JP2006069163A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus equipped with a stencil printing part capable of shortening a first printing time and an inkjet printing part, and to provide an image forming apparatus equipped with a stencil printing part capable of obtaining a good image forming article after jamming and an inkjet printing part. <P>SOLUTION: The image forming apparatus 1 is equipped with the stencil printing part 4 and the inkjet printing part 5 with a recording head 26, and forms a stencil printing image and/or an inkjet printing image on a paper 2. When the stencil printing image and the inkjet printing image are formed on the paper 2, the stencil printing part 4 performs a plate-ejecting operation and a plate-making operation before the stencil printing image 28 is formed, and the inkjet printing part 5 performs a recovery operation of the recording head 26 during the plate-ejecting operation and/or the plate-making operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of performing both image formation by a stencil printing method and image formation by an ink jet recording method.

  After a plate cylinder composed of a porous support cylinder and a master having a laminate structure in which a porous support is bonded to a thermoplastic resin film, the surface of the thermoplastic resin film of the master is heated and perforated by a thermal head. Wrapped around the plate cylinder, an appropriate amount of ink is supplied to the inner peripheral surface of the plate cylinder by ink supply means provided inside the plate cylinder, and the paper is pressed against the outer peripheral surface of the plate cylinder by pressing means such as a press roller or an impression cylinder. Thus, there is known a digital thermal stencil printing apparatus that performs printing by transferring ink oozed from a plate cylinder opening part and a master punching part onto a sheet. Such a stencil printing apparatus is mainly used when a large number of tens or more of the same image is required. This is because the cost per printed material is low and high-speed printing is possible, so that a large number of printed materials can be obtained in a short time.

  However, stencil printing always requires a plate (master) for printing, so if you want to print a small amount of one or several sheets, or if you want to print only a few different images for each of several tens of identical images. Cannot handle when you want to print. In addition, when printing corresponding to a plurality of originals and making them into a booklet, a collation operation is required after the printing operation, and an image like a copying apparatus capable of repeatedly outputting different original images in page order. There is a problem that it cannot respond to formation.

  Therefore, an image forming apparatus using a plateless image forming method such as an electrophotographic method or an ink jet method is more suitable for forming a small amount of various images. An image forming apparatus using a stencil printing method is more suitable. As described above, since the image forming apparatus has advantages and disadvantages according to the required image, it is necessary for the user who performs image formation to use them separately. However, if each type of image forming apparatus is held, the cost and installation are different. Since each space is doubled, it is usually necessary to use only an image forming apparatus corresponding to image formation that is frequently used. Therefore, an image forming apparatus including a stencil printing unit and an ink jet printing unit is described in, for example, “Patent Document 1” and “Patent Document 2”.

JP 2002-137514 A JP 2003-334993 A

  In the image forming apparatus provided with the above-described ink jet printing unit, the recovery operation for preventing clogging of the nozzles due to the drying of the ink caused by leaving the recording head unused for a predetermined time is preceded by the image forming operation. There is a need to do. This recovery operation includes wiping to wipe off the ink discharge surface of the recording head, empty discharge for discharging ink from the nozzles separately from the image forming operation, covering the ink discharge surface with a cap and reducing the pressure inside the cap with a pump, and storing ink from the nozzle. There is a suction operation for sucking, and the like is usually performed by appropriately combining them. This recovery operation is not normally performed at the image forming position on the paper, but is performed at a position dedicated to the recovery operation that is out of the image forming position.The stored ink discharged and sucked from the nozzles by the idle discharge and suction operations is The waste ink is stored in a dedicated waste ink tank.

  Further, since the above-described image forming apparatus also includes a stencil printing unit, it is necessary to perform a plate making operation for peeling the master from the plate cylinder and a plate making operation for making a stencil printing image on the master prior to image formation. Therefore, when the above recovery operation is performed after performing the plate discharging operation and the plate making operation, there is a problem that the first print time (FPT) that is the time until the first image formed product is obtained becomes long. .

  In the ink jet printing unit, the interval between the recording head and the paper is normally set to about 1 mm or less to form an image. Therefore, when a paper transport jam occurs in the ink jet printing unit, the paper and the recording head There is a problem that paper dust on the paper, stencil printing ink or inkjet ink transferred to the paper adheres to the recording head, and adversely affects the subsequent image formation.

