Patent Publication Number: US-2007103535-A1

Title: Image forming apparatus

Description:
The entire contents of the documents cited in this specification are herein incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      This invention belongs to a technical field of image forming apparatus such as ink-jet printers and electrophotographic printers, and relates particularly to image forming apparatus of a reduced size to which sheet-type recording media and roll-type recording media are both usable.  
      Prints of the images taken on a photographic film or with a digital camera are generally made by a photographic printer intended for commercial use such as a so-called minilab, whereupon printing paper (photosensitive material for silver halide photography) is exposed to light so as to project an image onto it (that is to say, an image is printed on printing paper), the exposed printing paper being subjected to wet processing involving the steps of development, bleaching, fixing and washing, and then dried to output it as a finished print.  
      Photographic printers using printing paper require troublesome maintenance and liquid waste disposal due to the wet-type processing. For these and other reasons, image forming apparatus capable of outputting a print with the quality of a photographic image (or photograph) by an ink-jet or electrophotographic method are coming into commercial uses.  
      Recording media for various image forming apparatus fall into two categories: sheet-type recording media in cut-sheet form which are generally used in at-home printers, and roll-type recording media in the form of a roll of continuous medium such as used in the ink-jet printer described in JP 2003-212402 A.  
      Generally speaking, roll-type recording media are less expensive while sheet-type ones have an advantage in allowing easier making of various prints differing in size or form.  
      It is therefore preferable in the case of commercial image forming apparatus and so forth to use a roll-type recording medium for the making of prints of an ordinary size which are to be made in huge amounts, and use a sheet-type recording medium for the making of prints having a postcard size or large-format size which will be made in small amounts.  
      In recent years, images are increasingly handled as digital data owing to the popularization of digital cameras and personal computers, which is bringing about processing of images in different situations to make a variety of prints. As a consequence, it is being required that both the large-scale processing at a low cost and the making of prints with diversified sizes be carried out by a single image forming apparatus. In other words, it is preferred that a sheet-type recording medium and a roll-type recording medium can be used in one and the same image forming apparatus.  
      On the other hand, image forming apparatus are preferably compact and of simple structure in terms of their setting in such places as the interior of a convenience store.  
      In this connection, a recording medium is charged (fed) into an image forming apparatus generally by loading a box-shaped case containing the medium in a predetermined loading position, with the case being either that called cassette and containing a sheet-type recording medium as a pile of cut sheets, or that called magazine and containing a roll-type recording medium as a rotatable roll.  
     SUMMARY OF THE INVENTION  
      The requirement as above cannot be filled by a printer in which roll-type recording media are exclusively used, such as described in JP 2003-212402 A, or a printer in which sheet-type recording media are exclusively used, such as intended for home use.  
      Image forming apparatus in which both the sheet-type recording media and roll-type recording media can be used are known indeed, including the ink-jet printer described in JP 2000-127357 A. Such an apparatus, however, should have a more complicated structure and a larger size because it requires two positions for the loading of a recording medium case, one dedicated to the cassette containing a sheet-type recording medium and the other dedicated to the magazine containing a roll-type recording medium.  
      An object of the present invention is to solve the above problems with the art and provide an image forming apparatus to which sheet-type recording media in cut-sheet form and roll-type recording media in the form of a roll of continuous medium are both usable and, moreover, which is compact.  
      The above object is achieved by providing according to the present invention an image forming apparatus comprising: a loading section for loading a recording medium; an image recording section for recording an image on the recording medium; and a transporting system for transporting the recording medium to the image recording section, wherein the loading section is provided with a cassette holder block for holding a bottom of a cassette containing the recording medium in a form of a pile of cut sheets, and a magazine receiver formed in the cassette holder block as a recess in which a magazine containing the recording medium in a form of a roll of continuous recording medium is to be inserted.  
      In the image forming apparatus of the present invention as above, the loading section preferably has a detection device for determining whether the cassette or the magazine is loaded, and a control unit for controlling recording medium delivery in accordance with a detection result obtained by the detection device.  
