US3323436A - Method and apparatus for development of film - Google Patents

Description

June 6, 1967 c. H. HAF'ER ETAL. 3,323,436

METHOD AND APPARATUS FOR DEVELOPMENT OF FILM Filed March 17, 1965 CITRIC ACID MG 1% i CAMERON H. HAFER HQ. 2 CAMILLE A. PLANTE BY M @W AGE/VT United States Patent 3,323,436 METHGD AND APPARATUS 'FGR DEVELQPMENT 0F FILM Cameron H. Hafer, Apalachin, and Camille A. Plante,

Johnson City, N.Y., assignors to International Business Machines Corporation, Armonk, N.Y., a corporation of New York Filed Mar. 17, 1965, Ser. No. 440,485 9 Claims. (Cl. 95-89) This invention relates to developing apparatus for sensitized materials and more particularly to an improved gaseous developing chamber used in connection with the development of ammonia process diazotype films and papers.

The present invention is especially significant in the mechanized production of diazo film duplicates of either silver or diazo film originals. Such film duplicates commonly occur as the analogue storage section of a socalled aperture card, that is to say, a punched tabulating card in which a section of the card has been removed and replaced with a piece of light-sensitive film. With document miniaturization technology approaching the point where the ability to resolve 1000 lines/mm. is becoming essential, diazo films are a first choice in such applications. Heretofore, however, the use of such diazo film aperture cards has been limited to so-called off-line applications since the ammonia developing process as heretofore practiced has been too slow and problem-ridden to make practical its use in an on-line information storing and disseminating system.

Until recently, the ammonia developing process was largely adaptedto the needs of diazo papers and, as is well known, the common practice is to use aqua ammonia as a source of ammonia along with the presence of heat. Aqua ammonia is dripped into a heated container Where substantially all of the ammonia together with a considerable proportion of the water-solvent is vaporized. Diazo paper or film is brought into contact with the hot, moist ammonia fumes by sliding the paper across perforations in a chamber or in some cases, by direct introduction of the film or paper into the chamber itself through sealing rolls. With this type of process, experience indicates that heat and a certain degree of moisture are quite essential in suitably developing diazo papers.

The employment of hot vapors of aqua ammonia for development has produced a number of difficulties. If an attempt is made to develop films and papers at ambient temperatures, the development is extremely slow with more than one pass through the development chamber oftentimes being required, the shades obtained are nontypical, and thus the process is quite unsatisfactory. In diazo products which contain several couplers and/or several diazos in order to secure a desired color, the actual shades obtained are found to depend to a great degree on the actual conditions of development. Thus, a hot, dry developing environment is prone to produce blue prints, while a cool, moist environment tends to yield yellow-brown hues. This is due to a variability in relative coupling rates with temperature. The amount of water present also creates problems in that too low a proportion of water leads to poor development and off-color shades, while too high a proportion of water leads to sodden prints, dye bleed, streaking, paper cockling and false colors. And of course in view of the high resolution requirements of the aperture card film pieces, no degree of dye bleed can be tolerated during development.

The above outlined difficulties associated with paper products become even more predominate in connection with developing diazo film products. Diazo films generally comprise a suitable transparent base, frequently a tough, dimensionally stable, polyester film to which has been bonded a resin matrix suitable for diazo sensitization. Sensitization is normally done by the use of a solventsensitizing component containing mixture. Cellulose acetate is typical of a suitable sensitizing layer. In view of the water-resistant characteristics of typical diazo film matrices, it can be understood that difiiculty ensues when aqua ammonia is employed. In addition to certain of the developing difiiculties mentioned for paper, new difiiculties arise, such as a tendency for the film to blush and haze under certain conditions of moisture and heat and a marked slowing down of the development rate owing to the difiiculty in securing a rapid penetration of the layer by the ammonia-water mixture. Furthermore, water-induced curl, always a major difiiculty with paper, can become uncontrollable with certain types of films.

