Patent Publication Number: US-11044373-B2

Title: Image forming apparatus and image forming method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 16/354,698, filed on Mar. 15, 2019, the entire contents of which is incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate generally to an image forming apparatus and an image forming method. 
     BACKGROUND 
     Graphics including photographs, graphs, etc. other than text may be included on the pages of a document. If density settings or the like of the graphics are not appropriate, clipped white levels may appear on an image or shadow blocks may appear on the image. Thus, an image forming apparatus having a function of test-printing a document comprising a plurality of pages has been proposed. 
     In this type of image forming apparatus, a first page or a single page designated by a user can be printed. The user can then set printing conditions such as density or color balance according to a result of the test printing. 
     However, since often the size of text is large or the percentage of blank space may be large on the first page of the document, it may be difficult to determine the appropriate printing settings for the document even if a test printing has been performed. In addition, it may also be difficult to determine printing settings even when one specific page is selected to be test printed by the user. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts an image forming apparatus according to a first embodiment. 
         FIG. 2  depicts a GUI screen. 
         FIG. 3  depicts an image forming unit. 
         FIG. 4  depicts a fixing apparatus. 
         FIG. 5  is a block diagram of a control system for an image forming apparatus. 
         FIG. 6  is a flowchart for describing aspects of a test printing. 
         FIGS. 7 to 11  are views for describing aspects of a GUI screen. 
         FIG. 12  is a view for describing aspects of a printing magnification. 
         FIG. 13  is a view for describing aspects of a printing magnification. 
         FIGS. 14 to 16  are views for describing aspects of a GUI screen. 
         FIG. 17  is a flowchart for describing aspects of a test printing by an image forming apparatus according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment, an image forming apparatus, comprises a document feeder configured to feed a document page by page; a scanner configured to scan the document fed by the document feeder page by page and generate image data of the document; a printing apparatus configured to print images on recording media based on the image data; an interface configured to receive print settings and a test printing command; and a controller. The controller configured to control the document feeder to feed pages of the document according to the print settings when the test printing command is received, acquire image data of the pages of the document fed by the document feeder, and control the printing apparatus to print images in a test printing, the images in the test printing comprising image data of the pages of the document fed by the document feeder. 
     First Embodiment 
     Hereinafter, an image forming apparatus according to first embodiment will be described with reference to drawings. For purposes of relational description, an XYZ coordinate system is used as an example. 
     The image forming apparatus  10  according to the first embodiment is a multi-function peripheral (MFP) as an example and will be referred to in this context as an MFP  10 . MFP  10  has a test printing function. The test printing function permits a confirming of a printing status. The MFP  10  can test-print a plurality of designated pages of a document compromising a plurality of pages. A user may then visually confirm the printing status, appropriately correct printing conditions such as printing density, printing magnification and color balance, and then prints all the pages of the document. 
     MFP 
       FIG. 1  is a view schematically illustrating the configuration of the MFP  10  according to the first embodiment. The MFP  10  includes a main body  11  and an auto document feeder (ADF)  13 . A document platen  12  formed of transparent glass is disposed at an upper portion of the main body  11  and the auto document feeder (ADF)  13  is provided on the upper surface side of the document platen  12  in a hinged and rotatable manner. An operation panel  14  is provided at the upper portion of the main body  11 . A scanner  15  for reading a document is provided below the document platen  12 . 
     The operation panel  14  includes various input keys, buttons, a graphical user interface (GUI) or the like.  FIG. 2  illustrates an example of a GUI screen displayed on the operation panel  14  including a touch panel to receive user input. As illustrated in  FIG. 2 , a power button  401 , a reset button  402 , a printing start button  403 , a ten key  404 , a field  405  for displaying the number of copies, a function display field  406 , a mode display field  407 , a  FIG. 408  indicating the position of a paper feed cassette and the like are provided on the GUI screen of the operation panel  14 . 
     In addition, various keys for setting the printing conditions are provided on the GUI screen. Specifically, a key  411  for setting an enlargement/reduction ratio, a key  412  for setting double-sided printing, a key  413  for setting a finishing mode (such as hole punching or stapling), a key  414  for selecting a document mode, a full color selection key  415 , a black/white density selection key  416 , an auto color selection key  417 , a density setting selection key  418 , and the like. In addition, a test printing key  410  is displayed on the GUI screen. 
     The auto document feeder  13  feeds a document that has a plurality of pages to the scanner  15  page by page. In addition, the auto document feeder  13  includes a counter  13   a  for counting the number of sheets of the conveyed and feeds the pages up to the page having the highest page number from among the plurality of page numbers of the pages designated by the user to be test-printed in a test printing. For example, when page 5, page 10, page 20, and page 30 of a document are each designated as pages to be test-printed, the auto document feeder  13  feeds 30 pages of the document and then stop feeding of subsequent pages. If a range from page 1 to page 4 is designated as pages of the document to be test-printed, the auto document feeder  13  feeds the document up to the fourth page of the document and stops feeding. 