      It is preferable that the roll of the continuous recording medium is contained in the magazine as being accompanied by disc-shaped members on both sides in a direction in which a roll shaft of the roll extends, and the loading section has a rotary shaft provided above the cassette holder block; a sheet delivering roller which abuts an uppermost sheet of the recording medium in the form of the pile of cut sheets in the cassette and is mounted on the rotary shaft; and disc rotating rollers which rotate the disc-shaped members in the magazine and are mounted on the rotary shaft at both sides of the sheet delivering roller, and that, when the cassette is loaded in the loading section, a sheet of the recording medium in a form of cut sheet is delivered from the cassette by the sheet delivering roller, and when the magazine is loaded in the loading section, the continuous recording medium in the form of the roll is delivered from the magazine by rotating the roll of the continuous recording medium by means of the disc rotating rollers.  
      It is also preferable that the loading section has: a cut-paper delivery unit for delivering a sheet of the recording medium in a form of cut sheet from the cassette; a rolled-paper delivery unit for delivering the continuous recording medium in the form of the roll from the magazine; a driving source for driving the cut-paper delivery unit and the rolled-paper delivery unit; a first transmission unit which includes a first clutch and transmits driving force of the driving source to the cut-paper delivery unit; and a second transmission unit which includes a second clutch and transmits the driving force of the driving source to the rolled-paper delivery unit.  
      Preferably, the cassette holder block has an extendable mechanism, and the cassette holder block is extendable in a direction in which a roll shaft of the roll of the continuous recording medium loaded in the loading section extends so that the cassette holder block and the magazine receiver are variable in size in the direction in which the roll shaft extends. In addition, the image forming apparatus of the present invention preferably comprises a regulation member for regulating the cassette held by the cassette holder block in position, with the regulation member being variable in position in itself.  
      It is also preferable that the roll of the continuous recording medium is contained in the magazine as being accompanied by disc-shaped members on both sides in a direction in which a roll shaft of the roll extends, and the loading section has: a rotary shaft provided above the cassette holder block; and plural pairs of disc rotating rollers mounted on the rotary shaft, each pair of disc rotating rollers rotating a pair of the disc-shaped members corresponding to each of plural rolls of the continuous recording medium with different widths in the magazine, and that the continuous recording medium in the form of the roll is delivered from the magazine by rotating the roll of the continuous recording medium by means of corresponding pair of the disc rotating rollers.  
      According to the present invention with the configuration as described above, the cassette containing a sheet-type recording medium in cut-sheet form and the magazine containing a roll-type recording medium in the form of a roll of continuous medium can be loaded in one and the same loading position. In other words, a sheet-type recording medium and a roll-type recording medium can be used in the same compact apparatus having no loading position dedicated to the cassette or magazine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the accompanying drawings:  
       FIG. 1A  is a schematic diagram showing an embodiment of the image forming apparatus according to the present invention;  
       FIG. 1B  is a schematic diagram showing a different loading state of the loading section of the image forming apparatus as shown in  FIG. 1A ;  
       FIG. 2A  is a cross-sectional view of the loading section as shown in  FIG. 1A ;  
       FIG. 2B  is a cross-sectional view of the loading section as shown in  FIG. 1B ;  
       FIG. 3  is a cross-sectional view of the loading section of the image forming apparatus according to the present invention, in the loading section, another embodiment of the magazine being loaded;  
       FIGS. 4A and 4B  are cross-sectional views showing different loading states of another embodiment of the loading section of the image forming apparatus according to the present invention, repectively; and  
       FIG. 5  is a cross-sectional view of yet another embodiment of the loading section of the image forming apparatus according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The image forming apparatus according to the present invention is now described in detail with reference to the preferred embodiments as shown in the accompanying drawings.  
       FIG. 1A  schematically shows a printer  10  as an embodiment of the image forming apparatus according to the present invention.  