Finally, a major source of difficulty with the development procedures currently employed, is a loss of resolution owing to diazo diffusion during the relatively slow development process. As noted earlier, photomaterial technology is approaching the point where the ability to resolve 1000 lines/ mm. is becoming essential. In order to accomplish this high resolution, it is fundamental that the image pattern laid down by light be preserved during subsequent processing steps. This implies that the motion of the imaging species during development can be only a few hundred molecular diameters. Clearly, in the case of the diazo film process, it is essential that the developing process be aimed at minimizing diazo diffusion; that is, that the diazo must be immobilized by dye formation as rapidly as possible. It is well known that diffusion rates are increased by an increase in temperature so that low temperature development is desirable. Further, it is necessary that an effective quantity of the developer composition he infused as rapidly as possible to the full depth of the resin matrix bearing the diazo image. The ammoniawater developer system is clearly not adapted to the attainment of these objectives, and, in fact, severe degradation of image resolution owing to diazo diffusion can be demonstrated in diazo systems in which heat during development is the prime factor in securing satisfactory image development.

In overcoming the above shortcomings of the ammonia-water developer system, there has been recently brought to light an improved system by which the development of both diazo films and papers may be carried out at ambient temperatures instead of the elevated temperatures hitherto used. This system is fully set forth in United States patent application Ser. No. 369,861, entitled, Diazo Development Process, assigned to the assignee of the present application. The improved process utilizes a liquid ammonia environment as a reaction solvent which results from the use of essentially pure ammonia gas or. anhydrous ammonia at a pressure sufficiently high that condensation of the gas can be expected to occur throughout the molecular pores of the matrix, be it film or paper. The coupling reaction is thus deemed to occur in a surround of liquid ammonia solvent .instead of an aqua ammonia surround. In spite of the fact that low temperature conditions are employed at which a lowering of development rate would be expected, there is actually achieved an increase in development rate of the order of hundreds of. times that possible with aqua ainmonia under the same conditions. Development is so nearly instantaneous that in combination with the relatively low temperatures employed, substantially no diazo diffusion occurs before the diazo is immobilized by dye formation. Also, an essentially constant temperature is possible so that relative coupling rates remain constant. The speed of the process results in a constant development time and blotch, haze and curl in forms are substantially reduced or eliminated. The sensitometric and color fidelity, the extreme rapidity of development and the very high efiiciency with which ammonia is used makes the process especially compatible with existing accounting machines so that online processing of aperture cards and aperture card duplicates becomes practical for the first time with ammonia developing systems.

One of the proposed methods for carrying out development by the improved high pressure process involves sandwiching a piece of film or paper between two closely fitting surfaces so that very little dead space or volume remains, Suitable gasketing means is provided to contain the material to be developed and, of course, a tight seal between the film and the developer platen is required. Then means are provided for introducing ammonia at slightly above ambient saturation pressure (usually from about 90 to 120 p.s.i. absolute) for a dwell time measured in fractions of a second (usually about 0.8 second suffices), followed by essentially instantaneous reduction in ammonia fumes allowed to escape to the atmosphere, either by pumping or by flushing the chamber into a vessel containing an ammonia absorbent.

Several types of apparatus are being proposed for carrying out the above described high pressure ammonia system' with particular emphasis being placed on a good tight film to developer platen seal, good control of the high pressure ammonia, and complete uniformity of development. Typical apparatus proposed are shown in United States patent application Ser. No. 430,094, entitled, Wash Ammonia Development Device, assigned to the assignee of the present application.

It is recognized that a problem exists with regard to obtaining uniformity of development due to the fact that before the high pressure ammonia is actually applied and at the time that the film and developer platen are brought together to effect a tight seal, air becomes entrapped between the film and platen developer cavity. If not removed, this entrapment of air impedes the action of the ammonia on the emulsion surface of the film and causes underdevelopment of the film in certain areas. In working on several solutions of this problem, it was found that the entrapped air can be completely removed and excellent results obtained with regard to uniform development of the film by utilizing the incoming high pressure ammonia to positively drive or wash the entrapped .air out of the developer cavity and remove it away from the surface of the image area of the film as that area is about to be developed.