     The scanner  15  reads a document page fed by the ADF  13  or a document page placed on the document platen  12  and generates image data. The scanner  15  includes an image sensor  16 . 
     The image sensor  16  reads the image of the document page while moving along the document platen  12  in a +X direction, when the image of the document page placed on the document platen  12  is being read. In addition, when the image of the document page fed to the document platen  12  by the auto document feeder  13  is being read, the image sensor  16  is maintained at a fixed position, which is illustrated in  FIG. 1 , to read images of each page of the sequentially fed document pages. 
     The main body  11  includes an image forming unit  17 , a fixing apparatus  50 , and a control device  80 . 
     Image Forming Unit 
     The image forming unit  17  is disposed inside the main body  11 . The image forming unit  17  forms an image on a recording medium, such as paper from a paper feed cassette  18 , based on the image data as read by the scanner  15  or otherwise image data created by a personal computer or the like. 
     The image forming unit  17  includes image forming units  20 Y,  20 M,  20 C and  20 K for forming latent images using toners of yellow (Y), magenta (M), cyan (C) and black (K), scanning heads  19 Y,  19 M,  19 C and  19 K provided in correspondence with the image forming units  20 Y,  20 M,  20 C and  20 K, an intermediate transfer belt  21  and the like. 
     The image forming units  20 Y,  20 M,  20 C and  20 K are disposed below the intermediate transfer belt  21 . In the image forming unit  17 , the image forming units  20 Y,  20 M,  20 C and  20 K are arranged from the −X side to the +X side. The scanning heads  19 Y,  19 M,  19 C and  19 K are disposed below the image forming units  20 Y,  20 M,  20 C and  20 K, respectively. 
       FIG. 3  is an enlarged view of the image forming unit  20 K from among the image forming units  20 Y,  20 M,  20 C and  20 K. The image forming units  20 Y,  20 M,  20 C and  20 K have the same configuration. Therefore, the configuration of each image forming unit will be described using the image forming unit  20 K as a representative example. 
     The image forming unit  20 K includes a photosensitive drum  22  as an image carrier. A charger  23 , a developing device  24 , a primary transfer roller  25 , a cleaner  26  are disposed around the photosensitive drum  22  in the direction indicated by arrow t. Laser light from the scanning head  19 K is used to expose the photosensitive drum  22 . By irradiating laser light on the surface of the rotating photosensitive drum  22 , a latent image is formed on the surface of the photosensitive drum  22 . 
     The charger  23  of the image forming unit  20 K uniformly charges the surface of the photosensitive drum  22 . The developing device  24  supplies a toner to the photosensitive drum  22  using a developing roller  24   a , to which a developing bias is applied, and develops an electrostatic latent image. The cleaner  26  removes the toner remaining on the surface of the photosensitive drum  22  using a blade  27 . The toner scraped off by the front end of the blade  27  is conveyed by an auger  28  in a longitudinal direction. 
     As illustrated in  FIG. 1 , the intermediate transfer belt  21  is stretched over a drive roller  31  and three driven rollers  32 . The intermediate transfer belt  21  rotates in a counterclockwise direction in  FIG. 1  by rotation of the drive roller  31 . In addition, as illustrated in  FIG. 1 , the intermediate transfer belt  21  is in contact with the upper surfaces of the photosensitive drums  22  of each of the image forming units  20 Y,  20 M,  20 C and  20 K. A primary transfer voltage is applied by the primary transfer roller  25  at a position facing the photosensitive drum  22  of the intermediate transfer belt  21 . Therefore, a toner image developed on the surface of the photosensitive drum  22  is transferred onto the intermediate transfer belt  21 , which is referred to as a primary transfer. 
     A secondary transfer roller  33  is disposed to face the drive roller  31 , over which the intermediate transfer belt  21  is stretched. When paper P passes between the drive roller  31  and the secondary transfer roller  33 , a secondary transfer voltage is applied to the paper P by the secondary transfer roller  33 . Therefore, a toner image formed on the intermediate transfer belt  21  is transferred onto the paper P, which is referred to as a secondary transfer. As illustrated in  FIG. 1 , a belt cleaner  34  is provided near the driven roller  32  of the intermediate transfer belt  21 . The toner remaining on the surface of the intermediate transfer belt  21  after the secondary transfer is removed by the belt cleaner  34 . 