      The printer  10  is adapted to record an image on recording paper A (as a recording medium) by an ink-jet method so as to output the image as a print, and comprises a loading section  12 , a cutter  14 , a back-printing unit  16 , an image recording section  18 , and a discharging section  20 .  
      It should be understood that the printer  10  may have any of various members of the conventional printer, such as a transporting roller pair, a guide roller, a guide member, and a sensor for detecting the recording paper A, as required in addition to the shown members.  
      In the loading section  12 , a magazine  24  containing roll-type recording paper Ar in the form of a roll of continuous recording paper or web-type recording paper (also referred to as rolled paper Ar) and a cassette  26  containing sheet-type recording paper Ac in the form of a pile of cut sheets (also referred to as a cut paper or papers Ac) are loaded.  
      The loading section  12  in  FIG. 1A  is in a state to have the magazine  24  loaded therein. The loading section  12  in a state to have the cassette  26  loaded therein is schematically shown in  FIG. 1B .  
       FIGS. 2A and 2B  each show schematically a cross section of the loading section  12  across the recording paper transporting direction (delivering direction) as seen from the rear side (toward a drawing-out port  24   c  of the magazine  24 ). The loading section  12  is in a state to have the magazine  24  loaded therein in  FIG. 2A , and in a state to have the cassette  26  loaded therein in  FIG. 2B .  
      The magazine  24  is a rectangular solid-shaped case in which the rolled paper Ar is to be contained.  
      In the example as shown in  FIGS. 1A and 2A , the recording paper Ar is contained in the magazine  24  as being rolled (wound) on a roll shaft and accompanied by disc-shaped members  28  on both sides in the direction in which the roll shaft extends (direction orthogonal to the recording paper delivering (transporting) direction; hereafter referred to as the width direction). The rolled paper Ar is thus sandwiched between the disc-shaped members  28  by, for instance, providing a projection in the center of each disc-shaped member  28  and inserting the projection into a center hole of each end of rolled paper Ar or either end of the roll shaft on which the web-type paper Ar is rolled.  
      Below in the magazine  24 , two support rollers  30  are rotatably arranged. The support rollers  30  extend in the width direction and are spaced apart from each other in the recording paper delivering direction (hereafter referred to as the transporting direction).  
      In the shown example, the rolled paper Ar is contained in the magazine  24  by resting the disc-shaped members  28  having the rolled paper Ar sandwiched between them on the support rollers  30 . Since the support rollers  30  extend in the width direction and are axially supported to be rotatable as mentioned above, the disc-shaped members  28  and, accordingly, the rolled paper Ar contained in the magazine  24  are rotatable in the transporting direction.  
      The magazine  24  and the disc-shaped members  28  are so dimensioned that upper parts of the members  28  rested on the support rollers  30  may protrude from the top of the magazine  24 . In order to realize such a configuration, slits  24   a  extending in the transporting direction to allow the penetration or protrusion of the disc-shaped members  28  are formed in the top of the magazine  24  in the positions determined in accordance with the size in the width direction of the roll of the rolled paper Ar to be contained. In the shown example, two slits  24   a  (as a pair) are formed symmetrically with respect to the center as defined in the width direction because the rolled paper Ar is sandwiched between two disc-shaped members  28  aligned in the width direction as described above.  
      In the shown example, the magazine  24  is also provided in its top with an opening  24   b  through which a sheet delivering roller  54  to be described later is inserted.  
      In addition, the magazine  24  has the drawing-out port  24   c  in the form of a slit through which the recording paper Ar is delivered. In the vicinity of the drawing-out port  24   c,  a guide roller  32  is placed which guides the recording paper Ar as unwound toward the drawing-out port  24   c.    
      When unwound, the recording paper Ar is drawn out such that it comes off the roll in the underpart thereof and moves upward to the guide roller  32 . Then, as being guided by the guide roller  32 , the recording paper Ar is drawn or pulled out of the magazine  24  through the drawing-out port  24   c.    
