WO1993020479A1

WO1993020479A1 - Photographic film handling system with stepper motor control

Info

Publication number: WO1993020479A1
Application number: PCT/US1992/002706
Authority: WO
Inventors: John W. Weiss; David M. Webb
Original assignee: Pako Corporation
Priority date: 1992-04-02
Filing date: 1992-04-02
Publication date: 1993-10-14

Abstract

A photosensive material processor (18) for developing photosensitive material has a first end with a photosensitive material inlet and a second end with a photosensitive material outlet. A processing mechanism (58, 60, 62) is disposed generally between the first and second ends. A transport device (70) is provided for transporting the film at least a portion of the way between the first and second ends. A stepper motor (66) is coupled to the transport device. The stepper motor (66) drives the transport device (70) to transport the photosensitive material between the first and second ends. A controller (66) is coupled to the stepper motor and controls the stepper motor in driving the transport device. The controller (66) controls the stepper motor based on processing parameters provided to the controller.

Description

PHOTOGRAPHICFILMHANDLINGSYSTEMWITH

STEPPERMOTORCONTROL

BACKGROUND OF THE INVENTION The present invention relates to a photographic film handling system. More particularly, the present invention relates to a photographic film handling system with stepper motor transport control.

A photographic film processing system typically includes three parts. In the fires* part, an image setter is used to set an image onto a sheet of photographic film. The image setter is typically manipulated by an operator who is setting the desired image through use of an electronic interface The image setter may set a portion of an image at a time, or the entire image, depending on the size of the image being set, the size of the sheet of film and the type of image setter being used.

Once the image has been set onto the film, the film must be processed or developed. A typical film processor includes a developer chemical bath. Sheets of film to be developed are moved through the bath. The chemical reaction produced when the film is introduced in the chemical bath develops the film.

In order to transport the film through the chemical bath, it is common for processors to have roller racks mounted within the developer solution. Several pairs of rollers are arranged within the roller racks. Each pair is arranged so that the surfaces of the rollers in the pair are in contact with one another. The sheets of film to be exposed to the chemistry are inserted between a first pair of rollers. As the first pair of rollers turns, the rollers grip and transport the film down into the chemical bath. Several other sets of rollers transport the film through the bath.

A final set of rollers is typically mounted for receiving and removing the sheets of film from the chemical bath. In many types of developers, the amount of time which the film is exposed to the chemical bath determines the degree to which the film is developed. Therefore, tight control of the rollers in transporting the film through the processor is very important. However, before the film can be developed, -.it must be removed from the image setter and moved to "the processor_or developer. Movement, of the film from the image setter to the processor has, in the past, been accomplished by human beings. In addition, certain automated transport devices have been developed. Those devices are commonly known as conveyors, bridges, or transporters. They will hereinafter be referred to collectively as conveyors.

It is very important that, in removing the film from the image setter, the conveyor removes the film at a precise speed which corresponds to the speed at which the image setter is delivering the film. If the conveyor pulls the film too quickly, the film can stretch. Also, if the conveyor moves too slowly, the film can be pushed against the conveyor in an unregulated fashion. Both types of mismatch in speed between the conveyor and the image setter result in imperfections in the finally developed film. Those imperfections are known as "artifacts", or "film faults". Thus, it is important that the conveyor determine the speed at which the image setter is providing the film. In addition, it is important that the conveyor' provide the film to the processor at thβjrprecise speed at which the processor is running. Failure to do so can also result in artifacts. Due to the nature of the control and positioning required in the image setter, they have generally accomplished film transportation with stepper motors. However, film transportation was accomplished in the automated conveyor, and the film processor, with DC type motors, AC motors with speed control or AC synchronous motors. Such motors are large in physical size, very-costly and may be only marginally accurate. Also, the brushes in such motors tend to wear out rather quickly. This makes any system having such motors a relatively high maintenance type system. Therefore, there is a continuing need to provide accurate and economical transport control in film handling systems.

