Patent Publication Number: US-8967749-B2

Title: Printing device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2012-174690 filed on Aug. 7, 2012. The entire disclosure of Japanese Patent Application No. 2012-174690 is hereby incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a printing device. 
     2. Background Technology 
     As with an ink jet printer, with a printing device for which a recording head that discharges ink drops is scanned over media it faces opposite to print, printing is done with paper feeding of paper from a feed cassette or a tray in which sheet form paper is housed, and the printed paper is ejected to a stacker. In recent years, as shown in Patent Document  1  noted hereafter, models that have built in devices for reversing the front and back of the paper, and models for which it is possible to mount a plurality of feed cassettes of different paper sizes have been manufactured, and there was a tendency for the paper conveyance path to become complex and for the conveyance path to become long. With this kind of model, with improvement of the processing capacity of the ink jet printer as a countermeasure, an attempt was made to shorten the time needed for conveying by accelerating the conveyance speed for conveying in the conveyance path. 
     Japanese Laid-open Patent Publication No. 2010-47014 (Patent Document 1) is an example of the related art. 
     SUMMARY 
     Problems to Be Solved by the Invention 
     However, by making the conveyance speed fast, noise occurred from the sliding part of the ink jet printer, and this was unpleasant for people in the vicinity. Also, when the conveyance speed was reduced in order to reduce noise from the ink jet printer, the printing efficiency of the ink jet printer decreased. 
     Means Used to Solve the Above-Mentioned Problems 
     The invention was creased to address at least a part of the problems described above, and can be realized in the following modes or application examples. 
     Application Example 1 
     The printing device of this application example is a printing device for spraying ink drops on media that faces opposite a recording head that moves in the scanning direction and that moves in the sub scan direction orthogonal to the scan direction to do printing based on print job data, equipped with a scan unit that moves the recording head back and forth in the scan direction according to the rotation of a first rotation means, a conveyance unit that extracts the media and supplies it according to the rotation of a second rotation means, conveys the media in the sub scan direction to match the movement of the recording head in order to print on the supplied media, and ejects the printed media, a reversal unit that works together with the rotation of the second rotation means and reverses the front and back of the media, and a control unit that controls the spraying of the ink drops from the recording head, the rotation of the first rotation means, and the rotation of the second rotation means, wherein the control unit switches the rotation speed of the second rotation means according to the accumulated number of sheets obtained by counting the number of media sheets printed based on the print job data when the print job data indicates printing on a plurality of sheets of the media. 
     With this kind of constitution, the rotation speed of the second rotation means is switched according to the accumulated sheet count obtained by counting the number of sheets of media printed based on the print job data, so the conveyance speed of the media changes according to the accumulated sheet count. Therefore, by appropriately changing the conveyance speed of the media according to the accumulated sheet count, it is possible to control the noise generated from the printing device and the printing efficiency of the printing device with good balance. 
     Application Example 2 
     With the printing device of the application example noted above, it is preferable that the control unit rotate the second rotation means at the rotation speed according to a first mode when the accumulated sheet count is less than a standard sheet count, and rotate the second rotation means at the rotation speed according to a second mode for conveying the media at a faster speed than the first mode when the accumulated sheet count is the standard sheet count or greater. 
     With this kind of constitution, the rotation speed when the printed accumulated sheet count is low is a slower speed than the rotation speed when the accumulated sheet count is high, so it is possible to suppress the noise from when printing starts until the standard sheet count is reached, and to improve the printing efficiency after the standard sheet count is exceeded. 
     Application Example 3 
     With the printing device of the application example noted above, it is preferable that the control unit switch the rotation speed corresponding to at least one of a first speed for the conveyance unit to extract the media, a second speed for conveying the extracted media to a printing position, a third speed for cooperating with the recording head that moves in the scan direction to move the media in the sub scan direction to print, a fourth speed for reversing the front and back of the printed media, and a fifth speed for ejecting the printed media. 
     With this kind of constitution, it is possible to do conveying efficiently by setting the rotation speed for each conveyance step. 
     Application Example 4 
     With the printing device of the application example noted above, when printing based on the second print job data within a designated elapsed time after the media has been printed based on the first print job data and ejected, it is also possible for the control unit to sum up the number of sheets for the first print job data to count. 