     As illustrated in  FIG. 1 , a paper feed roller  35  is provided between a paper feed cassette  18  and the secondary transfer roller  33 . The paper P taken from the paper feed cassette  18  by a pickup roller  18   a  provided near the paper feed cassette  18  is conveyed between the intermediate transfer belt  21  and the secondary transfer roller  33  by the paper feed roller  35 . 
     The fixing apparatus  50  is provided above the secondary transfer roller  33 . In addition, a paper discharge roller  37  is provided above the fixing apparatus  50 . The paper P passing through the intermediate transfer belt  21  and the secondary transfer roller  33  is heated by the fixing apparatus  50 . Therefore, a toner image is fixed to the paper P. The paper P passing through the fixing apparatus  50  is discharged to a paper discharge part  38  via the paper discharge roller  37 . 
     Fixing Apparatus 
       FIG. 4  is a view illustrating an example of the fixing apparatus  50 . The fixing apparatus  50  includes a fixing belt  51 , a pressure roller  52 , and a heater  60 . The heater  60  is provided on an inner surface of the fixing belt  51 . The fixing belt  51  heated by the heater  60  is a heating rotator for heating the paper P. 
     The fixing belt  51  is a cylindrical member extending in a longitudinal direction along a Y-axis direction, and has a length (the dimension in the Y-axis direction) that is greater than a width (dimension in the Y-axis as being conveyed along the conveyance path) of the paper P. The fixing belt  51  is made of, for example, a film of SUS (stainless steel) having a thickness 50 μm or a heat-resistant polyimide film having a thickness of 70 μm as a base material. A silicone rubber layer having a thickness 200 μm is formed on the surface of the base material. In addition, the silicone rubber layer is covered with a surface protective layer made of PFA resin (perfluoroalkoxy resin) or the like. The fixing belt  51  is supported to be rotatable about an axis parallel to the Y-axis. 
     The pressure roller  52  is a cylindrical member having a longitudinal direction as a Y-axis direction. The pressure roller  52  includes a core material  52   a  made of metal, such as aluminum, and a silicone rubber layer  52   b  laminated on the outer circumferential surface of the core material  52   a . The surface of the silicone rubber layer  52   b  is covered with PFA resin or the like. The pressure roller  52  has an outer diameter of about 25 mm and has the substantially same length (Y-direction axis) as the fixing belt  51 . The pressure roller  52  is pressed in a direction (−X direction) toward the fixing belt  51 . Therefore, the pressure roller  52  is pressed against the heater  60  with the fixing belt  51  therebetween. Accordingly, the surface of the pressure roller  52  and the surface of the fixing belt  51  are brought into tight contact with each other and form a nip through which the paper P passes from the lower side to the upper side (+Z direction). 
     In this fixing apparatus  50 , the paper P passes through the nip between the pressure roller  52  and the fixing belt  51 , each respectively rotating in the directions indicated by different arrows in  FIG. 4  by the rotation of the pressure roller  52 . Therefore, the paper P is heated and pressed and the toner image formed on the paper P is fixed to the paper P. 
     Control Device 
       FIG. 5  is a block diagram of a control system for the MFP  10 . The control system includes, for example, a control unit  100  (controller) for performing overall control of the MFP  10 , a bus line  110 , a read only memory (ROM)  120 , a random access memory (RAM)  121 , an interface  122 , the scanner  15 , an input/output control circuit  123 , a feed/conveyance control circuit  130 , an image forming control circuit  140  and a fixing control circuit  150 . The control unit  100  and each circuit are connected through the bus line  110 . The control device  80  includes the control unit  100 , the bus line  110 , the ROM  120 , the RAM  121 , the input/output control circuit  123 , the feed/conveyance control circuit  130 , the image forming control circuit  140  and the fixing control circuit  150 . 
     The ROM  120  stores a control program, control data, and the like for the basic operations of the MFP  10 . 
     The RAM  121  functions as a working memory/area of the control unit  100 . 
     The control unit  100  includes a CPU, for example. The control unit  100  executes a program stored in the ROM  120  or the like. Therefore, the various components of the MFP  10  are controlled by the control unit  100  and the process of forming an image on the paper is executed. In addition, when a test printing command is received, the control unit  100  performs control to feed sheets of document (as a sub-portion of the document) from the auto document feeder  13  according to the content of a printing condition setting command, then acquires image data and controls the main body  11  to test-print an image based on the acquired image data on the fed paper P. 
     The interface  122  receives a printing condition command and a test printing command. The interface  122  communicates with a device such as an external terminal used by a user. The interface  122  includes a wireless communication unit (such as a wireless LAN), a wired communication unit, a communication unit for accessing a removable data recording medium such as a universal serial bus (USB) memory device or the like. 
     The input/output control circuit  123  displays necessary information on the operation panel  14  or receives input from the operation panel  14 . The user can designate, for example, printing conditions such as the number of copies of a document to be made, printing density, and the like, by manipulating the operation panel  14 . 
