Patent Abstract:
Document feeder and image capturing device preventing empty stamping associated with improper positioning of printing unit. Document feeder A, conveying document originals from a document placement location, along a predetermined conveyance path ( 12 ), and to a document information-capturing location ( 5, 6 ), is furnished with: a printing unit ( 8 ), which is shiftable along the document widthwise direction approximately orthogonal to the document conveyance direction, and is for carrying out predetermined printing onto conveyed documents; and a detection unit (S 4 ), provided in the conveyance path further upstream in the conveyance direction than the printer unit ( 8 ), that detects whether a conveyed document will pass inside the limits of the range in which the printer unit ( 8 ) prints.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to document feeders for conveying document originals from a document placement location, along a predetermined conveyance path, and to a document information-capturing location, and also relates to image-capturing devices—such as facsimile machines, scanners, and photocopiers—furnished with such document feeders. 
     2. Description of the Related Art 
     Automatic document feeders (ADFs) that send out one-by-one and convey to a document information-capturing location document originals stacked on a document tray are long since well-known. In this class of document feeders, machines furnished with printing means that print text or other markings, such as “SCANNED” or “FAXED,” in an inconspicuous place on a document from which image information has been captured are also known. 
     One example of a document-information capturing device furnished with a document feeder having a printing means of this kind is disclosed in, for instance, Japanese Unexamined Pat. App. Pub. No. H09-18631. This document-information capturing device is equipped with, as a printing means, a stamper that stamps post-image-capturing documents with a mark. The stamper is supported on a guide rail stretching along the widthwise direction of the document (direction orthogonal to the document conveyance direction). Accordingly, a user can manually shift the stamper to any desired location in the document widthwise direction. 
     With the configuration disclosed in Pat. App. Pub. No. H09-18631, however, if the stamper is not set into an appropriate location, specifically, if a user makes an error as to the size of a document original—for example, if he or she mistakes the conveyed document to be in A4 landscape, even though it is in A4 portrait, orientation—and ends up situating the stamper in a position where the edge of a landscape-oriented A4 document would pass, because the document does not actually traverse the position where the stamper has been situated, a site where there is no document gets stamped in vain (gets empty-stamped) by the stamper, whereby the conveyance path is left gummed with ink, which leads to incidents of subsequent documents becoming splotched with the ink. Moreover, this problem is linked to ink wastage. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention, brought about focusing attention on the circumstances just described, is to make available a document feeder and image capturing device whereby empty stamping associated with improper positioning of the printing means is prevented. 
     In order to resolve the aforementioned issues, the present invention affords a document feeder that is for conveying document originals from a document placement location, along a predetermined conveyance path, and to a document information-capturing location, and that is furnished with: printing means, shiftable along the document widthwise direction being approximately orthogonal to the document conveyance direction, for carrying out predetermined printing onto conveyed documents; and detection means, provided in the conveyance path further upstream in the document-conveyance direction than the printing means, for detecting whether a conveyed document will pass inside the limits of the range in which the printing means prints. 
     Furthermore, the present invention also affords an image capturing device equipped with a document feeder of the above-described configuration, and an image capturing means for capturing image information from a conveyed document, in the document information-capturing location. 
     According to the present invention, within the conveyance path further upstream in the document-conveyance direction than the printing means, a detection means is provided to detect whether a conveyed document will traverse the printing range delimited by the printing means, thanks to which empty stamping associated with improper positioning of the printing means can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a sectional view illustrating an image capturing device furnished with a document feeder involving one embodiment of the of the present invention; 
         FIG. 2  is an oblique view illustrating the configuration of a printer unit and its environs; 
         FIG. 3  is an oblique view illustrating the configuration of a printer sensor and its environs, in a state in which a metal frame and plastic head-guide member fixed to the frame have been removed; 
         FIG. 4  is a block diagram representing the gross configuration of a CPU; and 
         FIG. 5  is a flowchart of operations in the image capturing device involving one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the present invention will now be explained based on the drawings provided. 
