves providing passageways between the associated first-mentioned grooves and said recess.

10, Processing apparatus as in claim 9 wherein the longitudinal extent of said recess is several times greater than the distance lengthwise of said path between corresponding portions of adjacent ones of said laterally extending grooves.

11. Processing apparatus as in claim 9 wherein the additional grooves in adjacent ones of said outwardly extending Walls are staggered laterally of said wall relative to one another.

References (Zited in the file of this patent UNITED STATES PATENTS 941,721 Moss Nov. 20, 1909 1,861,329 Uhlich et al May 31, 1932 2,495,053 Conaway et a1 J an. 17, 1950 3,0l2,l41 Thomiszer Dec. 5, 1961 3,074,332 Robinson Jan. 22, 1963 3,088,324 Jacobs May 7, 1963

Claims

1. PROCESSING APPARATUS FOR A WEB OF HEAT-DEVELOPABLE PHOTOGRAPHIC MATERIAL COMPRISING A BODY MEMBER OF RELATIVELY HIGH THERMAL CONDUCTIVELY HAVING A WEB-GUIDING SURFACE ACROSS WHICH SAID WEB IS TO BE DRAWN IN A PREDETERMINED PATH IN INTIMATE CONTACT THEREWITH, AND MEANS FOR SUPPLYING HEAT TO SAID BODY MEMBER, SAID WEB GUIDING SURFACE OF SAID BODY MEMBER BEING PROVIDED WITH A PLURALITY OF SPACED DEPRESSIONS IN FLUID COMMUNICATION WITH ONE ANOTHER AND EXTENDING OVER SUBSTANTIALLY THE ENTIRE WIDTH OF SAID SURFACE BUT TERMINATING SHORT OF THE LATERAL EDGES OF SAID PATH.