Also, in the past, film processors and conveyors typically had a fixed, hard-wired communication link. That link provided for very limited communication between the processor and conveyor. There was no means by which the processor and conveyor could interactively provide a wide variety of information to one another. SUMMARY OF THE INVENTION

A photosensitive material processor has a first end with an inlet and a second end with an outlet. Processing means is disposed generally between the first and second ends and processes the photosensitive material. Transport means transports the photosensitive material at least a portion of the way between the first and second ends. A stepper motor is coupled to the transport means for driving the transport means to transport the photosensitive material. A controller is coupled to the stepper motor for controlling the stepper motor in driving the transport means. The controller controls the stepper motor based on processing parameters provided to the controller.

Another feature of the present invention provides a variable communication link in a photosensitive material handling system between a conveyor and the processor. In one embodiment, the link is a serial RS232 link. This provides a communication link which supports a system with distributed control.

A third feature of the present invention provides speed detection means for determining the speed of the photosensitive material. The speed detection means is located on the conveyor in a photosensitive material handling system to detect the precise speed of the photosensitive material as it is delivered from an image setter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a photographic film handling system of the present invention.

FIG. 2A is a top view of a conveyor according to the present invention.

FIG. 2B is a side view of the conveyor shown in FIG. 2A with a portion cut away.

FIG. 2C is a block diagram of the control circuit controlling film transport in the conveyor shown in FIGS. 2A and 2B.

FIG. 3A is a block diagram of a photographic film processor according to the present invention.

FIG. 3B is a block diagram of the motor and drive circuit for the processor shown in FIG. 3A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS _.

FIG. 1 is a block diagram of a photographic film handling system 10. System 10 includes electronic interface 12, image setter 14, conveyor 16, photographic film processor 18 (processor 18) and optional operator interface 20.

While the present invention is described with reference to photographic film, the novel features of the invention can also be implemented in a system which handles other types of photosensitive material. Examples of photosensitive material include polyester or paper plate material, and photographic film or paper. For the sake of simplicity, the following discussion will proceed with reference only to photographic film. An operator interacts with image setter 14 through electronic interface 12 to set an image onto a sheet of photographic film. Electronic interface 12 may be any number of electronic interfaces currently commercially available, such as a Macintosh or IBM Personal Computer, a CRT, or a CAD system. Through electronic interface 12, the operator provides image parameters to image setter 14 so that image setter 14 sets the desired image onto the sheet of photographic film within image setter 14. The electronic link between electronic interface 12 and image setter 14 is indicated by dashed arrow 22. The electronic link can be accomplished by any number of known devices such as a serial RS232 interface with appropriate protocol.

Once image setter 14 has set the desired image on the sheet of photographic film, the photographic film is provided by image setter 14 to conveyor 16. This is indicated by arrow 24. Conveyor 16 primarily functions to deliver the film from image setter 14 to processor 18. Not only does conveyor 16 transport the film from image setter 14 to photographic film processor 18, but conveyor 16 also performs a speed determination and regulation function. In other words, the film received from image setter 14 cannot be provided to processor 18 until processor 18 is ready to receive the film. In addition, conveyor 16 must receive the film from image setter 14 at a precise speed which corresponds to the speed at which the film is being delivered from image setter 14 in order to avoid causing artifacts in the film. In most instances, the speed at which conveyor 16 receives the film is the same speed that the image setter is delivering the film. However, some image setters require resistance at the input of the conveyor. Thus, conveyor 16 may run slightly slower than image setter 14.

Once processor 18 is ready to accept the film from conveyor 16, conveyor 16 transports the film, at high speed (assuming it has been entirely received from image setter 14) to processor 18. When the film reaches processor 18, however, it is important that conveyor 16 again slow the film delivery to precisely match the speed at which the film is to be accepted at processor 18. Thus, conveyor 16 regulates the transport speed of the film so the film moves as quickly as possible, but so the transport speed still matches the speed of image setter 14 and processor 18. Delivery of the film from image setter 14 to processor 18, by conveyor 16, is indicated by arrow 26. in transporting the film, it is desirable that conveyor 16 be provided with a number of parameters. For example, it is desirable for conveyor 16 to know how fast the film is being provided by image setter 14. Conveyor 16 can do this in a number of ways, including sensing the film speed through, for example, optical sensors. Conveyor 16 is also configurable for. electronically communicating with image setter 14 along an electronic communication link indicated by arrow 28. Thus, conveyor 16 can receive a parameter indicative of film speed from image setter 28, along the electronic link indicated by arrow 28.

