Abstract:
In a digital printing apparatus, various modules each perform a specific function, such as paper feeding, marking sheets, interpreting image data from high-level formats, and performing finishing operations. One or more of these modules includes a board therein, which is able to communicate with another board within the apparatus by infrared or other wireless communication. Such wireless communication obviates the need for large and expensive wire harnesses. There may further be provided barrier structures within the apparatus to prevent crosstalk among various wireless-capable boards. The interaction of the modules facilitates a method of outputting prints.

Description:
FIELD OF THE INVENTION 
     The present invention relates to communication among control modules in a printing apparatus, such as a xerographic or ink-jet printer or copier. 
     BACKGROUND OF THE INVENTION 
     Digital printing apparatus, such as xerographic copiers or “laser printers,” or inkjet printers, are well known. Particularly in the high-speed range of the market, such printers are complicated electromechanical devices. Many such devices can be designed in modular fashion, with a customer buying or leasing only those portions of the apparatus that are desired. For example, a basic printer which simply outputs prints can be provided with a finisher module, which can staple sets of prints. The printer can be provided with a feeder module having extra paper trays for supplying paper of various sizes and types. The printer can further be associated with an input scanner, for obtaining digital data from hard copy originals, thus causing the printer to be able to operate as a copier. Even within the single “box” of a digital printer, there may be numerous hardware boards, each board having a distinct function within the printer, such as data management, image processing, and xerographic control. 
     In order to design a robust system of office equipment including printers and scanners, complicated connections must be made among the various boards within a printer, and also among the control systems of ancillary devices, such as finishers, paper supply feeders, and scanners, which may be associated with one or more printers. As is well known in the art, typical means of communication of complicated signal sets includes wire harnesses or flexible connectors. In the basic assembly of office equipment, design and management of these harnesses or connectors is a labor intensive process, and the presence of large harnesses may present reliability problems over the life of the equipment. When printers are combined with ancillary equipment to form larger systems, establishment of communication among the various modules similarly becomes a labor-intensive, reliability-sensitive process. 
     The present invention is directed to the novel use of wireless connections among individual boards and other modules in office equipment. 
     DESCRIPTION OF THE PRIOR ART 
     In the prior art, it is known to use infrared signals, using well known protocols, to convey image data from a general purpose computer to a printer. Examples of this principle are shown in U.S. Pat. Nos. 5,543,897; 5,510,876; 5,774,759; and 6,026,258. In each of these cases, however, the original image data which originates in a particular computer in is ultimately in a page description language (PDL) format, meaning that the image data is in the same format used for any standard communication between a computer and printer. The present invention, in contrast, relates to transfer of image and control data among individual modules, which together operate as a single digital printing apparatus. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, there is provided a printing apparatus for outputting prints based on digital image data, comprising a main control board and an image processing board, for processing digital image data from an image data source, and outputting processed digital image data which is substantially directly operative of printing hardware. A print engine includes printing hardware for placing marks on a print sheet based on the processed digital image data, and a print engine board for accepting digital image data and operating the hardware. Means are provided for facilitating wireless data transfer between at least two of the main control board, image processing board, and print engine board. 
     According to another aspect of the present invention, there is provided a printing apparatus for placing images on sheets, comprising a main portion, including a first board, and an ancillary module including an ancillary board. The ancillary module is at least one of a paper supply module including a supply control board and a finisher module including a finisher supply board. Means are provided for wireless data transfer between the first board and the ancillary board to facilitate placing an image on a sheet. 
     According to another aspect of the present invention, there is provided an ancillary module for use with a printing apparatus, the ancillary module being at least one of a paper supply module including a supply control board and a finisher module including a finisher supply board, comprising means for accepting wireless data transfer from a first board associated with a printing apparatus. 
     According to another aspect of the present invention, there is provided a method of outputting prints based on digital image data, comprising the step of transferring, in a wireless manner, processed digital image data which is substantially directly operative of printing hardware from a first board to a print engine control board. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a simplified elevational view showing the essential elements of a digital printing apparatus, in this case a digital copier and printer, incorporating the present invention. 
     FIG. 2 is a simplified elevational view showing the essential elements of various modules within a digital copier and printer, incorporating the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is an elevational view of a digital printing apparatus, specifically a digital copier and printer, incorporating the present invention. In general, the present invention is directed toward operation with office equipment which, at one stage or another, places marks in response to digital data originating from a computer or other image data source, such as an input scanner. The present invention is particularly useful for realization of large, modular based, copying and printing systems, where there may exist, in addition to the essential printing hardware, any number of selectable paper supply modules, finishers, etc. 
