JP6690562B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on paper.

  The image forming apparatus of Patent Document 1 is provided with a plurality of trays, detects a stain (abnormality) of the sheet at the time of feeding, and if there is no stain on both sides, performs double-sided printing and then accumulates in the discharge tray. If there is a stain on one side, it is stored in the back side blank paper tray, and if there is a stain on both sides, it is stored in the waste tray. In this way, the image forming apparatus sorts the sheets according to the presence or absence of the stain, and thus the sheets can be easily reused.

JP, 2003-195589, A

  However, in the image forming apparatus of Patent Document 1, when any one of the three trays becomes unavailable, it becomes difficult to sort the sheets.

  In view of the above-mentioned problems of the conventional technology, the present invention is capable of correctly printing a sheet in which an abnormality has been detected and a sheet in which abnormality has been detected, even when the sheet in which abnormality has been detected and the sheet that has been normally printed are discharged to the same discharge tray. The purpose is to facilitate separation from paper.

  To achieve the above object, an image forming apparatus according to a first aspect of the present invention is configured such that a sheet feeding unit that feeds a sheet, a transport unit that transports the sheet fed from the sheet feeding unit, and a transport unit that transports the sheet. An image forming unit that forms an image on a sheet, a sheet discharging unit that discharges the sheet from the image forming unit to the outside, and an abnormality detecting unit that detects an abnormality of the sheet conveyed to the conveying unit. The paper discharge unit includes a first paper discharge tray for accumulating the discharged paper, and the paper discharge unit discharges the paper at either a first speed or a second speed lower than the first speed. When the paper can be discharged to the paper discharge tray and the abnormality detection unit has not detected an abnormality, the paper discharge unit discharges the paper to the first paper discharge tray at the second speed, When the abnormality detection unit detects an abnormality, the paper discharge unit discharges the paper at the first speed by the first paper discharge. Characterized in that it discharged to Rei.

  According to the present invention, the speed at which the paper in which the abnormality is detected and the paper that has been printed normally are discharged to the paper discharge tray at different speeds makes it possible to determine the positions at which they are accumulated. It can be in different positions. As a result, even if the paper in which the abnormality is detected and the paper printed normally are accumulated in the same tray, the separation becomes easy.

FIG. 1 is a layout diagram showing a schematic configuration of a printer according to an embodiment. FIG. 3 is a block diagram illustrating an example of a hardware configuration of a printer. 6 is a flowchart illustrating an example of operation of the printer according to the exemplary embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking a printer 100 as an example of an image forming apparatus. Each element such as the configuration and arrangement described in the present embodiment does not limit the scope of the invention and is merely an example for explanation.

  Hereinafter, an inkjet printer 100 (corresponding to an image forming apparatus) having a fixed head unit 4 will be described as an example with reference to the drawings. Each element such as the configuration and arrangement described in the present embodiment does not limit the scope of the invention and is merely an example for explanation.

(Outline of printer 100)
First, the outline of the printer 100 according to the embodiment will be described with reference to FIG. FIG. 1 is a layout diagram showing a schematic configuration of a printer 100 according to the embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of the printer 100. In the following description, the up, down, left and right descriptions are based on the state shown in FIG. 1 unless otherwise noted.

  As shown in FIGS. 1 and 2, the printer 100 includes a paper feed tray 1, a transport unit 2 (transport unit), a paper discharge unit 3 (paper discharge unit), and a head unit 4 (image forming unit). The control unit 5, the storage unit 6, the operation panel 7, the communication unit 8, and the abnormality detection sensor S1 (abnormality detection unit).

  The paper feed tray 1 stacks and stores the paper P. A paper feed roller pair 11 is provided at the downstream end of the paper feed tray 1 in the paper transport direction. The pair of paper feed rollers 11 sequentially feed the accommodated paper sheets P one by one from the uppermost paper sheet P toward the transport unit 2.

  The transport unit 2 is provided on the downstream side (right side in FIG. 1) of the paper feed roller pair 11 in the paper transport direction. The transport unit 2 includes a drive roller 21, a driven roller 22, a transport belt 23, an encoder 24, a belt drive motor 25, and a carry-out roller pair 26.