In addition, it is advantageous for conveyor 16 to know the length of the film being provided by image setter 14. This can also either be sensed or provided along the electronic link indicated by arrow 28.

Further, it is desirable for conveyor 16 to know when image setter 14 has completed setting the image to the photographic film. In other words, the leading edge of the film may arrive at conveyor 16 before image setter 14 is entirely finished setting the image to the photographic film. In that case, conveyor 16 must not pull the film from image setter 14 until the complete image has been set and the film has been cut in image setter 14. The signal indicating that image setter 14 has finished setting the image to the photographic film is provided through the electronic link indicated by arrow 28.

Processor 18 receives the film from conveyor 16 and processes, or develops,"the film. Processor 18 receives processing parameters""from either an optional operator interface 20, through electronic link 30, or from one of the other components in film handling system

10 through electronic link 32. Electronic links 30 and 32 can be any type of commercially available electronic communications links, such as a serial RS232 communication link. The processing parameters received by processor 18 preferably include a wide range of parameters such as the size of the film to be processed,, the degree of development required for the film, the speed at which the film is to be moved through processor 18 and any other appropriate parameters. Once the film is processed, or developed, by processor 18, it is provided at an output of processor 18. This is indicated by arrow 34. Throughthe electronic communication links 22,

28, 30 and 32, each component in film handling system 10 is capable of electronically communicating with the other components. Links 22, 28, 30 and 32 can be electronic or optical links and are suitable for providing a plurality of variable parameters among the components of system 10. Such links can facilitate parallel or serial communication but are, in any case, more versatile than past hard-wired communication links. Links 22, 28, 30 and 32 may be of the type suitable for supporting a system having distributed control.

The versatility of the electronic communications links is important for a number of reasons. First, system 10 is essentially entirely automated in that there is very little human intervention required once the operator has provided image setter 14 with the requisite parameters to set a desired image to the film. In addition, transportation of film through system 10 is accomplished using a stepper motor 7 in image setter 14, a plurality of stepper motors SM1-SM3 in transporter 16 and a stepper motor 74 in processor 18. Since essentially all of the components are in electronic communication with one another, very tight handling control is achieved. The speed at which the film moves through the entire system 10, as well as the positioning of the film, is very tightly and accurately controllable. This is important in eliminating artifacts and in providing high quality developed film.

FIG. 2A is a top view of conveyor 16. Conveyor 16 includes guide 36, a plurality of rollers 38, 40, 42 and 44, three stepper motors SMI, SM2, SM3, a trap door motor Ml, five optical detectors or sensors SI, S2, S3, S4 and S5, a trap door 46, and conveyor control circuit 48.

Guide 36 of conveyor 16 is placed adjacent, but slightly apart from, image setter 14. Guide 36 does not touch image setter 14. Thus, no vibration is transmitted from conveyor 16 to image setter 14. As image setter 14 sets the image to the sheet of film, the film is provided to guide 36 in the direction indicated by arrow 50. Stepper motors SM1-SM3, trap door motor Ml and optical sensors S1-S5 are all coupled to conveyor control circuit 48. Conveyor control circuit 48, in this embodiment, receives control parameters from optical sensors S1-S5, and controls stepper motors SM1- SM3 and trap door motor Ml to transport the film through conveyor 16, to processor 18, in response to the transport parameters. While conveyor control circuit 48 could receive such inputs via serial communication link 28 from image setter 14, the presently preferred embodiment is through the use of optical sensors S1-S5, as shown in FIG. 2A. As film moves from image setter 14 in the direction indicated by arrow 50, the top roller of roller pair 38 is lifted out of the film path. The film first encounters optical sensor SI. The time that it takes for the leading edge of the film to move from optical sensor SI to optical sensor S2 provides conveyor control circuit 48 with a parameter indicative of the. speed at which the film is travelling. Knowing that speed, conveyor control circuit 48 controls the conveyor 16 to accommodate film transport at the precise speed required by image setter 14. In most cases this will be the speed at which the film is being delivered by image setter 14. As the film moves across conveyor 16, it encounters optical sensor 53. At that point, conveyor control circuit 48 stops roller 40, thereby halting advancement of the leading edge of the film through conveyor 16. Conveyor control circuit 48 then waits until image setter 14 is through with the film. Once the image setter is through with the film, conveyor control circuit 48 determines whether processor 18 is ready to develop the film moving through conveyor 16. If so, conveyor control circuit 48 controls stepper motors SM1-SM3 to rotate rollers 38, 40 and 42 to move the film quickly through conveyor 16 to the interface between conveyor 16 and processor 18. At that point, conveyor control circuit 48 controls stepper motors SM1- SM3 to move the film into processor 18 at the precise speed at which processor 18 is required to transport the film through the chemicals in processor 18.