     In the following description and claims, certain terms will be defined as follows. A module is an entity which performs some physical function, such as putting marks on a sheet, feeding a sheet, scanning a sheet, or stapling a sheet. A board is set of hardware and software which controls a module. Typically, a board is simply a circuit board, such as including a microprocessor or other chips, along with software which operates on the board; however, according to the present definition, a board may physically include multiple boards, or be formed in only a portion of a larger circuit board. As used herein, the word data shall generally apply to any type of data, particularly control data and image data. Control data is data which is either directly operative of hardware, or which results from an event experienced by hardware; for example, a pulse which causes a motor to draw a sheet from a stack is control data, as well as a signal which results when and a sensor detects a paper jam. In contrast, image data is data at which is symbolic of an image which is either recorded or which can be printed. As used herein, processed image data shall be defined as image data in a form which is substantially directly operative of a marking device, such as an ink jet printhead or a laser used in an electrophotographic apparatus. This processed image data is ultimately in a binary form which controls, for instance, whether a laser or a particular ink-jet ejector is actuated at a particular time; however, such processed image data can, according to the definition herein, be in a compressed form, such as by run-length encoding. In contrast, image data which is not processed as that term is here defined is in the form of a page description language (PCL, Adobe PostScript® ASCII etc.) or other highly structured format such as TIFF or a facsimile format. 
     Turning to FIG. 1, a digital printing apparatus having a main body generally indicated as  10  may further have associated therewith various substitutable ancillary modules, such as a separate paper supply module  12  or a finisher module  14 , as well as a separable input scanner  16 . In a typical arrangement of office equipment, the main body  10  includes the print engine, which is the set of software and hardware which places marks on sheets to result in prints. 
     Exercising general control over an entire system is preferably a main control board  20 . Foremost among auxiliary modules controlled by main control board  20  is the print engine  22 , which may be of any basic type known in the art, such as a xerographic “laser printer” apparatus, an ink jet device, or some equivalent. The important attribute of print engine  22  is that it places marks on sheets passing therethrough in accordance with processed digital image data, as defined above. Print engine  22  may further have associated therewith specialized paper feeding apparatus (not shown), such as a duplexing device, paper jam detectors, as well as provision for accepting paper feed signals, etc. Print engine  22  includes therein a print engine control board which converts control data and image data to operate the hardware therein (the print engine control board is not discretely shown in the Figure, as it is typical that such a board is integral to any design of a print engine that accepts digital data). Print engine  22  may also have associated therewith a removable marking material supply, such as shown as  24 , which may be in the form of a supply of toner or liquid ink of various colors. The print engine control board may have means for determining, either by direct measurement or inferred by a cumulative use, the amount of marking material associated with supply  24  at any given time. Indeed, the marking material supply  24  may itself have associated therewith a board which can interacte with other boards within the apparatus. 
     One source of image data to be supplied to print engine  22  under the control of main control board  20  is what is here called an image processing board  26 . Specifically, image processing board  26  may include one or more decomposers, or interpreters, meaning software which converts image data it receives into a form immediately usable by print engine  22 ; that is, the image processing board  26  receives digital image data and outputs processed digital image data. Typical examples of digital image data to be received by image processing board  26  include data in known page description languages, as well as other highly structured formats such as TIFF or facsimile formats. Depending on the particular design of the equipment, processed image data output from image processing board  26  may be transferred directly to the board within print engine  22 , or be routed through main control board  20 . 
     Another possible source of image data for outputting by print engine  22  is original hard copy images. Such hard copy images can be fed through a scanner  16 , of a general design which is known in the art. For purposes of describing the present invention, the scanner  16  may include a scanner control board indicated as  28 . Depending on the specific design of the apparatus, scanner control board  28  may include provisions for controlling the various motors for feeding the original sheets in series, and/or processing original data recorded by a photosensor such as indicated as  30 . Original image data collected by input scanner control board  28  is eventually directed to main control board  20  for placing in a form which is acceptable to print engine  22 , such as to create digital copies of the original images from scanner  16 . 
     Blank sheets on which images are to be printed by the print engine  22  can be stacked in one or more paper supply modules such as  12 , which will feed individual sheets to the print engine  22  when instructed to do so by main control board  20 . In a highly modular design of office equipment, a paper supply module  12  may include therein a supply module board  32 , which is designed to be a operated by the main control board  20  when a particular module  12  is installed relative to the main portion: indeed, in a high-speed system, it is typical to have numerous supply modules  12  be selectably available as different types of input sheets, of different sizes, weights, or colors. Alternately, such control data for drawing and feeding sheets may come from the print engine control board within print engine  22 . 
     After sheets are printed with images by print engine  22 , the print sheets are then directed to one or more finisher modules such as  14 . Each finisher module  14  may have included therein a finisher control board such as  34 , which in turn directly controls finisher hardware for performing finisher operations on sheets received in the module  14 . Typical among these types of finisher hardware are a stapler  36  or a folding device  38 . Another popular option for advanced finishing equipment is to provide multiple output trays or mailboxes (not shown), to which different sets of sheets are directed depending on the identity of the person ordering the print job. Signals to cause various parts of a finisher module  14  to perform various functions may originate within main control board  20  or from the print engine control board within print engine  22 , and are sent to finsher control board  34 . 
     With specific reference to the present invention, the various boards associated with the apparatus is shown in the Figure can variously be caused to interact with other boards by wireless data transfer, specifically by infrared communication. Various protocols for transferring data of any kind through infrared means are well known. The novelty of the present invention is that such infrared or other wireless communication takes place not merely from a host computer transferring image data in a highly structured format to a printing apparatus in general, but among the various specific modules within a digital printing apparatus. In the specific illustrated embodiment, the various possible paths of wireless data transfer are shown by heavy arrows among the illustrated modules; although certain key paths are illustrated, the present invention need not be limited to those shown in the Figure. 