  The present invention solves the above-described problems, and can provide an image forming apparatus including a stencil printing unit and an ink jet printing unit capable of shortening the first print time, and a good image formed product even after jam processing. An object of the present invention is to provide an image forming apparatus including a stencil printing unit and an ink jet printing unit.

  According to a first aspect of the present invention, there is provided an image forming apparatus that includes an ink jet printing unit having a recording head and a stencil printing unit, and forms a stencil printing image and / or an ink jet printing image on a paper. When forming an image and an inkjet printing image, the stencil printing unit performs a plate discharging operation and a plate making operation before forming the stencil printing image, and the ink jet printing unit performs the plate discharging operation and / or the plate making operation during the plate making operation. A recovery operation of the recording head is performed.

  According to a second aspect of the present invention, in an image forming apparatus that includes an ink jet printing unit having a recording head and a stencil printing unit and forms a stencil print image and / or an ink jet print image on a paper, ink jet printing on the paper. In the case where an image is formed and a paper transport jam occurs in the ink jet printing unit, the recovery operation of the recording head is performed after the jam processing.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect of the present invention, the image forming apparatus further includes a cover that is opened and closed during the jam processing of the inkjet printing unit, and after the jam processing and after the cover is closed A recovery operation of the recording head is performed.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect of the present invention, the image forming apparatus further includes a jam detecting unit that detects whether or not a paper transport jam has occurred in the ink jet printing unit.

  According to the present invention, the first image is formed by performing the recovery operation of the recording head provided in the ink jet printing unit during the stencil printing operation and / or the plate making operation of the stencil printing unit where image formation is not performed. It is possible to shorten the first print time, which is the time until a product is obtained, and to improve work efficiency. In addition, a paper transport jam occurs in the ink jet printing unit, and even if the recording head is soiled due to contact between the paper and the recording head, a recovery operation is performed immediately, thereby adversely affecting image quality during subsequent image formation. Therefore, it is possible to obtain an image-formed product having a good quality. In addition, a cover is provided in the inkjet printing section, and the recovery operation of the recording head is not performed immediately after the jam processing, and the recovery operation of the recording head is performed after the cover is closed. Therefore, it is possible to prevent damage by the recording head that moves, and to improve safety.

  FIG. 1 shows an image forming apparatus employing the first embodiment of the present invention. In FIG. 1, an image forming apparatus 1 includes a paper feeding unit 3 that feeds paper 2, a stencil printing unit 4 that performs stencil printing on the paper 2 fed from the paper feeding unit 3, and an inkjet image on the paper 2. An ink jet printing unit 5 for forming the paper, a paper discharge unit 6 for discharging the image-formed paper 2 to the outside of the apparatus, and the like.

  The paper feed unit 3 includes a paper feed tray 10 on which a large number of papers 2 are stacked, a paper feed roller 11 that feeds the paper 2 on the paper feed tray 10 from the uppermost one by one, and a paper feed roller 11. A registration roller pair 12 and the like are provided that temporarily stops the fed paper 2 and then feeds the paper 2 toward the stencil printing unit 4 at a predetermined timing.

  A plate making unit 7 is disposed on the upper right side of the stencil printing unit 4. The plate making section 7 cuts a master accommodating section 14 that accommodates a master 13 wound in a roll shape, a thermal head 15 and a platen roller 16 that are disposed downstream of the master accommodating section 14 in the master transport direction, and the master 13. A master cutting means 17, a master conveying roller pair 18 for nipping and conveying the master, and the like. The plate making unit 7 forms a perforated plate making image on the master 13, and then conveys the plate making master 19 toward the stencil printing unit 4.

  The stencil printing unit 4 is provided so as to be able to contact with and separate from a plate cylinder 20 made of a porous cylinder that winds the master-making master 19 made by the plate-making unit 7 on the outer peripheral surface, and the outer peripheral surface of the plate cylinder 20. A press roller 22; a peeling claw 23 for peeling the paper 2 from the outer peripheral surface of the plate cylinder 20; a belt transporting section 25 for transporting the peeled paper 2 while sucking it onto the belt surface by a suction fan 24; . An ink supply means 9 having an ink roller 21 and a doctor roller 8 is disposed inside the plate cylinder 20. The stencil printing unit 4 supplies the paper 2 fed from the paper feeding unit 3 to the pre-printed master 19 wound on the outer peripheral surface of the plate cylinder 20 by the press roller 22, thereby supplying from the ink supply unit 9. The ink thus transferred is transferred to the paper 2 to form a stencil image on the paper 2. On the upper left side of the plate cylinder 20, a plate removal device (not shown) that peels and discards the used master 19 from the outer peripheral surface of the plate cylinder 20 is disposed.