      The cassette  26  is a case in the form of a rectangular solid whose one face (top face) is open, and contains the cut papers Ac as a pile of cut sheets, as shown in  FIGS. 1B and 2B .  
      The cassette  26  has a table  36  on which the cut papers Ac are to be set as a pile of cut sheets. The table  36  is urged by a biasing member  38 , a spring for instance, upward (toward the open face of the cassette  26 ). Consequently, the cut paper or papers Ac contained in the cassette  26  are also urged upward.  
      The biasing member  38  urges the table  36  so that the cut paper or papers Ac may adequately be caused to abut or press against the sheet delivering roller  54  to be described later not only when the cassette  26  loaded in the loading section  12  contains the maximum number of cut sheets of the cut papers Ac but when only one sheet of the cut paper Ac remains in the cassette  26 .  
      The loading section  12  has a cassette holder block  40  formed therein which so holds the bottom of the cassette  26  rested on it that the cassette  26  may be loaded in the predetermined position. The cassette holder block  40  is provided with an upright wall  42  as a positioning member used for loading the cassette  26  in the predetermined position.  
      In the cassette holder block  40 , moreover, a magazine receiver  44  is formed as a recess having an opening of almost the same dimension as the bottom of the magazine  24 . In the shown example, the magazine  24  or rolled paper Ar contained therein is loaded in the predetermined position in the loading section  12  (of the printer  10 ) by inserting the magazine  24  into the magazine receiver  44 .  
      As described before, it is required recently that prints of various sizes be made by a single printer (image forming apparatus). In view of this, it is preferred in a commercial image forming apparatus to use rolled paper (roll-type recording paper) of a reduced cost for the making of prints of an ordinary size which are chiefly to be made and, in the case of making prints having a special size such as a large-format size, use cut papers (sheet-type recording papers) which are readily prepared as cut sheets varying in size. If, however, such two types of recording paper are intended for use in combination in the conventional printer, the printer needs a loading section for the magazine containing rolled paper and that for the cassette containing cut papers, leading to increase in production costs and size as well of the apparatus.  
      It is quite different for the printer  10  of the present invention, in which the holder block (loading section) for the cassette containing cut papers Ac is provided with a recess in which the magazine containing rolled paper Ar is inserted or loaded. In other words, according to the present invention, the magazine and the cassette can be loaded in the same loading section, which enables the combined use of rolled paper Ar and cut papers Ac in a compact printer of a simple structure.  
      In the loading section  12  of the printer  10  as shown, a motor  50  is provided which serves as a driving power source for the recording paper delivery, and a rotary shaft  56  is axially supported to be rotatable, on which shaft disc rotating rollers  52   a  and  52   b  for rotating the disc-shaped members as described above, and the sheet delivering roller  54  as well, are mounted.  
      A gear  58  is fixed to a rotor shaft  50   a  of the motor  50  on one hand and a gear  60  to the rotary shaft  56  on the other, with the gears  58  and  60  being engaged with each other. In consequence, the rotary shaft  56  and, as a matter of course, the disc rotating rollers  52   a  and  52   b  as well as the sheet delivering roller  54  mounted thereon are rotated when the motor  50  runs.  
      The disc rotating rollers  52   a  and  52   b  are rollers elastic to some extent, such as rubber rollers, and each of two pairs of rollers  52   a  and  52   b  are arranged in the positions which are determined in accordance with the size in the width direction of the relevant roll of the rolled paper Ar, and symmetrically with respect to the center as defined in the width direction (positions corresponding to the slits  24   a  as described above in the case of the pair of rollers  52   a ). In the shown example, the disc rotating rollers  52   a  are adapted for the rolled paper Ar of a larger width (size).  
      The disc rotating rollers  52   a  and  52   b  have such a diameter as allowing them to press against the disc-shaped members  28  protruding with the upper parts thereof from the magazine  24  so as to exert certain pressure on the members  28  when the magazine  24  is loaded in the loading section  12 .  
