US3090290A

US3090290A - Data processing system

Info

Publication number: US3090290A
Application number: US62611A
Authority: US
Inventors: Donald S Ross
Original assignee: Itek Corp
Current assignee: Northrop Grumman Guidance and Electronics Co Inc
Priority date: 1960-10-14
Filing date: 1960-10-14
Publication date: 1963-05-21
Anticipated expiration: 1980-05-21

Description

4 Sheets-Sheet 1 Filed 001;. 14, 1960 INVENTOR. DONALD s. ROSS I ATTORN Y May 21, 1963 n. 5. R085 DATA PROCESSING sysmu 4 Sheets-Sheet 2 Filed Oct. 14. 1960 INVENTOR.

ONALD 8. R088 BY m ATTORN Y y 1963 D. 5. R085 3,090,290

DATA PROCESSING SYSTEM Filed Oct. 14, 1960 4 Sheets-Sheet 3 FIG. 3.

INVENTOR. DONALD S. ROSS ATTORNEY United States Patent M 3,096,290 DATA PROCESSING SYSTEM Donald S. Ross, Lexington, Mass, assignor to ltelt Corporation, Waltharn, Mass, a corporation of Delaware Filed Oct. 14, 1960, Ser. No. 62,611 7 Claims. (Cl. 95-89) This invention relates generally to the art of data processing. More particularly, the invention relates to rapid and controlled continuous processing of data hearing photographic film.

While the invention is subject to a wide range of application it is especially suited for use in an automatic continuous processing system for processing film that is being exposed at a varying rate and a usable photograph is desired immediately after exposure irrespective of the exposure rate.

A major problem frequently encountered in modern photographic work is the requirement for the rapid processing of high quality negative or positive images for visual examination, telemetering, or some other use where quick access to the recorded information is essential. In many instances the need for rapid access to the photographic image is accompanied by a variable film output rate from a recording station. This poses a problem, in that the processor must accommodate film coming to it at cycling rates which vary. By way of example the cycling rate may vary from one frame per second to ten frames per second. The average film velocity would vary from less than one inch per second for 70 mm. film to 45 inches per second for five inch film. The same is true in many continuous strip photographic applications, where the exposure rate may vary from instant to instant.

In a photographic system, when the environmental conditions of camera, camera lens, film emulsion type and illumination are chosen, the processing material response time is then determined. Therefore, the processing rate at which the processor is to operate is fixed. Where one or all of the above conditions are varied, the rate of operation for the processor must also be changed. Processing rates per frame may vary from less than one second for four and one-half inch film to as high as fortyeight seconds for 70 mm. film. Frequently, there are no means available to compensate the processor for these variations in conditions; as for example, in a reconnaisance missile or satellite.

The prior art, for example, as shown in US. Patent No. 2,446,668, discloses apparatus with which it is possible to photograph, process, and project images in a short interval. The apparatus is of the type in which the film is fed to and from each of the exposure processing and projecting stations in rapid succession by a single film feeding means, which is driven by a motor and which motor constitutes the sole driving means for the complete apparatus. No provision is made to adapt the motor to another rate of film feed or to a periodically varying rate of film feed.

In addition, there are many applications where there is a time delay between the separate stages of the photographic process. Several known devices employ stored loops, excessive rebate length, intermittent processing or continuous processing with rate control by solution temperature variations. Each method required complex equipment that is relatively high in weight and large in size. In addition, processing apparatus employing processing solutions in liquid form tend to be too heavy and bulky for use in reconnaisance missiles and satellite application.

The problem of accommodating continuous processing having a preselected processing time and a data bearing film moving at an indeterminate velocity is solved in this invention by providing a servomechanism to automati cally vary the length of film being processed in proportion to the film velocity, thereby maintaining the length of time the film is processed equal to the preselected processing time.

An object of this invention is to provide an improved data processing system for processing data bearing film.

A further object of this invention is to provide an improved data processing system for continually processing data bearing film.

A further object of this invention is to provide an improved data processing system for continuously processing data bearing film irrespective of the film velocity to the system.

A further object of this invention is to provide a data processing system for processing data bearing film that is light in weight and compact.