     Application Example 5 
     With the printing device of the application example noted above, it is also possible for the standard sheet count to be changed by a designated operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the attached drawings which form a part of this original disclosure: 
         FIG. 1  is a perspective view of a printer of an embodiment of the invention; 
         FIG. 2  is a side cross section view showing the paper conveyance path of the printer of the embodiment of the invention; 
         FIG. 3  is a perspective view showing the interior of the printer of the embodiment of the invention; 
         FIG. 4  is a perspective view of the carriage seen from the housing bottom surface side; 
         FIG. 5  is a block diagram showing the electrical configuration of the printer of the embodiment of the invention; 
         FIG. 6  is a drawing showing an example of a speed table; 
         FIG. 7  is a flow chart showing the printing process of the printer; and 
         FIG. 8  is a flow chart showing the paper ejection process. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Following, we will describe an embodiment of the invention while referring to the drawings. 
     Embodiment 
     Following, we will describe an embodiment with the printing device in a specific form as a printer based on  FIG. 1  through  FIG. 8 . 
       FIG. 1  is a perspective view of the printer of this embodiment. As shown in this  FIG. 1 , the printer  11  is equipped with a device main unit  12  having a roughly rectangular solid shape, and an operating panel  13  used for input operation by the user provided on the front surface (right surface in  FIG. 1 ) of the device main unit  12 . The operating panel  13  is constituted to be able to rotate forward in relation to the front surface of the device main unit  12  with its top part as the rotation axis. A display unit  14  consisting of a liquid crystal panel or the like and an operating panel  15  consisting of a plurality of operating switches are equipped on the operating panel  13 . Included in the operating unit  15  are a power switch  15   a  for doing the on/off operation of the print  11  power, a selection switch  15   b  for doing the selection operation of desired selection items on the menu screen displayed on the display unit  14  and the like. 
     Also, a feed cassette  16  in which multiple sheets of paper P as an example of the media can be housed is mounted in a detachable state (able to be inserted and removed) at the bottom side position of the operating panel  13  on the front surface of the device main unit  12 . Inside the device main unit  12 , the carriage  18  is grasped and guided by a pair of guide rails  19  (see  FIG. 3 ) built so as to extend in the scan direction X orthogonal to the conveyance direction Y, and is provided in a state by which it can move back and forth along the scan direction X. A recording head  20  for printing using the ink jet method is attached to the bottom part of the carriage  18 . This recording head  20  has a plurality of nozzles for spraying ink drops on the conveyed paper P. 
     The already printed paper Pd is ejected in the direction shown by the white outline arrow in  FIG. 1  from an ejection port exposed when a cover  21  is in an open state, the cover provided in a rotatable state with the bottom part as the rotation axis on the front surface of the feed cassette  16 . At this time, a stacker  23  (see  FIG. 2 ), which is a roughly square flat shaped single tray housed inside the device main unit  12 , is pulled out in advance to the outside direction of the device main unit  12  from the cover  21 , and the ejected already printed paper Pd is ejected onto the stacker  23 . Moreover, on the back part of the device main unit  12  is provided an opening and closing type cover  22  that closes the insertion port for which insertion is possible by manual feeding of the paper P, and it is also possible to open this cover  22  and insert the paper P by hand feeding from the insertion port. 
     Next, we will describe the structural elements on the paper conveyance path while referring to  FIG. 2 . Moreover, with  FIG. 2 , the stacker  23  is driven, and the cover  21  is opened by being pressed by the stacker  23  projecting midway from the device main unit  12 . As shown in  FIG. 2 , the device main unit  12  is equipped with a cassette feed unit  25 , a feed unit  26 , a media conveyance unit  27 , a recording unit  28 , and a forwarding unit  29 . Among these, the cassette feed unit  25 , the feed unit  26 , the media conveyance unit  27 , and the forwarding unit  29  function as the conveyance unit that conveys the paper P. The conveyance unit is constituted so that the power is transmitted from the conveyance motor  33  (see  FIG. 5 ) which is the second rotation means via a gear train means such as gears or the like. The cassette feed unit  25  is equipped with a feed cassette  16 , a pickup roller  17  provided above the feed cassette  16 , and a separation unit  30  provided at a position facing opposite the front edge of the paper P housed in the feed cassette  16 . 
     The pickup roller  17  is provided on a swing unit  32  that swings with a swing axis  31  as the center, and is rotationally driven by the force transmitted from the conveyance motor  33 . The pickup roller  17  feeds the topmost paper P from the feed cassette  16  to the feed path by contacting the topmost paper P of the paper P housed in the feed cassette  16  and rotating. At this time, the topmost paper P sent out from the feed cassette  16  by the rotation of the pickup roller  17  is separated from the next paper P and thereafter by the separation unit  30 . 