      The sheet delivering roller  54  is made of a material having an adequate frictional force such as rubber, and is located in the recording paper transporting plane in the center of recording paper as defined in the width direction.  
      The diameter of the sheet delivering roller  54  is such that the roller  54  does not come into contact with the rolled paper Ar in the magazine  24  loaded, even if the roll of the rolled paper Ar has the maximum diameter correspondingly.  
      As described before, the rolled paper Ar is contained in the magazine  24  as being sandwiched between the disc-shaped members  28 , whereupon the members  28  (and the rolled paper Ar) are rotatably supported by the support rollers  30 . Accordingly, the recording paper Ar can be delivered from the magazine  24  loaded in the loading section  12  by rotating the rotary shaft  56  or disc rotating rollers  52   a  and  52   b  mounted thereon and thereby rotating the roll of the rolled paper Ar.  
      The cut papers Ac are contained in the cassette  26  as a pile of cut sheets and urged by the biasing member  38  from below. When the cassette  26  is loaded in the loading section  12 , the uppermost sheet of cut paper Ac is caused to abut or press against the sheet delivering roller  54 . Accordingly, the cut sheets of recording paper Ac can be delivered from the cassette  26  loaded in the loading section  12  by rotating the rotary shaft  56  or sheet delivering roller  54  mounted thereon.  
      In other words, according to the configuration of the shown example in which the disc rotating rollers  52   a  and  52   b  as well as the sheet delivering roller  54  are mounted on a single rotary shaft, both the rolled paper Ar and the cut paper Ac can be delivered from the loading section  12  by a simple driving mechanism including the sole motor  50 .  
      As shown in  FIGS. 1A and 1B , the loading section  12  has a detection means  22 .  
      The detection means  22  is used to determine whether the magazine  24  or the cassette  26  is loaded in the loading section  12 . In accordance with the detection result, running of the motor  50  and other factors in the control of delivery of recording paper (rolled paper Ar or cut paper Ac) from the loading section  12  (magazine  24  or cassette  26 ) are selected in the loading section  12 .  
      The detection means  22  is not particularly limited, and any of those used in a variety of printers and so forth for the determination of recording paper type, for instance, may be employed.  
      In an exemplary detection means, barcords and a barcord reader are utilized. It is also possible to provide on each of the magazine  24  and the cassette  26  projections which are specific in position, number, shape or the like to the relevant magazine or cassette, and detect the projections with a sensor and so forth.  
      The magazine  24  as shown in  FIG. 2A  is suited to only one width of the rolled paper Ar, and provided in its top with a pair of (namely, two) slits  24   a  for allowing the protrusion of the disc-shaped members  28 . The present invention, however, is in no way limited to this configuration.  
      The magazine of the present invention may be adapted to two widths of the rolled paper Ar as is the case with a magazine  61  shown in  FIG. 3  which is provided with two pairs of (namely, four) slits  61   a  and  61   b,  with each pair being symmetrical with respect to the center as defined in the width direction. It is also possible that the magazine is adapted to three or more widths of the rolled paper Ar, and provided with three or more pairs of slits.  
      With such configurations, adaptation to multiple widths of the rolled paper Ar can be achieved under a simple structure, which in turn leads to limited magazine variations.  
       FIGS. 4A and 4B  illustrate another example of the loading section of the present invention. In the loading section as shown, a corresponding magazine is loaded in  FIG. 4A , and a cassette  26  in  FIG. 4B .  
      The loading section as shown in  FIGS. 4A and 4B  is identical to the loading section  12  of  FIGS. 2A and 2B  in many elements, so that like reference characters are imparted to such elements, on which description will not be repeated in general. The cassette  26  as shown in  FIG. 4B  is identical to that of  FIGS. 1B and 2B .  
      As seen from  FIG. 4A , a magazine  64  loaded in a loading section  62  as shown in  FIGS. 4A and 4B  contains rolled paper Ar which is not sandwiched between such members as the disc-shaped members  28  but remains simply rolled on a roll shaft  66 .  
