Abstract:
Pyrazolo-quinazoline derivatives of formula (Ia) or (Ib) as defined in the specification, and pharmeceutically acceptable salts thereof, process for their preparation and pharmaceutical composition comprising them are disclosed; the compounds of the invention maybe useful in therapy, in the treatment of diseases associated with a disregulated protein kinase activity, like cancer.

Description:
BACKGROUND OF THE INVENTION 
   This application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2005-28064 filed in Japan on Feb. 3, 2005, the entire contents of which are hereby incorporated by reference. 
   The present invention relates to an image forming apparatus provided with a paper post-processing portion. 
   In recent years, as image forming apparatuses come to have multiple functions, development of paper post-processing apparatuses that perform post-processing for printed paper has been advancing. Examples of functions of such paper post-processing apparatuses include a staple function, a hole-punching function, and a binding function. However, a processing mechanism for any paper post-processing apparatus having such functions has been enlarged. Thus, when a compact image forming apparatus is provided with a paper post-processing apparatus, it is necessary to dispose the paper post-processing apparatus outside the image forming apparatus. 
   Disposing the paper post-processing apparatus outside the image forming apparatus in this manner leads to the problem not only that the area occupied by the apparatus as a whole increases but also that the electric power consumption of the apparatus as a whole increases. For example, with an electrical wiring specification generally adopted in Japan (outlet wiring: 100V, 15A), there is the possibility that the rated electric power is exceeded. In this case, the trouble is caused that it is necessary to separately wire the image forming apparatus and the paper post-processing apparatus. 
   Thus, a technique has been proposed in which a paper post-processing apparatus itself is designed so as to be compact, and the paper post-processing apparatus is disposed within a space formed in an image forming apparatus instead of disposing it outside the image forming apparatus (see JP 2003-335449A, for example). More specifically, the paper post-processing apparatus is disposed using a space formed by an original reading portion, a printing portion, and a paper-feed portion in order to solve the above-described problems. 
   On the other hand, in the image forming apparatus provided with such a conventional paper post-processing apparatus as described above, a configuration is adopted in which a discharge tray portion that can be extended or retracted is disposed on the downstream side of the paper post-processing apparatus, and the discharge tray portion is used as a paper holding portion for staple processing when staple processing is performed with the paper post-processing apparatus. 
   Furthermore, with this retractable discharge tray portion, unless the discharge tray portion is used in an extended state, discharged paper cannot be placed on the discharge tray portion and the paper falls from the discharge tray portion, depending on the types (large size such as B4 and A3, for example) of paper to be discharged. More specifically, when staple processing is performed for paper of a large size, if the discharge tray portion is retracted, then the problem is caused not only that paper falls but also that the staple processing cannot be performed. 
   SUMMARY OF THE INVENTION 
   The present invention was devised in order to solve the above-described problems of conventional techniques, and an object thereof is to provide an image forming apparatus in which paper after printing is reliably prevented from falling from a discharge tray portion and staple processing can be reliably performed, by performing print processing after confirming an extended/retracted state of the discharge tray portion, based on the request contents when a print request has been made. 
   In order to solve the above-described problems, an image forming apparatus according to the present invention is an image forming apparatus having a configuration in which an original reading portion is disposed in an upper portion of an apparatus main body, a paper-feed portion is disposed in a lower portion of the apparatus main body, a printing portion is disposed between the original reading portion and the paper-feed portion, a paper post-processing portion is disposed in a space portion of the apparatus main body formed by the original reading portion, the printing portion, and the paper-feed portion, and a discharge tray portion that can be extended and retracted, to which recording paper after post-processing is discharged, is disposed on the downstream side of the paper post-processing portion, wherein a control portion performs print processing after confirming an extended/retracted state of the discharge tray portion, based on the type of recording paper that is to be used and presence/absence of a request for post-processing by the paper post-processing portion, when a print request has been made. Herein, the apparatus main body refers to the portions in the image forming apparatus other than the paper post-processing portion and the discharge tray portion. 
   More specifically, the control portion is configured so as to confirm an extended/retracted state of the discharge tray portion when the type of recording paper that is to be used is the paper size with which it is necessary to extend the discharge tray portion. Furthermore, the control portion is configured so as to confirm an extended/retracted state of the discharge tray portion when a request for post-processing by the paper post-processing portion is a request for staple processing. A configuration is adopted in which a warning portion gives warning so as to extend the discharge tray portion when a result of the confirmation shows that the discharge tray portion is retracted. Herein, as the method for giving warning, a method by which a warning message is displayed on a crystal liquid display panel provided on the apparatus main body, a method for letting an LED or other components flicker (or operate), and a method for sounding an electronic buzzer, for example, are conceivable. By giving such warning, a user can extend the discharge tray portion before printing is started. 
   In this case, a configuration may be adopted in which an extended/retracted state of the discharge tray portion is confirmed based on a detection signal from an extension/retraction detection sensor for detecting extension/retraction of the discharge tray portion. Furthermore, a paper detection sensor for detecting presence/absence of recording paper, which has been conventionally disposed on the discharge tray portion, may be used also as the extension/retraction detection sensor. By using the paper detection sensor also for this purpose, it is possible to suppress an increase in the number of components and a complexity of the configuration. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view showing a schematic configuration of a compound machine in which the present invention is applied. 
       FIG. 2  is a view showing a schematic configuration of a paper post-processing portion and a discharge tray of the compound machine. 