  The drive roller 21 receives the drive force of the belt drive motor 25 (see FIG. 2) and rotates. The driven roller 22 is provided such that its axis line is parallel to that of the drive roller 21. The conveyor belt 23 is an endless belt stretched around the driving roller 21 and the driven roller 22. The driving roller 21 rotates by receiving the driving force of the belt driving motor 25 (see FIG. 2). The conveyor belt 23 is rotated by the rotation of the drive roller 21. As a result, the paper P on the conveyor belt 23 is conveyed in the direction of arrow X in FIG. 1, that is, the direction indicated by the arrow X is the conveyance direction of the paper P.

  The encoder 24 is connected to the drive roller 21 or the driven roller 22 that stretches the transport belt 23. The encoder 24 outputs a pulse according to the amount of rotational displacement (rotation angle) of the rotary shaft of the driving roller 21 or the driven roller 22 (for example, one pulse for a fraction of a circle or a half circle, which can be set arbitrarily). The control unit 5 counts the number of pulses transmitted from the encoder 24 and grasps the feed amount of the paper P from the rotation amount. Further, the control unit 5 grasps the rotation speed of the belt drive motor 25 based on the period of the signal from the encoder 24, and controls the rotation speed of the belt drive motor 25 so that the sheet conveyance speed becomes constant. That is, the control unit 5 detects the speed of the paper P conveyed by the encoder 24, and adjusts the speed of the paper P by the belt drive motor 25.

  The carry-out roller pair 26 is provided on the downstream side of the transport belt 23 in the paper transport direction. The carry-out roller pair 26 carries out the paper P on which the image is recorded (printed) by the head unit 4 from the transport unit 2 to the paper discharge unit 3.

  As shown in FIG. 1, the head unit 4 is arranged above the transport belt 23. The head unit 4 includes a head unit 4C that ejects cyan ink, a head unit 4M that ejects magenta ink, a head unit 4Y that ejects yellow ink, and a head unit 4K that ejects black ink from the upstream side in the paper transport direction. Are arranged in order. These heads 4C to 4K are filled with inks of four different colors (cyan, magenta, yellow and black), respectively. Then, ink of each color is ejected from each of the head units 4C to 4K, and a color image is recorded (printed) on the paper P. In the present embodiment, an example in which the head portions 4 for four colors are provided will be described, but the head portions 4 for other colors may be provided. The head units 4C to 4K are similar to each other, and for the common description, the reference numerals (C, M, Y, K) indicating the colors may be omitted below, and the head units 4 may be simply referred to.

  As shown in FIG. 2, each head unit 4 (4C to 4K) includes a plurality of nozzles 42 and a plurality of drivers 41 that control the ejection of ink from each nozzle 42. For example, about 2500 nozzles (2500 dots) are provided in each head unit 4, depending on the printable paper size in the specifications. The number of nozzles 42 provided in each head unit 4 may be less than 2500 or may be 2500 or more.

  Each nozzle 42 is formed by making a hole in a metal plate by etching or the like. A piezoelectric element (not shown) is provided for each nozzle 42. The driver 41 applies a voltage to a piezoelectric element that ejects ink, in accordance with control data, among the piezoelectric elements under its control. For example, the control unit 5 (image processing unit 52) transmits information indicating the operation of each nozzle 42 (information indicating the presence / absence of ejection or density, control data) to each driver 41 in one ejection drive unit. . Each driver 41 applies a voltage to the piezoelectric element corresponding to the nozzle 42 from which ink should be ejected, based on the information indicating the operation of each nozzle 42. As a result, the piezoelectric element is deformed in shape by the voltage application, and pressure is applied to the flow path (not shown) for supplying the ink to the nozzle 42. Then, the pressure to the flow path propagates, and the ink is ejected from the nozzle 42.