At the time the leading edge of the sheet of film encounters optical sensor S3 and roller 40 is stopped, if image setter 14 is not finished with the film, conveyor control circuit 48 controls trap door motor Ml to open trap door 46 in the surface of conveyor 16. Meanwhile, image setter 14 continues to provide the film to the conveyor 16. With trap door 46 open, a space is provided to allow the film to bow downward as it is gathered from image setter 14, until image setter 14 is finished with the film. At that point, conveyor control circuit 48 again determines whether processor 18 is ready for the film, and, if so, controls the stepper motors to move the film quickly to the interface between conveyor 16 and processor 18. Then the film transport speed is slowed to match the speed at which it is to be moved through processor 18. Optical sensors S4 and S5 provide conveyor control circuit 48 with sensor inputs indicating that trap door 46 is open or closed, respectively.

If image setter 14 is through with the film before it reaches sensor S3, conveyor control circuit 48 causes roller 38 to be lowered into contact with the film. Roller 38 then drives the film through roller 40 to sensor S3.

FIG. 2B is a side view of conveyor 16 shown in FIG. 2A, with a portion cut away. FIG. 2B more clearly illustrates the ccvrtrol of trap door 46. In FIG. 2B, trap door 46 is shown in its open position. A portion of a sheet of photographic film 52 is also shown.

In advancing from image setter 14, film 52 encounters optical sensor S3. At that time, image setter 14 is not through with the film 52. Therefore, conveyor control circuit 48 stops stepper motor SM2 and roller 40 thereby halting the advancement of the leading edge of film 52 through conveyor 16. However, conveyor control circuit 48 continues to control stepper motor SMI so that the upper roller in roller pair 38 is raised and the lower roller continues to receive the sheet of film 52 from image setter 14 at the speed required by image setter 14. Conveyor control circuit 48 then opens trap door 46. By opening trap door 46, film 52 is allowed to bow downward into the position shown in FIG. 2B. Film 52 continues to be gathered from image setter. 14 and held in the position shown in FIG. 2B until image setter 14 is finished and processor 18 is ready to process another sheet of film. At that time, conveyor control circuit 48 controls the stepper motors to advance film 52 quickly to the interface between conveyor 16 and processor 18. Once film 52 has been transported to clear sensor S3, conveyor control circuit 48 controls trap door motor Ml to close trap door 46. Operation of conveyor 16 is then resumed as normal.

FIG. 2C is a more detailed block diagram of conveyor control circuit 48. Conveyor control circuit 48 includes a microprocessor 54, motor control circuit 55, and motor drivers 56. Microprocessor 54 is suitable for providing and receiving information through an electronic communication link, such as links 28 and 32. Microprocessor 54 receives the optical sensor inputs from sensors S1-S5. Also, microprocessor 54 provides an output to motor control circuit 55. The output from microprocessor 54 is representative of the desired control of the various stepper motors SM1-SM3. Motor control circuit 55, in turn, provides an output to motor drivers 56. The outputs from motor control circuit 55 cause motor drivers 56 to control stepper motors SM1-SM3 accordingly. Microprocessor 54 also controls trap door motor Ml through relay 57. if electronic communication is not provided between conveyor control circuit 48 and image setter 14, microprocessor 54 is programmed with the control variables identifying any number of commercially available image setters. For example, a dip switch or jumper setting can be provided to microprocessor 54 indicating which type of image setter is coupled to. conveyor 16. Based on those inputs, microprocessor 54 configures itself to control motor control circuits 55, motor drivers 56, stepper motors SM1-SM3 and trap door motor Ml accordingly.