As used in this specification, the term monobath defines a viscous solution of photographic processing material used to simultaneously develop and fix a latent image. As used in the specification, the term photographic film is intended to define the combination of a carrier and any of the well known photosensitive materials. As used in the specification, the term thixotropy defines the property or phenomenon exhibited by certain gels of becoming fiuid when vibrated, pressurized, and/ or placed under shear. As used in this specification, the term thixotropic photographic processing ge is defined as a viscous solution of photographic processing material in a thixotropic responsive gel medium.

For a better understanding of the present invention, together with other and further examples thereof, reference is made to the following description taken in connection with the accompanying drawings, and the scope will be pointed out in the appended claims.

In the drawings:

FIG. 1 is a schematic block diagram illustrating the operation of the preferred embodiment of the present invention;

FIG. 2 is a partially schematic perspective view of the preferred embodiment of a one-stage film processing apparatus embodying the present invention;

FIG. 3 is a cross-sectional view of the belt, processing material, film, and pressure roller taken along line 3-3 in FIG. 2;

FIG. 4 is a cross-sectional view of a thixotropic gel applicator taken along line 44 in FIG. 2; and

FIG. 5 is a schematic block diagram of another embodiment of the present invention.

Referring now to FIG. 1 there is schematically illustrated the broad operation of a continuous processor embodying the present invention.

The system broadly operates to continuously process a data bearing filin a preselected time irrespective of the film velocity. in order to accomplish this the system operates to vary the length of film in a processing means in accordance with the film velocity, so that ti e film remains in the processing means for the preselected time. As illustrated, a data bearing film 23 moves at an indeterminate velocity V from a source 4-5. The film 23 is transported through a continuous processing means 16 over two rollers l2 and 14, which form part of the conveyance means. The roller 12 defines the entrance to the processing means and roller 14 the exit therefrom. In addition rollers 12 and i4 transport the film through processing means 16 at the film velocity V The film length control means includes a film velocity sensor 22 for sensing the film velocity V and producing a signal indicative of film velocity V a reference velocity signal generator 47 computes a reference velocity V from the relationship V =L,./ T, where V corresponds to the reference velocity, L corresponds to a selected value of film length in the processing means, and T corresponds to the preselected processing time of the processing medium; and a velocity comparator 27 for comparing reference velocity V and film velocity V and producing an error velocity signal AV indicative of the algebraic difference of the two velocities V and V 0 respectively. The error velocity AV may have a positive or negative value depending on the magnitude of the two velocities V and V respectively. The positive or negative value indicates the direction and distance of movement required to vary the length of film in the processing means. The film length control means 23 receives, as an input, the error velocity signal AV and drives rack and pinion 31 and 31a attached to frame 3t up or down. The frame 30, in turn, is attached to a translatable roller 17. The movement of frame 36 up and down varies the length of the film in the processing means in accordance with the error velocity AV, whereby the film remains in the processing means 16 the preselected time T irrespective of the film velocity V Referring now in more detail to the drawings and with particular reference to FIG. 2 there is here illustrated a preferred embodiment of the invention for thixotropic photographic processing. The data processing system includes a source 45 of moving data bearing film 23, moving in the direction of the arrows A at an indeterminate velocity V The processing means includes a processing medium applicator ltl located adjacent to a conveyance means. The conveyance means includes a belt 11 which is passed over a drive roller 12, under a pressure roller 1%, a guide roller 17, over a tension roller 14, under a tension roller 15, over a guide roller 29, and under an idler roller 21 and back to roller 12 to form a continuous loop. A film velocity sensor 22 is located adjacent to the exposed film 23 entering the processing means and is coupled to a variable servo-motor 25 through computer 27 for varying the rotational velocity in accordance with the film velocity V The servo-motor 25 drives the roller 12 through a shaft 37. A pressure roller 19 is adjacent to the belt 11 over roller 12 for holding the film 23 against a processing gel 34 to be described hereinafter.