  Further, by changing the voltage applied to each piezoelectric element by each driver 41, the ejection speed and the ejection amount of the ink ejected from the nozzle 42 can be changed. For example, the voltage applied to the piezoelectric element can be made smaller than the reference voltage applied to the piezoelectric element. As a result, the driver 41 can adjust the ink ejection speed and the ejection amount with respect to the reference ink ejection speed and the ejection amount to give a difference in the density of one dot.

  The transport unit 2 transports the paper P so that the paper P advances by one dot for each ink ejection from the nozzle 42. An image is formed on the paper P by ejecting ink from the head unit 4 (4C, 4M, 4Y, 4K) onto the paper P being transported by the transport unit 2. The paper P on which the image is formed is sent to the paper discharge unit 3 by the carry-out roller pair 26.

  The paper discharge unit 3 includes a transport path 30, a first paper discharge tray 31, a second paper discharge tray 32, a first paper discharge roller pair 33, a second paper discharge roller pair 34, a switching unit 35, Equipped with.

  The transport path 30 is a guide for guiding the paper P, and includes a first transport path 301 and a second transport path 302. The first transport path 301 guides the paper P carried out by the carry-out roller pair 26 to the first paper discharge tray 31. Further, the second transport path 302 guides the paper P carried out by the carry-out roller pair 26 to the second paper discharge tray 32.

  The paper P guided to the first transport path 301 is discharged to the first paper discharge tray 31 by the first paper discharge roller pair 33. The first discharge roller pair 33 can change the rotation speed, that is, the conveyance speed of the paper P. The first paper ejection roller pair 33 can eject the paper P to the first paper ejection tray 31 at the first speed. Further, the first paper discharge roller pair 33 can discharge the paper P to the first paper discharge tray 31 at a second speed lower than the first speed.

  The first paper discharge tray 31 is a tray that can store the discharged paper P. The first paper discharge tray 31 is horizontally long, and has a first storage area 311 that is far from the first paper discharge roller pair 33, and a second storage area 312 that is closer to the first paper discharge roller pair 33 than the first storage area 311. Have. The paper P ejected to the first paper ejection roller pair 33 at the first speed is accumulated in the first accumulation area 311. Further, the paper P discharged to the first paper discharge roller pair 33 at the second speed is accumulated in the second accumulation area 312. That is, when the sheet P is discharged to the first sheet discharge tray 31 in the sheet discharge unit 3, the sheet P is accumulated in either the first accumulation area 311 or the second accumulation area 312 depending on the sheet discharge speed. Is possible.

  The first speed and the second speed are the speeds of the paper P when the paper P is completely discharged from the first paper discharge roller pair 33. The first speed can be the same as the speed at which the paper P is being conveyed inside the printer 100. The second speed is slower than the first speed, and the speed is adjusted by the first paper discharge roller pair 33, for example. That is, even the paper P discharged at the second speed is conveyed at the same speed as the first speed inside the printer 100. Then, the first paper discharge roller pair 33 reduces the rotation speed before the paper P is completely discharged to decelerate the paper P, and adjusts to the second speed when the paper P is completely abolished. To do.

  The second storage area 312 is an area for storing the normally printed sheets P. Therefore, the second speed is preferably as slow as possible so that the sheets P are accumulated in a certain amount.

  The paper P guided to the second transport path 302 is discharged to the second paper discharge tray 32 by the second paper discharge roller pair 34. The second paper discharge tray 32 is a tray that can store the discharged paper P. The second paper discharge tray 32 is a tray from which the abnormal paper P is discharged when the abnormality detection sensor S1 detects an abnormality in the paper P. The paper P on which the image is normally formed by the head unit 4 is ejected to the first paper ejection tray 31, and the abnormal paper P is ejected when the second paper ejection tray 32 is unusable. It is a tray. Regarding the abnormality of the paper P, the details of discharging the abnormal paper P will be described later. Further, the second paper discharge tray 32 may be omitted. In that case, both the normally printed sheet P and the abnormal sheet P are discharged to the first discharge tray 31.

  The switching unit 35 sets the conveyance destination of the paper P discharged from the discharge roller pair 26 to the first conveyance path 301 (that is, the first paper ejection tray 31 side) or the second conveyance path 302 (that is, the second paper ejection tray 32). Side).