       FIG. 3  is a perspective view showing the paper post-processing portion and the discharge tray of the compound machine, illustrating a state in which the discharge tray is retracted and raised and in which a cover is closed. 
       FIG. 4  is a perspective view showing a state in which the discharge tray of the compound machine is lowered. 
       FIG. 5  is a perspective view showing a state in which the discharge tray of the compound machine is extended. 
       FIG. 6  is a perspective view showing a state in which the cover of the compound machine is open. 
       FIG. 7  is a functional block diagram showing the configuration of a main portion of a control portion that accommodates, for example, a circuit substrate for controlling an image forming process of the compound machine according to this embodiment and an interface substrate for receiving image data from an external device. 
       FIG. 8  is a flowchart for illustrating a print processing operation by the control portion of the compound machine when a print request has been made. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Hereinafter, embodiments of the present invention are described with reference to the drawings. 
   In this embodiment, a case is described in which an image forming apparatus provided with a paper post-processing portion according to the present invention is applied in a compound machine.  FIG. 1  shows the outline of the internal configuration of the compound machine. First, the overall configuration of the compound machine is described. 
   As shown in  FIG. 1 , a compound machine  1  is provided with a scanner portion  2  as image reading means, an image forming portion  3 , an original automatic feed portion  4 , and a paper post-processing portion  5  as paper post-processing means. It should be noted that for the sake of convenience, the portions in the compound machine  1  other than the paper post-processing portion  5  and a discharge tray  8  are referred to as an “apparatus main body”. 
   The compound machine  1  has a copier mode, a printer mode, and a FAX mode as image forming modes in which an image is formed on recording paper (including recording media such as OHP) and the modes are selected by a user. Hereinafter, components of the compound machine  1  are described, and then operation in print processing according to the present invention is described. 
   Description of the Scanner Portion  2   
   The scanner portion  2  is a portion that creates original image data by reading an image of an original that has been placed on an original stage  41  made of transparent glass, for example, or an image of originals that are fed page by page from the original automatic feed portion  4 . This scanner portion  2  is provided with an exposing light source  21 , a plurality of reflecting mirrors  22 ,  23 , and  24 , an imaging lens  25 , and a photoelectric transducer (CCD: charge coupled device)  26 . 
   The exposing light source  21  irradiates light to an original that has been placed on the original stage  41  of the original automatic feed portion  4  or an original that is transported from the original automatic feed portion  4 . As shown in  FIG. 1  in which an optical path is indicated by the dashed dotted line A, the reflecting mirrors  22 ,  23 , and  24  reflect reflected light from the original in the leftward direction in  FIG. 1 , then reflect that light downward, then reflect that light in the rightward direction in  FIG. 1  toward the imaging lens  25 . 
   There are the following two original image reading operations. On the one hand, when reading an original that has been placed on the original stage  41  (when used as a “sheet fixing system”), the exposing light source  21  and the reflecting mirrors  22 ,  23 , and  24  scan in the horizontal direction along the original stage  41 , and read an image of the entire original. On the other hand, when reading an original that is transported from the original automatic feed portion  4  (when used as a “sheet moving system”), the exposing light source  21  and the reflecting mirrors  22 ,  23 , and  24  are fixed in the positions shown in  FIG. 1 , and an image is read when the original passes an original reading portion  42  of the original automatic feed portion  4  described below. 
   Light that has been reflected by the reflecting mirrors  22 ,  23 , and  24  and has passed the imaging lens  25  is guided to the photoelectric transducer  26 , and the reflected light is converted to an electrical signal (original image data) in this photoelectric transducer  26 . 
   Description of the Image Forming Portion  3   
   The image forming portion  3  is provided with an image forming system  31  as printing means, and a paper transport system  32 . 
   The image forming system  31  is provided with a laser scanning unit  31   a  and a photosensitive drum  31   b  as a drum-type image carrier. The laser scanning unit  31   a  irradiates the surface of the photosensitive drum  31   b  with laser light based on the original image data that has been converted in the photoelectric transducer  26 , or image data that has been input from an external terminal apparatus, for example. The photosensitive drum  31   b  rotates in the direction indicated by the arrow in  FIG. 1 , and by laser light from the laser scanning unit  31   a  being irradiated, an electrostatic latent image is formed on the surface of the photosensitive drum  31   b.    
   In addition to the laser scanning unit  31   a,  a development unit (development mechanism)  31   c,  an unshown transfer unit (transfer mechanism) having a transfer roller  31   d,  a cleaning unit (cleaning mechanism)  31   e,  an unshown charge removal device, and an unshown charging unit (charging mechanism) having a charging roller  31   f  are arranged in order in the circumferential direction around the outer circumference of the photosensitive drum  31   b.    
   The development unit  31   c  develops the electrostatic latent image that has been formed on the surface of the photosensitive drum  31   b  into a visible image with toner (manifesting agent). The transfer roller  31   d  transfers the toner image that has been formed on the surface of the photosensitive drum  31   b  to recording paper as a recording medium. The cleaning unit  31   e  removes toner remaining on the surface of the photosensitive drum  31   b  after toner transfer. The charge removal device removes an electrical charge remaining on the surface of the photosensitive drum  31   b.  The charging roller  31   f  charges the surface of the photosensitive drum  31   b  to a predetermined potential before an electrostatic latent image is formed. 
