Abstract:
In an image input scanner, as would be found in a digital copier, images are recorded from a first side of each of a plurality of sheets in a set by a first image scanning module (ISM-1) and from a second side of each of a plurality of sheets in a set by a second image scanning module (ISM-2) in standard operation. If it is determined that ISM-1 is not operating in a satisfactory manner, the user is advised through a user interface to record the second side images with ISM-2, and then place the set of sheets in a predetermined orientation in the scanner so that ISM-2 can record the first side images as well.

Description:
TECHNICAL FIELD  
       [0001]     The present disclosure relates to the scanning of original hard-copy images into electronic form, as would be found, for example, in a digital copier or other scanner.  
       BACKGROUND  
       [0002]     Digital copiers and scanners, in which original images on one or both sides of a series of sheets are scanned into digital data which is subsequently used for making copies or other purposes, are well known.  FIG. 1  is a simplified elevational view of a certain kind of digital scanner  10  (which can be a portion of a digital copier), in which there are provided two separate image scanning modules. Sheets bearing images to be recorded are initially stacked in an input tray  12 . In a standard or conventional scanning operation, individual sheets are successively drawn from the stack in tray  12 , by a mechanism such as including friction wheel  14 , as is generally familiar in the art. As shown in the illustrated embodiment, each drawn sheet is first exposed at an image scanning module, which includes a cover glass  16 , lamp  18 , and scanning bar  20 . This first image scanning module reads the downward-facing side of each sheet as the sheet passes over the cover glass  16 : the lamp  18  illuminates a small strip of the image, while scanning bar  20  records the image.  
         [0003]     Further, in a standard or conventional scanning operation, after exposure of an image on one side of the sheet, the sheet is effectively inverted by passage (such as with motorized rollers, as generally shown) through inversion path  22 , at the end of which is another image scanning module, including cover glass  24 , lamp  26 , and scanning bar  30 . As can be seen, each sheet passing through scanner  10  is exposed first on one side, by one image scanning module, and then on the other side, by the other image scanning module. In this way, each sheet is scanned (i.e., the image thereon is recorded) on both sides, in an essentially single motion, without having to be re-scanned or have its directional motion reversed, as is known in other, single-scanning-module arrangements. The scanned sheets are then re-accumulated in catch tray  32 .  
         [0004]     Each scanning bar  20 ,  30  is a photosensitive device, typically including one or more linear arrays of photosensors, which record light reflected from a series of small, pixel-size areas on the image-bearing sheet as the sheet is moved therepast. Each bar can be, for instance, a page-width array of photosensors, such as each including several abutted silicon chips, or can comprise a single device with associated optics.  
         [0005]     In  FIG. 1 , the second image scanning module (ISM) along the sheet path is generally referred to as ISM-1, because that is the ISM that typically scans the front-side images in standard simplex (one-sided) operation, when the sheets are placed face-up in tray  12 . The first image scanning module along the path is referred to as ISM-2, because that ISM typically records the “back” side images in normal operation. However, in different hardware embodiments, an image scanning module corresponding to ISM-2, which records images on the “back” sides of sheets in tray  12 , can be disposed downstream of ISM-1 along the path, or ISM-2 can be disposed substantially at the same location along the path as ISM-1, so that corresponding portions of two sides of a sheet are recorded substantially simultaneously. In such cases, ISM-1 would point downward whereas ISM-2 points upward to illuminate and record an image. Also, ISM-2 can be designed to travel under a stationary platen (not shown) for recording of images on stationary items, in a manner familiar in digital copiers.  
         [0006]     Typically associated with a scanner such as  10 , whether it is a stand-alone input scanner or an effective part of a larger apparatus such as a digital copier, is a central control system, here generally indicated as  40 , which includes software and hardware for operating the mechanical parts of scanner  10 , as well as controlling the flow of image data from each scanning bar  30  to form useable image data in a memory, such as for subsequent printing. The control system  40  further interacts with a user interface  50 , such as would appear on the control panel of a digital copier, to display messages to a human user standing near the scanner  10 .  
         [0007]     One practical challenge for a scanner such as shown in  FIG. 1  is using the apparatus when one of the two image scanning modules becomes inoperative or an unsatisfactory output, for instance when one of the scanning bar  20 ,  30  does not work properly, or if one of the lamps  18 ,  26  burns out. It may be useful to provide a system by which the remaining functional image scanning module can nonetheless be used to scan both sides of double-sided imaged sheets.  
       PRIOR ART  
       [0008]     U.S. Pat. No. 6,091,929 shows a system in which a user interface associated with a digital copier provides detailed instructions for a user of the scanner, with attention to obtaining correct staple position in the output document.  