Microprocessor 54 can be any suitable commerciallyavailablemicroprocessorormicrocontroller circuit. In this preferred embodiment, microprocessor 54 is an Intel 8051 family microcontroller. Also, in this preferred embodiment, motor control circuit 55 is a PBM3960 controller chip manufactured by Ericsson Components, Inc. Motor drivers 56 can also be any suitable driver circuits such as the PBL3771 and PBL3774 driver circuits manufactured by Ericsson Components, Inc.

FIG. 3A shows a side view of processor 18 which is shown partially in schematic form. Processor 18 includes processing liquid tanks 58, 60 and 62 and a dryer 64. Processor 18 also includes motor and control circuit 66 as well as sensors 56 and 57. Photosensitive sheets are transported through processor 18 along path 68. During processing, the photosensitive sheets flow along path 68 between a plurality of roller pairs 70 located in roller racks in various processing stations such as processing liquid tanks 58, 60 and 62, as well as dryer 64. The various roller pairs 70 form a transport system for transporting the sheets of photosensitive material through processor 18, and the roller pairs define path 68 which extends through processor 18. In one typical type of photoprocessor, liquid tank 58 contains developer solution (a chemical solution for reducing exposed silver ions) , liquid tank 60 contains fix solution (a chemical solution for removing undeveloped silver ions) , and liquid tank 62 contains a wash solution. A photosensitive sheet (e.g. , the photographic film) is sequentially passed through developer, fix and wash solutions to chemically process and develop the photographic images latent in the film. The photosensitive sheet is then passed through a dryer portion 64 in processor 18 where, in this preferred embodiment, tempered air is directed at the sheet of film from both sides so that the sheet is dried for additional handling. Motor and control circuit 66 receives inputs from conveyor 16, and can also receive inputs from sensors S6 and S7 and the optional operator interface 20. Based on the inputs received, motor and control circuit 66 controls roller pairs 70 to transport the photographic film along path 68 through processor 18 at a desired speed.

Motor and control circuit 66 also provides conveyor 16 with a signal indicating whether processor 18 is ready to receive another sheet of photographic film for processing. In this preferred embodiment, processor 18 includes sensors S6 and S7 for sensing the leading and trailing edges of the photographic film sheets as they move along path 68. As soon as the photographic film sheets move to a certain point (i.e., when they are far enough along path 68), processor 18 provides conveyor 16 with a signal indicating that processor 18 is ready to receive another sheet. In another embodiment, motor and control circuit 66 receives input parameters through electronic communication links 22, 28, and 32 or through electronic communication link 30, which indicate the size of the sheet of photographic film being developed. Based on the speed at which motor and control circuit 66 moves the sheet of photographic film through processor 18, and based on the size of the film, motor and control circuit 66 determines when it is ready to receive another sheet of film. FIG. 3B shows a more detailed block diagram of motor and control circuit 66. Motor and control circuit 66 includes microprocessor 72, motor control circuit 73, motor driver 74, stepper motor 75, and drive transfer mechanism 76. Microprocessor 72 receives inputs from conveyor 16 or optional operator interface 20. Based on those inputs, microprocessor 72 provides an output representative of desired control of stepper motor 7 to motor control circuit 73. Based on the input from microprocessor 72, motor control circuit 73 provides an output to motor driver 74 for appropriate control of stepper motor 75. Stepper motor 75, in turn, applies a drive output to drive transfer mechanism 76. Drive transfer mechanism 76 transfers the output torque from stepper motor 75 to roller pairs 70 in processor 18. The input received by microprocessor 72 can be any number of process parameters required to control transport of film through processor 18 along path 68. Such parameters can include the speed at which the film is to be moved through tanks 58, 60 and 62, the length of time which the film must spend in each of the tanks, the size of the film, or any number of other desired process parameters. Microprocessor 72 either receives the process parameters from optional operator interface 20, or from any other of the elements in the handling system, such as electronic interface 12, image setter 14, or conveyor 16, along electronic communication links- 22, 28 and 32. Drive transfer mechanism 76 mechanically or electrically couples the drive output from stepper motor 75 to the roller pairs 70 in processor 18. In this preferred embodiment, drive transfer mechanism 76 is a system of drive chains or belts and gears, coupled between stepper motor 75, and the roller pairs 70 in processor 18, to transfer the torque from the output of stepper motor 75 to the roller pairs 70. Since stepper motor 75 is more accurate and, therefore, allows more exact control than previously used DC type motors, motor and control circuit 66 provides improved transport control of the film through processor 18 along path 68.