The film length control means includes a computer 27 for receiving a film velocity signal V and a programmed value of processing time to compute a value of film length. The computer may be programmed for a reference velocity indicative of a reference length from the relationship V,=L,/ T as discussed with reference to FIG. 1. In addition to function as a reference velocity signal generator, the computer 27 also functions as a velocity comparator for comparing the actual film velocity and reference film velocity for producing an error signal indicative of the required change in length needed to maintain the film in the processor for the preselected processing time. A position sensor 29 is attached to a frame 30 and is coupled to computer 27 for feeding back the actual length of film in the processor to the comparator. This provides in indication of the required direction of change needed, that is, increase or decrease of length. The driving means includes a rack and pinion 31 and 31a, respectively, attached to the frame 30 and attached to a reversible servo-motor 28. Servo-motor 28 is coupled to computer 27 for varying the film length through the rack and pinion 31 and 31a whereby the film is processed for the preselected time irrespective of said film velocity.

In operation, the system is preset for operation within an expected film velocity range. A preselected processing time is programmed on the computer 27 in accordance with the criterion to be stated hereinafter. The data processing system becomes functional when the film velocity sensor 22 senses the velocity of film 23 emerging from the source 45. Sensor 22 produced a signal indicative of the film velocity V and transmits the signal to the computer 27. The computer 27 transmits the velocity to the variable speed servo-motor 25 directly to vary the rotational velocity of servo-motor 25 equal to the film velocity V Servo-motor 25 is connected to roller 12 by a shaft 37 whereby the roller 12 has a rotational velocity equal to the film velocity V The roller 12, in turn drives belt 11 for transporting the film 23.

In the preferred embodiment, belt 11 is constructed of stainless steel because of its flexibility, high heat of conductivity, ease of fabrication and photographic compatability. However, belt 11 may be constructed with a pair of ridges 32 parallel to its lateral edges. The ridges 32 are separated from each other a distance substantially equal to the width of film 23. The ridges prevent lateral flow of the processing medium 34 from the belt 11.

Refer-ring once again to FIG. 2, belt 11 passes over roller 12, under roller 17, and over

rollers

14, 15, 20, 21, and back to roller 12.

Rollers

15, 17, 20, and 21 are slave rollers, that is, they are not positively driven. All rollers have a plurality of sprockets 38 to mesh with a plurality of apertures 33 through belt 11 arranged parallel to both lateral edges of belt 11 and between ridges 32 and lateral edges of belt 11. Uses of sprockets 38 and apertures 33 maintain positive drive and prevent slippage of belt 11 on the rollers.

Rollers

12, 14, and 21 are fixed relative to each other.

A processing loop is described by belt '11 from roller 12, under roller 17, to roller 14. Roller 12 is disposed at the entrance of the processing loop and roller 14 is disposed at the exit therefrom. A return loop is described by belt 11 from

rollers

14, 15, 20, and 21 to roller 12. Roller 14 is tendency driven by a belt 40 between pulley 41 attached to shaft 37 and a slip clutch 42 attached to shaft 43 of the roller 14. The ratio of pulleys 41 and slip clutch 42 permits roller 14 to revolve at a slightly higher rotational velocity than roller .12 whereby constant tension is maintained on belt 11 passing through the processing loop. The slip clutch 42 direction of rotation is maintained in the direction of rotation of motor 25. Roller 15 is suspended by a pair of springs 44 to maintain constant tension on belt 11 passing through the return loop. Since roller 12 positively drives the belt 11, the

'veloctiy of belt 11 is equal to the film velocity V Film 23 is placed on the belt 11 between ridges 3'2 simultaneous with the passage of belt 11 over roller 12. Film 23 is between ridges 32 with the exposed surface of film 23 facing the belt 11, and remains in the processing loop until belt 11 arrives at roller 14 after passing under roller 17. At roller 14 belt 11 enters the return loop while film 23 proceeds to a further operable position not shown.

The characteristics of the photosensitive material, the processing material, and the desired use to which the data is to be applied determine the processing rate. A value of temperature is determined to speed processing without damage to the film. This evaluation determines the allowable processing time during which the film is to be processed to the desired output. It is this value of processing time that is programmed into computer 27.

Simultaneous with the input of film 23 to belt 11 the roller frame 30 is translated to vary the length of belt 11 in the processing loop. A signal indicative of the velocity transmitted to computer 27 is evaluated with the programmed value of processing time to calculate a value of film length in the processing loop. This value represents the length of film 23 which must remain in the processing loop to obtain the desired result.

