Patent Publication Number: US-9844954-B2

Title: Document feeders for printers and printers comprising the document feeders

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a national stage entry from international Application No. PCT/EP2014/055486, filed on Mar. 19, 2014, in the Receiving Office (“RO/EP”) of the European Patent Office (“EPO”), and published as International Publication No. WO 2015/139742 A1 on Sep. 24, 2015, the entire contents of are incorporated herein by reference. 
     The present invention relates to a printer or the like. More in particular, the present invention relates to an improved document feeder for a printer. 
     In the present description and claims the term “printer” should be intended as including any peripheral device to be connected (by any means, such as through a cable, a wireless link, an infrared link or the like) to a computer, a personal computer, a smart phone or the like and configured for managing sheets. Examples of “printer” are: a printer for printing one single sheet of paper or a plurality of sheets of paper possibly connected together; a printer for printing one or more sheets of a material other than paper; a scanner, a facsimile machine or a peripheral incorporating two or more of the above functionalities. 
     In the art, several different designs of printers are known. The difference being at least in the printing technology (laser printing, ink-jet printing, dot-matrix printing, . . . ) and/or in the main intended use (domestic use, small office use, large companies use, . . . ). Printers which are designed for private use or use by a rather reduced number of people as in a small office are generally rather compact in size because they are intended to be supported on a desk or table in proximity of the computer of the user. 
     The present description will refer more specifically to printers designed for use in a bank, post office, public office or the like. The above specific reference to bank (including post office or the like) environment is not intended to limit the scope of protection in no way and the present invention is equally applicable to printers to be used in any other private or business environment. 
     Several different documents are fed by a bank clerk into a printer. The documents are different one from the others at least because of their nature, shape and size. Some documents are fed singularly, some others are fed in stacks or the like. 
     In the art, automatic document feeder devices (briefly, ADF) are known. An ADF is used when a plurality of documents, arranged in stacks, is fed in a printer: the document which is at the top of the stack is taken by the ADF and conducted to the printing stage(s) within the printer. 
     Each of the documents to be fed can comprise a single sheet or a plurality of sheets (multi-copy documents). Those which comprise a plurality of sheets typically comprise a single glued edge where sheets are glued together. The other edges are not glued. Typically, the glued edge is the leading edge, namely the edge which is first fed. In other documents, the glued edge is a lateral edge. 
     SUMMARY OF THE INVENTION 
     The Applicant has noticed that feeding a small size document or a multi-copy document having a glued lateral edge into a feeding opening of a printer can be disadvantageous. In particular, in certain printers wherein the rim of the feeding opening is at a certain distance from the aligning devices starting the paper path, it is not possible to position the small size document or the multi-copy document by hand. In fact, the operator, due to the dimensions and shape of the printer body, can not see and properly identify the aligning devices and/or the infrared detectors and he can not arrange the document appropriately. 
     The Applicant has also noted that a known ADF can not be used to feed a multi-copy document having a glued lateral edge up to the alignment device. This because the known ADF would identify a multi-copy document having a glued lateral edge as a plurality of single sheets. Therefore, a known ADF would tend to separate the top sheet from the other(s) sheet(s). 
     In view of the above, the Applicant has tackled the problem of feeding a small size document or a multi-copy document having a glued lateral edge at least from a feeding opening of a printer to an alignment device and/or to a presence detector. 
     The Applicant has observed that the above problem can be solved by a document feeder for a printer or the like with a lower part provided with a sliding element which, in at least an operation mode of the document feeder, has a portion projecting with respect to a retaining surface for supporting a lower face of the document in such a way that at least a portion of said document is maintained raised with respect to the retaining surface. 
     According to a first aspect, the present invention relates to a document feeder for a printer or the like, wherein the document feeder comprises a upper part and a lower part, wherein said upper part comprises a feeding roller arrangement for engaging with an upper face of a document and wherein said lower part comprises a retaining surface, wherein said lower part also comprises a sliding element which, in at least an operation mode of the document feeder, has a portion projecting with respect to said retaining surface for supporting a lower face of the document in such a way that at least a portion of said document is raised with respect to said retaining surface. 
     The sliding element may comprise a sliding teeth which is rotatable around a rotation axis. 
     The lower part may comprise a spring for spring loading the sliding element in the projecting position. 
     The spring may be preloaded with a load between 10 g and 30 g. 
     The sliding element may be comprised with a thermoplastic material. For instance, it can comprise a blend of polyphenylene oxide and polystyrene. 
     At least the projecting portion of said sliding element has a friction coefficient between about 1.0 and 1.1. 
     The lower part can be movable in such a way that it can become recessed below a floor of a feeding opening of the printer. 