  The ink jet printing unit 5 includes an ink jet recording head 26 disposed above the transport path of the paper 2, a pair of paper transport rollers 27 and 29 disposed on the upstream and downstream sides in the paper transport direction of the ink jet recording head 26, and the paper to be transported. 2, a lower guide plate 31 for guiding 2, a paper detection sensor 32 that is a reflection type sensor for detecting the leading end of the paper 2 in the conveyance direction and setting a start reference for inkjet printing on the paper 2. Each pair of paper transport rollers 27 and 29 transports the paper 2 at a predetermined inkjet printing speed. The conveyance speed at this time is set to be equal to or higher than the discharge conveyance speed of the stencil printing unit 4.

  In each pair of paper transport rollers 27 and 29, the roller positioned above the paper transport path is in direct contact with the stencil image formed on the paper 2, so that the peripheral surface is finely protected to prevent stains due to undried ink. It is desirable to use those having unevenness. Specifically, it is effective to attach a film or the like in which fine ceramic abrasive grains or fine glass beads are scattered on the circumferential surface of the roller.

  The ink jet recording head 26 is configured to be movable in a paper width direction orthogonal to the paper transport direction by a moving mechanism 36. As shown in FIG. 2, a holding portion 71 that is guided by a guide rail 70 provided on a frame 75 and is movable in the paper width direction, which is the left-right direction in the figure, is integrally provided on the upper portion of the inkjet recording head 26. It has been. A lead screw 73 is screwed into the ink jet recording head 26, and when the lead screw 73 is rotationally driven by a stepping motor 72 provided on the frame 75, the ink jet recording head 26 is moved in the paper width direction. . The position of the inkjet recording head 26 is detected by a home position sensor 74 provided on the guide rail 70 and detecting the initial position of the inkjet recording head 26 and the number of steps of the stepping motor 72. In the drawing, reference numeral 76 denotes a removable ink container, reference numeral 77 denotes an ink delivery pump, reference numeral 78 denotes an ink transport pipe, and reference numeral H denotes the ink jet recording head 26 in the paper width direction. The image formable length is shown.

  The moving mechanism 36 described above moves and adjusts the position of the inkjet print image formed on the paper 2 in the paper width direction. The position of the inkjet print image formed on the sheet 2 in the sheet conveyance direction is adjusted and moved according to the operation timing of the inkjet recording head 26. The ink jet recording head 26 receives image data sent from a personal computer 45 (see FIG. 5) connected to the image forming apparatus 1 or a variable data recording memory 48 (see FIG. 5) provided inside the image forming apparatus 1. Based on this, image formation is performed. Further, the stencil printing unit 4 moves and adjusts the position of the stencil printing image formed on the paper 2, that is, the position of the paper 2 with respect to the plate making image of the master-making master 19 wound on the outer peripheral surface of the plate cylinder 20. A moving mechanism (not shown) is provided. As the moving mechanism (not shown), for example, the same moving mechanisms 80 and 280 disclosed in JP-A-9-104159 can be used.

  In FIG. 3, the image formable length in the paper width direction of the inkjet recording head 26 is H, and the plate making length in the paper width direction of the stencil printing unit 4 is K. Usually, the plate making length K is set to about 290 mm in order to enable A3 size stencil printing. However, if the image formable length H is the same as this, the inkjet recording head 26 becomes very expensive. Therefore, in this embodiment, in order to make the inkjet recording head 26 inexpensive, the image formable length H is set to about 60 to 100 mm. In this image forming apparatus 1, the part where the ink jet recording head 26 wants to form an image is a part of the entire image such as the addressed part or the serial number part. is there. 3, reference numeral 28 indicates a stencil print image formed on the paper 2, and reference numeral 30 indicates an ink jet print image formed on the paper 2.

  Further, as indicated by a two-dot chain line in FIG. 3, the ink jet recording head 26 is moved to a retracted position that is a position dedicated to the recovery operation during the recovery operation. When the ink jet recording head 26 occupies the retracted position, a wiper member (not shown) provided so as to freely move in and out of the moving path protrudes and contacts the ink ejection surface of the ink jet recording head 26 that moves to the retracted position. Perform wiping. When the ink jet recording head 26 occupies the retracted position, a cap (not shown) covers the ink ejection surface, and a pump (not shown) decompresses the cap and sucks the stored ink from the nozzles. Irrespective ejection for ejecting ink from the nozzles is performed regardless of the image forming operation. In the present embodiment, an example in which the recovery operation is performed in the order of wiping, suction operation, and idle ejection has been described. However, as the recovery operation, it is not necessary to perform all of these in this order, and the order and operation content can be changed as appropriate. .