   When an image is formed on recording paper, the surface of the photosensitive drum  31   b  is charged to a predetermined potential by the charging roller  31   f,  and the laser scanning unit  31   a  irradiates the surface of the photosensitive drum  31   b  with laser light based on the original image data. Subsequently, the development unit  31   c  develops a visible image with toner on the surface of the photosensitive drum  31   b,  and the toner image is transferred to the recording paper by the transfer roller  31   d.  Subsequently, the toner remaining on the surface of the photosensitive drum  31   b  is removed by the cleaning unit  31   e,  and the electrical charge remaining on the surface of the photosensitive drum  31   b  is removed by the charge removal device. Accordingly, one cycle of the image forming operation (print operation) on recording paper is concluded. It is possible to successively form images on a plurality of pages of recording paper by repeating this cycle. 
   On the other hand, the paper transport system  32  allows the image forming system  31  to form an image by page by page transporting recording paper accommodated in the paper cassette  33  as feed means or recording paper placed on the manual tray  34 , and discharges the recording paper on which an image has been formed, via the paper post-processing portion  5  described below, to the discharge tray  8  as discharge means. The discharge tray  8  is provided above the paper cassette  33  and below the scanner portion  2 . A detailed description of the discharge tray  8  is given below. 
   The paper transport system  32  is provided with a main transport path  36  and a reverse transport path  37  in the apparatus main body, and a main transport path  51  and a switchback transport path  52  in the paper post-processing portion  5  shown in  FIG. 2 . The main transport path  36  of the apparatus main body and the main transport path  51  of the paper post-processing portion  5  are connected to each other at discharge rollers  36   e  of the apparatus main body serving as the boundary. A description of the main transport path  51  and the switchback transport path  52  of the paper post-processing portion  5  is given below. In the compound machine  1 , the recording paper is transported through the paper transport system  32  with a so-called center reference. More specifically, the recording paper is transported with the center position of the recording paper in the widthwise direction (the direction perpendicular to the transport direction of the recording paper) used as a reference. 
   In the apparatus main body, one end side of the main transport path  36  is branched into two, with one branch end being opposed to the discharge side of the paper cassette  33  and the other branch end being opposed to the discharge side of the manual tray  34 . Furthermore, the other end side of the main transport path  36  is opposed to a punching unit  60  of the paper post-processing portion  5 . One end side of the reverse transport path  37  is connected to the main transport path  36  on the upstream side (the lower side in  FIG. 1 ) of the position at which the transfer roller  31   d  is disposed, and the other end side is connected to the main transport path  36  on the downstream side (the upper side in  FIG. 1 ) of the position at which the transfer roller  31   d  is disposed. 
   A pickup roller  36   a  with a semicircular-shaped cross section is disposed at one branch end (the portion opposed to the discharge side of the paper cassette  33 ) of the main transport path  36 . Due to rotation of this pickup roller  36   a,  it is possible to intermittently feed the recording paper accommodated in the paper cassette  33  page by page to the main transport path  36 . In a similar manner, a pickup roller  36   b  with a semicircular-shaped cross section is disposed at the other branch end (the portion opposed to the discharge side of the manual tray  34 ) of the main transport path  36 . Due to rotation of this pickup roller  36   b,  it is possible to intermittently feed the recording paper placed on the manual tray  34  page by page to the main transport path  36 . 
   Registration rollers  36   d  are arranged on the upstream side of the position at which the transfer roller  31   d  is disposed in this main transport path  36 . The registration rollers  36   d  transport recording paper while matching the positions of the recording paper and the toner image on the surface of the photosensitive drum  31   b.    
   On the downstream side of the position at which the transfer roller  31   d  is disposed on the main transport path  36 , a fixing unit  39  is disposed that is provided with a pair of rollers including a hot roller  39   a  and a pressure roller  39   b  for fixing the toner image transferred to the recording paper with heat. Furthermore, at the downstream end of the main transport path  36 , the discharge rollers  36   e  for discharging the recording paper to the paper post-processing portion  5  are arranged at the boundary with the main transport path  51  of the paper post-processing portion  5 . 
   A branch catch  38  is disposed at the position at which the upstream end of the reverse transport path  37  is connected to the main transport path  36 . This branch catch  38  can rotate around a horizontal axis between a first position (the position indicated by the solid line) in  FIG. 1  and a second position that opens the reverse transport path  37  by rotating from the first position in the counterclockwise direction in  FIG. 1 . When the branch catch  38  is in the first position, recording paper is transported toward the main transport path  51  of the paper post-processing portion  5 . When the branch catch  38  is in the second position, recording paper can be fed to the reverse transport path  37 . 
   Transport rollers  37   a  are arranged on the reverse transport path  37 . When the recording paper that has been switchbacked on the switchback transport path  52  in the paper post-processing portion  5  is fed to the reverse transport path  37 , the recording paper is transported by the transport rollers  37   a,  so that the recording paper is guided onto the main transport path  36  on the upstream side of the registration rollers  36   d  to be transported on the main transport path  36  again toward the transfer roller  31   d.  More specifically, an image can be formed on the rear face of the recording paper. 
   Description of the Original Automatic Feed portion  4   
   The original automatic feed portion  4  is configured as a so-called automatic duplex original transport apparatus. The original automatic feed portion  4  can be used as a sheet moving system, and is provided with an original tray  43  as an original placement portion, a middle tray  44 , an original discharge tray  45  as an original discharge portion, and an original transport system  46  that transports an original between the trays  43 ,  44 , and  45 . 