     The lower part may be rotatable. 
     The feeding roller arrangement may comprise two motorized feeding rollers. 
     The outer surface of the feeding rollers may be profitably covered or lined with a layer providing a rather high friction with a document. Such layer could be a rubber or the like. 
     The feeding roller arrangement may comprise a trough between the two feeding rollers. 
     According to a second aspect, the present invention relates to a printer comprising a feeding opening comprising a floor, further comprising a document feeder as set forth above. 
     The printer may also comprise sensor means for detecting a document presence. 
     In one embodiment, one document output is selected among a plurality of outputs according to the detected size of the document. In turn, the size of the document may be detected based on said sensor means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will be better understood by reading the following detailed description, to be read by referring to the accompanying drawings, wherein: 
         FIG. 1  is a axonometric view of a printer according to an embodiment of the present invention; 
         FIG. 2 a    is a simplified cross section of the printer of  FIG. 1 , with a document which is at about the beginning of the paper path; 
         FIG. 2 b    is an enlarged view of a portion of  FIG. 2   a;    
         FIG. 3 a    is a partial view of the printer, without the printer body, showing the improved document feeder according to an embodiment of the present invention in a first operation mode; 
         FIGS. 3 b  and 3 c    are simplified cross sections of the improved document feeder according to an embodiment of the present invention in the first operation mode; 
         FIG. 4  is a view as the one of  FIG. 3 b    for the second operation mode; 
         FIG. 5 a    is a view corresponding to  FIG. 3 a    for the third operation mode; 
         FIG. 5 b    is a simplified cross section of the improved document feeder according to an embodiment of the present invention in the third operation mode; 
         FIG. 6  is a simplified front cross section of the improved document feeder according to an embodiment of the present invention in the first operation mode with a document; 
         FIGS. 7 a , 7 b  and 7 c    are simplified axonometric views of the lower component of the improved document feeder according to an embodiment of the present invention; and 
         FIG. 8  is a view of an exemplary document which is glued along a lateral side. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
       FIG. 1  schematically shows a printer  1  according to an embodiment of the present invention. The printer  1  comprises a main body  11 . The printer comprises a feeding opening  12  for feeding one or more documents D to the printer and an upper output paper tray  14 . Additional output paper trays or output paper trays arranged in different positions could be provided without changing the scope of protection of the present invention. A document D, after being printed, could be also returned to the feeding opening. 
     For the present description and claims, the term “document” will indicate a layer of material to be threated. Such a layer of material may comprise one or more sheets. The sheets may be connected (typically glued) together along a front edge or a lateral edge. The sheet(s) may be at least partially pre-printed or may be “white” sheets (without any characters and digits thereon). The sheet(s) can be essentially made of, or can comprise, paper or the like.  FIG. 8  shows an exemplary document D formed by two sheets S 1 , S 2  which are glued along only a lateral side (left side in  FIG. 8 ). At the opposite lateral side, the sheets S 1 , S 2  are not connected together as it is shown in  FIG. 8 . The two sheets are also not connected along leading edge LE and trailing edge TE. 
       FIGS. 2 a  and 2 b    are cross sections of a printer provided with an improved document feeder ADF according to an embodiment of the present invention. While the various parts will become more clear with reference to other Figures (showing enlarged parts), it should be first remarked that the printer comprises a feeding opening  12  with a corresponding feeding opening edge  12 ″ and a feeding opening floor  12 ′ on which a document D is laid. 
     The document D is shown with enlarged thickness for improving clarity. Also shown in  FIG. 2 b    is an axis  13 ′ of document position detectors  13  which are configured for detecting that a document D is present when it is between an infrared emitter and a corresponding receiver. Downwardly, there are provided alignment devices, printing arrangements and transportation means. 
     In one embodiment of printer, the document output is selected among a plurality of documents outputs according to the detected size of the document. In turn, the size of the document may be detected based on sensor means (typically said infrared document detectors  13 ). 
       FIG. 3 a   , is a partial enlarged view showing the feeding opening  12  of printer  1  with the printer body removed for a better view and understanding of the improved document feeder ADF according to an embodiment of the present invention. 
     The document feeder ADF of the present invention can operate substantially according to three operation modes or also according to less than three operation modes. The first operation mode is adapted to feed a single document, possibly made of two or more sheets connected along an edge, which could be a lateral edge ( FIG. 8 ). The second operation mode is adapted to feed a plurality of documents, arranged in a stack. The third operation mode is a manual mode for feeding documents manually. The three operation modes will be disclosed below. 
     The improved document feeder ADF comprises an upper part  100  and a lower part  200  which will be described separately in the following description. 