     A feed unit  26  provided on the feed path downstream side of the separation unit  30  is equipped with a feed drive roller  34  driven by the conveyance motor  33 , a separation roller  35 , and a feed driven roller  36 . The separation roller  35  ejects the topmost paper P by contacting the feed drive roller  34  and performing separation again in relation to the paper P, and reliably sends only the topmost ejected paper P to the feed path downstream side. 
     Also, the paper P grasped between the feed drive roller  34  and the feed driven roller  36  is conveyed to the media conveyance unit  27 . The media conveyance unit  27  is equipped with a conveyance drive roller  37  similarly driven by the conveyance motor  33 , and a conveyance driven roller  38  which is in pressure contact with the conveyance drive roller  37  and driven to rotate. The paper P is sent further to the downstream side by the media conveyance unit  27 . Using the mechanism described above, the paper P is separated from the feed cassette  16  in which it is housed and fed (supplied) to the printing area. 
     The recording unit  28  provided in the printing area, specifically at the downstream side of the media conveyance unit  27 , is equipped with the carriage  18 , the recording head  20 , and a support platform  39  facing opposite the recording head  20 . In the process of the carriage  18  moving back and forth in the scan direction (X direction) while being guided by the pair of guide rails  19  by the power of the carriage motor  40  (see  FIG. 5 ) which is the first rotation means, the recording head  20  selectively sprays a plurality of ink drops on the paper P. At this time, by the conveyance motor  33  rotating in one direction, an image is formed on the paper P moving in the sub scan direction (−Y direction) which is the paper P conveyance direction. At this time, the top surface of the support platform  39  functions as a support surface for supporting the paper P. Moreover, the carriage motor  40  and the pair of guide rails  19  constitute the scanning unit. 
     The forwarding unit  29  provided at the downstream side of the support platform  39  is equipped with a first roller  41  driven by the conveyance motor  33 , and a second roller  42  in contact with the first roller  41  and driven to rotate. Then, the paper Pd for which recording was performed is forwarded by the forwarding unit  29 . Working in this way, the paper Pd recorded by the recording unit  28  is grasped by the first roller  41  and the second roller  42 , and is ejected to the stacker  23  provided on the front surface side of the device main unit  12 . 
     Also, with this printer  11 , a paper reversal unit  50  (see  FIG. 5 ) is equipped as a reversal unit for reversing the paper P when performing printing on both the back and front surfaces of the paper P. Here, we will describe the paper P reversal method. After recording on one side of the paper P by the recording unit  28 , with the paper P, the side which is the paper back edge when recording is executed on one side becomes the front edge and is returned to the upstream side of the media conveyance unit  28  by the reverse feed operation of the media conveyance unit  27  and the forwarding unit  29 . Furthermore, the paper P is sent to a reversal path  54  by the reverse feed operation of the media conveyance unit  27 . The paper P sent within the reversal path  54  is grasped by the feed drive roller  34  and the reversal roller  52  and returned again to the feed path. 
     The paper P returned to the feed path is again sent to the media conveyance unit  27  further to the feed path downstream side by the feed drive roller  34  via the separation roller  35  and the feed driven roller  36 . At this time, the one side and the other side of the paper P are reversed with a curve, and the other side faces opposite the recording head  20 . The paper P is sent to the recording unit  28  by the media conveyance unit  27 . The paper P for which recording is performed on the other side by the recording unit  28  is grasped by the forwarding unit  29 , and is ejected to the stacker  23  provided on the device front side. Next,  FIG. 3  is a perspective view of the printer  11 . The carriage  18  of the recording unit  28  moves back and forth in the scan direction guided by the pair of guide rails  19  as the “guide member” extending in the scan direction of the recording head  20 . The pair of guide rails  19  is equipped with a main guide rail  166  attached to the device main unit  12  at the device back surface side, specifically, the +Y direction side, and a sub guide rail  168  attached to the device main unit  12  at the device front surface side, specifically, the −Y direction side, and these hold the carriage  18  with a bridging structure. 
     Next,  FIG. 4  is a perspective view of the carriage  18  seen from the bottom surface side of the device main unit  12 . This carriage  18  is equipped with a housing  188 , an ink cartridge housing unit  190  provided on the top part of the housing  188  for housing a plurality of ink cartridges, the recording head  20  arranged so as to face opposite the support platform  39  at an opening part provided on the bottom part of the housing  188 , and a gap adjustment unit  82  for adjusting the gap between the recording head  20  and the support surface of the support platform  39  that supports the paper P. This gap adjustment unit  82 , though not illustrated, is constituted so that the gap changes within a designated range following the shape of an internally equipped cam when pressure is applied to the side bottom part of the housing  188 . 