Several techniques can be used to control the stepper motors throughout the film handling system. For example, full step control can be provided in which full current is initially provided to the windings of the stepper motor. Then, the current is reversed in the windings, one at a time, to vary the speed and positioning of the motor. Also, half step control can be provided. Half step control is very similar to full step control except that there is a period between energization of both windings and reversing energization in one winding when there is no current flowing in one of the coils. In other words, only one of the two coils is energized. This provides control in steps which are half the size of those in full step control.

However, in the present embodiment, microstep control is used. In microstep control, the current through the windings is not simply turned on or off as it is in full step and half step control. Rather, the current through the windings is regulated in very small steps. This causes the film handling system to operate, much more quietly, and it also reduces vibration throughout the film handling system.

It should be noted that operator interface 20 can be one of a variety of operator interfaces, such as a microcomputer, a CRT, or a hand held control device for programming microprocessor 72. Also, image setter 14 can be any type of commercially available image setter, such as are available from Autologic, Inc. and Information International Inc.

Finally, a variety of commercially available stepper motors can be used in the present invention. For example, it is common to use a stepper motor which has 200 steps per revolution. However, with a simple software adjustment, a stepper motor with 400 steps per revolution, or essentially any other number of steps per revolution can be used. Factors which are typically considered in choosing a stepper motor for the present invention are the frame size of the motor, its speed (generally in steps per second) and the amount of torque delivery provided by the motor. Thus, the particular stepper motor chosen may vary with different applications. Stepper motors which have been found to work are those commercially available through Pacific Scientific, Inc. and Oriental Motors, Inc.

In sum, the present invention provides a photographic film processor, and an entire photographic film handling system with stepper motor control. The resultant system provides accurate and tight speed and positioning control of the film throughout the entire system from image setter 14 to processor 18. Thus, the entire system is capable of running at very exact speed., with the components of the system having closely matched speeds for efficient and high quality film processing. By placing stepper motors in the film handling system, not only is the accuracy of speed and position control greatly increased over DC type motors, but the stepper motors also provide lower maintenance since there are no brushes to wear in the motors. Further, the stepper motors are much less costly and much smaller yet have a wide range of speeds.

The present system also provides a communication link between all components in the film handling system. The communication link is suitable for transmitting a plurality of variable parameters. This gives the system more flexibility and interactive operation than was capable with previous systems having fixed, hard-wired communication links. Thus, process control parameters can be passed from one component in the film handling system to another to achieve accurate transport control of the film through the system.

Finally, the present invention provides means by which the conveyor can determine the speed of the film being provided by the image setter. This allows the conveyor to quickly adjust its reception speed to the speed required by the particular image setter.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A photosensitive material processor for developing photosensitive material, comprising: a first end having a photosensitive material inlet; a second end having a photosensitive material outlet; processing means, disposed generally between the first and second ends, for processing the photosensitive material; transport means for transporting the photosensitive material at least a portion of the way between the first and second ends; a stepper motor coupled to the transport means, the stepper motor driving the transport means to transport the photosensitive material; and a controller, coupled to the stepper motor, for controlling the stepper motor in driving the transport means based on processing parameters provided to the controller.

2. The developer of claim 1 wherein the processing means comprises: a plurality of processing stations.

3. The processor of claim 2 wherein the processing stations comprise: a plurality of processing tanks; and a dryer.

4. The processor of claim 2 wherein the transport means comprises: a plurality of rollers arranged so that rotation of the rollers transports the photosensitive material through at least a portion of the processing stations.