     The feed/conveyance control circuit  130  is a unit for controlling a motor group  131  for driving the pickup roller  18   a , the paper feed roller  35 , and the paper discharge roller  37  of a paper P conveyance path. The feed/conveyance control circuit  130  controls the motor group  131  according to the detection result of various types of sensors  132  provided near the paper feed cassette  18 , or otherwise provided on the conveyance path, based on a control signal from the control unit  100 . 
     The image forming control circuit  140  controls the photosensitive drums  22 , the chargers  23 , the scanning heads  19 Y,  19 M,  19 C and  19 K, the developing devices  24  and the primary transfer rollers  25  based on the control signal from the control unit  100  corresponding to the printing conditions as set. 
     The fixing control circuit  150  controls a drive motor  151  for rotating the pressure roller  52  of the fixing apparatus  50  based on the control signal from the control unit  100 . 
     Image Forming Process 
     In the MFP  10 , an image forming process for printing on paper P according to a printing command from the user is performed. The image forming process is performed, for example, when image data received through the interface  122  is to be printed or when image data generated by the scanner  15  is to be printed. 
     In the image forming process, as illustrated in  FIG. 1 , the paper P is taken out from the paper feed cassette  18  by the pickup roller  18   a  and is conveyed by the paper feed roller  35  between the intermediate transfer belt  21  and the secondary transfer roller  33 . 
     In parallel with the above operations, toner images are respectively formed on the photosensitive drums  22  of the image forming units  20 Y,  20 M,  20 C and  20 K. The toner images formed on the photosensitive drums  22  of the image forming units  20 Y,  20 M,  20 C and  20 K are sequentially transferred onto the intermediate transfer belt  21 . Therefore, a toner image of yellow (Y), a toner image of magenta (M), a toner image of cyan (C) and a toner image of black (K) are all formed on the intermediate transfer belt  21 . 
     When the paper P conveyed between the intermediate transfer belt  21  and the secondary transfer roller  33  passes through the intermediate transfer belt  21  and the secondary transfer roller  33 , toner images formed on the intermediate transfer belt  21  are transferred onto the paper P. Therefore, a toner image formed by the toners of yellow (Y), magenta (M), cyan (C) and black (K) is transferred to the paper P. 
     The paper P, on which the toner image has been formed, passes through the fixing apparatus  50 . The paper P is heated and pressed by passing through the fixing apparatus  50 . Therefore, the toner image is fixed to the paper P and the image is printed on the paper P. The paper P is then discharged to the paper discharge part  38  via the paper discharge roller  37 . 
     Test Printing 
     Next, test printing of the MFP  10  will be described. The paper P is set in the paper feed cassette  18  in advance. A GUI screen illustrated in  FIG. 2  is displayed on the operation panel  14 . The user presses a “test printing” key  410  illustrated in  FIG. 2 , thereby starting the test printing. 
     When the “test printing” key  410  is pressed, the control unit  100  then displays the GUI screen illustrated in  FIG. 7  on the operation panel  14 . As illustrated in  FIG. 7 , a screen for selecting a unit of test printing is displayed on the GUI screen. Specifically, a “one copy” key  421 , a “one-page designation” key  422 , and a “multiple-page designation” key  423  are displayed. The “one copy” key  421  is a key for selecting a test-printing mode having all pages in the document test-printed. The “one-page designation” key  422  is a key for selecting a test-printing mode in which one designated page of the document is test-printed. The “multiple-page designation” key  423  is a key for selecting a test-printing mode in which a plurality of pages of the document are designated to be test-printed. The case where the “multiple-page designation” key  423  is selected will be described in detail with reference to the flowchart illustrated in  FIG. 6 . 
     As illustrated in  FIG. 7 , a “printing condition change” key  424  and a “test printing end” key  425  are also displayed on the GUI screen. If the “printing condition change” key  424  is pressed, the control unit  100  causes the process to transition to ACT 21 see ( FIG. 6 ) and displays the GUI screen illustrated in  FIG. 15  on the operation panel  14  without performing a test printing. In addition, if the “test printing end” key  425  is pressed, the control unit  100  ends test printing and again displays the GUI screen illustrated in  FIG. 2  on the operation panel  14 . 
     If the “multiple-page designation” key  423  is pressed, the control unit  100  displays the GUI screen illustrated in  FIG. 8  on the operation panel  14 . As illustrated in  FIG. 8 , a screen for selecting the method of designating page numbers of the document to be test-printed is displayed on the GUI screen. Specifically, an “individual designation” key  431  and a “range designation” key  432  are displayed. The “individual designation” key  431  is for selecting a mode for designating a plurality of pages to be test-printed using a specific page number or page numbers. The “range designation” key  432  is for selecting a mode for designating a plurality of pages to be test-printed using a page range. 