     The most important areas of data transfer, particularly for non-processed and processed digital image data transfer, exist between main control board  20  and print engine  22 , as well as between main control board  20  and image processing board  26 . In either case, the data which is transferred between various pairs of modules may comprise either or both control data, such as relating to paper feeding and paper jams, and image data, particularly processed image data which can be directed to the control board within print engine  22 . 
     Further according to possible embodiments of the present invention, there may further be wireless data transfer between the main control board  20  or other boards within the apparatus and control boards associated with the supply module  12  or the finisher module  14 , that is the supply control board  32  or finisher control module  34 , or multiple instances of either such boards. Operation of, for example, the control board  32  associated with one supply module  12  may be as follows. When, in the course of operating the printing apparatus to output prints, it is necessary for a blank sheet to be drawn from a feeder module  12  through print engine  22 , a signal is sent by wireless means from either main control board  20  or print engine  22  itself to the feeder control board  32 . If there exist multiple supply modules  12  each with its own control board  32 , the signal can be directed, through means associated with the standard protocols, to be responded to only by the board  32  associated with the stack of input sheets desired to be drawn from. Similarly, with finisher module  34 , at a particular time following the printing of a sheet by print engine  22 , or more specifically, a particular sheet in a set, the main control board  20  can send a signal by wireless means to control board  34  in finisher module  14 , for example, to command the stapler  36  to staple a set of accumulated sheets. In the claims herein, a supply module such as  12  and a finisher module such as  14  (or any other kind of module) are referred to generically as an ancillary module, having an ancillary board. 
     A particular advantage of using wireless communication among modules associated with paper supply and finishing is that advanced systems with numerous selectable supply and finisher modules can be readily assembled simply by placing the desired modules along the paper path of the apparatus as a whole; because of the wireless communication between main control board  20  and the boards such as  32  and  34  in the supply and finisher modules, no complicated hardware connection must be made by a casual user setting up the printing apparatus. In the case of the wireless connection between the print engine control board and a board such as main control board  20  or image processing board  26 , even though the Figure shows these two boards inside the same main body  10 , it is conceivable that the print engine board could be disposed in a module separate from modules containing boards sending processed image data thereto: for instance, a module containing a print engine with associated control board could be simply placed in a room with one or more modules which, at various times, send processed image data thereto. 
     If it is desired to use a digital printing apparatus as a digital copier, such as for copying original hard copy images, a scanner  16  can be placed in the vicinity of the main body  10  of the digital printing apparatus, having main control board  20  therein. In such a case, the wireless data transfer from scanner control board  28  to main control board  20  may include both image data and control data. Depending on a particular design of a system, the image data may directed from scanner control board  28  to main control board  20  or perhaps directly to the print engine control board in print engine  22 . 
     According to a preferred embodiment of the present invention, all the various boards which emit and/or receive infrared signals in the course of interacting with other boards share a single power supply  40 . It may be desirable to extend the power supply lines (not shown) from the power supply  40  within main body  10  to the various ancillary modules such as  12  and  14 ; i.e., have a wire-based connection of the power supply even if the data connection among the main portion and ancillary modules is wireless. 
     In a practical embodiment of the present invention, it may be desirable to configure the various wireless-capable modules in such a way that there is a relatively clear path between and a board acting as an emitter of infrared signals and a board intended to receive infrared signals. Many commercial types of infrared emitters are reasonably directional, and therefore the infrared transmitter can be aimed toward an area where a receiver module is likely to be disposed. Alternately, or to improve performance, barriers, such as shown for example as  42  or  44  in the Figure, which are largely infrared impermeable, may be set up in various configurations within the equipment. These barriers may be made of any infrared impermeable material, such as heavy plastic. These barriers will reduce crosstalk among different modules in the apparatus, and can be designed (in terms of material and/or configuration) to restrict travel of the type of energy used for any kind of wireless data transfer, such as microwave or ultrasound. 
     Although the preferred embodiment of the present invention involves use of known infrared communication hardware and protocols, other types of wireless communication among the various boards may be contemplated. Microwave or ultrasound communication may be practical in certain circumstances. For ancillary modules such as  12  or  14  which must be directly abutted to main portion  10 , a simple optical coupling between modules may be practical. 
     FIG. 2 is a simplified elevational view showing the modules  20 ,  22 ,  26  and  28 , such as described above in the context of a printing or copying apparatus. As can be seen in FIG. 2, each module includes an “emitter” portion  50  and a “receiver” portion  52 . The emitter portion functions to transmit data, in a wireless form, to other modules as per the basic functions of a particular module. In turn, the receiver portion  52  of each module includes hardware to receive such wireless data for the purpose of the module. In possible embodiments of the invention, the emitter  50  can transmit data in the form of infrared radiation, RF, microwave, ultrasound, or any other form which does not require a solid medium through which to convey signals.