To effectively carry out this wash approach it is necessary to provide someplace for the entrapped air to go Where it can be contained away from the surface of the film without breaking the tight film to developer platen seal and without incurring. any ammonia leakage which would reduce the effectiveness of development and which would also release undesirable fumes to the atmosphere. To accomplish this, a second cavity is provided into which the entrapped air is driven and this cavity is preferably located on the opposite or back side of the developer platen so that the air will be contained away from the surface of the film. Suitable ports for the flow of ammonia into the development cavity and for the flow of entrapped air from the development cavity into the air cavity are provided, which ports and cavities lie entirely within the sealed area of the platen so that there is no leakage of ammonia. Also, suitable valve means are provided for exhausting the ammonia into an ammonia absorbent device at the end of each development cycle prior to removing the film and breaking the film to platen seal to further prevent any ammonia leakage to the atmosphere.

Accordingly, a principal object of the present invention is to provide a novel method of utilizing the high pressure ammonia development process to accomplish high speed, uniform development of sensitized films and papers with no ammonia leakage.

A further object of the present invention is to provide a novel method of utilizing the high pressure ammonia development process to accomplish high speed, uniform development of a film area and wherein air entrapped between the film and development platen is washed away from the film area by the incoming ammonia.

Another object of the present invention is to provide a novel development device for effectively carrying out the Wash development method of the preceding object.

A still further object of the present invention is to provide a novel high pressure ammonia development device having a development platen provided with a development cavity on one side and an air reservoir cavity on the opposite side which is adapted to receive and contain entrapped air driven out of the development cavity by incoming ammonia.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a partial sectional view of a preferred em bodiment of a high pressure ammonia development de vice constructed in accordance with the principles of the present invention.

FIG. 2 is an enlarged front plan view of the development platen showing the ammonia development cavity.

FIG. 3 is a vertical sectional view taken on line 3-3 of FIG. 2 showing both the ammonia development cavity and the air reservoir cavity.

Referring to the drawings and particularly to FIG. 1, the development mechanism comprises a 3-way solenoid valve 10, a housing 11, a development platen 12 and a back-up platen 13-. The valve 10 serves to control the introduction of high pressure ammonia into a develop ment cavity 14 recessed in the film side of the development platen and the valve also serves to exhaust the ammonia out of the development platen and into an absorber device 15 at the end of each development Cycle.

The high pressure ammonia employed may be anywhere in the range of 50 to 120 p.s.i.g., however, in actual practice, it is preferable to use refrigeration grade ar1- hydrous ammonia at a pressure of :5 p.s.i.g. In the present embodiment, the supply is 2 pound ammonia in a number 4 bottle, as indicated at 16'. It will be understood that other sizes of supply may be used. The 3 way valve 10 is attached to the housing 11 and the ammonia supply 16 is connected to a passageway 17 in the valve by way of a turn on-turn off valve 18 and a pressure regulator 18a. As indicated in FIG. 1, at sub stantially room temperature of 70 F., for example, the pressure of the ammonia in the bottle 16 would be in the order of 128 p.s.i.g. The pressure would decrease under decreased temperature conditions and increase under increased temperature conditions. Therefore, the pressure regulator 18a is provided to regulate the ammonia pressure so that it will be preferably at 80 p.s.i.g. when it enters the valve 10. When development of film is not to take place, a solenoid member 19 in the 3-way valve Will be in its down position, as shown in FIG. 1, to seal off passageway 17 and prevent the ammonia from reaching the development cavity 14.

Referring particularly to FIGS. 2 and 3, in the present embodiment, the development platen 12 comprises a circular metallic member having a substantially rectangular recessed area in one side which defines the relatively thin development cavity 14. The configuration of the cavity is shown as being substantially rectangular to correspond to the configuration of the image area of the film pieces generally mounted in aperture cards but, of course, it will be understood that any configuration could be used. The development cavity 14 is on the film side of the platen and is necessarily thin, having a preferred depth in actual construction of .010 inch. A thin develop ment cavity is deemed important since it will minimize the amount of air that becomes entrapped between the film piece and the cavity and at the same time it will enable the inrushing ammonia to wash or drive out of the cavity what air is entrapped and to uniformly develop the film image area more effectively and with greater speed and also to reduce the amount of ammonia used.