       FIG. 1  is a sectional view of an image capturing device  100  equipped with a document feeder of the present invention. The image capturing device  100 , which adopts the present invention, will now be explained with reference to  FIG. 1 . The image capturing device  100  can be used as a stand-alone scanner connected to a PC or network, or as part of an MFP (multi-function peripheral) connected to an image-forming apparatus such as a printer or the like. Reference mark A labels a document feeder installed on the image capturing device  100 . The document feeder A conveys a document original (simply “original” hereinafter) along a predetermined conveyance path to pass the original over a first contact glass  1  surface of the image capturing unit H used as the image capturing means. Note that the image capturing device  100  has a CPU 150  used as the control means that controls operations of the document feeder A and the image capturing unit H. 
     The image capturing unit H is equipped with a first reading unit  3  that reads images on an original by irradiating light from a light source such as a lamp or the like onto an original conveyed via the first contact glass  1 ; reflecting the reflected light by a plurality of mirrors via a lens and then photoelectrically converting that by photoelectric conversion means such as CCD or the like. Note that the top surface of the first contact glass  1  composes the first reading position  5  (a document information-capturing location of the document feeder A) of the image capturing unit H. 
     Also, the image capturing unit H is equipped with a second contact glass  2  where an original can be set. A thick original, such as a book or the like, can be placed on the second contact glass  2  by opening the document feeder A, and then moving a first reading unit  3  in a sub-scanning direction to read images on that original on the second contact glass  2 . 
     The document feeder A is equipped with a feeder tray T that stacks a plurality of originals using a center alignment; and a discharge tray  11  disposed under the feeder tray T to store read originals. Two guide members  901  are mounted on the feeder tray T to enable their movement in a width direction (a direction substantially perpendicular to the direction of original conveyance) of the feeder tray T based on substantially the center thereof. The originals in the feeder tray T are set aligned to the center of the feeder tray T by these two guide members  901  touching both sides of the originals stacked in the feeder tray T. Therefore, originals are aligned to the center while being conveyed through the entire conveyance from the feeder tray T to the discharge tray  11 . Specifically, the guide member  901  is composed of center-referent delivery means that feeds an original P so that a centerline L 2  of the original P width direction X is aligned substantially to a centerline L 1  of the conveyance path (see  FIG. 2 ) for both rollers  21  and  22  described below. Furthermore, a pressing cover  13  composed of a porous member such as sponge or the like and a film member such as white Mylar that presses against the second contact glass  2 , and a U-shaped conveyance path  12  that conveys an original from the feeder tray T to the discharge tray  11  are provided. 
     A second reading unit  4  (at a document information-capturing location of the document feeder A) for reading an original is provided at the bend of a U-shaped conveyance path  12 . The second reading unit  4  is composed to read original images by irradiating light from a light source such as a lamp or the like on an original conveyed via a third contact glass  7  that forms part of the conveyance path  12  as a second reading position  6 , then to photoelectrically convert that light, reflected by a plurality of mirrors into a lens, using photoelectric conversion means such as a CCD or the like. Specifically, to greatly shorten the image reading process times of both sides of an original, this apparatus is configured to read one side of an original that passes over the second reading position  6  of the conveyance path  12  using the second reading unit  4  described above, and to read the other side of the original at the first reading position  5  using the first reading unit  3 . 
     The U-shaped conveyance path  12  is equipped with kick roller  21  that kicks out an original from the feeder tray T; separating means composed of a feed roller  22  and separating pad  23  that separate originals conveyed from the kick roller  21  into single sheets to be fed; a pair of registration rollers  24  that remove any skewing in the original by aligning the leading edge of the original when it is fed from the feed roller  22  and the leading edge of the original engages the pair of registration rollers  24  and then drive to convey the original to a downstream side; a pair of feed rollers  25  that feed the original from the registration rollers  24  toward the second reading position  6  and the first reading position  5 ; a pair of first reading rollers  26  that convey the original from the pair of feed rollers  25  to the second reading position  6 ; a pair of second reading rollers  27  that convey the original one side thereof read at the second reading position  6  to the first reading position  5 ; a pair of third reading rollers  28  that convey out from the first reading position  5  the original the other side thereof read at the first reading position  5 ; a pair of first discharge rollers (conveyance rollers)  29  that receives the original both sides thereof read from the pair of third reading rollers  28  and conveys the original toward the discharge tray  11 ; and a pair of second discharge rollers (conveyance rollers)  30  that discharge the original into the discharge tray  11 . The pair of first discharge rollers  29  and the pair of second discharge rollers  30  are positioned at an upstream side and a downstream side of conveyance direction of the printer unit  8  to grip both sides of the original traversing the printer unit  8  for conveyance. 