  The paper feed roller pair 11, the drive roller 21, the carry-out roller pair 26, the first paper discharge roller pair 33, and the second paper discharge roller pair 34 described above are each connected to a motor and rotationally driven by the motor. . Each motor is controlled by the control unit 5. For example, the control unit 5 controls the rotation speed of the motor that drives the first paper ejection roller pair 33, thereby controlling the rotation speed of the first paper ejection roller pair 33. As a result, the first paper discharge roller pair 33 can abolish the paper P at the first speed or the second speed slower than the first speed. In the following description, the description of the motor may be omitted and the control unit 5 may be referred to as rotating the roller. In that case, however, it is assumed that the drive of the motor connected to the motor is controlled. .

  The control unit 5 controls the recording operation (printing operation) of the printer 100. The control unit 5 includes a main control unit that performs overall control and image processing, an engine control unit that controls ON / OFF of a motor or the like that rotates image recording and various kinds of rotating bodies, an image processing control unit that performs image processing, and the like. It is also possible to provide a plurality of types of control units by dividing them according to the function and the processing content.

  The control unit 5 includes a CPU 51 and an image processing unit 52. The CPU 51 is a central processing unit. Then, the control unit 5 is communicatively connected to the storage unit 6. For example, the storage unit 6 includes a non-volatile and volatile storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), and a flash ROM. The storage unit 6 stores a control program, control data, image data, and the like. The CPU 51 performs calculations and the like based on the control program and control data stored in the storage unit 6, and issues a control signal to each unit of the printer 100.

  Further, the control unit 5 is connected to the communication unit 8. The communication unit 8 is communicatively connected to an external computer 200 (for example, a personal computer or a server) or a scanner 300 that reads an image recorded on a sheet P and generates image data via a network or a cable. The communication unit 8 includes various connectors, sockets, controllers for communication control, chips, memories and the like. Then, the communication unit 8 receives print data (for example, data including image data, print setting data, etc.) for causing the printer 100 to perform printing from the external computer 200 or scanner 300. When the communication unit 8 receives the print data, the control unit 5 operates the head units 4 and the transport unit 2 based on the print data to print.

  The image processing unit 52 performs various image processing on various image data such as image data received from the computer 200 and image data stored in the storage unit 6. Note that the image processing unit 52 can perform a wide variety of image processing, and the image processing unit 52 can perform known image processing. Then, based on the image data indicating the content to be printed on the paper P, the image processing unit 52 finally prints an image for each pixel (dot) indicating the presence or absence of dot formation (ink ejection) and the ejection amount. Convert to data. The image processing unit 52 adjusts the printing image data according to the position of the nozzle 42 in the paper conveyance direction for each color, and transmits control data (details will be described later) to the driver 41 of each head unit 4. The image processing unit 52 may be functionally realized by the CPU 51 of the control unit 5, the storage unit 6, and the program.

  The control unit 5 (image processing unit 52) is connected to each head unit 4 and gives an operation instruction to each head unit 4. Each head unit 4 is provided with a driver 41 that actually controls the ejection of ink from each nozzle 42. Each driver 41 ejects ink simultaneously from each nozzle 42 in a fixed cycle. In addition, each driver 41 adjusts the presence or absence of ink ejection from each nozzle 42 and the amount of ink ejected based on the adjusted dot data, and determines the gradation (dot area) of dots formed on the recording medium. Control. For example, each driver 41 changes the drive voltage value or drive pulse width applied to each nozzle 42 based on an instruction from the control unit 5 to adjust the presence or absence of ink ejection and the ejection amount.

  In addition, as shown in FIG. 2, the control unit 5 includes the paper feed roller pair 11, (the carry-out roller pair 26 of) the transport unit 2, the first paper discharge roller pair 33, the second paper discharge roller pair 34, The switching unit 35 is connected to each unit that constitutes the printer 100, such as the abnormality detection sensor S1. Then, the control unit 5 controls the operation of each unit and gives an instruction. For example, the operation panel 7 includes hard keys (not shown) and a display unit (not shown) that includes a touch panel and displays soft keys. The operation panel 7 receives an input made by pressing a hard key or a soft key. The operation panel 7 recognizes the input content and transmits data indicating the input content to the control unit 5. The control unit 5 causes each part to perform an operation according to the input content.