Bordering around the outside of the development cavity is a rubber sealing ring which protrudes from the surface of the platen 12 by approximately .020 inch. When the back-up platen 13 positions the film piece against the sealing ring 20 and the high pressure ammonia is admitted to the development cavity, an absolutely leak proof chamber is formed about the emulsion side of the film and the escape of ammonia gas is eliminated thus eliminating odors and allowing the high concentration of ammonia in the cavity to effect uniform development of the film.

On the reverse or back side of the development platen there is formed another recessed area which defines an air entrapment cavity or reservoir 21 into which the entrapped air in the development cavity 14 is driven and contained. Although not necessary, excellent results have been obtained with the entrapment cavity 21 provided with the same configuration as the development cavity and located in alignment therewith. Also, in actual construction, the air cavity 21 is given a depth of approximately .015 inch. The resulting 2:3 ratio in volume between the development cavity and the air reservoir cavity has proven to be ideal in actual operation of the development mechanism.

As shown in FIG. 2, a central entrance port 22 is provided in the platen for admitting the high pressure ammonia'into the development cavity 14 substantially at the center thereof and ten ports 23 are provided which are equally spaced around the edges of the cavities to communicate the trapped air in the development cavity back to the reservoir or entrapment cavity 21. In actual construction, the ports 22 and 23 are given a diameter of approximately .031 inch. With this preferred arrangement of ports, the incoming ammonia from the central port 22 is able to diffuse effectively and instantly spread in all directions to fill the development cavity and contact all portions of the film image area at substantially the same time to carry out uniform development. Also, the arrangement of the ring of ports 23 around all extremities of the cavities allows all of the entrapped. air in the development cavity to be instantly and simultaneously removed from all portions of the development cavity to further enhance uniform development of the film. It can be seen that with the present arrangement of ports, the entire image area of the film will be quickly and effectively washed. This is an important and desirable feature.

Provided around the outside of the air cavity 21 is a rubber sealing ring 24 which is identical to the sealing ring 20 and screw holes 25 are provided for screwing the development platen 12 tight against the housing 11, as shown in FIG. 1, so that the air cavity is leak proof. The platen is mounted so that the central port 22 is in alignment with passageway 26 in the 3-way valve 10. Passageway 26 is normally blocked from the ammonia supply when the solenoid member 19 is in its down position, as shown. A rubber O-ring seal 27 is provided to seal the connection between the valve and the central port 22 to prevent the incoming ammonia from leaking into the air cavity 21.

In the operation of the mechanism, a film record card 28 would be suitably transported from an exposure station, for example, to, a position between the back-up platen 13 and the development cavity 14. As shown in FIG. 1, the film card 28 may be of the well-known type which usually comprises cardstock of approximately .007 inch thickness, an apertured area 29-having a recessed shoulder around its perimeter, and a film piece 30 secured over the aperture and to the recessed shoulder. The film piece may have a thickness which varies, for example, from .003 to .005 inch. A suitable movable card stop (not shown) is employed to locate the card and, of course, the emulsion side of the film piece would be toward the development cavity. The card is located so that the image area on the film piece will be confined within the sealing ring 20 when the card is pushed against the development platen.

After the card has been properly located, a suitabie toggle mechanism (not shown) operates to push the backup platen and card against the development platen. The image area of the film is positively held adjacent to the development cavity 14 during the development cycle with the ring seal 20 effectively sealing the resulting development chamber formed by the cavity and film.

Next, the solenoid member 19 is operated upwardly, from the position shown in FIG. 1, to effectively seal oif an exhaust passageway 31 which is connected to the absorbent device 15 and also to open up the passageways 17 and 26. The high pressure ammonia from source 16 is now free to flow through the passageways 17 and 26 and the central port 22 to fill the development cavity 14. Air is entrapped in the development cavity during the platen sealing operation and the inrushing ammonia gas, spreading out in all directions from the center port 22, instantly forces or washes the entrapped air to the outside of the chamber and through the ten port holes 23 and into the reservoir or air entrapment cavity 21. Thus, high concentrations of entrapped air, detrimental to development, are instantly displaced or removed from the emulsion surface of the film and uniform development of the image area quickly takes place.