     Next, we will describe the electrical configuration of the printer  11  based on  FIG. 5 . As shown in  FIG. 5 , the printer  11  is equipped with a controller  70  that is in charge of various controls. The controller  70  is connected to be able to communicate with the host device  200  via a communication interface  71 . The controller  70  controls the printing operation of the printer  11  and the like based on the print job data received from the host device  200 . The host device  200  is assumed to be a personal computer, for example, and has a printer driver  201  built in. The host device  200  is equipped with an input unit  202  consisting of a keyboard and a mouse, and by the user operating the input unit  202 , printing condition information is input on the setting screen displayed by the printer driver  201  on a monitor (not illustrated). With this embodiment, the printing condition information includes settings such as the number of sheets to print, the paper type, the paper size, the printing mode indicating the printing quality, the two sided printing mode for performing printing on both the front and back surfaces and the like. 
     The printer driver  201  generates print image data of the image for which printing execution was indicated based on the printing condition information, generates print job data by adding the control command including the printing condition information as a header to the print image data, and sends the generated print job data to the printer  11 . As an output system, a display unit  14 , a carriage motor  40 , and a conveyance motor  33  are connected to the controller  70 . Also, as an input system, the operating unit  15  including the power switch  15   a , a linear encoder  72 , a rotary encoder  73 , and a paper detection sensor  74  are connected to the controller  70 . 
     Also, the controller  70  is equipped with a computer  75 , a display driver  76 , a head driver  77 , and motor drivers  78  and  79 . The computer  75  drives the recording head  20  via the head driver  77  based on the print job data, and by spraying ink drops from the recording head  20 , draws an image or the like based on the printing image data. Also, the computer  75  does drive control of the carriage motor  40  via the motor driver  78 , and controls the movement of the carriage  18  in the scan direction X. At this time, the computer  75  comprehends the movement position of the carriage  18  with the home position as the source point, for example, by counting the input pulses from the linear encoder  72  using a counter (not illustrated). 
     Furthermore, the computer  75  drives the conveyance motor  33  via the motor driver  79 . Here, a power transmission switching unit  81  is interposed on the power transmission path of the conveyance motor  33 . The power transmission switching unit  81  switches the transmission destination according to the rotation direction of the conveyance motor  33 . Specifically, when the conveyance motor  33  rotates in one direction, the power transmission switching unit  81  rotates the switching lever (not illustrated) in one direction by rotation of the conveyance motor  33 , and has it project in the movement area of the carriage  18 . In this case, the conveyance motor  33  rotates the paper P in the conveyance direction from the downstream direction to the upstream direction. By the switching lever rotating, the state is such that it is possible to abut the gap adjustment unit  82 , and in this state, when the carriage motor  40  is rotated, pressing force is transmitted to the gap adjustment unit  82 . 
     Also, when the conveyance motor  33  rotates in the reverse direction to the one direction (forward direction), the power transmission switching unit  81  rotates the switching lever in the reverse direction and returns it to a non-abutting state. In this case, the conveyance motor  33  rotates in the direction that conveys the paper P from the upstream direction to the downstream direction. 
     Returning to  FIG. 5 , the gap adjustment unit  82  uses the pressing force transmitted from the switching lever based on instructions of the controller  70  and adjusts the gap by moving the recording head  20 . The gap adjustment unit  82  moves the recording head  20  in the direction regulating the gap so that the distance between the spray surface of the recording head  20  and the media support surface is a designated set value according to printing condition information such as the media type, size, printing mode and the like. 
     The paper reversal unit  50  has the function of reversing the front and back of the paper P which is single sheet paper by the conveyance motor  33  and the reversal roller  52  performing a designated rotation based on instructions of the motor driver  79 . The computer  75  prints on one side of the paper P initially when the print job data shows the two sided printing mode, and the printed paper P is received by the paper reversal unit  50  in a state grasped by the first roller  41 , and the front and back are reversed. The reversed paper P is again conveyed to the recording unit  28 , the other side is printed, and it is ejected. 