5. The processor of claim 4 wherein the stepper motor is coupled to the rollers to drive the rotation of the rollers.

6. The processor of claim 1 wherein the processing parameters are representative of photosensitive material size so the controller controls the stepper motor based on size of the photosensitive material being processed.

7. The processor of claim 1 wherein the processing parameters are representative of time required for processing the photosensitive material so the controller controls the stepper motor based on the time required to process the photosensitive material.

8. The processor of claim 1 wherein the processing parameters are representative of a desired photosensitive material transport speed.

9. A photosensitive material handling system in which an image setter sets an image on photosensitive material, the system comprising: processing means for processing the photosensitive material after an image is set oh the photosensitive material. the processing means including a controller for controlling the processing means; conveyor means, disposed generally adjacent the processing means, for transporting the photosensitive material from the image setter to the processing means, the conveyor means including a controller for controlling transportation of the photosensitive material in the conveyor means; and a communication link coupling the controller of the processing means with the controller of the conveyor means, the communication link providing communication of a plurality of variable parameters between the controller of the processing means and the controller of the conveyor means.

10. The photosensitive material handling system of claim 9 wherein the communication link is an electronic communication link.

11. The photosensitive material handling system of claim 9 wherein the communication link is an optical communication link.

12. The photosensitive material handling system of claim 9 wherein the communication link is a parallel data communication link between the controller of the processing means and the controller of the conveyor means.

13. Thephotosensitive material handling system of. claim 9 wherein the communication link is a serial communication link between the controller of the. processing means and the controller of the conveyor means.

14. Thephotosensitivematerialhandling system of claim 9 wherein the communication link comprises: a serial RS232 communication link between the controller of the processing means and the controller and the conveyor means.

15. Thephotosensitivematerial handling system of claim 9 wherein the processing means comprises: transport means for transporting the photosensitive material in the processing means; and a stepper motor coupled to the transport means to drive the transport means, the controller of the processing means being coupled to the stepper motor to control the stepper motor.

16. The photosensitive material handling system of claim 9 wherein the communication link is configured to support distributed control in the photosensitive material handling system.

17. A photosensitive material handling system in which an image setter sets an image on photosensitive material, the system comprising: processing means for processing the photosensitive material after an image is set on the photosensitive material,, the processing means including transport means for transporting the. photosensitive material in the processing means; conveyor means, disposed generally adjacent the processing means, for transporting the photosensitive material between the image setter and the processing means, the conveyor means including a motor for driving the conveyor means to accomplish transportation of the photosensitive material; speed detection means, coupled to the conveyor means, for detecting a speed at which the photosensitive material is provided to the conveyor means by the image setter; and control means, coupled to the conveyor means and the speed detection means, for controlling transportation of the photosensitive material as the photosensitive material moves through the conveyor means based on the speed detected by the detection means.

18. The system of claim 17 wherein the conveyor means has an inlet end for receiving the photosensitive material from the image setter and an outlet end for providing the photosensitive material to the processing means, and wherein the speed detection means is located proximate the inlet end of the conveyor means.

19. The system of claim 18 wherein the speed detection means comprises: a first sensing means for sensing the. presence of the photosensitive material and providing a signal indicative of the presence of the photosensitive material to the control means; and a second sensing means located more closely to the outlet end of the conveyor means than the first sensing means, the second sensing means sensing the presence of the photosensitive material and providing a signal indicative of the presence of the photosensitive material to the control means, wherein the control means determines the speed at which the photosensitive material is traveling based on a time differential between the signal received by the first sensing means and the signal received by the second sensing means.

20. The system of claim 19 wherein the first and second sensing means comprise: first and second optical sensors, respectively.

21. The system of claim 19 wherein the first and second sensing means comprise: first and second mechanical sensors, respectively.

22. The system of claim 17 wherein the control, means comprises: a first controller in the processing means; and a second controller in the conveyor means, the first and second controllers being coupled by an electronic communication link which provides communication of variable communication parameters.

23. The system of claim 22 wherein the electronic communication link is configured to support distributed control in the photosensitive material handling system.

24. The system of claim 17 wherein the transport means comprises: a stepper motor controlled by the control means; and a plurality of roller pairs coupled to the stepper motor, the roller pairs transporting the photosensitive material through the processing means.