  A paper discharge unit 6 is disposed on the downstream side of the inkjet printing unit 5 in the paper conveyance direction. The paper discharge unit 6 is transported by the belt transport unit 34 and the belt transport unit 34 that transport the paper 2 on which the image is formed in the stencil printing unit 4 and / or the ink jet printing unit 5 while sucking the paper 2 on the belt surface by the suction fan 33. And a paper discharge tray 35 on which the image-formed paper 2 is stacked.

  An image reading unit 40 is disposed above the stencil printing unit 4. The image reading unit 40 has a known configuration including a movable scanning unit 41 that reads an image on the document 42, an image sensor 43 such as a CCD to which image data scanned by the scanning unit 41 is input, and the like.

  FIG. 4 shows an operation panel of the image forming apparatus 1. In the figure, the operation panel 50 is disposed on the upper front surface of the apparatus main body of the image forming apparatus 1. The operation panel 50 includes a plate making start key 51, a print start key 52, a trial printing key 53, a stop key 54, a ten key 55, a clear key 56, a display device 57 including a 7-segment LED, a display device 58 including an LCD, and four directions. A key 59, a print switching key 60, and the like are provided. Various numerical values are entered in the display device 57, and the display device 58 has a hierarchical structure and displays various information. The four-way key 59 has an up key 59a, a down key 59b, a left key 59c, and a right key 59d, and is used for various settings. The print switching key 60 is a select switch, and image formation by the image forming apparatus 1 is performed for image formation by only the stencil printing unit 4, image formation by only the ink jet printing unit 5, image formation by the stencil printing unit 4 and the ink jet printing unit 5. Selectively switch to either.

  FIG. 5 is a control block diagram of the image forming apparatus 1. The image forming apparatus 1 shown in the present embodiment includes an image processing device 37 inside the apparatus main body, and common image data read by the image reading unit 40 and image-formed by the stencil printing unit 4 is the image processing device 37. After the predetermined image processing is performed in the common image data processing device 38, the image data is sent to the thermal head drive control device 44 via the image forming unit selection means 39 in the image processing device 37, and based on this data. Then, each heating element of the thermal head 15 selectively generates heat, and the master 13 is punched.

  On the other hand, the variable image data sent from the personal computer 45 and subjected to image formation in the inkjet printing unit 5 is subjected to predetermined image processing by the variable image data processing device 46 and then passed through the image forming unit selection means 39. Based on this data, the ink jet recording head 26 selectively ejects ink to form an image based on this data. Alternatively, the variable image data sent from the variable data recording memory 48 in which necessary image data is recorded in advance is sent to the ink jet head driving device 47 via the image forming unit selecting means 39, and the ink jet is based on this data. The recording head 26 selectively ejects ink to form an image. The operation of the ink jet recording head 26 with respect to the conveyed paper 2 is controlled by a recording head positioning drive control device 49.

  Based on the above-described configuration, the operation of forming a stencil print image and an inkjet print image on the paper 2 using the image forming apparatus 1 in the first embodiment will be described below. The operator switches the print switching key 60 on the operation panel 50 to the “inkjet + stencil” position, sets the document 42 in the image reading unit 40, and presses the plate making start key 51. When the plate making start key 51 is pressed, the scanning unit 41 scans the image of the document 42 and sends this data to the image sensor 43, and a plate discharging device (not shown) is activated to be used from the outer peripheral surface of the plate cylinder 20. The master-making master 19 is peeled off. After completion of the plate removal operation, the plate cylinder 20 rotates to a predetermined plate supply standby position and stops, and a clamper (not shown) provided on the outer peripheral surface is opened to enter a plate supply standby state.

  When the plate cylinder 20 enters a plate feed standby state, the platen roller 16 and the master transport roller pair 18 are operated to send out the master 13. The sent master 13 is punched and made based on the image data sent to the image sensor 43 when passing through the thermal head 15. The master 13, which has been subjected to plate making and becomes a plate-made master 19, is clamped by a clamper of the plate cylinder 20, and then the plate cylinder 20 is driven to rotate at the same peripheral speed as the conveying speed of the master 13. It is wound on the outer peripheral surface. When the master 13 for one plate is conveyed, the master cutting means 17 is actuated to cut the master 13 and the winding operation is completed.