(Abnormality detection sensor)
The abnormality detection sensor S1 detects whether or not there is an abnormality in the paper P fed from the paper feed roller pair 11. The abnormalities of the paper P include double feeding in which a plurality of papers P are simultaneously fed, conveyance of a folded paper P, and the like. Then, the abnormality detection sensor S1 detects an abnormality of the paper P fed from the paper feed roller pair 11 by utilizing a conventionally known element and detection method. The abnormality detection sensor S1 is arranged downstream of the paper feed roller pair 11 in the paper transport direction and upstream of the transport unit 2.

(Printer operation)
The operation of the printer 100 according to the present invention will be described with reference to the drawings. FIG. 3 is a flowchart showing the operation of the printer 100 according to the present invention. As shown in FIG. 3, the control unit 5 confirms whether or not the user has performed a print execution operation on the operation panel 7 (step S101). When the print execution operation is not performed (No in step S101), the control unit 5 waits until the print execution operation is performed.

  When the print execution operation is performed (Yes in step S101), the control unit 5 drives the paper feed roller pair 11 (step S102), and starts feeding the paper P from the paper feed tray 1. The control unit 5 accesses the abnormality detection sensor S1 and confirms an abnormality (double feeding, folding, etc.) in the fed paper P (step S103). When no abnormality of the paper P is detected (No in step S103), the printing of the paper P currently being printed is continued (step S104).

  Then, the control unit 5 controls the switching unit 35 to select the first transport path 301 as the transport destination of the paper P (step S105). Then, after printing is completed, the paper P is conveyed to the paper discharge unit 3 by the carry-out roller pair 26. Then, the controller 5 drives the first paper discharge roller pair 33 so that the paper P is discharged to the first paper discharge tray 31 at the second speed (step S106). As a result, the normally printed paper P is stored in the second storage area 312 of the first paper discharge tray 31. As a result, the normally printed paper P (that is, the paper P having no abnormality) is accumulated in the second accumulation area 312 of the first paper ejection tray 31.

  The control unit 5 confirms whether all printing is completed (step S107). When all printing is not completed (No in step S107), the control unit 5 feeds a new paper P and continues printing, that is, returns to step S102. If all printing is completed (Yes in step S107), the process ends.

  On the other hand, if an abnormality is detected in step 103 (Yes in step S103), the control unit 5 stops the paper feed roller pair 11 (step S108). Thereby, the feeding of the paper P is stopped after the abnormality is detected. Then, the control unit 5 confirms whether or not the head unit 4 is currently printing on the paper P (step S109). When printing is being performed (Yes in step S109), the control unit 5 prints the paper P that is currently being printed (step S110). After the printing is completed, the control unit 5 switches the switching unit 35 so that the destination of the sheet is the first transport path 301 (step S111). Then, the control unit 5 drives the first paper discharge roller pair 33 so that the paper P is discharged to the first paper discharge tray 31 at the second speed (step S112). As a result, the normally printed paper P (that is, the paper P having no abnormality) is accumulated in the second accumulation area 312 of the first paper ejection tray 31.

  In step S109, if the printing is not currently being performed (No in step S109) and the printed paper P is discharged to the first discharge tray 31 in step S112, the control unit 5 determines that the second discharge tray It is confirmed whether 32 can be used (step S113). Here, the reason why the second paper ejection tray 32 cannot be used is that a post-processing device that performs stapling, punching, or the like is connected instead of the second paper ejection tray 32, or the second paper ejection is performed. There is a case where the roller pair 34 is out of order, but the invention is not limited thereto.