      The magazine  64  axially supports the roll shaft  66  to be rotatable, while allowing its protrusion from the magazine itself in the width direction, so that the rolled paper Ar is rotatable in the magazine  64 .  
      In the loading section  62 , a rotary shaft  68  is axially supported to be rotatable. The rotary shaft  68  has no such rollers as the disc rotating rollers  52   a  or  52   b  but only a sheet delivering roller  54  fixed thereto.  
      Similar to the previous example, a gear  60  is fixed to the rotary shaft  68 , and the gear  60  is engaged with a gear  58  of a motor  50 . The rotary shaft  68  is provided with a clutch  70  with which transmission of the rotating power of the motor  50  to the sheet delivering roller  54  is made effective or not at will.  
      Also in the loading section  62 , a rotary shaft  72  is axially supported to be rotatable in the position where the shaft  72  is in alignment with the roll shaft  66  of the rolled paper Ar contained in the magazine  64  and loaded as such in the loading section  62 .  
      The rotary shaft  72  has a gear  73  fixed thereto and engaged with the gear  58  of the motor  50 . At the end of the rotary shaft  72  opposite from the gear  73 , a coupler  74  is arranged which is connected with the roll shaft  66  of the rolled paper Ar so as to rotate the roll shaft  66  through the rotation of the shaft  72 . The rotary shaft  72  is further provided with a clutch  76  with which transmission of the rotating power of the motor  50  to the coupler  74  is made effective or not at will.  
      Thus in the loading section  62  as shown in  FIGS. 4A and 4B , delivery of recording paper can be carried out as follows: When the magazine  64  is loaded in a magazine receiver  44 , the recording paper Ar is delivered from the magazine  64  by connecting the coupler  74  with the roll shaft  66 , throwing in the clutch  76  and throwing out the clutch  70 , and then driving the motor  50  so as to rotate the roll of the rolled paper Ar.  
      When the cassette  26  is loaded on a cassette holder block  40 , the cut paper Ac is delivered from the cassette  26  similarly to the example shown in  FIGS. 1B and 2B  by throwing in the clutch  70  and throwing out the clutch  76 , and then driving the motor  50 .  
      In the examples as described above, the magazine receiver  44  and the cassette holder block  40  each have a fixed size, although, according to the present invention, both may be adjustable in size.  
      As an example, a cassette holder block  40   a  as shown in  FIG. 5  is of a nested structure and extendable in the width direction as indicated by arrows a, that is to say, the cassette holder block  40   a  and the magazine receiver  44  are variable in size (the magazine receiver  44  being smaller as the cassette holder block  40   a  is larger, naturally) and, accordingly, the magazine ( 24 ; See  FIG. 1A ) and cassette ( 26 ; See  FIG. 1B ) to be loaded can have a variety of sizes.  
      In that case, disc rotating rollers are provided depending on the magazines ( 24 ) of different sizes that can be loaded. In the example as shown in  FIG. 5 , three pairs of disc rotating rollers  52   a,    52   b  and  52   c  are provided corresponding to three widths of the rolls of the rolled paper Ar contained in different magazines ( 24 ).  
      In the shown example, it is preferred that a plurality of guide plates  80  different in thickness be prepared beforehand, and the loaded cassette ( 26 ) be appropriately regulated in position in the width direction as indicated by arrows b by arranging the guide plates having thicknesses suitable for the size of the cassette ( 26 ) in such a manner as shown in  FIG. 5 .  
      The cassette ( 26 ) may also be regulated appropriately in position in the width direction by using a wall  42  which is of a nested structure similar to the cassette holder block  40   a  and extendable in the width direction, or again, by using extendable guide plates of a nested structure.  