     The upper part  100  comprises a support plate  101  which is hinged around an axis  102  so that it can be rotated upwardly as shown at least in  FIGS. 2 b , 3 a  and 3 b   . The support plate  102  in turn supports a pressing roller  103  and a first gear wheel  104  which is coaxial with the pressing roller  103 . An electric motor (not shown) transmits rotation movement to pressing roller  103  through the first gear wheel  104  and further gears  105 , belts and/or chains. 
     When the pressing roller is rotated downwardly (second operation mode) and it is caused to rotate, it transports the document which is in contact with towards the printing stages. 
     In the first and third operation modes, the support plate is rotated upwardly and the pressing roller is in a non working configuration. In such a configuration, the pressing roller is either not caused to rotate or it is rotating but is anyway not engaging any documents. This because it is raised with respect to the floor  12 ′ of the feeding opening  12 . 
     Preferably, the above mentioned motor is also connected to a feeding roller arrangement  110 . A feeding roller arrangement  110  according to an embodiment of the present invention is also shown in  FIG. 6 . Feeding roller arrangement  110  may comprise a shaft  111  with two feeding rollers  112  mounted thereon. The feeding rollers  112  can be axially separated by a central throat or trough  115 . 
     In embodiments of the invention, the outer surface of feeding rollers  112  is covered or lined with a material  113  providing a rather high friction with a document. Such covering material  113  could comprise a rubber material. Such rubber material could be, profitably, similar to a track with a recursive pattern of blocks. Friction coefficient of the covering material could be about 1.0-1.1 in compliance with ASTM 0618 Standard Test Mode. 
     The outer surface of feeding rollers  112  can be covered by a rubber such as EPDM 70±5 Shore A. 
     The outer surface  113  of the feeding rollers  112  is at a distance from the floor  12 ′ of the feeding opening  12 . 
     In embodiments of the invention, the throat  115  which is arranged axially between the feeding rollers  112  has an outer diameter lower than the diameter of the feeding rollers  112 , possibly covered or lined as said above. 
     The outer diameter of the feeding rollers  113  (including the friction lining) can be from about 16 mm to about 20 mm. In one embodiment, the feeding roller diameter is about 19 mm±0.2 mm. 
     The outer diameter of the trough  115  can be from about 14 mm to about 18 mm. In one embodiment, the trough diameter is about 16 mm±0.1 mm. 
     Profitably, the shaft  111  can be made in two sections. 
     The feeding rollers  112  can be made of a plastic material such as a thermoplastic material. In one embodiment the feeding rollers can be made of a blend of polyphenylene oxide (PPO) and polystyrene (PS). A preferred material is Noryl® SE 1, GFN2, FN 215 or any other polyphenylene ether. Alternative materials could be: ABS (Acrylonitrile butadiene styrene) polymer, PET, LDPE, MDPE or HDPE or a resin material or a combination thereof. 
     As said above, the improved document feeder ADF comprises also a lower part  200  cooperating with the upper part  100  for properly feeding certain documents D (as the document D of  FIG. 8 ). The lower part  200  comprises a slide shoe  201  which, in operation, can (at least partially) project upwardly from a floor  12 ′ of the feeding opening  12 . The slide shoe  201  is also shown in  FIGS. 7 a , 7 b  and 7 c   . It can have a substantially concave shape with an upper retaining surface  202 , two lateral sides  203  and an open lower surface  204 . The upper surface  202  and the two lateral sides  203  delimit a volume  205  which is open at the bottom  204 . 
     In use, the upper retaining surface  202  of the slide shoe  201  faces the feeding rollers  112  of the upper part  100  of the improved document feeder ADF of the present invention. 
     Two pins  207  project outwardly, in opposite directions, from the lateral sides  203  of the slide shoe  201 . The pins  207  lay on a common axis. 
     A C shaped arm  208  is connected to the slide shoe  201  and projects downwardly. 
     The lower part  200  of the improved document feeder ADF comprises also a sliding element  210 , such as sliding teeth  210 . The sliding teeth  210  is arranged so that in at least one operation condition, it projects partially from the upper retaining surface  202  of the slide shoe  201  through a window  211 . Preferably, the sliding teeth  210  and its window  211  are arranged centrally with respect to the lateral sides  203  of the slide shoe  201 . 