  When the second paper ejection tray 32 can be used (Yes in step S113), the control unit 5 switches the switching unit 35 so that the conveyance destination of the paper P is the second conveyance path 302 (step S114). Then, the control unit 5 discharges the paper P, for which the abnormality is detected by the second paper discharge roller pair 34, to the second paper discharge tray 32 (step S115). When the abnormality detection sensor S1 detects an abnormality, the sheet P for which the abnormality has been detected may be sandwiched between the pair of paper feed rollers 11. In this case, the control unit 5 rotates the paper feed roller pair 11 until the paper P in which the abnormality is detected is separated from the paper feed roller pair 11. Then, the control unit 5 confirms whether or not the discharge of the abnormal paper P is completed (step S116). The confirmation of the discharge may be performed by providing a sensor on the second discharge tray 32 and detecting it by the sensor, or by detecting it based on the time after the pair of paper feed rollers 11 is stopped in step S108. Good.

  When the abnormal paper P is not completely discharged (No in step S116), the process returns to step S115, and the second paper discharge roller pair 34 continues the paper discharge. When the discharge of the abnormal paper P to the second discharge tray 32 is completed (Yes in step S116), the printing operation is ended.

  When the second paper discharge tray 32 cannot be used (No in step S113), the control unit 5 switches the switching unit 35 so that the conveyance destination of the paper P is the first conveyance path 301 (step S117). ). Then, the control unit 5 drives the first paper discharge roller pair 33 so that the paper P is discharged to the first paper discharge tray 31 at the first speed (step S118). As a result, the sheet P for which the abnormality has been detected is discharged (flyed) at the first speed that is faster than the second speed, and the sheet P that is farther from the first discharging roller pair 33 than the second accumulation area 312 is. It is stored in one storage area 311.

  When the abnormality detection sensor S1 detects an abnormality, the sheet P for which the abnormality has been detected may be sandwiched between the pair of paper feed rollers 11. In this case, the control unit 5 rotates the paper feed roller pair 11 until the paper P in which the abnormality is detected is separated from the paper feed roller pair 11. Then, the control unit 5 confirms whether or not the discharge of the abnormal paper P is completed (step S119).

  When the abnormal paper P is not completely discharged (No in step S119), the process returns to step S118, and the first paper discharge roller pair 33 continues the paper discharge. When the discharge of the abnormal paper P to the first paper discharge tray 31 is completed (Yes in step S119), the printing operation is completed.

  According to the present embodiment, when an abnormality such as double feeding is detected, the abnormal paper P is discharged to the second paper discharge tray 32, or when the second paper discharge tray 32 is unusable, it is normal. The sheet P is discharged to the same first sheet discharge tray 31 as the sheet P on which various printing has been performed. Then, the first paper discharge roller pair 33 discharges the paper P for which normal printing has been completed to the first paper discharge tray 31 at a second speed, and the paper P for which an abnormality has been detected is faster than the second speed. Paper is discharged to the first paper discharge tray 31 at one speed. Therefore, it is possible to prevent the normally printed sheets and the abnormal sheets from being mixed. As a result, the user can easily distinguish the abnormal sheet from the normally printed sheet.

  In the above operation, the printing is interrupted when an abnormality is detected, but the invention is not limited to this. The printing may be restarted after the discharge of the sheet in which the abnormality is detected ends.

  As described above, in the actual printer 100, when an abnormality is detected in the paper P, such as a multi-feed in which a plurality of sheets are fed at the same time or the feeding of a bent sheet, an abnormality is detected. The head does not print on the printed paper. As a result, by not printing on the overlapping sheets of paper, it is possible to prevent the head portion from ejecting ink in the state of being close to the sheets, and it is possible to prevent the head portion from being contaminated and clogging. In addition, by not printing on the folded paper, it is possible to prevent the inside of the printer 100 from becoming dirty due to the ink being sprayed on the area where there is no paper. As a result, it is possible to prevent the paper from getting dirty during printing.

  Further, in the above-described embodiment, as the abnormality, the double feed in which a plurality of sheets are fed at the same time and the sheet in which a folded sheet is fed are taken as examples, but the present invention is not limited to this. For example, it is possible to detect a dirty paper sheet or a paper sheet on which printing is to be performed (a surface facing the head portion during conveyance) as an abnormal paper sheet. As the abnormal paper, there is a paper that is not suitable for printing by the head unit.