  In the above-described plate discharging operation and / or plate making operation, the inkjet printing unit 5 performs the recovery operation of the inkjet recording head 26. When the plate discharging operation is started, the stepping motor 72 is operated to move the ink jet recording head 26 to the retracted position. During this movement, a wiper member (not shown) projects on the movement path of the ink jet recording head 26, and the ink discharge surface of the ink jet recording head 26 is wiped to remove dust, ink, paper dust, and the like attached thereto. When the ink jet recording head 26 occupies the retracted position, a cap (not shown) covers the ink discharge surface, and a pump (not shown) decompresses the inside of the cap to perform a suction operation. After the suction operation, an idle discharge is performed. Residual ink remaining in the nozzles of the ink jet recording head 26 is removed by this suction operation and idle discharge, and clogging of ink in the nozzles or occurrence of image defects due to mixed color ink remaining in the nozzles is prevented. . The recovery operation is completed by the above-described series of operations, and then the inkjet recording head 26 is moved to the image forming position set by the operation of the stepping motor 72. This series of recovery operations is performed during the plate discharging operation or the plate making operation of the stencil printing unit 4 or during the plate discharging operation and the plate making operation.

  After the winding operation is completed, the paper feed roller 11 is operated to feed one sheet 2 from the paper feed tray 10, and the plate cylinder 20 is rotated at a low speed. The fed paper 2 is temporarily stopped by the registration roller pair 12 and then fed between the plate cylinder 20 and the press roller 22 at a predetermined timing. Then, the press roller 22 is swung at a predetermined timing, and the paper 2 is brought into pressure contact with the plate-making master 19 wound on the outer peripheral surface of the plate cylinder 20. The ink supplied to the inner peripheral surface of the plate cylinder 20 by the ink roller 21 by this pressure contact is transferred to the paper 2 through the opening portion of the plate cylinder 20 and the perforated portion of the master 19 and the so-called printing operation is performed. Done. The sheet 2 to which the stencil printing image, which is the printing image, is transferred by the printing operation is peeled off from the plate-making master 19 on the plate cylinder 20 by the peeling claw 23 and then sent to the belt transport unit 25 and further downstream. It is conveyed.

  The sheet 2 sent by the belt conveying unit 25 is conveyed to the ink jet printing unit 5 by the sheet conveying roller pair 27. During this printing operation, the ink jet printing unit 5 does not perform image formation, and the sheet 2 on which the printing image has been transferred is conveyed further downstream by the sheet conveying roller pair 29 and is discharged via the belt conveying unit 34. The paper is discharged onto the paper tray 35.

  When the trial printing key 53 is pressed by the operator after the printing operation in the stencil printing unit 4 is completed, the sheet feeding roller 11 is activated to feed one sheet 2 from the sheet feeding tray 10. The plate cylinder 20 is rotationally driven at a rotational peripheral speed corresponding to the set printing speed. The fed paper 2 is timed by the registration roller pair 12 and then sent between the plate cylinder 20 and the press roller 22, and the stencil printing image is transferred by the press roller 22 swinging. . Thereafter, the sheet 2 is conveyed by the belt conveying unit 25 and the sheet conveying roller pair 27, and when the leading end is detected by the sheet detection sensor 32, the inkjet is performed based on the image data sent from the personal computer 45 or the variable data recording memory 48. The recording head 26 operates and an ink jet print image is formed on the upper surface thereof. The sheet 2 on which the stencil printing image and the inkjet printing image are formed is further conveyed by the sheet conveying roller pair 29 and the belt conveying unit 34 and is discharged onto the sheet discharge tray 35.

  After the position or density of each image is confirmed by the above-described test printing operation, when the print start key 52 is pressed after the number of images formed on the display device 57 is set by the operator, the paper feed roller 11 is activated. Then, the paper 2 is continuously fed from the paper feed tray 10 and the plate cylinder 20 is rotationally driven at a rotational peripheral speed corresponding to the set printing speed, and the image forming operation is performed in the same manner as in the trial printing operation. Is done. When the set number of image forming sheets is consumed, the operation of the image forming apparatus 1 is stopped, and the image forming apparatus 1 again enters the image forming standby state.