   The original transport system  46  is provided with a main transport path  47  for transporting an original that has been placed on the original tray  43  via the original reading portion  42  to the middle tray  44  or the original discharge tray  45 , and a sub transport path  48  for feeding an original on the middle tray  44  to the main transport path  47 . 
   An original pickup roller  47   a  and a stacking roller  47   b  are arranged at the upstream end (the portion opposed to the discharge side of the original tray  43 ) of the main transport path  47 . A stacking plate  47   c  is disposed on the lower side of the stacking roller  47   b.  In accordance with rotation of the original pickup roller  47   a,  one page of the original on the original tray  43  passes between the stacking roller  47   b  and the stacking plate  47   c  and is fed to the main transport path  47 . PS rollers  47   e  and  47   e  are arranged on the downstream side of a linking portion (portion B in  FIG. 1 ) between the main transport path  47  and the sub transport path  48 . These PS rollers  47   e  and  47   e  adjust the leading edge of the original and the image read timing of the scanner portion  2  and feed the original to the original reading portion  42 . More specifically, the PS rollers  47   e  and  47   e  temporarily stop transport of the original with the original in a fed state, adjust the above-described timing, and feed the original to the original reading portion  42 . 
   The original reading portion  42  is provided with a glass platen  42   a  and an original pressing plate  42   b,  and when the original fed from the PS rollers  47   e  and  47   e  passes between the glass platen  42   a  and the original pressing plate  42   b,  light from the exposing light source  21  passes through the glass platen  42   a  and is irradiated onto the original. At this time, original image data is acquired by the scanner portion  2 . Biasing force is conferred on the rear face (top face) of the original pressing plate  42   b  by an unshown coil spring. Thus, the original pressing plate  42   b  is in contact with the glass platen  42   a  with a predetermined pressure, and when the original passes the original reading portion  42 , the original is prevented from rising up from the glass platen  42   a.    
   Transport rollers  47   f  and original discharge rollers  47   g  are provided on the downstream side of the glass platen  42   a.  An original that has passed on the glass platen  42   a  passes the transport rollers  47   f  and the original discharge rollers  47   g  and is discharged to the middle tray  44  or the original discharge tray  45 . 
   A middle tray swinging plate  44   a  is disposed between the original discharge rollers  47   g  and the middle tray  44 . The middle tray swinging plate  44   a  swings centered on the end portion on the side of the middle tray  44 , and can swing between a position  1  (the position indicated by the solid line) in  FIG. 1  and a position  2  flipped upward from the position  1 . When the middle tray swinging plate  44   a  is in the position  2 , an original that has been discharged from the original discharge rollers  47   g  is recovered to the original discharge tray  45 . On the other hand, when the middle tray swinging plate  44   a  is in the position  1 , an original that has been discharged from the original discharge rollers  47   g  is discharged to the middle tray  44 . When paper is discharged to the middle tray  44 , the marginal edge of the original is in a state sandwiched between the original discharge rollers  47   g  and  47   g,  the original is fed to the sub transport path  48  by the reverse rotation of the original discharge rollers  47   g  from this state, and the original is sent via this sub transport path  48  again onto the main transport path  47 . This reverse rotation operation of the original discharge rollers  47   g  is performed such that the timing for sending the original onto the main transport path  47  and the image read timing are adjusted. Accordingly, an image on the rear face of the original is read by the image reading portion  42 . 
   Description of the Paper Post-Processing Portion  5  and the Discharge Tray  8   
   The paper post-processing portion  5  makes it possible to perform a plurality of types of paper post-processing such as punching processing and staple processing for the recording paper that is discharged from the apparatus main body after print processing is finished. Such paper post-processing in the paper post-processing portion  5  is, as described below, performed when there is a request for paper post-processing as a print condition when a print request has been made. 
   In this example, a configuration is adopted in which the paper post-processing portion  5  and the discharge tray  8  are provided using a space C formed by the apparatus main body of the compound machine  1  instead of providing them outside the apparatus main body. More specifically, the apparatus main body of the compound machine  1  adopts a configuration in which the paper cassette  33 , the image forming portion  3  (the image forming system  31 ), and the scanner portion  2  are arranged in approximately the shape of a U, and the paper post-processing portion  5  and the discharge tray  8  are provided in the internal U-shaped space C formed by this apparatus main body. Accordingly, it is possible to arrange the paper post-processing portion  5  and the discharge tray  8  in a limited space within the compound machine  1 , and a plurality of types of paper post-processing can be performed for the recording paper. Furthermore, the area occupied by the compound machine  1  provided with the paper post-processing portion  5  is suppressed and it is possible to achieve space conservation. 
   Hereinafter, the paper post-processing portion  5  and the discharge tray  8  are described in detail using  FIGS. 2 to 6 . It should be noted that the transport direction (the direction shown in  FIG. 3 ) of recording paper is referred to as a “paper transport direction”, and the widthwise direction (the direction shown in  FIG. 3 ) of recording paper perpendicular to the paper transport direction is referred to as a “paper widthwise direction”. 