       SUMMARY  
       [0009]     There is provided a method of operating an image input scanner, the image input scanner including a first image scanning module (ISM) for recording images from a first side of each of a plurality of sheets in standard operation, and a second image scanning module (ISM) for recording images from a second side of each of a plurality of sheets in standard operation, the first ISM and the second ISM being arranged along a path, a tray disposed at a beginning of the path for retaining a stack of sheets for scanning by the first ISM and the second ISM, and a user interface operative associated with the image input scanner. An output of the first ISM is determined to be unsatisfactory. An instruction is communicated through the user interface to arrange the plurality of sheets in the tray in a predetermined orientation. The first side of each of the plurality of sheets is recorded with the second ISM.  
         [0010]     There is provided a method of operating an image input scanner, the image input scanner including a first image scanning module (ISM) for recording images from a first side of each of a plurality of sheets in standard operation, and a second image scanning module (ISM) for recording images from a second side of each of a plurality of sheets in standard operation, the first ISM and the second ISM being arranged along a path, a tray disposed at a beginning of the path for retaining a stack of sheets for scanning by the first ISM and the second ISM, and a user interface operative associated with the image input scanner. When an output of the first ISM is determined to be unsatisfactory, it is communicated through the user interface that the first ISM is outputting degraded image data. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a simplified elevational view of a certain kind of digital scanner.  
         [0012]      FIGS. 2-8  represent portions of a flowchart reflecting the operation of a control system, interacting with a scanner and user interface as in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0013]     The overall function of the described embodiment is to facilitate a “limp-along” operation of a two-imaging-station scanner, such as shown in  FIG. 1  above, whereby two imaged sides of an original set of hard-copy sheets can be successfully scanned if one of the image scanning modules is inoperative. The method addresses situations in which either scanning station or ISM is operating in an unsatisfactory manner, e.g., is found to output degraded data (such as when the optical path associated therewith is dirty, or there is some other malfunction), or if the scanning station or ISM is not at all operational (such as when the associated lamp is burnt out). In brief, in “limp-along” mode, the one functioning scanning bar is used to scan first one side of each of a series of sheets, and then the other side of each of the series of sheets. Successful completion of the scanning requires coordination of instructions to the human user, as would be displayed to the user through a user interface  50  as shown in  FIG. 1 , with data flows from the functioning image scanning module, so that the final result of the scanning operation, a data set related to series of scanned page images, is identical to a data set that would have been obtained through conventional scanning with the scanner  10 .  
         [0014]      FIGS. 2-8  represent portions of a flowchart reflecting the operation of a control system  40 , interacting with both scanner  10  and user interface  50  as shown in  FIG. 1 . The overall function of the described operation is to determine the operating condition of each ISM-1 and ISM-2 and, in turn, instruct the user to operate the scanner for best results. The determination of whether one or the other ISM is operating in an unsatisfactory manner can be performed in various ways, depending on an particular embodiment. For instance, if the output of one ISM is consistent with mostly black pixels, this can be an indication of a major failure such as lamp burnout or loss of data connection; if the output data is consistent with streaking in the scanned image, as would occur for instance with dirt occluding a portion of the scanner bar, a downstream algorithm can detect such a condition and determine that the image quality is thus degraded. Various types of unsatisfactory image data and strategies for detecting them can be contemplated. Alternatively, if the human user happens to know, such as based on prior experience, that one ISM is operating in an unsatisfactory manner, the user can indicate the determination such as through user interface  50 .  
         [0015]     In  FIGS. 2 and 3 , which together form a single flowchart, a copy job (which can be more generally considered a scanning job) is initiated by a human user. At step  200 , the human user indicates, through the user interface  50  to control system  40 , whether a simplex (one side of each document sheet) or duplex (both sides of each document) scan is desired. If a simplex job is desired, all that matters is that the particular scanning station which is facing the imaged side of the sheets is operational. In this case, as shown at  202 , if what is here called image scanning module or ISM-1, the image scanning module including scanning bar  30  is working, the copies are run normally. If, however, ISM-1 is not operational or outputting image data of degraded quality (step  204 ), a user is displayed an option of re-scanning using the other image scanning module module, ISM-2. The selection by the user of the unconventional ISM for a particular purpose is called here a “productivity maintenance mode” or PMM, and various PMM&#39;s will be described below. If ISM-1 is not working but ISM-2 is desired for simplex scanning, the method initiates a PMM (step  210 ) which will be described in detail below. If ISM-2 is desired to be used for simplex scanning (step  206 ) but does not output image data satisfactorily (step  208 ), then the user is given the option of either accepting the degraded image data (step  302 ) or invoking a suitable PMM (step  304 ).  