  According to the above-described configuration, the recovery operation of the ink jet recording head 26 provided in the ink jet printing unit 5 is performed during the plate discharging operation and / or the plate making operation of the stencil printing unit 4 in which image formation is not performed. The first print time, which is the time until the first image formed product is obtained, can be shortened, and the working efficiency can be improved.

  In the first embodiment described above, an example is shown in which image formation is performed only on the paper 2 in the stencil printing unit 4 during the printing operation, but image formation is performed in both the stencil printing unit 4 and the inkjet printing unit 5. It is good also as composition which performs.

  FIG. 6 shows an image forming apparatus 61 employing the second embodiment of the present invention. Compared with the image forming apparatus 1 shown in the first embodiment, the image forming apparatus 61 does not perform a recovery operation during the plate-forming operation, and serves as a jam detection unit that detects whether or not a paper transport jam has occurred. The difference is only in that the sheet detection sensor 62 is provided, and the other configuration is the same.

  A paper detection sensor 62 composed of a reflective sensor similar to the paper detection sensor 32 is disposed on the downstream side of the lower guide plate 31 in the paper conveyance direction. The sheet detection sensor 62 detects the sheet 2 immediately after the sheet detection sensor 32 detects the sheet 2 and outputs a signal to the inkjet head driving device 47 as shown in FIG. The paper detection sensors 32 and 62 stop outputting signals when the paper 2 passes.

  The operation when forming a stencil print image and an ink jet print image on the paper 2 using the image forming apparatus 61 in the second embodiment will be described below. The operator switches the print switching key 60 on the operation panel 61 to the “inkjet + stencil” position, sets the document 42 in the image reading unit 40, and presses the plate making start key 51. When the plate making start key 51 is pressed, the plate making operation and the winding operation are performed as in the first embodiment, and the plate making master 19 is wound on the outer peripheral surface of the plate cylinder 20. At this time, the ink jet printing unit 5 does not perform the recovery operation.

  After the winding operation is completed, the paper feed roller 11 is activated and the plate cylinder 20 is rotationally driven at a low speed, so that the plate making operation is performed as in the first embodiment. No image forming operation is performed in the ink jet printing unit 5, and only the printing image is formed on the paper 2 in the stencil printing unit 4. The sheet 2 on which the printing image is formed is discharged onto the paper discharge tray 35, and the printing operation is completed, and the image forming apparatus 1 enters an image forming standby state.

  After the image forming apparatus 1 enters the image formation standby state, when the test printing key 53 is pressed by the operator, a test printing operation is performed as in the first embodiment, and a stencil printing image and an ink jet printing image are formed. The sheet 2 thus discharged is discharged onto the discharge tray 35. After the position or density of each image is confirmed by the above-described test printing operation, when the print start key 52 is pressed after the number of image formations is set on the display device 57 by the operator, the paper is fed from the paper feed unit 3. Are continuously fed and an image forming operation is performed in the same manner as in the trial printing operation.

  At the time of printing, trial printing, and printing, the paper detection sensors 32 and 62 detect the paper 2 and output a signal to the inkjet head driving device 47, and then the signals from the paper detection sensors 32 and 62 are detected. If the output is not stopped within a predetermined time, it is determined that a paper transport jam has occurred in the inkjet printing unit 5, and the operation of the image forming apparatus 1 is interrupted. In this case, the paper detection sensor 32 also functions as jam detection means. Then, when the paper 2 jammed in the ink jet printing unit 5 is removed by the operator, the stepping motor 72 is driven to move the ink jet recording head 26 to the retracted position, and the recovery operation is performed as in the first embodiment. . Thereafter, when the operator presses the print start key 52, the interrupted operation is resumed.

  According to the above-described configuration, even when a paper conveyance jam occurs in the ink jet printing unit 5 and the ink jet recording head 26 is soiled due to contact between the paper 2 and the ink jet recording head 26, a recovery operation is performed immediately after. Thus, it is possible to prevent the image quality from being adversely affected during the subsequent image formation, and to obtain a good quality image formed product.

  In the second embodiment, the case where the printing switching key 60 is switched to the “inkjet + stencil” position to form a stencil printing image and an inkjet printing image on the paper 2 has been described. The present invention may be applied to the case where only the inkjet print image is formed on the paper 2 by switching to the position "." Further, in the second embodiment, the image forming is not performed in the ink jet printing unit 5 on the paper 2 that has been subjected to printing by the stencil printing unit 4, but ink jet printing is performed on the paper 2 that has been subjected to printing. The unit 5 may be configured to perform image formation. Further, in the second embodiment, similarly to the first embodiment, a recovery operation may be performed during the plate discharging operation and the plate making operation.