     The following will now explain original conveyance operations using the document feeder A configured as described above. First, originals are detected to be stacked on the feeder tray T by an empty sensor S 1 . If a paper feed instruction is received from the image capturing unit H, the kick roller  21  and feed roller  22  are driven. This kicks out originals which are separated to feed a single sheet by the separating means. Also, when a registration sensor S 2  detects a leading edge of the fed original, the original is fed a predetermined amount from the point that the original was detected to engage the leading edge of the original at a nipping point of the pair of registration rollers  24 . This aligns the leading edge of the original to remove any skew of the original. Then, the pair of registration rollers  24 , the pair of feed rollers  25  and the pairs of reading rollers  26 ,  27 , and  28  are driven. This conveys the original along the U-shaped conveyance path  12  to feed it to a downstream discharge tray, turning the original over from front to back in the process. In the U-shaped conveyance path, the original passes by the second reading position  6  and the first reading position  5  in that order. In the process to pass through the second reading position  6  and the first reading position  5 , one surface of the original is read at the second reading position  6 , and the other side of the original is read at the first reading position  5 . 
     The leading edge of the original is detected by a discharge sensor unit S 3 , and the pair of the first discharge rollers  29  and the pair of the second discharge rollers  30  drive up to the point where the leading edge of the original reaches the pair of the first discharge rollers  29 . This operation reads both sides of the original at the second reading position  6  and the first reading position  5 , then the pair of first discharge rollers  29  and the second discharge rollers  30  discharge the original to the discharge tray  11 . Note that the discharge sensor unit S 3  is disposed near the center of the conveyance path to detect any size of originals. This sensor unit is composed of a lever  9  that is rotated by the leading edge of the original coming into contact therewith, and a sensor  10  that detects the leading edge of the original by detecting a member mounted to the shaft of the lever  9 . Specifically, the discharge sensor unit S 3  functions as an original passing detection means that detects the passing of a conveyed original. Then, after a predetermined amount of time after the trailing edge of the original is detected by the discharge sensor unit S 3 , the drives of the first discharge rollers  29  and the second discharge rollers  30  are stopped and the reading operation is ended. Note that the discharge sensor unit S 3  is used as a sensor that detects the leading edge of the original to measure the timing to drive the printer head  800 , as described in detail below. 
     Note that a shingle-feed detection sensor (shingle-feed detection means) GS that detects a “shingle-feeding” of a plurality of overlapped originals is provided in the conveyance path  12  between the registration rollers  24  and the feed roller  25 , in the document feeder A according to this embodiment of the present invention. This shingle-feed detection sensor GS is configured to detect a shingle-feed of originals by a received vibration level of ultrasonic waves. The sensor GS disposes an emitter that emits ultrasonic waves, and a receiver that receives the ultrasonic waves opposite to each other to sandwich the path. The printer unit  8  is disposed in the conveyance path  12  between the first discharge rollers  29  and the second discharge rollers  30  (in other words further downstream than the document information-capturing location  5 ) as the printing means. The printer unit  8  prints a maximum of 40 characters on the original surface of the original conveyed by the first discharge rollers  29  and second discharge rollers  30 , and prints characters to notify the user whether shingle-feeding of originals has occurred when shingle-feeding of originals has been detected. A printer sensor S 4  (detection means) is provided at an upstream side of the printer unit  8  and the first discharge rollers  29 , to detect whether an original is at the print head printing position, or more specifically whether the conveyed original has passed inside a range of a printing region (inside are range for printer head movement) for printing by the printer head (printer unit  8 ). The printer sensor S 4  is composed of a reflective type sensor, and is installed to move along with the movement of the printer unit  8  in the original width direction. 
     The printer unit  8  will now be explained in detail with reference to  FIG. 2 . 
     As shown in the drawing, the printer unit  8  has an ink-jet type printer head  800 , and a head support portion  801  that detachably mounts and supports the printer head  800 . A cable  812  is connected to the printer head  800  to receive a print start command or character data and to supply power. 
