Abstract:
A system for processing printing plates ( 100 ) includes plurality of printing plate processing stations ( 108, 116, 120, 124 ) arranged in a serial chain configuration. The first station in the chain configuration is adapted to receive printing plates ( 132 ), apply station specific treatment to the printing plates and convey ( 112 ) the printing plates after the specific treatment is performed to the next station in the chain configuration. A system controller ( 104 ) adapted to monitor and control each of the plate processing stations.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to monitoring and control of imaging of printing plates. 
       BACKGROUND OF THE INVENTION 
       [0002]    A prepress production system usually includes a series of units, wherein each unit serves a different function in the production line. A typical configuration will include an imaging device, which receives a blank plate, images it, and hands it over to the next unit. The following units may include a plate processor, oven post bake device, gumming device, a stacker, a bender, or other. The plate is transported either manually between the various units or automatically via a dedicated conveyor linking between two adjacent units.  FIG. 1  illustrates series of plate production units linked together, forming a pipelined configuration. 
         [0003]    A typical line will utilize several units having different functions. Those different apparatuses are usually manufactured by plurality of vendors, and seldom communicate with each other. On-line monitoring of the plate status in the prepress production line is a critical element in achieving sufficient production efficiency. The ability to monitor and report plate condition in each stage in the production line is necessary to save time and reduce consumables waste. 
         [0004]    Most of the units in the prepress production line lack, or possess limited, external interfaces. This fact makes the interface with such units, for example plate oven or plate processor very difficult. In order to introduce plate monitoring and control capabilities, it is essential to provide connectivity between the various prepress production line devices. The invention proposes methods and system to overcome the limitation discussed above. 
       SUMMARY OF THE INVENTION 
       [0005]    Briefly, according to one aspect of the present invention a system for processing printing plates includes a plurality of printing plate processing stations arranged in a serial chain configuration. The first station in the chain configuration is adapted to receive printing plates, apply station specific treatment to the printing plates, and convey the printing plates to the next station in the chain configuration. A system controller monitors and controls each of the plate processing stations. A plate inspecting device comprises an electronic communication element and at least one inspecting element attached to each of the stations. The plate inspecting device inspects and measures the printing plates and sends the measurement status data to the controller via the communication element. 
         [0006]    The controller is configured to receive the status data of the printing plate from each of the plate inspecting devices and to analyze the data by comparing it to anticipated status data. The controller monitors the system according to the comparison. 
         [0007]    These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic illustrating plate production system using various stations, such as imaging, developing and post production; 
           [0009]      FIG. 2  is a schematic illustrating plate inspecting device; and 
           [0010]      FIG. 3  is a schematic illustrating plate production system controlled by client-server configuration. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
         [0012]    Printing plates are imaged by using optho-mechanical plate imaging systems such as by the Magnus family of plate imaging device, made by Eastman Kodak Company. The imaged plate is further processed by post imaging devices such as plate developer (plate processor), plate oven treatment, or other relevant processes, which are essential to fix the plate for mounting on a printing press. For clarity purposes, the term plate preparation station (or station) is used in this document to describe the various steps for printing plate preparation, some of which are mentioned above. 
         [0013]    The linkage between the stations in the plate preparation sequence is done, either manually by moving the plate between stations or by utilizing automatic conveyors to move the plate from one station to the next one. For example, when a plate is imaged, it is taken off the imaging device and loaded into a plate developing station and so on, manually or via an in-line plate conveyor  112  as is depicted in  FIG. 1 . 
         [0014]    A plate preparation system  100  is shown in  FIG. 1 . The printing plate  132  is moved from one station to the next, by automatic plate conveyors  112 . The plate conveyors  112  are adapted to move the plate from one station and load the plate into the next station in the sequence for further processing. The stations used during plate preparation may have been manufactured by a variety of vendors, and often are of different technological generations. This makes automatic coordination between the stations cumbersome. The stations are often not equipped with external communication or command and control means, which makes the task of plate preparation status gathering difficult. 
         [0015]    The present invention describes methods and apparatus for providing efficient status and control means during plate preparation. Referring to  FIG. 1 , plate preparation system controller  104  gathers the status information pertaining to plate preparation process throughout the entire plate preparation workflow. 
         [0016]      FIG. 3  shows a plate preparation system  100  operated via a computer client application  304 , the client application can be executed on controller  104  or on a different computer that is configured to communicate with controller  104 . The client application  304  communicates with controller  104  through the network  320 . Controller  104  controls and monitors an imaging device  108  via control lines  136 . The configuration on client-server architecture enables controller  104  operator to monitor and control the plate preparation system  100  through client application  304  whether in proximity to controller  104 , or alternatively from a remote site, such as from home, over a digital network  320 . Controller  104  can monitor and control more than a single plate production system  100  in parallel. The various preparation systems  100  may reside in different geographical location. 
         [0017]    The imaging device  108  images printing plate  132 . At imaging completion, a printing plate  132  is ejected from imaging device  108  onto a plate conveyor  112 , and automatically loaded inline into the plate developer  116 . Plate inspecting device  128  inspects the movement of plate  132  into plate developer  116 . 