   As shown in  FIG. 2 , the paper post-processing portion  5  is disposed on the downstream side of the discharge rollers  36   e  of the apparatus main body. The punching unit  60  provided with a hole-punching function and a staple unit  70  provided with a staple function are arranged as a paper post-processing unit in the paper post-processing portion  5 . The front face (face on the near side) of the paper post-processing portion  5  is covered by a cover  50  that can be opened and closed. In the paper post-processing portion  5 , the punching unit  60  is disposed on the upstream side and the staple unit  70  is disposed on the downstream side. On the downstream side of the paper post-processing portion  5 , the discharge tray  8  is disposed. The recording paper that is discharged from the discharge rollers  36   e  passes the punching unit  60  and the staple unit  70  and is discharged to the discharge tray  8 . The discharge tray  8  is used as a paper holding portion for staple processing when staple processing is performed with the staple unit  70  of the paper post-processing portion  5 . 
   Description of the Punching Unit  60   
   The punching unit  60  performs hole-punching processing (punching processing) for the recording paper that is discharged from the discharge rollers  36   e.  The punching unit  60  is provided with a hole-punching mechanism portion  61 , a guide plate  62 , and a punch waste accommodating box  63 , for example. Furthermore, as the paper transport system  32  described above, the main transport path  51  is formed. In the punching unit  60 , transport rollers  56  are arranged on the main transport path  51 . It should be noted that unlike the staple unit  70  described below, the punching unit  60  is fixed on the apparatus main body. 
   In the punching unit  60 , if there is a request for punching processing as a print condition when a print request has been made, then recording paper that has been transported to the punching unit  60  is stopped on the guide plate  62  and punch holes are made page by page with the hole-punching mechanism portion  61 . A configuration is adopted in which at that time, punch holes are made at positions determined based on the printing paper size. 
   The hole-punching mechanism portion  61  is disposed in the upper portion of the punching unit  60 . The hole-punching mechanism portion  61  is provided with two core members  64  with a diameter corresponding to the diameter of a punch hole, at locations with a predetermined spacing therebetween in the paper widthwise direction. The core members  64  are arranged such that they can be vertically raised or lowered, and make punch holes through the recording paper when the core members  64  are lowered. Furthermore, the core members  64  are arranged such that they can move back and forth in the direction along the paper transport direction and in the direction along the paper widthwise direction, so that it is possible to match the position when punching processing is performed, as described below. 
   The guide plate  62  is disposed below the hole-punching mechanism portion  61 . Opening portions corresponding to predetermined positions at which punch holes are made are formed on the guide plate  62 . The punch waste accommodating box  63  is disposed in the lower portion of the punching unit  60 , so that the punch waste accommodating box  63  recovers punch waste generated in hole-punching processing. The punch waste accommodating box  63  is disposed such that it can slide in the paper widthwise direction, so that it can be removed to the near side when the cover  50  is opened as described below. Accordingly, punch waste accommodated in the punch waste accommodating box  63  can be removed. 
   When punching processing is performed with the punching unit  60 , the core members  64  of the hole-punching mechanism portion  61  are moved to positions corresponding to the above-described positions determined based on the printing paper size. 
   In addition to the above, the core members  64  of the hole-punching mechanism portion  61  of the punching unit  60  can be moved for fine adjustment such that punch holes can be accurately made at the above-described positions determined based on the printing paper size. A description of the fine adjustment movement has been omitted. 
   Description of the Staple Unit  70   
   The staple unit  70  performs staple processing for the recording paper that is transported from the punching unit  60  on the upstream side. The staple unit  70  is disposed such that it can slide in the direction along the paper transport direction when the cover  50  is opened upward so as to be opened in the near direction. Furthermore, the staple unit  70  is disposed such that it can be engaged with or removed from the punching unit  60  disposed on the upstream side of the staple unit  70 , as described below. 
   The staple unit  70  is provided with a staple mechanism portion  71 , a staple stage  72 , adjusting plates  73 , and discharge rollers  74 , for example. Furthermore, as the paper transport system  32  described above, the main transport path  51  and the switchback transport path  52  are formed. In the staple unit  70 , a branch catch  53  for switching the direction in which recording paper is guided and discharge rollers  54  for discharging recording paper to the staple stage  72  are provided at the position at which the downstream side on the main transport path  51  is connected to the upstream side on the switchback transport path  52 . Furthermore, switchback rollers  55  are provided on the downstream side on the switchback transport path  52 . 
   In the staple unit  70 , if there is a request for staple processing as a print condition when a print request has been made, then the staple mechanism portion  71  performs staple processing for a predetermined number of pages of recording paper placed on the staple stage  72 . At this time, staple processing is performed at the position determined based on the printing paper size and a desired staple position. The desired staple position refers to the position at which staple processing desired by a user is performed, such as fastening at one location in the upper left corner portion of the recording paper or fastening at two locations in the left end portion, for example. 
   The staple mechanism portion  71  is disposed below the discharge rollers  54 , and binds the trailing end portion of recording paper placed on the staple stage  72  with staples. The staple mechanism portion  71  is configured such that it can move back and forth in the paper widthwise direction, so that staple processing can be performed at the above-described position determined based on the printing paper size and the desired staple position. When staple processing is performed with the staple unit  70 , the staple mechanism portion  71  is moved to a position corresponding to the above-described position determined based on the printing paper size and the desired staple position. 