     The head support portion  801  is supported by a resin head guide member  802  fastened to a metal frame  803  and moves in a width direction (shown as the arrows X in the drawing) of the original over a conveyance guide  805  that forms an original conveyance path. The head guide member  802  has a substantially rectangular opening  804  formed along the Xdirection of the width of the original from substantially the center to one side (the front side in the drawing) of the apparatus. Two screw holes are formed in the head support portion  801 . By inserting and tightening screws  811  into the screw holes in the head support portion  801  from above the opening  804 , the head support portion  801  can be movably supported by the head guide member  802 . Note that the opening  804  is formed to be only half of the original conveyance path so the range of movement it is only approximately half of the original conveyance path. A projection  810  is formed on the head support portion  801  so the user can grip that projection  810  and move the head support portion  801 . Note that the opening  813  that guides the printer sensor S 4  when the printer sensor S 4  is moved in the width direction of the original, described in further detail below, is formed in the frame  803 . In the same way as the opening  804  is formed to guide the printer head  800 , the opening  813  is approximately half the size of the original conveyance path along the original width in the Xdirection. 
     A plurality of printing openings  806  formed to match printing positions of each size of the originals is formed in the conveyance guide  805 . There is a rib  807  formed along the original width in the Xdirection downstream of the printer head  800 . A plurality of grooves  808  is formed in the rib  807  to correspond to each original size. A groove engaging portion  809  that engages the grooves  808  is formed on the head support portion  801 . The printer head  800  is fastened to predetermined printing positions that correspond to the original sizes by the engagement of the grooves  808  and groove engaging portion  809 . (Specifically, the grooves  808  and groove engaging portion  809  compose positioning means  814  that selectively positions (to fasten the printer head  800  at predetermined printing positions that correspond to the original sizes) the printer head  800  (printing means) at a plurality of positions along the original width direction.) Also, characters and the like are printed on the original via the printing opening  806  at each printing position. Note that by setting the original size (for example A4 or A3) that the grooves  808  corresponded to, near the grooves  808 , it is convenient for the user because it is possible to know where the printer head  800  should be fastened. 
     The printer sensor S 4  will now be explained in detail with reference to  FIG. 3 . 
     A sensor support portion  815 , made of a synthetic resin (plastic), that supports the printer sensor S 4  is fastened to the upstream side (in the direction of conveyance) of the head support portion  801 . (The printer sensor S 4  and the printer unit  8  are integrated.) A reflective type sensor is mounted to the sensor support portion  815 , and the printer head  800  and printer sensor S 4  shift unitarily. The printer sensor S 4  detects the passing of the conveyed original via the opening  816  formed in the conveyance guide  805 , but the detection position of the original in the width direction of the printer sensor S 4  is set to be several millimeters to the outside of the conveyance width direction than the printing position of the printer head  800 . For that reason, a determination of whether the original is at the printing position of the printer head  800  is securely performed. (This is to determine whether an original has been conveyed to the printing position of the printer head  800 ; specifically whether the conveyed original is within the print region of the printer head  800 .) Also, screw holes are formed in the sensor support portion  815  for the insertion of screws  14 . By tightening screws  14  from above the opening  813  shown in  FIG. 2 , that is guided in the opening  813  and movement is more stable. Note that the distance between the printer sensor S 4  and printer head  800  should be as short as is possible to reduce the affects of original skewing and to increase the detection accuracy. Also, the first discharge rollers  29  are disposed near an upstream side of the printer head  8 ; the second discharge rollers  30  are disposed near a downstream side thereof. These pairs of rollers nip the printed original at the upstream and downstream sides of the printing position thereby reducing shaking of the original that occurs during its conveyance and contributing to a good quality printed image. 