         [0018]      FIG. 2  depicts a more elaborate structure for plate inspecting device  128 . Plate inspecting device  128  may include at least one or more of the following inspecting elements  216  in addition to camera  204 : pH sensor, humidity sensor, temperature sensor, plate movement sensor, plate sensitivity detector. 
         [0019]    Camera  204 , or alternative detecting system, will inspect the movement of printing plate  132 , and reports the status of printing plate  132  to controller  104  via communication link  208 . The communication link  208  may be wireless communication. This process will be repeated between all other stations at which printing plate  132  should be treated during plate the plate production stage, such as plate movement between plate developer  116  via plate conveyor  112  into plate oven  120 , and between plate oven  120  into an additional plate production station  124  via plate conveyor  112 , or any other plate processing device configured in the plate processing workflow, such as gumming device, pre-bake or post-baked stacker  312  (shown in  FIG. 3 ). 
         [0020]    The status information pertaining to plate progress within the plate production system, or the plate condition will be sensed and reported back to controller  104  and the status will be displayed to the user. The monitoring of printing plate  132  is achieved by few different methods. The plate movement pace is measured and calibrated for each device in the plate preparation workflow, the calibration take into account the size of the plate to be treated. The above measurements are configured into controller  104 . The controller anticipates the processing time required to process printing plate  132  for each processing station according to the acquired measurements. The plate inspecting devices  128  will report the status of printing plate  132  to the controller  104 . In the cases where printing plate  132  was anticipated to complete processing in one of the stations, and plate inspecting device  128  was not able to locate the plate in the anticipated position, controller  104  will warn the user on an abnormal situation. 
         [0021]    In another embodiment each plate is equipped with a unique barcode or with an RFID unique identifier. Those embodiments requires equipping device  128  with barcode and/or RFID readers. 
         [0022]    Device  128  can be interfaced via inspecting device interface  212  to plate processing stations equipped with electronic interfaces. As discussed in the background section, many of the devices used during plate preparation such as plate developer  116 , plate oven  120 , or additional plate preparation lack, or possess limited external interfaces for digital status reporting purposes. The proposed invention suggests upgrading these legacy type of devices and equipping them with inspecting and status reporting means. 
         [0023]    The plate inspecting device  128  or alternative plate inspecting elements  216  can operate independently both in inspecting and collecting the status data of the equipment to which it is attached, as well as sending the collected information to the plate preparation system controller  104 . Identical inspecting devices can be used for all the machinery configured in the plate preparation system  100  chain. 
         [0024]    The data collection by controller  104  may help, for example, to decide on adjusting processor  116  roller speed to comply with the type and/or size of processed printing plate  132 . Similarly plate oven  120  can be adjusted for electricity usage optimization. Specific alerts can be prepared and sent by controller  104  by generating electronic mail messages  324 , or short message service (SMS) messages  328  into cellular phone  308 . 
         [0025]    Additional data may be collected such as plate and plate developing chemicals condition, by deploying measurement sensors such as PH level, humidity and temperature sensors, throughout plate preparation system  100  and stations. Controller  104  may change system parameters such as baking temperature or adjust replenishing plate developer  116  chemistry fluid to gain better fluid conductivity, thus improving plate development quality. 
         [0026]    In another embodiment, fresh chemicals in plate developer  116  will yield better quality plates, than plates developed without fresh chemicals. By reading density levels of a developed plate with a densitometer sensor and sending data to controller  104 , controller  104  can change the exposure parameters of the imaging device  108 , thus strengthening exposure laser to overcome “weakening” of developer development chemistry. 
         [0027]    An additional example relates to the pace of plate movement in system  100 . The plate movement motor speed is known, as well as plate length, and those parameters it can be estimated by controller  104  by the time it takes a plate to move between stations in plate preparation system  100 . 
         [0028]    Status reports  316  can be generated and printed by controller  104 . The reports can be for example:
       1. Media-Job report—a detailed expose job description that will include date/time/name/separation/plate/operator. The report will also include a summary of plate usage per plate type/plate number and plate area.   2. Processor report—a detailed report on specific plate developer working features. This report will include developer parameters such as developer temperature, conductivity, and speed.   3. Efficiency report—a detailed report on the behavior of the prepress device. This report may include device working statistics data such as working time versus idle time.   4. Plate consumption report—a report on the prepress plate consumption in the prepress device, depending on the plate type, size.   5. Estimated ink usage at the printing stage report—this report can is compiled by an analysis of the image data to be imaged on plate, conditioned on the plate type and plate developing chemistry.       
 
         [0034]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention. 
       PARTS LIST 
       [0000]    
       
           100  plate preparation system 
           104  plate preparation system controller 
           108  imaging device 
           112  plate conveyor 
           116  plate developer (plate processor) 
           120  plate oven 
           124  additional plate production station 
           128  plate inspecting device 
           132  printing plate 
           136  control lines 
           204  camera or alternative plate inspecting means 
           208  communication link 
           212  inspecting device interface 
           216  inspecting elements 
           304  client application 
           308  cellular phone 
           312  plate stacker 
           316  status report 
           320  network 
           324  email messages 
           328  SMS messages