  FIG. 8 shows a modification of the second embodiment of the present invention. Compared with the second embodiment described above, this modification is different only in that it has a cover 63 that can be freely opened and closed on the front side of the apparatus of the inkjet printing unit 5, and the other configurations are the same. The cover 63 is supported at its right edge by a hinge (not shown) and can be opened and closed from the left edge to the front side of the apparatus. The cover 63 is closed on the apparatus body side corresponding to the left edge to be opened and closed. An open / close sensor (not shown) is provided for detecting whether or not it is being operated. The open / close sensor (not shown) is formed by a limit switch, for example, and is turned on when the cover 63 is closed and outputs a signal to the ink-jet head driving device 47, and is turned off when the cover 63 is opened to turn off the ink-jet head driving device 47. Stop signal output to.

  According to this modification, when a paper transport jam occurs in the inkjet printing unit 5, the cover 63 is opened to remove the jammed paper 2, and then the cover 63 is closed. As a result, the output of the signal from at least one of the respective paper detection sensors 32 and 62 to the ink jet head driving device 47 is interrupted when the paper 2 is removed, and the ink jet recording head is immediately determined that the removal of the paper 2 is completed. 26, and when the cover 63 is closed and a signal is output from the opening / closing sensor (not shown) to the inkjet head driving device 47, the recovery operation of the inkjet recording head 26 is performed. Can be prevented from being damaged by the ink jet recording head 26 that is moved by the recovery operation, and safety can be improved.

  In the above-described embodiments and modifications, the recovery operation of the ink jet recording head 26 is performed in the ink jet printing unit 5 after the jam processing after the paper transport jam has occurred during the plate discharging operation and / or the plate making operation of the stencil printing unit 4. However, for example, the recovery operation may be performed when the paper 2 is replenished on the paper feed tray 10 after the paper 2 has run out in the paper feed unit 3. Also with this configuration, the recovery operation can be performed except during the image forming operation, and a good image can be obtained without reducing the working efficiency.

1 is a schematic front view of an image forming apparatus employing a first embodiment of the present invention. It is the schematic of the inkjet printing part used for the 1st and 2nd embodiment of this invention. It is a figure for demonstrating the image range of the stencil printing part and inkjet printing part in the 1st and 2nd embodiment of this invention. It is the schematic of the operation panel used for the 1st and 2nd embodiment of this invention. FIG. 2 is a control block diagram of the image forming apparatus used in the first embodiment of the present invention. It is a schematic front view of the image forming apparatus which employ | adopted the 2nd Embodiment of this invention. FIG. 6 is a control block diagram of an image forming apparatus used in a second embodiment of the present invention. It is a schematic front view of the image forming apparatus which shows the modification of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,61 Image forming apparatus 2 Paper 4 Stencil printing part 5 Inkjet printing part 26 Recording head (inkjet recording head)
28 Stencil printing image 30 Inkjet printing image 32, 62 Jam detection means (paper detection sensor)
63 Cover

Claims (4)

In an image forming apparatus that includes an inkjet printing unit having a recording head and a stencil printing unit, and forms a stencil printing image and / or an inkjet printing image on paper,
When forming a stencil printing image and an inkjet printing image on paper, the stencil printing unit performs a plate discharging operation and a plate making operation before forming the stencil printing image, and the ink jet printing unit performs the plate discharging operation and / or An image forming apparatus, wherein a recovery operation of the recording head is performed during the plate making operation. In an image forming apparatus that includes an inkjet printing unit having a recording head and a stencil printing unit, and forms a stencil printing image and / or an inkjet printing image on paper,
An image forming apparatus, wherein when an ink jet print image is formed on a paper sheet and a paper transport jam occurs in the ink jet printing unit, the recovery operation of the recording head is performed after the jam processing. The image forming apparatus according to claim 2.
An image forming apparatus comprising: a cover that is opened and closed during jam processing of the ink jet printing unit; and the recovery operation of the recording head is performed after the jam processing and after the cover is closed. The image forming apparatus according to claim 2 or 3,
An image forming apparatus comprising jam detecting means for detecting whether or not a paper transport jam has occurred in the ink jet printing section.

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