     When the “individual designation” key  431  is pressed (ACT 11: No), the control unit  100  displays the GUI screen illustrated in  FIG. 9  on the operation panel  14 . As illustrated in  FIG. 9 , a page designation field  434  for designating the page numbers to be test-printed is displayed on the GUI screen. Here, the case where eight page numbers are to be designated for test printing will be described. The user inputs the page numbers of the pages to be test-printed using the ten key  404  (ACT 12). For example, the user inputs the designated page number “3” and signals an input decision using the key “#”. Next, the user inputs “5 #”, “6 #” and so forth up to eight total selections. The selected page numbers of the document as designated by the user are displayed in the page designation field  434  (3 P, 5 P, 6 P, 10 P, 30 P, 35 P, 50 P, 80 P). 
     When input of the page numbers to be test-printed is finished, the user next selects a “printing magnification” key  440  or a “one-sided/double-sided” key  450 . When the “printing magnification” key  440  is pressed, the control unit  100  causes the process to transition to ACT 14. When the “one-sided/double-sided” key  450  is pressed, the control unit  100  causes the process to transition to ACT 16. 
     If the “range designation” key  432  is pressed (ACT 11: Yes) on the GUI screen of  FIG. 8 , the control unit  100  displays the GUI screen illustrated in  FIG. 10  on the operation panel  14 . As illustrated in  FIG. 10 , a leading page number display field  436  for the test printing and a last page number display field  437  of the test printing are displayed on the GUI screen. The user inputs a page range to be test-printed using the ten key  404  (ACT 13). For example, when page 5 to page 9 are to be designated, the user inputs “5”, “#”, “9” and “#”, thereby selecting the page range (page 5 to page 9, inclusive). The page numbers of the document as designated by the user are displayed in the leading page number display field  436  and the last page number display field  437 . 
     Next, the case where the “printing magnification” key  440  is pressed will be described. When the “printing magnification” key  440  is pressed (ACT 14: Yes), the control unit  100  displays the GUI screen illustrated in  FIG. 11  on the operation panel  14 . As illustrated in  FIG. 11 , a “2in1” key  441  and a “4in1” key  442  are displayed on the GUI screen. The “2in1” key  441  is a key for selecting a mode in which printing of two pages of the document on a single sheet of the paper P is performed as illustrated in  FIG. 12 . That is, the document page size is set to 70% original size and printed. The “4in1” key  441  is a key for selecting a mode for printing four pages of the document on one page of the paper P as illustrated in  FIG. 13 . That is, the document is set to 50% original size and printed. When the “2in1” key  441  or the “4in1” key  442  is pressed (ACT 14: Yes), the control unit  100  receives an instruction for the printing magnification designated by the user (ACT 15). In addition, when the user does not select the “printing magnification” key  440  (ACT 14: No), the control unit  100  sets 100% (the same size) as printing magnification. 
     Next, the case where the “one-sided/double-sided” key  450  is pressed will be described. If the “one-sided/double-sided” key  450  is pressed, the control unit  100  displays the GUI screen illustrated in  FIG. 14  on the operation panel  14 . As illustrated in  FIG. 14 , a “one-sided printing” key  451  and a “double-sided printing” key  452  are displayed on the GUI screen. If the user selects the “one-sided printing” key  451  (ACT 16: No), the control unit  100  performs test-printing on only one side of the paper P (ACT 17). For example, if the test printing range is 4 pages and the “2in1” key  441  is selected, two sheets of paper P are used for the test printing. If the user selects the “double-sided printing” key  452  (ACT 16: Yes), the control unit  100  performs test printing on both sides of the paper P (ACT 18). For example, when the test printing range is 4 pages and a “2in1” key  441  is selected, a single sheet of paper P (printed on both sides) is used for the test printing. 
     In the process of ACT 17 and ACT 18, the control unit  100  feeds the document from the auto document feeder  13  up to the page having a largest page number among the plurality of page numbers designated by the user to be test-printed and then stops feeding of the document. For example, when the total number of pages of the document is 100 pages and the largest page number among the plurality of page numbers designated by the user to be test-printed is page 9, the control unit  100  controls the auto document feeder  13  to feed the document up to the ninth page. The control unit  100  controls the auto document feeder  13  to feed the document corresponding to the page numbers or the page range acquired in ACT 12 or ACT 13 and to acquire image data, and controls the image forming unit  17  to print an image based on the image data on to the paper P. When test printing of the designated pages is finished, the control unit  100  displays the GUI screen illustrated in  FIG. 7  on the operation panel  14 . 
