JP2006168888A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent jam from occurring when a paper remains in a device in feeding of the paper from a manual single-paper feeding tray. <P>SOLUTION: A shutter member 144 is disposed swingably, for opening/closing a manual feeding port 143 from a manual single-paper feeding tray 141. The shutter member 144 can be switched between a position where it swings in conjunction with the swing of an open/close guide plate 110 and a position where it does not swing. A shutter solenoid 150 is disposed to swing the shutter member 144 up to the position where it swings in conjunction with the open/close guide plate 110. Manual feeding is prohibited when the manual single-paper feeding tray 141 is just set at a use position, and the constitution for opening/closing operations of the shutter member 144 is simplified by swinging the shutter member 144 in conjunction with the open/close guide plate 110. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus provided with a manual sheet feeding unit.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a printer / fax / copier multifunction machine, for example, a recording head (image forming means) constituted by a liquid discharge head for discharging a recording liquid droplet is used. While conveying a recording medium (hereinafter referred to as “paper”, the material is not limited, and a recording medium, a transfer material, etc. are also used synonymously), a recording liquid droplet (hereinafter also referred to as an ink droplet). ) Is attached to a sheet of paper, and an ink jet recording apparatus that forms an image (recording, printing, printing, and printing are also used synonymously), an image forming apparatus that forms an image by an electrophotographic method, and the like are known.

By the way, in the conventional image forming apparatus, as described in Patent Documents 1 and 2, for example, a large number of sheets are placed in order to feed a sheet for forming an image into the apparatus main body. Paper feed tray, paper feed cassette that can store a large amount of paper, manual feed tray (part) that allows users to set multiple sheets for feeding paper manually by hand, one sheet A plurality of paper feeding means such as a single manual feed tray can be provided.
JP-A-3-138256 Japanese Patent Laid-Open No. 9-235029

Further, as described in Patent Document 3, paper can be fed from a paper discharge tray. After an image is formed on the fed paper, the paper is again discharged to the paper discharge tray, so that the manual paper feed unit is Some are omitted.
Japanese Patent No. 2698699

Further, as described in Patent Document 4, a manual paper feed table is provided to be openable and closable so as to open and close the manual paper feed table so that the manual paper feed table is lowered when the manual paper feed table is opened to the manual paper feed position. By providing a shielding member that moves up and down in conjunction to activate / deactivate the manual feed detection unit, and by feeding paper to the manual feed table, the shield member can be separated from the manual feed detection unit to enable manual feeding. There is something that is detected and displayed.
No. 7-3403

In addition, as described in Patent Document 5, some image forming apparatuses perform alignment by forming a loop on a sheet, and the sheet is sent to an image forming unit by a registration roller device.
JP-A-6-64792

  However, in the above-described image forming apparatuses described in Patent Documents 1 and 2, since the paper can be manually fed when the manual feed tray is in a state in which manual feeding can be performed, the image is not contained in the apparatus. If the paper being formed remains, it may be transported in an overlapping manner, and jamming may occur. Similarly, even in the image forming apparatus described in Patent Document 3, when the paper is manually fed from the paper discharge tray, the image is first formed from the inside of the apparatus only by using the paper discharge tray as a manual feed tray. If the operation of discharging the paper to the paper discharge tray side is performed, there is a risk of jamming.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of performing manual sheet feeding stably without causing a jam or the like.

  In order to solve the above-described problems, an image forming apparatus according to the present invention is provided with a swingable shutter member that opens and closes a manual paper feed port from a manual paper feed unit.

  Here, a swingable opening / closing guide member for forming a slack in the recording medium is provided in the conveyance path of the recording medium from the paper feeding unit to the image forming unit, and the manual insertion is performed downstream of the opening / closing guide member. It is preferable to provide a configuration in which a paper feed port is arranged so that swinging of the opening / closing guide member and opening / closing of the shutter member are interlocked.

  In this case, the shutter member is preferably disposed so as to be switchable between a position not interlocked with the opening / closing guide member and a position interlocking with the shutter member, and the shutter member is switched from a position not interlocked with the opening / closing guide member to a position interlocked. Preferably means are provided. And it is preferable that the switching means is an electric drive means, or that the switching means is a tray of a manual paper feed unit that is attached to the apparatus main body so as to be opened and closed.

  Moreover, it is preferable that the shutter member has an inclined portion that extends obliquely upward with respect to the paper feeding direction. Further, it is preferable that the opening / closing guide member also serves as a guide for a recording medium fed from the manual sheet feeding unit. Furthermore, when the manual paper feed unit is set to the manual feedable position and the recording medium remains in the apparatus, the shutter member may be closed until the recording medium is discharged. preferable.