         [0016]      FIGS. 4 and 5  together form a single flowchart, showing steps in response to the human user desiring a duplex scanning job (see step  400  in  FIGS. 3 and 4 ). If both ISM-1 and ISM-2 are working, as generally shown at  402 , the scanning job proceeds normally. If ISM-2 is not working, a duplex routine which will be described below is initiated (step  404 ). If ISM-1 is not working but ISM-2 is working (step  406 ), the user is given an option (step  502 ) of permitting the scanning with degraded quality (step  504 ), or entering a PMM for avoiding use of the defective scanner (steps  506  or  508 ). Similarly, with the steps initiated at step  410 , if ISM-2 is outputting data in a degraded manner or not at all, the user is presented with various options to do the scanning in degraded mode (step  510 ) or in a special PMM (step  512 ); or, if neither ISM-1 or ISM-2 are at all functional, the user is informed through the user interface (step  412 ). Continuing with  FIG. 4 , at the steps starting with step  414 , if ISM-2 is not operational but ISM-1 is degraded, the user can select a suitable PMM (step  416 ).  
         [0017]      FIG. 6  is a portion of a flowchart extending from step  404  in  FIG. 4 . In this series of steps, if ISM-1 is working but ISM-2 is not, a user can choose to accept degraded data from ISM-2 (step  602 ); or, if ISM-2 is not operational, enter a PMM (steps  604  or  606 ).  
         [0018]      FIG. 7  shows, in parallel, a series of “productivity maintenance modes” or PMM&#39;s, which are brought into operation by the specific conditions in the above flowcharts. Returning momentarily to  FIGS. 2 and 3 , if ISM-1 is not working but ISM-2 is desired for simplex scanning, the method initiates a PMM (step  210 ), the user is informed to place the original documents face-down in tray  12  (as shown in  FIG. 1 ) so that ISM-2 (with scanner bar  20  as shown in  FIG. 1 ) can scan the face-down images (step  702 ). If ISM-2 is desired to be used for simplex scanning, because ISM-1 is not operational (step  206 ) but ISM-2 does not output image data satisfactorily (step  208 ), then the user is given the option of another PMM (step  304 ), in which ISM-2 scans the face-down images (step  704 ) but the user is informed, such as through user interface  50 , that the resulting image quality will be degraded (step  706 ). In either case of steps  702  or  704 , when the images to be scanned are placed face-down in tray  12 , the order of page scanning is N-to-1, i.e., the last page of the set will be scanned first: in such a case, downstream image processing, such as associated with control system  40 , must take into account the page order of the incoming images, particularly in the context of digital copying, so that the copied set is printed out in a 1-to-N page order.  
         [0019]     Further shown in  FIG. 7  is the PMM invoked at step  416  above, when ISM-2 is not operational but ISM-1 is degraded, and duplex scanning is desired. In this PMM, ISM-1 is used to scan first the first side images (i.e., the odd-numbered page images in a duplex set) in one operation (step  710 ); and then the user is instructed (step  712 ) to place the same set, face down, in tray  12  for scanning of the second side images (the even-numbered page images in a duplex set) by ISM-1 (step  714 ). At roughly the same time, the user must be advised or warned that image quality may be degraded (step  716 ). As the odd page images are accumulated in memory as a set before any of the even page images are scanned, at the end of the scanning process the two sets of page images must be interleaved before the data is used for copying; for this reason the user is advised (such as through user interface  50 ) that printing of copies will begin only after all scanning is complete (step  718 ). Also, the scanning order of the first-side images is 1-to-N while the scanning order of the second side images in N-to-1, and this must be taken into account when the page image data is accumulated in memory.  
         [0020]      FIG. 8  shows further PMM&#39;s as invoked according to the conditions described above. The PMM at step  512  is invoked when ISM-1 is inoperative and ISM-2 is outputting data in a degraded manner: in such a case, after informing the user that printing/copying will begin when scanning is complete (step  802 ), and that image quality may be degraded (step  804 ), the second side of each sheet in the set is scanned 1-to-N by ISM-2 (step  806 ). Then, the user is instructed through user interface  50  to place the set in tray  12  face down, for N-to-1 scanning of the first side of each sheet in the set (step  810 ).  
         [0021]     The PMM invoked by steps  506  or  508  above is initiated when ISM-1 is not working but ISM-2 is working. In such a case, the second side of each sheet in the set is scanned 1-to-N by ISM-2 (step  812 ). Then, the user is instructed through user interface  50  to place the set in tray  12  face down (step  814 ), for N-to-1 scanning of the first side of each sheet in the set (step  816 ). The PMM invoked by steps  604  or  606  above is initiated in the case where ISM-1 is working but ISM-2 is not operational. In such a case, the second side of each sheet in the set is scanned 1-to-N by ISM-1 (step  818 ). Then, the user is instructed through user interface  50  to place the set in tray  12  face down (step  820 ), for N-to-1 scanning of the first side of each sheet in the set (step  822 ).  
         [0022]     In effect, the ability to use one ISM for recording images on both sides of a series of sheets when the other ISM is unsatisfactory enables a scanner or copier to retain a general usefulness for a period of time before the scanner or copier is repaired, thus maintaining productivity of the apparatus.  
         [0023]     The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.