     The user checks the result of test printing (ACT 19). If the user wants to change the printing conditions, the “printing condition change” key  424  is pressed. If the “printing condition change” key  424  is pressed (ACT 20: Yes), the control unit  100  displays the GUI screen illustrated in  FIG. 15  on the operation panel  14 . As illustrated in  FIG. 15 , a “copy density” key  461 , a “printing magnification” key  462 , a “document mode” key  463  and a “color balance” key  464  are displayed on the GUI screen. 
     The “copy density” key  461  is a key for selecting correction of a printing parameter corresponding to printing density. Here, the copy density is defined to have levels of 1 to 10 and an initial value is set to level 5. The “printing magnification” key  462  is a key for selecting correction of the printing parameter indicating the magnification or reduction ratio when the document is printed. The printing magnification is variable in a range of 50% to 200%, for example, with an initial value set to 100%. The “document mode” key  463  is a key for selecting whether the document is a text document or a photograph document and thus to change printing parameters according to preset modes according to document type. The initial value of document mode is set to the text document. The “color balance” key  464  is a key for selecting correction of the printing parameter indicating the color balance of printing. Color balance is, for example, defined to have levels of +3 to −3, and the initial value is set to level ±0. Color balance may be individually set for each of yellow (Y), magenta (M), cyan (C) and black (K). 
     Here, the case where the “copy density” key  461  is pressed will be described in detail. When the “copy density” key  461  is pressed, the GUI screen illustrated in  FIG. 16  is displayed on the operation panel  14 . As illustrated in  FIG. 16 , a density setting display field  471 , an “UP” key  472 , a “DOWN” key  473 , a density graph  474  and an “OK” key  475  are displayed on the GUI screen. 
     If the “UP” key  472  is pressed, the printing condition is changed such that the copy density is increased. If the “DOWN” key  473  is pressed, the printing condition is changed such that the copy density is decreased. The currently designated copy density is displayed in the density setting display field  471 . In addition, the currently designated copy density is also displayed by shading in the density graph  474 . If the “OK” key  475  is pressed, a change of the printing condition is set (ACT 21). When the “OK” key  475  is pressed, the control unit  100  displays the GUI screen illustrated in  FIG. 7  on the operation panel  14 . 
     If test printing is to be performed again (ACT 22: No), the user again selects keys illustrated in  FIG. 7 . The control unit  100  repeats the process of ACT 11 to ACT 22. 
     If the printing condition is not to be corrected (ACT 20: No), the user presses the “test printing end” key  425  illustrated in  FIG. 7 . When the “test printing end” key  425  is pressed (ACT 22: Yes), the control unit  100  finishes the test printing and displays the GUI screen illustrated in  FIG. 2  on the operation panel  14 . 
     Thereafter, when the user presses a printing start button  403  illustrated in  FIG. 2 , the control unit  100  controls the auto document feeder  13  to feed all the pages of the document to the scanner  15  and to acquire image data. The control unit  100  controls the image forming unit  17  to make the selected number of copies under the set printing conditions. For example, if the copy density is set to “7” and the number of copies of the document is set to 100, when the user presses the printing start button  403 , the MFP  10  makes 100 copies of the document under the printing condition corresponding to the copy density of “7”. 
     If a reset button  402  is pressed during the test printing processing, the control unit  100  ends the test printing and displays the GUI screen illustrated in  FIG. 2  on the operation panel  14 . 
     As described above, the image forming apparatus according to the first embodiment test-prints some pages of a document having a plurality of pages. Therefore, it is possible to shorten a time required to set the correct printing conditions since the printing conditions can be appropriately set without restarting test printing. 
     In addition, when test printing is performed, the control unit  100  controls the auto document feeder  13  to feed the document up to the page having the highest page number among the pages designated by the user to be test-printed. When the total number of pages of the document is large and all pages must be scanned for a test printing, it may take a considerable time to provide the result of the test printing. By stopping reading of the document at a highest page number designated for test printing, the user can more quickly acquire the result of the test printing. 
     In addition, the image forming apparatus according to the first embodiment has a function of displaying the GUI screen for selecting a mode for designating the page numbers of the pages to be test-printed by input of the individual page numbers and a mode for designating the page numbers of the pages to be test-printed using a page range. The user can thus make a selection permitting a check of a page including only text, a page including graphics, and a page including a photograph in a single test printing by designating appropriate page numbers of the document to be test-printed. Therefore, it is possible to reduce the need to restart or redo the test printing and to thus shorten the time required for the user to set the printing conditions appropriately for a mixed text and graphics document or the like. 
     In addition, the user can simplify setting operations by selecting the mode for performing the test page designation by using a page range. Even in such a mode, it is possible to appropriately set the printing conditions without restarting test printing by test-printing a plurality of pages. 