Rollers

17 and 20 are positionally fixed relative to each other on frame 30 and are capable of vertical movement relative to roller 12. Rack and pinion 31 and 31a, respectively, are attached to frame 30. Position sensor 29 is attached to frame 30 to determine the instantaneous position of

rollers

17 and 20 relative to roller 12. A signal representative of this position is transmitted to computer 27. Computer 27 calculates a resultant command signal. The value is indicative of the distance and direction of vertical movement frame 30 must undergo to change the position of

rollers

17 and 20 relative to roller 12. The change in position of

rollers

17 and 20 will alter the configuration of both processing and return loops. This command signal is transmitted to reversible servomotor- 28. servo motor 28 will move rack and pinion '31 and 31m respectively with subsequent movement of frame 30 through the correct distance and direction. Thus the length of the film in the processing loop is varied in accordance with film velocity V Film 23 will remain in the processing loop the preselected length of time irrespective of film velocity V in the processing loop.

Referring to FIGS. 3 and 4, the processing means in the monobath thixotropic film processing embodiment becomes operative with the movement of belt '11. A predetermined quantity of monobath thixotropic photographic processing gel 34 is stored in applicator 10. The gel 34 is maintained under pressure by a pressure plate 35 and at a pressure such that gel 34 will not leave applicator 10 while belt 11 is stationary. As belt 11 moves into the processing loop belt 11, in contact with a variable orifice 36, becomes a shearing arm receiving a predetermined amount of gel 34 through orifice 36-. The resultant pressure exerted by pressure plate 35 and the shearing force liquefies a surface of gel 34 applied to belt 11. The surface liquefied is the free surface of the medium. Gel 34 is applied to belt 11 by applicator 10' between ridges 32. As belt 1 1 with gel 34 passes over roller 12 film 23 is transported by belt 11 through the processing loop. The combination of belt 11 and film 23, with gel 34 between, is nipped between roller 12 and pressure roller 19. This action insures uniform thickness of gel 34 and establishes uniform contact between the exposed surface of film 23 and the liquid surface of gel 34.

Ridges 32 also acts to prevent gel 34 from oozing from between belt 11 and film 23. A pair of

heaters

16 and 18 maintain belt 11 at the constant temperature predetermined to reduce processing time without damage to the film. The liquid surface of gel 34 acts on the exposed surface of film 23 to process the latent image contained therein during the required processing time at the velocity of belt 11. Belt cleaner 13 removes exhausted gel as film 23 proceeds to the next stage, and belt 11 proceeds into the return loop.

While there have been described an apparatus which processes film automatically and adapts automatically to the film velocity, the effect has been accomplished without complex equipment because the gel layer is, for example, approximately two mils in thickness. By way of illustration, 1,000 feet of five-inch film may be processed with approximately 120 cubic inches of material weighing six pounds as compared to twice the volume using ordinary viscous solution or ten times the volume using spray methods. The result is a great reduction in weight and size. The process can be adapted to process film to a desired degree of quality without difiiculty utilizing any processing material formulated previously or contemplated. By controlling the processing technique it is possible to produce a usable photograph with the desired degree of acuitance and resolution in periods of less than ten seconds from the moment of exposure to the projected position.

A series of modules, each substantially as previously described, can be interconnected to process exposed film in a series of stages where each stage is a modular unit modified to the particular purpose of that stage. Thus there may be two stage processing where one stage is development and one stage is fixing; or there may be three stage processing where there is two stage development and one stage fixing. In FIG. there is shown a schematic diagram of a three stage processor. Stage A develops film to a predetermined value of density. The actual value of density of the film emerging from stage A is determined by densitometer 39. This value is transmitted to computer 27 to modify the value of processing loop length in stage B to complete the development of film 23 to the desired 6 level of density. Stage C has been modified to fix the developed image in film 23.

While there have been described what are at present considered to be the preferred embodiments of this inventor, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is therefore aimed in the appending claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

A data processing system, comprising: a source of moving data bearing film, said film having an indeterminate velocity; processing means, including a processing medium for continuously processing said film, the time of processing being preselected in accordance with selected characteristics of said medium and film; conveyance means coupled to said source and processing means for transporting said film through said processing means at said film velocity; film length control means coupled to said conveyance and processing means for controlling the length of film in said processing means, said control means including a reference velocity signal generator for producing a reference velocity signal proportional to said preselected time, a film density sensor for producing a signal indicative of said film density and modifying said reference velocity signal proportional to said film density, for providing controlled density of said processed film, a film velocity sensor for producing a signal indicative of said film velocity, a velocity comparator for producing an error signal in accordance with the algebraic difference of said velocity signals; and driving means coupled to said film length control means adapted for receiving said error signal, said driving means adjusting the film length in said processing means in accordance with said modified error signal, whereby said film is processed for said preselected time irrespective of said film velocity.