      The printer  10  (image forming apparatus) according to the present invention may be adapted for a so-called multiple line transporting method. In that case, the recording paper A is prepared as a plurality of sheets set in a row in the width direction, and the sheets of paper A are fed as such to the image recording section  18  and subjected to image recording so as to improve productivity.  
      In order to allow multiple line transportation of recording paper, a plurality of such loading sections as shown in  FIGS. 2A, 2B ,  3 ,  4 A,  4 B and  5  may be provided as being set in a row in the width direction. The loading sections employed may be the same or different from one another.  
      The recording paper delivered from the loading section  12  (magazine  24  or cassette  26 ) is transported by a drawing-out roller pair  84  to the cutter  14 . The cutter  14  is used when the magazine  24  is loaded in the loading section  12 , to be more specific, used to cut the continuous recording paper Ar into sheets having sizes corresponding to those of desired prints. The cutter  14  is a conventional guillotine cutter, for instance.  
      With the magazine  24  being loaded in the loading section  12 , delivering of the recording paper Ar from the loading section  12  and transporting of the recording paper Ar by the drawing-out roller pair  84  are stopped at the time the length of the recording paper Ar downstream from the cutter  14  has met a desired print size. The cutter  14  is then actuated to cut the recording paper Ar (rolled paper Ar), and a sheet of recording paper having a size identical to a desired print size, which is herein referred to as sheet of recording paper A, is thus obtained. Naturally, the cutter  14  is not actuated when the cassette  26  is loaded in the loading section  12 .  
      The sheet of recording paper A is transported from the cutter  14  to the back-printing unit  16 .  
      In the back-printing unit  16 , back printing (recording of back prints) is performed on the back side (side on which no images are recorded) of the sheet of recording paper A using, for instance, an impact dot matrix printer. Alternatively, an ink-jet printer or thermal printer may be used for back printing.  
      The contents of back printing are not particularly limited, and their examples include various such pieces of information as standardized in the field of photoprinting.  
      The sheet of recording paper A bearing the back prints recorded in the back-printing unit  16  is then transported to the image recording section  18 .  
      The image recording section  18  is adapted to perform image recording (image forming) on the sheet of recording paper A by ink-jet printing, and comprises a transporting system  88  which is located on the upstream side in the section  18 , a recording unit  90 , and a transporting system  92  which is located on the downstream side in the section  18 .  
      The transporting system  88  on the upstream side transports the sheet of recording paper A to the recording unit  90 , and further transports the sheet for scanning when it is subjected to the image recording by the recording unit  90 .  
      The transporting system  92  on the downstream side transports the sheet of recording paper A for scanning when it is subjected to the image recording by the recording unit  90 , and transports the sheet of recording paper A bearing the image recorded by the recording unit  90  (namely, the print thus made) to the discharging section  20 .  
      The transporting system  88  and the transporting system  92  are the same in configuration.  
      Each system is constructed by a belt conveyer which is composed of an endless belt  94  with a large number of through holes and four rollers  96  about which the belt  94  rotates; and a support  98  which is so arranged up inside the loop of the belt conveyer (endless belt  94 ) that it abuts in place on the inner surface of the endless belt  94 .  
      The support  98  has a hollow body whose top is provided with a large number of through holes, and a suction means  98   a  such as a fan is arranged in its interior. Consequently, the sheet of recording paper A can be attracted by suction and brought into moderate contact with the support  98  or rather the endless belt  94  by driving the suction means  98   a.    
      The sheet of recording paper A transported to either of the transporting systems  88  and  92  is then transported by the belt conveyer composed of the endless belt  94  and the rollers  96  while brought into moderate contact with the endless belt  94  by driving the suction means  98   a.    
      Owing to such a configuration, the transporting systems  88  and  92  located on the upstream and downstream sides, respectively, can feed the sheet of recording paper A to the recording unit  90  and further transporte the sheet for scanning while surely preventing the lifting of the sheet due to curling and so forth. Moreover, the transporting system  92  on the downstream side can transport the sheet of recording paper A after image recording to the discharging section  20  without coming into contact with the sheet surface bearing the image recorded.  