     In addition, the image forming apparatus according to the first embodiment has a function of displaying the GUI screen for designating a printing magnification on the operation panel  14 . By printing a plurality of pages of the document on a single sheet of paper, it is possible to reduce the amount of printing paper used in the test printing. 
     In addition, the image forming apparatus according to the first embodiment has a function of displaying the GUI screen on the operation panel  14  for selecting whether the test printing uses one-sided printing or double-sided printing. By performing double-sided printing in this context, it is possible to reduce the amount of printing paper used for test printing. 
     In addition, in the above description, when test printing is performed, the auto document feeder  13  feeds the document up to the page having the highest page number among the page numbers designated by the user to be test-printed and stops the feeding of subsequent pages. However, the operation of the auto document feeder  13  is not limited thereto in all examples. For example, all the pages of the document may be fed to the scanner  15  and the scanner may store the image data of all the pages in a memory. In this case, the control unit  100  reads the image data of the pages designated for the test printing from the memory and controls the image forming unit  17  as a printing apparatus to perform test printing. 
     Second Embodiment 
     In the first embodiment, the case where the user sets the mode for test printing by designation of pages to be test-printed and a printing magnification and the like was described. However, there may be users who think manual selection of test printing settings for each document is troublesome work. In the second embodiment, a case where designation of pages to be test-printed and printing magnification are preset in advance will be described with reference to  FIG. 17 . 
     In the second embodiment, if the “test printing” key  410  illustrated in  FIG. 2  is pressed, the test printing process illustrated in  FIG. 17  starts. When the test printing starts, the control unit  100  sets the test printing conditions to preset conditions (ACT 10). Specifically, the control unit  100  sets test printing to a “multiple-page setting” mode. In addition, the control unit  100  makes a “multiple-page designation” with a “range designation” setting. For example, the control unit  100  sets page 1 to page 4 of each document as the designated page range. In addition, the control unit  100  sets printing magnification to “2in1”. In addition, the control unit  100  sets printing mode to “double-sided printing”. Since the test printing mode, designation of pages, and printing magnification are automatically set, the GUI screens illustrated in  FIGS. 8, 9, 10, 11 and 14  are not required to be displayed. In the test printing, page 1 and page 2 of the document are reduced to 70% and printed on the front surface of a single sheet of paper P and page 3 and page 4 are reduced to 70% and printed on the rear surface of the single sheet of paper P. 
     For example, assume that the total number of pages of the document 100 pages. In the above example, since the largest page number among the page numbers to be test-printed is set to page 4, the control unit  100  controls the auto document feeder  13  to feed the document only up to the fourth page of the document. The control unit  100  acquires the image data from the first to fourth pages of the document and controls the image forming unit  17  to test-print based on the image data of the corresponding fed pages to be on both sides of a single sheet of paper P by using the printing magnification of “2in1”. 
     When test printing is finished, the control unit  100  displays the GUI screen illustrated in  FIG. 7  on the operation panel  14 . The processing of ACT 19 to ACT 22 is equivalent to the description for the first embodiment. The initial values for the designated range, printing magnification, double-sided/one-sided printing selection to be used in the test printing are stored in memory. In addition, the user may change these initial values according to user preference. 
     Third Embodiment 
     In the second embodiment, the case where the setting operation is simplified for the user by presetting the test printing mode, designation of pages to be test-printed and printing magnification. However, there are other methods of simplifying setting operations for the user. For example, when test printing is already set to the multiple-page designation, then the multiple-page designation is set to individual page designations, printing magnification is set to 70%, and double-sided printing are set as fixed conditions, and the user may only designate the individual pages to be test-printed. 
     If the “test printing” key  410  is pressed, the control unit  100  displays the GUI screen illustrated in  FIG. 9  on the operation panel  14 . The user then inputs “3”, “#”, “5”, “#” etc. as the designated pages of the document to be test printed. When input of the designated pages is finished, the user presses the printing start button  403 . The MFP  10  performs double-sided printing of the designated pages of the document with a “2in1” setting. If the user presses the printing start button  403  without designating any pages, the MFP  10  performs double-sided printing of page 1 to page 4 (as a default selection of pages of the document) with a “2in1” setting. 
     For example, assume that the number of pages of the document is 100 pages and the user designates four separate pages (that is, here the third, fifth, seventh, and ninth pages) of the document as pages to be test-printed. The highest page number among the plurality of page numbers of the pages designated by the user to be test-printed is page 9. The control unit  100  controls the auto document feeder  13  to feed the document up to its ninth page. The control unit  100  acquires the image data of the third, fifth, seventh, and ninth pages of the document and controls the image forming unit  17  to test-print image data of the corresponding pages on both sides of paper P with a printing magnification of “2in1”. If the user does not designate any pages, then the control unit  100  controls the auto document feeder  13  to feed the document up to the fourth page of the document (according to a default selection of pages). 