     As shown in  FIG. 7 b   , the sliding teeth  210  is mounted rotatable around an axis  213  extending in the open volume  205  of the slide shoe  201  from one lateral side  203  to the opposed one. The rotation axis  213  of the teeth  210  can be parallel to the rotation axis of the projecting pins  207 . Preferably, a spring  214  is provided for maintaining the teeth  210  projecting upwardly with respect to the surface  202  of the slide shoe  201 . When the teeth  210  becomes subject to a load higher than a threshold load, the sliding teeth  210  rotates downwardly within the volume  205  of the slide shoe and it does not project upwardly from the retaining surface  202  of the slide shoe  201 . If the load is removed, the sliding teeth  210  returns back in the projecting position. The spring is preloaded. The preload can be from about 10 g to 30 g. In embodiments of the invention, the preload can be of about 20 g. In general terms, the preload corresponds substantially to the weight of a document to be singularly feed in the printer. 
     Preferably, the projecting end of the sliding teeth  210  has a width substantially corresponding to the width of the trough  115 . More precisely, the width of the sliding teeth  210  is such that it can engage with the friction surface  116  provided on the surface of the trough  115 . 
     Preferably, the upper retaining surface  202  of the slide shoe  201  is covered with, lined with or made of (at least partially) a material providing a rather high friction with a document, which is typically made of paper of the like. In embodiments of the invention, the material of the upper surface  202  of the slide shoe  201  may be of rubber or the like. Friction coefficient of the covering material could be about 1.0-1.1 in compliance with ASTM 0618 Standard Test Mode. The upper retaining surface  202  can be covered by a rubber such as EPDM 70±5 Shore A. 
     Preferably, at least the projecting part of the sliding teeth  210  is made of a material providing a rather low friction with a document, typically made of paper or the like. In one embodiment, at least the projecting part of the sliding teeth  210  can be made of a blend of polyphenylene oxide (PPO) and polystyrene (PS). A preferred material is Noryl® SE 1, GFN2, FN 215 or any other polyphenylene ether. Alternative materials could be: ABS (Acrylonitrile butadiene styrene) polymer, PET, LDPE, MDPE or HDPE or a resin material or a combination thereof. 
     In other embodiments, the sliding teeth  210  can be replaced by a small wheel, a roller or the like. 
     According to the first operation mode ( FIGS. 3 b , 3 c    and  6 ), the outer surface  113  of the feeding rollers  112  is at a distance from the retaining surface  202  of the slide shoe  201 . In other words, the feeding rollers  112  are not in contact with the retaining surface  202  of the slide shoe  201 . The distance between the surface  202  and the rubberized outer surface  113  of the feeding rollers  112  can be of about 1 to 2 mm. However, the sliding teeth  210  is projecting upwardly in the trough  115 . 
     When a document D to be processed by the printer  1  is fed to the document feeder ADF in the first operation mode, the document D is slidingly supported by the projecting sliding teeth  210  and gently pushed upwardly towards the feeding rollers  112 . However, the lower face of the document is not retained by the rubberized retaining surface  202  of the slide shoe  201 , due to the projecting sliding teeth  210 . 
     This operation mode is particularly profitable and convenient for feeding multi-copy documents because the lower sheet of the document is not retained with respect to the upper sheet. Therefore, it can be used for multi-copy documents connected along a lateral edge and not along a leading edge. Advantageously, peeling of the sheets does not occur. 
     The first operating mode can be selected manually, for instance by pressing a proper button. As an alternative, it can be automatically selected through use of proper sensor(s). 
     According to the second mode ( FIG. 4 ), the rubberized outer surface  113  of the feeding rollers  112  is substantially in contact with the retaining surface  202  of the slide shoe  201 . In principle, the sliding teeth  210  is projecting upwardly in the trough  115  but this has no influence with the transport of the document. In fact, the document maintained between the feeding rollers  112  presses the sliding teeth  210  downwardly. This operation mode is particularly profitable and convenient for feeding single-sheet documents which become sandwiched between the rubberized surfaces  113  of the feeding rollers  112  and of the retaining surface  202  of the slide shoe  201 . The single-sheet documents can come from a stack of documents (not shown). The top document of the stack is provided by the pressing roller  103  of the upper part  100  of the document feeder ADF. 
     The third operation mode is shown in  FIGS. 5 a  and 5 b    (as well as in  FIGS. 2 a  and 2 b   ). According to this third mode, the lower part  200  of the document feeder ADF is rotated so that it becomes recessed below the floor  12 ′ of the feeding opening  12 . In this configuration, it does not obstacles any document fed into the printer  1 . Such documents can be fed manually. 
     The third operation mode is adapted to feed into the printer documents having a larger size than the size of the documents fed in the first operation mode. Such documents can be, for instance, documents having an A4 size or a similar size. The documents can be fed manually by a user who can properly arrange them at the alignment device(s) without being obstructed by the shape of the feeding opening  12 .