2. A data processing system for a moving strip of photographic film comprising:

an endless belt conveyor;

means for driving said conveyor at a velocity corresponding to the velocity of movement of said film;

means for applying a uniform coating of a semi-fluid processing medium to said belt conveyor;

means for bringing said film into face-to-face contact with a traverse of said conveyor to which said processing medium has been applied; and

means for varying the path length of said traverse as a function of the velocity of movement of said film,

whereby said film is processed in a manner that is independent of the velocity of movement of said film.

3. A data processing system as in claim 2, wherein said belt has disposed thereon a pair of ridges parallel to each other and to the edges of said belt, said ridges being adapted for retaining said processing medium on said belt.

4. A data processing system as in claim 2, wherein said last named means includes:

a device for measuring the density of said film to vary the length of said traverse as a function of said density.

5. A data processing system for a moving strip of photographic film comprising:

an endless belt conveyor;

means for bringing said film into face-to-face contact with a traverse of said conveyor to which said processing medium has been applied;

a roller for guiding said belt conveyor; and

means for altering the position of said roller thereby to vary the path length of said traverse as a function of the velocity of movement of said film,

whereby said film is processed in a manner that is in- 7 dependent of the velocity of movement of said film.

6. A data processing system as in claim 5, said last named means including:

a movable mounting device for said roller and a positional servo mechanism coupled to said mounting device.

7. A data processing system for a moving strip of photographic film comprising:

an endless belt conveyor;

means for applying a uniform layer of a processing medium dispersed in a thixotropic gel to said belt conveyor;

means for bringing said film into face-to-face contact with a traverse of said conveyor to which said processing medium has been applied, said means ineluding;

a roller for creating pressure between said film and coating; and

References Cited in the file of this patent UNITED STATES PATENTS 2,945,429 Grant July 19, 1960

Claims

1. A DATA PROCESSING SYSTEM, COMPRISING: A SOURCE OF MOVING DATA BEARING FILM, SAID FILM HAVING AN INDETERMINATE VELOCITY; PROCESSING MEANS, INCLUDING A PROCESSING MEDIUM FOR CONTINUOUSLY PROCESSING SAID FILM, THE TIME OF PROCESSING BEING PRESELECTED IN ACCORDANCE WITH SELECTED CHARACTERISTICS OF SAID MEDIUM AND FILM; CONVEYANCE MEANS COUPLED TO SAID SOURCE AND PROCESSING MEANS FOR TRANSPORTING SAID FILM THROUGHI SAID PROCESSING MEANS AT SAID FILM VELOCITY; FILM LENGTH CONTROL MEANS COUPLED TO SAID CONVEYANCE AND PROCESSING MEANS FOR CONTROLLING THE LENGTH OF FILM IN SAID PROCESSING MEANS, SAID CONTROL MEANS INCLUDING A REFERENCE VELOCITY SIGNAL GENERATOR FOR PRODUCING A REFERENCE VELOCITY SIGNAL PROPORTIONAL TO SAID PRESELECTED TIME, A FILM DENSITY SENSOR FOR PRODUCING A SIGNAL INDICATIVE OF SAID FILM DENSITY AND MODIFYING SAID REFERENCE VELOCITY SIGNAL PROPORTIONAL TO SAID FILM DENSITY, FOR PROVIDING CONTROLLED DENSITY OF SAID PROCESSED FILM, A FILM VELOCITY SENSOR FOR PRODUCING A SIGNAL INDICATIVE OF SAID FILM VELOCITY, A VELOCITY COMPARATOR FOR PRODUCING AN ERROR SIGNAL IN ACCORDANCE WITH THE ALGEBRAIC DIFFERENCE OF SAID VELOCITY SIGNALS; AND DRIVING MEANS COUPLED TO SAID FILM