The length of development cycle required depends upon the type of diazo film being developed. In tests made with the present device on two types of commercially available diazo film identified as Unit Gamma, manufactured by General Aniline and Film Company, and K Tone, manufactured by the Technifax Corporation, it was found that ammonia at p.s.i.g. and at ambient or room temperature fully developed the Unit Gamma film in 0.8 second and the K Tone film in 0.25 second.

At the end of the required development cycle the 3- way valve is d e-energized to return the solenoid member 19 back down to the position shown in FIG. 1. As a result, the entrance passageway 17 is closed and the exhaust passageway 31 is opened to connect the development chamber 14 to atmospheric pressure. The spent anhydrous ammonia gas now flows out of the cavities, back through the center port 22, the passageways 26 and 31 and into the absorbent device 15 which contains a suitable absorbent 32, such as citric acid, or the like.

After the development chamber pressure drops to atmospheric and the ammonia gas is exhausted, the backup platen 13 is pulled away from the card 28 andthe card stop is removed allowing the card to be expelled from the device. It is desirable to exhaust the gas and reduce the cavities to atmospheric pressure before the platen seal is broken.

It is important to note that the arrangement of the entry port 22 and the exit ports 23 is such that the sweeping out of the air by the ammonia occurs across the full image area of the film. Also, the placement of the air entrapment cavity 21 on the reverse or back side of the development platen and substantially in the central portion thereof insures that the entrapped air will be contained during development completely away from the emulsion surface of the film. Of course, other arrangements of cavities and ports could be used to carry out the principles of the present invention, however, our preferred embodiment describedabove provides excellent results.

A distinct advantage of using the present high pressure ammonia development device in connection with film record cards is that the card surrounding the film area does not have to be subjected to an ammonia chamber. This eliminates any wetting or change in color of the card itself. In the preferred embodiment shown, the configuration and area of the chambers 14 and 21 are substantially identical to each other and correspond to the configuration and area of the film piece to be developed. As such, the material area outside of the sensitized portion to be developed is not affected. Of course, it will be understood that use of the present device is not limited to the development of film record cards alone. Any form of photosensitive material may be developed with equal results such as, for example, unmounted film pieces and emulsion coated papers, which material need not necessarily be of the diazo type. Also, gasses or fluids other than ammonia may be employed.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. A device for developing material by applying a fluid substance under pressure to a sensitized area of said material comprising:

a development platen having a first cavity in one side thereof,

a seal member surrounding said first cavity and shaped to enclose said sensitized area,

a back-up platen operative to hold said sensitized area against said seal whereby a development chamber is formed with said first cavity,

a second cavity on the opposite side of said development platen,

sealing means for said second cavity whereby an air entrapment chamber is formed,

a port for conducting said pressurized substance into said first cavity substantially at the center thereof whereby said substance will spread out in all directions throughout said development chamber, and

a plurality of individual ports arranged around the periphery of said first cavity which communicate with said air entrapment chamber whereby entrapped air in said development chamber is forced by said substance to flow into said air entrapment chamber thus enabling said sensitized area to be contacted by said fluid substance in the absence of air. 2. A device for developing material as defined in claim 1 wherein said fluid substance comprises anhydrous ammonia at a pressure anywhere in the range of 50 to 120 psi.

3. A device for developing material as defined in claim 1 wherein the configuration and area of said development and, air entrapment chambers are substantially identical and correspond to the configuration and area of the sensitized material to be developed.

4. A device for developing material as defined in claim 1 wherein the volumes of said development and air entrapment chambers have an approximate ratio of 2:3, respectively.

5. A device for developing material as defined in claim 1 wherein all of said ports are circular and of the same area, the area of each port being quite small'in comparison to the area of said chambers.

6. A device for developing material as defined in claim 1 wherein said development and air entrapment cham bers are in alignment with each other and are located substantially in the central portion of said development platen.