  Further, in the above-described embodiment, the inkjet printer having the fixed head unit 4 is described as the image forming apparatus, but an inkjet printer having a movable head unit in which the head unit 4 moves may be used. Further, the printer is not limited to the inkjet printer, and an electrophotographic printer (so-called laser printer) can have the same configuration.

  An example of an image forming apparatus according to the present invention is capable of forming an image on a sheet fed by a sheet feeding section, a conveying section for conveying the sheet supplied from the sheet feeding section, and the sheet conveyed by the conveying section. An image forming unit, a paper discharging unit that discharges the paper from the image forming unit to the outside, and an abnormality detecting unit that detects an abnormality of the paper conveyed to the conveying unit. , A first paper discharge tray for accumulating the discharged paper, and the paper discharge unit discharges the paper to the paper discharge tray at either a first speed or a second speed slower than the first speed. If the paper is available and the abnormality detecting unit does not detect an abnormality, the paper ejecting unit ejects the paper to the first paper ejection tray at the second speed, and the abnormality detecting unit detects the abnormality. If detected, the paper discharge unit discharges the paper to the first paper discharge tray at the first speed. The features.

  With such a configuration, it is possible to intentionally change the position at which the sheets are accumulated in the first sheet ejection tray, depending on the speed of the sheet when ejecting the sheet. Then, the first speed is set when the paper in which the abnormality is detected is discharged, and the second speed is set lower than the first speed when the normally printed paper is discharged. Therefore, even if the paper ejection tray is only the first paper ejection tray, it is possible to separately store the paper in which the abnormality is detected and the paper that is normally printed. As a result, the user does not need to sort the sheets in which the abnormality has been detected while checking the discharged sheet bundle one by one, and the convenience for the user can be improved. Since the normally printed sheets are ejected at the second speed, which is slower than the first speed, the normally printed sheets are accumulated in a certain amount. It is possible to save the trouble of collecting the bundle of sheets, and it is possible to improve the convenience for the user.

  In the above configuration, when the abnormality detection unit detects an abnormality in the sheet, when the image forming unit is forming an image on the sheet, the image on the sheet conveyed after the sheet being image-formed is displayed. Forming is stopped, the paper discharge unit discharges the paper up to the paper being image-formed at the second speed, and the paper conveyed after the paper being image-formed is discharged at the first speed. May stop the supply of the paper after detecting the abnormality.

  By doing so, it is possible to prevent printing on the paper in which the abnormality is detected. As a result, unreasonable force is applied to the image forming section, or the image forming section prints on a part without paper, which may cause the image forming section to malfunction or be damaged, or stain the surrounding area. As a result, it is possible to prevent the paper from becoming dirty. As a result, the frequency of repairs and maintenance can be reduced, and the convenience for the user can be improved.

  In the above-described configuration, the paper discharge unit includes a second paper discharge tray that is different from the first paper discharge tray, and either the first paper discharge tray or the second paper discharge tray in a conveyance path along which the paper is conveyed. And a switching unit for switching the destination of the sheet, when the abnormality detecting unit detects an abnormality in the sheet, the switching is performed when the sheet can be discharged to the second discharge tray. The unit switches the conveyance destination of the sheet to the second discharge tray side, and when the sheet cannot be discharged to the second discharge tray, the switching unit changes the conveyance destination of the sheet to the first discharge tray. You may switch to the paper tray side. As a result, an image forming apparatus capable of ejecting normally printed paper to the first paper ejection tray and ejecting paper for which an abnormality has been detected to the second paper ejection tray. Even when the sheet cannot be discharged to the first sheet, it is possible to separately store the normally printed sheet and the sheet in which the abnormality is detected in the first sheet discharge tray.

  In the above configuration, when the image forming unit is forming an image on the sheet when the abnormality detecting unit detects an abnormality of the sheet, the image on the sheet conveyed after the sheet being image-formed is displayed. The formation may be stopped, the switching unit may convey at least the paper on which the image is being formed to the first paper discharge tray, and the supply unit may stop the supply of the paper after detecting the abnormality.

  Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the gist of the invention.

  The present invention can be used for an image forming apparatus.

100 Printer (Image Forming Apparatus) 1 Paper Feed Tray 2 Conveying Unit (Conveying Unit) 21 Drive Roller 22 Driven Roller 23 Conveying Belt 24 Encoder 25 Belt Drive Motor 26 Discharging Roller Pair 3 Discharging Unit (Discharging Unit) 30 Conveying Path 301 1st conveyance path 302 2nd conveyance path 31 1st paper ejection tray 32 2nd paper ejection tray 33 1st paper ejection roller pair 34 2nd paper ejection roller pair 35 Switching section S1 Abnormality detection sensor 4 (4C, 4M, 4Y, 4K) Head unit (image forming unit)
5 control unit 6 storage unit 7 operation panel 8 communication unit

Claims (4)

A paper feed section for feeding paper,
A transport unit for transporting the paper supplied from the paper feed unit,
An image forming unit for forming an image on a sheet being conveyed by the conveying unit,
A paper discharge unit for discharging the paper from the image forming unit to the outside,
And an abnormality detection unit for detecting an abnormality of the paper for which is supplied to the transport section,
The paper discharge unit includes a first paper discharge tray for accumulating the discharged paper,
The paper discharge unit can discharge the paper to the first paper discharge tray at either a first speed or a second speed lower than the first speed,
If the abnormality detecting unit does not detect the abnormality of the paper sheet fed to the conveyance section, the sheet discharge unit, before Symbol first discharge the sheet on which the image is formed by the second speed by the image forming section It was discharged to the paper tray, when the abnormality detector detects the abnormality of the paper to be the supply, the discharge unit has an abnormality is detected the paper to the first paper discharge tray before SL at the first speed Can be ejected ,
When the abnormality detecting unit detects an abnormality in the sheet supplied to the conveying unit, the sheet feeding unit stops the sheet supply after the abnormality is detected, and the abnormality detecting unit causes the sheet feeding unit to stop feeding the sheet. If an abnormality is detected in the paper supplied to the conveying unit while the paper is being supplied from the paper feeding unit, the paper feeding unit temporarily stops the paper feeding roller pair provided in the paper feeding unit and then An image forming apparatus , wherein the operation of the paper feed roller pair is stopped after the paper feed roller pair is continuously operated until the paper in which the abnormality is detected is separated from the pair . When the abnormality detection unit detects an abnormality in the sheet supplied to the conveyance unit ,
If there is paper in the image forming by the image forming section to stop the formation of the image on the sheet conveyed after than the paper in the image forming,
The sheet discharge unit, wherein while discharging paper sheets to the paper in an image formed by the second speed, the claim of the sheet conveyed after the sheet in the image forming it discharged in the first speed 1 The image forming apparatus according to item 1. The paper output unit includes a second paper output tray different from the first paper output tray;
And a switching unit that switches a destination of the sheet to one of the first sheet discharge tray and the second sheet discharge tray in a sheet conveyance path along which the sheet is conveyed,
When the abnormality detection unit detects an abnormality in the sheet supplied to the conveyance unit ,
When it is possible to discharge the sheet to the second sheet discharge tray, the switching unit switches the conveyance destination of the sheet in which the abnormality is detected to the second sheet discharge tray side,
The image forming apparatus according to claim 1, wherein, when the sheet cannot be discharged to the second discharge tray, the switching unit switches the conveyance destination of the sheet in which the abnormality is detected to the first discharge tray side. apparatus. If abnormalities of the sheet supplied to the transport section by the abnormality detecting portion is paper in the image forming in by the image forming unit when it is detected, to a sheet conveyed after than the paper in the image forming Stop image formation,
The switching unit is conveyed to the sheet of at least the during image formation on the first sheet discharge tray,
The image forming apparatus according to claim 3, wherein the paper feeding unit stops the feeding of paper after the abnormality is detected.

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