       FIG. 4  shows a schematic configuration of the CPU 150  (see  FIG. 1 , control means) that controls the overall image capturing device  100  that includes the image capturing unit H and the document feeder A. The CPU 150  calls up an execution program for the reading process from the ROM. Then, the CPU 150  controls the apparatus according to the execution program to convey the original and read images on the original. Particularly, in this embodiment, the CPU 150  controls the printing operation of the printer head  800 . Note that each of the sensors described above, namely sensors GS, S 3  and S 4  are electrically connected to the CPU 150 . Also, a warning unit (warning means)  190  such as an LCD panel or PC screen or the like, is electrically connected to issue a warning when the position along the original width direction of the printer head  800  is improper. As a more detailed example of the warning unit, a PC is the monitor when it is possible to operate the system via a PC driver, if, for example, the image capturing device  100  is connected to a PC or network. Also, if a liquid crystal display panel is equipped on the image capturing device  100 , that liquid crystal display panel can be implemented to be a monitor. 
     The operations of the image capturing device  100  having the configuration described above will now be explained in detail with reference to the flowchart of  FIG. 5 . 
     Initially, the user moves the printer head  800  to a predetermined position according to the original size prior to reading the original at the image capturing device  100 . Along with this, the printer sensor S 4  also shifts with it unitarily. Also, the characters and numbers to be printed are predetermined as default, but they can be freely changed using a driver screen on the PC for example to provide further convenience for the user. 
     Next, when the start button on the image capturing unit H is pressed, conveyance of the original on the feeder tray Twill begin when by selecting start key on the PC screen (Step ST 1 ). The original on the feeder tray T is kicked out by the kick roller  21  and conveyed by the feed roller  22 . Then, it is conveyed by the registration rollers  24  and feed rollers  25 . The shingle-feed detection sensor GS detects whether a plurality of originals have been shingle-fed (Step ST 2 ). If shingle-feeding is not detected, the conveyance of the original is continued according to the normal reading mode. After the original is read at the first reading position  5  and/or the second reading position, the original is discharged to the discharge tray  11 . 
     If shingle-feeding is detected, the system enters the shingle-feed detection mode. In the same way as with the normal reading mode, the feed rollers  25 , first reading rollers  26 , second reading rollers  27  and the third reading rollers  28  are rotated to continue feeding the original, but reading is not performed on the originals at either of the reading positions  5  or  6 . Next, the system determines whether the leading edge of the original has reached the lever  9  (that is, whether the leading edge of the original has been detected by the discharge sensor unit S 3 ) (Step ST 3 ). When the leading edge of the original has been detected, it means that it has passed the position of the lever  9 . If the leading edge of the original is not detected, the original stopped somewhere in the conveyance path up to the lever  9 , so the drive of each roller is stopped and the user is notified of a jam. Next, the printer sensor S 4  detects the presence of the original (Step ST 4 ). If the original is detected by the printer sensor S 4  (in other words, if the conveyed original has passed within a range of the print head  800  print region) and the original has passed the printing position, it means that the printer head  800  is set the proper position for the size of the original, so the control from the CPU 150  drives the printer head  800  to print characters on the original (Step ST 5 ). Note that printing is set to start after a predetermined amount of time has passed after detection of the leading edge of the original by the discharge sensor unit S 3  at step ST 3 , by measuring from the detection of the discharge sensor unit S 3 . (In other words, printing is performed by the printer head  800  at a predetermined timing based on detection by the discharge sensor unit S 3 .) This configuration allows for the starting time to be set freely from the detection of the leading edge of the original to the start of printing allowing the user to freely change the position to print characters in the original conveyance direction, further increasing user convenience. 
     At step ST 4 , if the original is not detected by the printer sensor S 4 , it means that the original is not at the printing position of the printer head  800  (the conveyed original has not passed within the range of the printing region of the printer head  800 ). In other words, this means that the setting position of the original size and the printer head  800  are incorrect. For example, the conveyed original is A4 portrait, but the printer head  800  is positioned for A4 landscape. In such cases, the CPU 150  does not drive the printer head  800 , but displays an error message that the setting position of the printer head  800  is incorrect on the warning unit  190  such as a PC screen or the operation panel on the image capturing unit H (Step ST 6 , or a warning sound can be issued). 
     As another preferred embodiment, a printer drive unit  500  such as a motor for automatically moving the printer head  800  as shown with the dashed lines of  FIG. 4 , can be provided to automatically move the printer head  800  rather than manually move it. The printer drive unit  500  can be configured to be controlled by the CPU 150 . Also, as shown at the dashed lines in  FIG. 5 , when a determination is performed at step ST 4 , the CPU 150  automatically moves the printer head  800  to the proper position to enable it to print onto the conveyed original (Steps ST 7  and ST 8 ). 