7. A device for developing material having a sensitized area comprising:

a development platen having a first cavity in one side thereof,

a seal member surrounding said first cavity and shaped to enclose said sensitized area,

a back-up platen operative to hold said sensitized area against said seal whereby a development chamber is formed with said first cavity,

a second cavity on the opposite side of said development platen,

sealing means for said second cavity whereby an air entrapment chamber is formed,

an entrance port opening into said first cavity at substantially the center thereof,

a source of pressurized gas adapted to develop said sensitized material,

an absorbent device for said gas,

valve means connected between said source of gas, ab-

sorbent device and said entrance port,

an operating member in said valve means operable to seal ofi said absorbent device and admit said gas to said entrance port whereby said gas will spread out in all directions throughout said development chamber, and

a plurality of individual ports arranged around the periphery of said first cavity which communicate with said second cavity whereby entrapped air in said development chamber is forced by said gas to flow into said air entrapment chamber thus enabling said sensitized area to be developed in the absence of air,

said operating member being operable after development to seal off said source of gas and open said absorbent device whereby the gas in said chambers will flow out of said development platen through said entrance port and into said absorbent device.

8. A device for developing material as defined in claim 7 wherein said valve means and operating member effectively reduces said chambers to atmospheric pressure after development and prior to the release of said backup platen.

9. A device for developing a sensitized surface on a material by applying a high pressure developer fluid thereto comprising:

a development platen including a wall with a recessed portion whose opposite pairs of sides define an outwardly facing rectangular cavity adapted to face the sensitized surface;

a seal member surrounding said rectangular cavity and shaped to encompass the sensitized surface to be developed; 1

a back-up platen operative to hold the material against said seal member and defining with said cavity a rectangular development chamber for the sensitized surface and wherein air is trapped;

an inner air entrapment chamber disposed in back of said cavity in said wall;

a plurality of circular ports in said wall and spaced along at least one pair of the opposite sides of said rectangular cavity to directly connect said development'chamber with said air entrapment chamber;

a circular entrance port extending through said wall and substantially centrally located in said cavity for admitting the high pressure developer fluid into said rectangular development chamber for distribution throughout; and

said entering developer fiuid simultaneously displacing the trapped air through said outlet ports into said air entrapment chamberand spreading throughout said rectangular development chamber to contact and develop the entire exposed sensitized surface on the material.

No references cited.

NORTON ANSHER, Primary Examiner.

F. L. BRAUN, Assistant Examiner.

Claims (1)

1. A DEVICE FOR DEVELOPING MATERIAL BY APPLYING A FLUID SUBSTANCE UNDER PRESSURE TO A SENSITIZED AREA OF SAID MATERIAL COMPRISING: A DEVELOPMENT PLATEN HAVING A FIRST CAVITY IN ONE SIDE THEREOF, A SEAL MEMBER SURROUNDING SAID FIRST CAVITY AND SHAPED TO ENCLOSE SAID SENSITIZED AREA, A BACK-UP PLATEN OPERATIVE TO HOLD SAID SENSITIZED AREA AGAINST SAID SEAL WHEREBY A DEVELOPMENT CHAMBER IS FORMED WITH SAID FIRST CAVITY, A SECOND CAVITY ON THE OPPOSITE SIDE OF SAID DEVELOPMENT PLATEN, SEALING MEANS FOR SAID SECOND CAVITY WHEREBY AN AIR ENTRAPMENT CHAMBER IS FORMED, A PORT FOR CONDUCTING SAID PRESSURIZED SUBSTANCE INTO SAID FIRST CAVITY SUBSTANTIALLY AT THE CENTER THEREOF WHEREBY SAID SUBSTANCE WILL SPREAD OUT IN ALL DIRECTIONS THROUGHOUT SAID DEVELOPMENT CHAMBER, AND A PLURALITY OF INDIVIDUAL PORTS ARRANGED AROUND THE PERIPHERY OF SAID FIRST CAVITY WHICH COMMUNICATE WITH SAID AIR ENTRAPMENT CHAMBER WHEREBY ENTRAPPED AIR IN SAID DEVELOPMENT CHAMBER IS FORCED BY SAID SUBSTANCE TO FLOW INTO SAID AIR ENTRAPMENT CHAMBER THUS ENABLING SAID SENSITIZED AREA TO BE CONTACTED BY SAID FLUID SUBSTANCE IN THE ABSENCE OF AIR.

Images