   Recording paper discharged from the discharge rollers  54  is placed on the staple stage  72 , and the staple stage  72  serves as a processing stage for staple processing performed by the staple mechanism portion  71 . The staple stage  72  is disposed with the downstream side in the paper transport direction sloped upward. When staple processing is performed, the recording paper discharged from the discharge rollers  54  slides along the slope of the staple stage  72  to the upstream side in the paper transport direction due to the paper&#39;s own weight. On the other hand, when staple processing is not performed, the recording paper is discharged from the discharge rollers  74  to the discharge tray  8 . 
   The adjusting plates  73  are arranged so as to be opposed to each other on both sides of the top face (the face on which the recording paper is discharged) of the staple stage  72  in the direction along the paper widthwise direction. A pair of adjusting plates  73  is arranged such that they can move back and forth in the paper widthwise direction. When staple processing is performed with the staple unit  70 , by moving the adjusting plates  73  in the paper widthwise direction, adjustment in the paper widthwise direction is performed for each page of recording paper discharged onto the staple stage  72 . At this time, the adjusting plates  73  are moved in accordance with a movable width determined based on the printing paper size, that is, based on the size of the recording paper that is being transported. The back and forth movement of the pair of adjusting plates  73  is, for example, possible with a rack and pinion mechanism. 
   Description of the Discharge Tray  8   
   The discharge tray  8  is disposed, together with the paper post-processing portion  5  described above, in the internal U-shaped space C formed by the apparatus main body of the compound machine  1 . Recording paper on which paper post-processing such as punching processing and staple processing has been performed in the paper post-processing portion  5  is discharged to the discharge tray  8 . The discharge tray  8  is disposed such that it can be extended or retracted in the paper transport direction (the direction in which recording paper is discharged). Furthermore, it is disposed such that it can be vertically raised or lowered. In addition, it is disposed such that it can slide with respect to the apparatus main body. 
   As shown in  FIGS. 3 and 5 , the discharge tray  8  is formed as a tray that can be extended or retracted within a range of one to three stages in the direction along the paper transport direction. In this example, the discharge tray  8  is configured such that it can be manually extended or retracted in the paper transport direction by a user in accordance with the printing paper size. 
   The discharge tray  8  is provided with a first discharge tray  81 , a second discharge tray  82 , and a third discharge tray  83 . The first discharge tray  81  is a tray of the largest size and is disposed closest to the paper post-processing portion  5 . The first discharge tray  81  is formed to have a length that does not project from the lateral face (lateral wall) of the compound machine  1 . The first discharge tray  81  is integrally attached to the apparatus main body, and has a structure in which a movement in the direction along the paper transport direction is impossible. 
   The second discharge tray  82  is a tray of a medium size and is accommodated in an accommodating portion  81   a  formed in the first discharge tray  81 . The second discharge tray  82  is disposed such that it can move forward and backward in the direction along the paper transport direction. The third discharge tray  83  is a tray of the smallest size and is accommodated in an accommodating portion  82   a  formed in the second discharge tray  82 . The third discharge tray  83  is disposed such that it can move forward and backward in the direction along the paper transport direction. 
   As shown in  FIG. 3 , in a state where the discharge tray  8  is retracted to only one stage, the length in the direction along the paper transport direction of the discharge tray  8  is the shortest, the third discharge tray  83  is completely accommodated in the second discharge tray  82 , and the second discharge tray  82  is completely accommodated in the first discharge tray  81 . At that time, the length in the direction along the paper transport direction of the discharge tray  8  is equal to the length in the direction along the paper transport direction of the first discharge tray  81 , and is the length that does not project from the lateral face of the compound machine  1 . A configuration is adopted in which the discharge tray  8  does not project from the apparatus main body in this manner in a state where the discharge tray  8  is retracted most, so that the discharge tray  8  can be accommodated in a space of the apparatus main body when the compound machine  1  is not used. 
   On the contrary, as shown in  FIG. 5 , in a state where the discharge tray  8  is extended to three stages, the length in the direction along the paper transport direction of the discharge tray  8  is the longest, the second discharge tray  82  projects to a maximum extent from the first discharge tray  81 , and the third discharge tray  83  projects to a maximum extent from this second discharge tray  82 . At that time, the length in the direction along the paper transport direction of the discharge tray  8  is longer than the length in the paper transport direction of recording paper of the largest size (such as A3 horizontal size) that can be printed with the compound machine  1 . Accordingly, when the discharge tray  8  is extended to a maximum length, even recording paper of the largest size (such as A3 horizontal size) that can be printed can be stably placed. As described below, the discharge tray  8  is configured such that it can slide together with the staple unit  70 . Even when the discharge tray  8  is led to slide in a state where recording paper is placed on the discharge tray  8 , the recording paper does not fall from the discharge tray  8 . 
   As described above, the discharge tray  8  is disposed such that it can be extended or retracted in the direction along the paper transport direction, and thus it is possible to use the discharge tray  8  after adjusting it to an optimal length in accordance with the printing paper size. 
   Furthermore, an opening portion  82   b  is formed in the vicinity of the base end portion on the upper face of the second discharge tray  82 , and an operation lever  91   a  of a first paper detection sensor  91  is disposed so as to project upward from the opening portion  82   b.  The operation lever  91   a  is biased such that it always projects upward, and when the second discharge tray  82  is accommodated in the first discharge tray  81 , the operation lever  91   a  is pressed downward by the upper face of the internal wall of the first discharge tray  81 . Then, when the second discharge tray  82  is completely pulled out from the first discharge tray  81  (in a state shown in  FIG. 5 ), the operation lever  91   a  rotates to return to the normal position projecting upward from the opening portion  82   b.  In this embodiment, the first paper detection sensor  91  is disposed so as to be off in a state where the operation lever  91   a  projects upward, and so as to be on in a state where the operation lever  91   a  is pressed downward by the upper face of the internal wall of the first discharge tray  81 . 