     As described above, with this embodiment, the printer sensor S 4  is provided in the conveyance path upstream in the direction of conveyance of the printer unit  8 , as detection means to detect whether a conveyed original has passed within a range of the printer unit  8  printing region, so it is possible to prevent improper printing that occurs when the position of the printer unit  8  is incorrect. In other words, it is possible to prevent mis-printing or the wasted consumption of ink that occurs when the printer head  800  because the setting positions of the conveyed original size and printer unit  8  are incorrect. 
     Furthermore, with this embodiment, the printer sensor S 4  is integrated to the printer unit  8  and is configured to travel unitarily with the printer unit  8  along the width direction of the original, so the detection position of the printer sensor S 4  varies along with the movement of the printer unit  8 , and therefore not only is it possible to efficiently and accurately detect according to original size, no interlocking mechanism is required to interlock the printer sensor S 4  to the movement of the printer unit  8 . This contributes to a simplified structure, a lower number of components and to a more compact overall apparatus. Also, in addition to this configuration, with this embodiment, the printer sensor S 4  is positioned further outside of the width direction of the original than the printer unit  8 , so not only is the passage of the original detected by the printer sensor S 4 , but it is possible to accurately determine whether the original is within the printing range of the printer unit  8 . 
     The embodiment equips the warning unit  190  that warns when the position of the printer unit  8  is improper so mis-printing of the printer head  800  is further prevented. Particularly, as with the other preferred embodiment described above, if the printer unit  8  is automatically moved to the proper position when the printer unit  8  position is incorrect, mis-printing of the printer unit  8  can be securely prevented. 
     Also, with this embodiment, a detection sensor unit S 3  that detects the passing of the original is equipped in addition to the printer sensor S 4 , so it is possible to attain accurate determinations by a determining unit  150 B. In other words, if the discharge sensor unit S 3  is equipped substantially in the center of the conveyance path that conveys originals using a center reference, any size of original is detected by the sensor  10  of the sensor unit S 3  making it possible to accurately convey the original. Therefore, if the setting position of the printer head  800  is incorrect, the original will not be detected by the printer sensor S 4 , even though it was detected by the sensor  10 , making it possible to determine that the setting position of the printer head  800  is incorrect, and to output an error message. However, if the sensor  10  did not exist, when the original is not detected by the printer sensor S 4 , it cannot be determined whether the original was actually not conveyed or the setting position of the printer head  800  is incorrect. Therefore, it would not be possible to output an error message that the setting position of the printer head  800  is incorrect. 
     Also, the original is conveyed based on a center reference so the printer sensor S 4  and the printer unit  8  only have to move substantially half the width direction of the conveyance path. Therefore, the apparatus is more compact, power consumption is conserved and the forming is simplified. 
     Note that the present invention is not limited to the aforementioned embodiment; It is anticipated that various modifications and alternative designs may be made without departing from the scope of the invention. For example, this embodiment equips upstream of the printer sensor S 4  a discharge detection sensor S 3  that detects the leading edge of the original. The drive timing (print start timing) for the printer head  800  is set based on the detection time of the discharge sensor S 3 , but it is also acceptable to determine the drive timing of the printer head  800  by the printer sensor S 4  and not equip the discharge sensor unit S 3 . (In other words, printing is performed by the printer head  800  at a predetermined timing based on detection by the printer sensor S 4 .) According to the embodiment described, in the event a shingle-feed of originals is detected by the shingle-feed detection sensor GS, printing is performed on the original by the printer head  800  but this is not to be construed as a limitation. To simply print characters to confirm that the original has been read, or if using a facsimile machine to print characters indicating that the original has be faxed, it is acceptable to set characters to print on an operation panel disposed on a PC screen or image capturing device. Also, according to the embodiment described, originals are conveyed based on a center alignment, but this is not to be construed as a limitation. Originals can also be conveyed along a side position of the conveyance path. Still further, the embodiment positions a discharge sensor unit S 3  upstream of the printer sensor S 4 . However, the discharge sensor S 3  can also be disposed at a downstream side of the printer sensor S 4 .

Technology Classification (CPC): 7