     The computer  75  shown in  FIG. 5  is equipped with, for example, a CPU, ASIC (application specific IC), RAM, ROM, and non-volatile memory or the like. Various types of programs are stored in the ROM or non-volatile memory. With the computer  75 , the plurality of functional units shown in  FIG. 5  are realized by the CPU executing the programs stored in the ROM or non-volatile memory. With this embodiment, the computer  75  is equipped with a main control unit  83 , a printing control unit  84 , and a memory  86  as the plurality of functional units. These are not limited to being software constitutions using the computer  75 , but can also be hardware constitutions of electronic circuits (e.g. custom ICs) or the like, or can be constituted by coordination of software and hardware. 
     The main control unit  83  is equipped with a job receiving unit  87 , an error detection unit  88 , and a power control unit  90 . The job receiving unit  87  receives print job data from the host device  200 , or receives print job data for printing image data input to the printer  11  from a portable memory device such as a memory card, USB memory or the like connected to the printer  11 . The error detection unit  88  detects errors such as paper jams or the like, and the power control unit  90  controls the supply of power to each unit within the printer  11 . Also, the printing control unit  84  is equipped with a head control unit  91 , a carriage control unit  92 , a conveyance control unit  93 , and a conveyance speed setting unit  85 . 
     The head control unit  91  controls the recording head  20  via the head driver  77  based on the printing image data received from the main control unit  83 , and performs control to have the recording head  20  spray ink drops. The carriage control unit  92  controls the carriage motor  40  via the motor driver  78 , and controls driving of the carriage  18  in the scan direction X. The conveyance control unit  93  controls the conveyance motor  33  via the motor driver  79 , and controls the paper P feeding and conveyance, as well as the rotation of the switching lever. Moreover, the rotation speed of the conveyance motor  33  is instructed from the conveyance speed setting unit  85 . 
     The conveyance speed setting unit  85  sets the conveyance speed for conveying the paper P by the conveyance motor  33  according to the printed sheet count printed with the first print job, and instructs the rotation speed corresponding to the set speed to the conveyance control unit  93 . With this embodiment, the conveyance speed setting unit  85  holds the print counter function for counting the number of sheets printed internally, and the conveyance speed of the paper P to be printed next is switched according to the counted printed sheet count (accumulated sheet count). Moreover, for the conveyance speed, forwarding speeds from separating one sheet of the paper P housed in the feed cassette  16 , conveying it to the printing area, and up to ejection after printing are assumed. Also, two modes are assumed for speed switching, a quiet mode (first mode) applied with the first print job until a designated printed sheet count is reached, and a normal mode (second mode) applied when the designated printed sheet count (standard sheet count) is exceeded, but the invention is not limited to two mode switching. The speed data for the quiet mode and the normal mode, for example as shown by the speed table shown in  FIG. 5 , are preset at conveyance speed corresponding to the respective steps of paper extraction, paper conveyance, printing, reverse conveyance, and ejection (first speed, second speed, third speed, fourth speed, and fifth speed). With the quiet mode, compared to the normal mode, the conveyance speed, specifically the rotation speed of the conveyance motor  33 , is a lower speed, and in particular, the speed data is set so as to be able to reduce the noise level that occurs in the vicinity of the feed cassette  16  during paper feeding. 
     Moreover, the mode switching step can be a series of steps of the paper feed step up to before printing, the printing step, and the paper ejection step after printing, or it can be only one of the paper feed step or the paper ejection step. Also, the speed table can be made in even more detail according to the paper type, the paper size, the printing mode and the like, which are printing condition information. The conveyance speed setting unit  85  has the print sheet count shown by the printing counter reset to the initial value when the printing subject is new print job data. However, when the second print job data is printed within a designated time after the paper Pd already printed according to the first print job data is ejected, the conveyance speed setting unit  85  does not reset the count of the printed sheet count to the initial value, but rather sums up to count. Moreover, with this embodiment, 5 seconds is assumed as the designated time, but the time is not limited to this. 
     The memory  86  assumes RAM or non-volatile memory. In the memory  86 , reference data necessary for the control units  83  and  84  to perform various controls, such as the speed table or the like, are stored. Also, in the memory  86 , the calculation results of the control units  83  and  84  and the status administration flags and the like are stored.  FIG. 7  is a flow chart showing a series of printing processes of the printer  11 . The process is executed when printing is performed on the printing paper P. When the process starts, the computer  75  judges whether or not this is print job data of a new print job (step S 300 ). Here, when it is judged that this is not new print job data (No at step S 300 ), the computer  75  advances to step S 306 . On the other hand, when it is judged that it is new print job data (Yes at step S 300 ), the computer  75  judges whether  5  seconds or more have elapsed since the final already printed paper Pd was ejected (step S 302 ). 