      As seen from the above, the recording unit  90  is located between the transporting systems  88  and  92 .  
      The recording unit  90  includes a conventional recording means  100  of an ink-jet type using an ink-jet recording head (hereafter referred to simply as recording head) and a reference guide  102  for regulating the sheet of recording paper A in position in the vertical direction, and is adapted to record full-color images by a conventional ink-jet recording method.  
      The method of image recording (image forming) by the recording means  100  is not particularly limited, and any method employed in conventional ink-jet printers is usable.  
      Thus, the recording means  100  may record images by a so-called full width array method (FWA method) in which a line head provided with a raw of nozzles (nozzles for ejecting ink droplets) is used, with the nozzle raw having a length exceeding the maximum width of the sheet of recording paper A, and image recording is carried out by arranging or fixing the line head so that the nozzle raw may extend in the width direction, and transporting (for scanning) the sheet of recording paper A continuously. Alternatively, the method of image recording by the recording means  100  may be a so-called partial width array method (PWA method) in which a small recording head is so mounted on a carriage (scanning means) that its nozzle raw may extend parallel to the direction in which the sheet of recording paper A is transported, and image recording is carried out by transporting the sheet of recording paper A intermittently and moving the recording head for scanning in the width direction when the transportation of the sheet of recording paper A is stopped.  
      In this regard, the transporting systems  88  and  92  located on the upstream and downstream sides, respectively, will transport the sheet of recording paper A continuously in the case of the recording means  100  recording images by a FWA method, and intermittently in the case of the recording means  100  recording images by a PWA method.  
      The reference guide  102  supports the sheet of recording paper A from below to regulate it in position in the vertical direction (direction in which ink droplets are ejected) as predetermined (that is to say, make the distance between the recording head and the sheet of recording paper A as predetermined).  
      Similar to the support  98 , the reference guide  102  has a hollow body whose top is provided with a large number of through holes, and a suction means  102   a  such as a fan is arranged in its interior. Consequently, the reference guide  102  can regulate the sheet of recording paper A in position in a specified direction while attracting the sheet by suction to a state of moderate contact with the reference guide  102  itself so as to prevent the sheet from lifting due to curling and so forth.  
      The measures for preventing the sheet of recording paper A from lifting off the reference guide  102  is not limited to suction, and various known measures including electrostatic ones are also usable.  
      If necessary, the reference guide  102  may have an ink sump in the form of a groove which is formed corresponding to the width of the sheet of recording paper A in order to prevent contamination by ink during the making of a so-called frameless print having an image recorded over its entire surface.  
      It should be noted that images are not recorded exclusively in an ink-jet manner in the image forming apparatus according to the present invention, and various known methods of image recording are also usable. Examples of such methods include a method in which a photosensitive material for silver halide photography used as recording paper is exposed imagewise to recording light such as a light beam so as to record a latent image thereon, and then subjected to wet processing; a method of recording images in an electrophotographic manner; a method of recording images by thermal recording; and a method in which a photosensitive, heat-developing recording material used as recording paper is exposed imagewise to recording light such as a light beam so as to record a latent image thereon, and then subjected to heat development.  
      The sheet of recording paper A bearing the image recorded (print) is transported by the transporting system  92  on the downstream side to the discharging section  20 . Above the transporting system  92 , or between the transporting system  92  and the discharging section  20 , a means for causing ink to dry such as a heater or fan may be provided.  
      The discharging section  20  is a conventional sorter which includes an endless belt  104  and a large number of bins  106  secured to the endless belt  104  along its circumference. Each time the prints for one order have been discharged, the endless belt  104  is rotated as predetermined in magnitude to replace the bin containing the discharged prints by a vacant one, so that prints are collected as being sorted by orders.  
      The image forming apparatus according to the present invention is herein described in detail, although the present invention is in no way limited to the above description. Various modifications or improvements thereof are readily possible within the scope of the invention.