   In a similar manner, an opening portion  83   a  is formed in the vicinity of the base end portion on the upper face of the third discharge tray  83 , and an operation lever  92   a  of a second paper detection sensor  92  is disposed so as to project upward from the opening portion  83   a.  The operation lever  92   a  is biased such that it always projects upwards, and when the third discharge tray  83  is accommodated in the second discharge tray  82 , the operation lever  92   a  is pressed downward by the upper face of the internal wall of the second discharge tray  82 . Then, when the third discharge tray  83  is completely pulled out from the second discharge tray  82  (in a state shown in  FIG. 5 ), the operation lever  92   a  rotates to return to the normal position projecting upward from the opening portion  83   a.  In this embodiment, the second paper detection sensor  92  is disposed so as to be off in a state where the operation lever  92   a  projects upward, and so as to be on in a state where the operation lever  92   a  is pressed downward by the upper face of the internal wall of the second discharge tray  82 . 
   In other words, the first paper detection sensor  91  and the second paper detection sensor  92  are off in a state where the trays  82  and  83  are pulled out, and when recording paper after printing is discharged and placed on the trays  82  and  83 , the placed recording paper presses down the operation levers  91   a  and  92   a  downward, resulting that the first paper detection sensor  91  and the second paper detection sensor  92  are turned on. Then, they are turned off again when the recording paper after printing is taken out of the discharge tray  8  by a user. Accordingly, it is possible to detect whether or not there is recording paper on the discharge tray  8 . 
   Furthermore, the first and the second paper detection sensors  91  and  92  can be used also as extension/retraction detection sensors that detect whether or not the second discharge tray  82  and the third discharge tray  83  are pulled out before printing is started. More specifically, before printing is started, if the first paper detection sensor  91  is on, then it can be determined that the second discharge tray  82  is not pulled out from the first discharge tray  81 , and if the first paper detection sensor  91  is off, then it can be determined that the second discharge tray  82  is pulled out from the first discharge tray  81 . Furthermore, before printing is started, if the second paper detection sensor  92  is on, then it can be determined that the third discharge tray  83  is not pulled out from the second discharge tray  82 , and if the second paper detection sensor  92  is off, then it can be determined that the third discharge tray  83  is pulled out from the second discharge tray  82 . 
   Furthermore, as shown in  FIGS. 3 and 4 , the discharge tray  8  is formed as a tray that can be vertically raised or lowered. In this example, a configuration is adopted in which the discharge tray  8  is raised or lowered in accordance with the amount (the number of pages) of recording paper placed thereon. 
   The amount of recording paper that is discharged to the discharge tray  8  is detected by an upper limit sensor  84  provided in the vicinity of the discharge roller  74  on the lower side. The upper limit sensor  84  is provided as a contact-type sensor. When the uppermost face of the recording paper that is placed on the discharge tray  8  reaches a predetermined height, the upper limit sensor  84  is turned on. Accordingly, it is detected that the discharge tray  8  is full. When a full state is detected in this manner, the discharge tray  8  is lowered only by a predetermined distance. When the discharge tray  8  is lowered in this manner, the upper limit sensor  84  is turned off. The amount of the recording paper that is placed on the discharge tray  8  is detected based on a switching between on/off of the upper limit sensor  84 . In this example, the home position of the discharge tray  8  is set at the position (the position shown in  FIG. 3 ) obtained by raising the discharge tray  8  to the uppermost, and the end portion on the upstream side on the discharge tray  8  is disposed directly below the discharge rollers  74 . A configuration is adopted in which the discharge tray  8  is gradually lowered as the amount of recording paper placed on the discharge tray  8  increases. It should be noted that the upper limit sensor  84  may be provided as an optical sensor. 
   As described above, the discharge tray  8  is disposed such that it can be extended or retracted, and it is raised or lowered, the first discharge tray  81  is raised or lowered, and the second discharge tray  82  and the third discharge tray  83  are raised or lowered together with the first discharge tray  81 . 
   The first discharge tray  81  is raised or lowered in the following manner, for example. A drive portion  85  for raising or lowering the first discharge tray  81  is disposed on the rear side of the first discharge tray  81 . A drive belt (not shown) is accommodated in the drive portion  85 , and the drive belt can be driven by an unshown electric power source for driving, which is connected to a wiring  86 . A support member for supporting the front-end portion of the first discharge tray  81  is connected to the drive portion  85 . The support member is disposed such that it vertically moves back and forth by driving the drive belt. Then, a motive power of the drive belt in the drive portion  85  is transmitted via the support member to the first discharge tray  81 , so that the first discharge tray  81  is raised or lowered. Furthermore, an arm  88  for supporting the first discharge tray  81  is provided in the lower portion of the first discharge tray  81 . The arm  88  is disposed between the first discharge tray  81  and a bottom portion  89 . The arm  88  is disposed so as to be bent in the shape of an L, and the bending angle can be changed. The bending degree of the arm  88  changes in accordance with the position to which the first discharge tray  81  has been raised or lowered. Protrusions are arranged at the end portion, closer to the paper post-processing portion  5 , of the first discharge tray  81 . The protrusions are engaged with vertically extending groove portions arranged on the paper post-processing portion  5 , such that the protrusions can slide in the groove portions. 