     Here, when it is judged that 5 seconds or more have not elapsed (No at step S 302 ), the computer  75  advances to step S 306 . On the other hand, when it is judged that 5 seconds or more have elapsed (Yes at step S 302 ), the computer  75  resets the printing counter to the initial value, and advances to step S 306 . At step S 306 , the computer  75  judges whether or not the print count is a designated printed sheet count or greater. Here, when it is judged that the print count is the designated printed sheet count or greater (Yes at step S 306 ), the computer  75  fetches the normal mode speed data from the speed table (step S 308 ), and advances to step S 312 . On the other hand, when it is judged that the print count is less than the designated printed sheet count (No at step S 306 ), the computer  75  fetches the quiet mode speed data from the speed table (step S 310 ) and advances to step S 312 . 
     Moreover, with this embodiment, the designated printed sheet count is 4. As a result, for the printing from the initial first sheet to the third sheet, quiet mode speed data is fetched, and from the fourth sheet and thereafter, the normal mode speed data is fetched. The reason that the designated printed sheet count was set to 4 is in order to try to make it quiet during printing for individual users assuming use in the home with a small printed sheet count, and to improve printing efficiency for corporate users assuming use in an office with a large printed sheet count. For example, as one embodiment, by making the quiet mode rotation speed about 25% slower than with the normal mode, the operating sound of the printer  11  is reduced from 50.4 db to 49.6 db. Moreover, this designated printed sheet count can be a fixed value, or it can be a mode set by the user from on a setting screen (not illustrated) of the printer driver  201 , or it is possible to also assume a mode of setting it from the operating unit  15  of the operating panel  13 . 
     At step S 312 , the computer  75  separates the paper P housed in the feed cassette  16  and based on the fetched speed data, conveys the paper P to the printing area. Subsequently, the carriage  18  moves back and forth in the scan direction and ink drops are selectively sprayed, and an image is printed on the paper P (step S 314 ). Next, the computer  75  executes the paper ejection process (step S 316 ) and the series of processes ends.  FIG. 8  is a flow chart showing the paper ejection process. Initially, the computer  75  judges whether or not there is a next page to be printed based on the print job data during the process (step S 320 ). Here, when it is judged that there is no next page to be printed (No at step S 320 ), it advances to step S 332 . 
     On the other hand, when it is judged that there is a next page to be printed (Yes at step S 320 ), the computer  75  judges whether or not this is in the two sided printing mode (step S 322 ). Here, when it is judged that this is not the two sided printing mode (No at step S 322 ), the computer  75  increases the print count by two (step S 324 ), and advances to step S 332 . On the other hand, when it is judged that it is the two sided printing mode (Yes at step S 322 ), the computer  75  increases the print count by one (step S 326 ), and judges whether or not both the front and back of the paper P have been printed (step S 328 ). 
     Moreover, during two sided printing, the count is increased by one, and during one sided printing, the count is increased by two, so it is possible to correctly fetch the printed sheet count when it is either case of two sided printing or one sided printing. Here, when it is judged that both the front and back of the paper P have already been printed (Yes at step S 328 ), it advances to step S 332 . At step S 332 , the ejection process of ejecting the already printed paper P in the printing area onto the stacker  23  is executed, the paper ejection timing is recorded (step S 334 ), and the series of processes ends. On the other hand, when it is judged that one side of the paper P has already been printed but the other side has not been printed (No at step S 328 ), the reversal process of reversing the front and back of the paper P for the other side of the printer P to be printed is executed (steep S 330 ), and the series of paper ejection processes ends. 
     With the embodiment described above, the following kinds of effects are exhibited. 
     (1) When printing according to one print job data, from the initial first sheet to the third sheet, the paper P is conveyed in the quiet mode that makes the rotation speed of the conveyance motor  33  a slower speed, so it is possible to reduce the noise generated during conveyance, and from the fourth sheet and thereafter, the paper P is conveyed in the normal mode at a faster speed than the first sheet to the third sheet for the rotation speed of the conveyance motor  33 , so it is possible to increase the printing efficiency, and thus it is possible to control the reduction of noise and the improvement of printing efficiency with good balance. 
     (2) For the speed data for the quiet mode and the normal mode, the conveyance speed is set according to each process in the speed table, so it is possible to instruct an optimal speed for each process. 
     For the device for implementing the kinds of methods described above, there are cases when this is realized with a standalone device, and cases when this is realized by combining a plurality of devices, and items that include the various modes.