     Fourth Embodiment 
     The MFP  10  according to the fourth embodiment sets the test printing conditions such that only one sheet of paper P is used for test printing and printing magnification is set to be as close to 100% as possible in view of the number of designated pages. Specifically, the MFP  10  selects “2in1”, “4in1” or the like such that only one sheet of paper P is used for test printing. If the total number of pages of the document is two or more, then MFP  10  selects “double-sided printing”. For example, if the number of designated pages for test printing is two, the MFP  10  sets printing magnification to 100% and performs double-sided printing as a test printing. When the number of designated pages of test printing is four, the MFP  10  sets “2in1” and performs double-sided printing as test printing. 
     For example, assume that the total number of pages of the document is 100 and the page numbers of the pages designated by the user to be test-printed are page 5 and page 9. The control unit  100  controls the auto document feeder  13  to feed the document up to the ninth page. The control unit  100  acquires the image data of the fifth and the ninth page of the document and controls the image forming unit  17  to test-print the images of the fifth and ninth pages of the document on the two sides of a single sheet of paper P at printing magnification of 100%. 
     The image forming apparatus according to the fourth embodiment has a function of printing the pages designated to be test-printed on both sides a single sheet of paper. Therefore, it is possible to reduce the amount of printing paper used for test printing. 
     Fifth Embodiment 
     The MFP  10  according to the fifth embodiment has a function of setting the number of sheets of paper P to be used for test printing to 1 and then upon the pressing of the test printing  410  button, the test printing process is performed under the same printing conditions as an actual printing after the user sets a printing setting from the GUI screen illustrated in  FIG. 2 . For example, when printing magnification is “2in1” for actual printing, the MFP  10  also sets printing magnification for test printing to “2in1”. In such a case, it is possible to test-print two or four individual pages of document depending on whether the printing condition is for one-sided printing or double-sided printing since the number of sheets of paper P to be used for test printing has been limited to 1. When test printing is performed, even if the total number of sheets of document placed on the auto document feeder  13  is four or more (e.g., ten), the auto document feeder  13  stops after the designated two or four pages of document have been conveyed. 
     In addition, when printing magnification of the actual printing is “4in1”, the MFP  10  sets printing magnification of test printing to “4in1”. In this case, since the number of sheets of paper P used for test printing is limited to 1, it is possible to test-print four or eight individual pages of document depending on whether the printing condition is set to be one-sided printing or double-sided printing. As in the case of “2in1” actual print setting, the only those sheets of document required for test printing the designated pages on one sheet of paper P according to the printing conditions are fed through the ADF  13  by the test printing instruction and test printing can be performed without scanning every page of the document. 
     If the test printing end button  425  is pressed to finish test printing and any remaining pages of the document which have not been conveyed by the auto document feeder  13  are present, a screen for checking whether the remaining document is to be printed under the same conditions as the test printing may be displayed on the GUI and printing may be continuously performed according to the input from the user on this screen display. Alternatively, a request for removal of the remaining pages of the document may be displayed on the GUI and the user may be prompted to reset the document to be actually printed in the auto document feeder  13  again. 
     In addition, the above-described GUI screens are exemplary and the present disclosure is not limited thereto. In addition, the printing parameters are also exemplary and the present disclosure is not limited thereto. In addition, the flowchart illustrated in  FIG. 6  is exemplary and the present disclosure is not limited thereto. For example, the flowchart may be considered to depict a process of transitioning to a subroutine for each key pressed on each GUI screen illustrated. In addition, a timer may be provided, and the GUI screen may be changed when a predetermined time has elapsed. In addition, a key for extending a time until the GUI screen is changed may be provided. In addition, a “confirm” key may be provided on each GUI screen and a next GUI screen may be displayed using the pressing of the “confirm” key as a trigger. 
     In addition, although the case of displaying the GUI screen on the operation panel  14  of the MFP  10  is described in the above description, the display of the GUI screen is not limited to the operation panel  14 . For example, when a personal computer is used to remotely control the MFP  10 , a screen of the personal computer may be used as a user interface to display a GUI screen or the like in the same manner otherwise depicted as being on operation panel  14 . Specifically, an above-described GUI screen can be displayed on a liquid crystal screen of a personal computer or the like by application software installed in the personal computer or the like. Such a personal computer or the like then supplies conditions input by the user via the GUI screen to the input/output control circuit  123  of the MFP  10 . The control unit  100  performs test printing based on the conditions acquired via the input/output control circuit  123 . 
     In the above example embodiments, the case where the image forming apparatus  10  is a multifunctional peripheral was described. The present disclosure is not limited thereto and the image forming apparatus  10  may be a laser printer or the like. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the present disclosure. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the present disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the present disclosure.