   The entire description of the compound machine  1  has been given above. 
     FIG. 7  is a functional block diagram showing the configuration of a main portion of a control portion that accommodates, for example, a circuit substrate for controlling an image forming process of the thus configured compound machine  1  and an interface substrate for receiving image data from an external device. 
   A control portion  90  is constituted mainly by a CPU  911 , which is a central processing unit, and also by an image information receiving portion  912 , an original reading portion  913 , an image processing portion  914 , an operation portion (input/display portion)  915 , a drive portion  916 , a paper-feed portion  917 , a printing portion  918 , a discharge portion  919 , a post-processing portion  920 , and a temperature control portion  921 . Herein, the first paper detection sensor  91  and the second paper detection sensor  92  described above are included in the discharge portion  919 . 
   Next, referring to a flowchart shown in  FIG. 8 , a print processing operation by the control portion  90  when a print request has been made is described. 
   When a user operates the operation portion  915  such as a liquid crystal display panel of the apparatus main body to set various print contents (such as the paper type, the number of pages to be printed, and whether or not post-processing is to be performed), so that a print request is made (step S 1 ), then the control portion  90  first confirms whether or not there is a request for staple processing for printed paper (step S 2 ). If the result shows that there is a request for staple processing (if determined to be Yes in step S 2 ), then a detection state (on/off state) of the first and the second paper detection sensors  91  and  92  is confirmed, so that it is determined whether or not the discharge tray  8  is extended as described above (step S 3 ). If the result shows that the discharge tray  8  is extended, that is, if at least either one of the first paper detection sensor  91  and the second paper detection sensor  92  is off (if determined to be Yes in step S 3 ), then print processing is started as it is (step S 4 ), and when the print processing is performed to the last (if determined to be Yes in step S 5 ), then the procedure returns to a standby state until the next print request is made. 
   On the other hand, if there is a request for staple processing and if the discharge tray  8  is retracted, that is, if both of the first paper detection sensor  91  and the second paper detection sensor  92  are on (if determined to be Yes in step S 2  and No in step S 3 ), then the control portion  90  displays a message urging the discharge tray  8  to be extended, on the liquid crystal display panel of the operation portion  915  (step S 6 ) and monitors the first paper detection sensor  91  and the second paper detection sensor  92 , so as to monitor whether or not at least either one of the sensors is switched from on to off (step S 7 ). If the user looking at this warning message extends the discharge tray  8  and thus at least either one of the first paper detection sensor  91  and the second paper detection sensor  92  is switched from on to off (if determined to be Yes in step S 7 ), then the control portion  90  starts print processing (step S 4 ), and when the print processing is performed to the last (if determined to be Yes in step S 5 ), then the procedure returns to a standby state until the next print request is made. 
   On the other hand, if there is no request for staple processing in step S 2  (if determined to be No), then it is determined whether or not the size of paper on which a print request has been made is longer than the discharge tray  8  in a retracted state (that is, whether or not it is the size at which the paper cannot be placed on the discharge tray  8  unless it is used in an extended state), based on the print contents set by the user (step S 8 ). More specifically, when the discharge tray  8  in a retracted state corresponds to the A4 vertical size, if recording paper with a size of B4 vertical or A3 vertical is used, then it is determined to be Yes in step S 8 . If determined to be Yes in step S 8  in this manner, then the control portion  90  displays a message urging the discharge tray  8  to be extended, on the liquid crystal display panel of the operation portion  915  (step S 6 ) and monitors the first paper detection sensor  91  and the second paper detection sensor  92 , so as to monitor whether or not at least either one of the sensors is switched from on to off (step S 7 ). If the user looking at this warning message extends the discharge tray  8  and thus at least either one of the first paper detection sensor  91  and the second paper detection sensor  92  is switched from on to off (if determined to be Yes in step S 7 ), then the control portion  90  starts print processing (step S 4 ), and when the print processing is performed to the last (if determined to be Yes in step S 5 ), then the procedure returns to a standby state until the next print request is made. 
   On the other hand, if it is determined that the size of paper on which a print request has been made is equal to or shorter than the discharge tray  8  in a retracted state in step S 8  (if determined to be No in step S 8 ), then print processing is started as it is (step S 4 ), and when the print processing is performed to the last (if determined to be Yes in step S 5 ), then the procedure returns to a standby state until the next print request is made. 
   It should be noted that although when a print request has been made, first it is confirmed whether or not there is staple processing to be performed (step S 2 ), and then the size of paper on which a print request has been made is confirmed (step S 3 ) in the above description on the operation, this order may be in reverse. Furthermore, in the above description on the operation, a configuration is adopted in which a warning message is displayed on a liquid crystal display panel as a warning portion, but the warning portion is not limited to this, and it is possible to give warning, for example, by letting an LED or other components flicker (or operate), or letting an electronic buzzer make a buzzer sound, and a use of them in combination is also possible. 
   The present invention can be embodied and practiced in other different forms without departing from the spirit and essential characteristics thereof. Therefore, the above-described embodiments are considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations and modifications falling within the equivalency range of the appended claims are intended to be embraced therein.