  According to the image forming apparatus of the present invention, since the shutter member that opens and closes the paper feed port of the manual paper feed unit is provided, the shutter member is kept closed even when the manual paper feed unit is in a state where manual feed is possible. As a result, when the recording medium remains in the machine, the recording medium is not manually fed and jamming can be prevented.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An outline of an example of an image forming apparatus according to the present invention will be described with reference to FIGS. 1 is a schematic configuration diagram showing the overall configuration of the image forming apparatus, FIG. 2 is a plan explanatory view of an image forming unit and a sub-scanning conveying unit of the apparatus, FIG. 3 is a side explanatory view, and FIG. FIG. 6 is an explanatory diagram of a sheet conveyance path related to sheet feeding.

  This image forming apparatus includes an image forming unit (means) 2 for forming an image while conveying a sheet and a sub-scanning conveying unit (means) 3 for conveying a sheet inside the apparatus main body 1 (enclosure). And the like, and a sheet 5 is fed one by one from a sheet feeding unit (means) 4 including a sheet feeding cassette provided at the bottom of the apparatus body 1, and the sheet 5 is fed by the sub-scanning conveying unit 3 to the image forming unit 2. In the case of single-sided printing, after the droplets are ejected onto the paper 5 by the image forming unit 2 while being conveyed at a position opposite to the image forming unit 2, in the case of single-sided printing, the apparatus is passed through the paper discharge conveying unit (means) 7. The paper 5 is discharged onto a paper discharge tray 8 formed on the upper surface of the main body 1, and in the case of double-sided printing, it is sent from the middle of the paper discharge conveyance unit 7 to the double-side unit 10 provided at the bottom of the apparatus main body 1, and the switch Back transport, feed again to the sub-scan transport unit 3 and images on both sides It is discharged onto the discharge tray 8 after the form.

  The image forming apparatus also has an image reading unit (scanner) for reading an image above the discharge tray 8 above the apparatus main body 1 as an input system for image data (print data) formed by the image forming unit 2. Part) 11. The image reading unit 11 includes a scanning optical system 15 including an illumination light source 13 and a mirror 14 and a scanning optical system 18 including mirrors 16 and 17. The scanned document image is read as an image signal by the image reading element 20 disposed behind the lens 19, and the read image signal is digitized and subjected to image processing, and the image-processed print data is printed. be able to.

  Further, this image forming apparatus uses an information processing apparatus such as an external personal computer, an image reading apparatus such as an image scanner, and an imaging apparatus such as a digital camera as an input system for image data (print data) formed by the image forming unit 2. For example, print data including image data from the host side can be received via a cable or a network, and the received print data can be processed and printed.

  Here, as shown in FIG. 2, the image forming unit 2 of the image forming apparatus holds the carriage 23 movably in the main scanning direction by the guide rod 21 and a guide stay (not shown), and is driven by the main scanning motor 27. It moves and scans in the main scanning direction via a timing belt 29 spanned between the pulley 28A and the driven pulley 28B.

  A recording head 24 including a droplet discharge head for discharging droplets of each color is mounted on the carriage 23, the carriage 23 is moved in the main scanning direction, and the sheet 5 is transferred to the sheet by the sub-scanning conveyance unit 3. A shuttle type is used in which droplets are ejected from the recording head 24 while feeding in the transport direction (sub-scanning direction) to form an image. A line-type head can also be used.

  The recording head 24 has two droplet discharge heads 24k1 and 24k2 that discharge black (Bk) ink, respectively, and one each that discharges cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Each of the sub-tanks 25 mounted on the carriage 23 is composed of a total of five liquid droplet ejection heads (hereinafter referred to as “recording head 24” when the colors are not distinguished). Of ink is supplied.

  On the other hand, as shown in FIG. 1, a recording liquid cartridge containing black (Bk) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink from the front of the apparatus main body 1 to the cartridge mounting portion. Each color ink cartridge 26 can be detachably mounted, and ink is supplied from each color ink cartridge 26 to each color sub-tank 25. The black ink is supplied from one ink cartridge 26 to the two sub tanks 25.

  The recording head 24 uses a piezoelectric element as a pressure generating means (actuator means) for pressurizing the ink in the ink flow path (pressure generation chamber) to deform the vibration plate that forms the wall surface of the ink flow path. A so-called piezo type that discharges ink droplets by changing the volume in the flow channel, or discharges ink droplets with a pressure generated by heating the ink in the ink flow channel using a heating resistor to generate bubbles. The so-called thermal type, the diaphragm that forms the wall surface of the ink flow path and the electrode are placed opposite to each other, and the diaphragm is deformed by the electrostatic force generated between the vibration plate and the electrode, thereby the ink flow path inner volume It is possible to use an electrostatic type or the like that discharges ink droplets by changing the above.

  Further, as shown in FIG. 2, a maintenance / recovery device 121 for maintaining and recovering the nozzle state of the recording head 24 is disposed in the non-printing area on one side in the scanning direction of the carriage 23. The maintenance / recovery device 121 includes five moisturizing caps 122k2, 122k1, 122c, 122m, and 122y for capping the nozzle surfaces of the five recording heads 24 (“moisturizing caps” when colors are not distinguished). 122 ”), a single suction cap 123, a wiper blade 124 for wiping the nozzle surface of the recording head 24, and discharge (empty discharge) of droplets that do not contribute to recording (image formation). For example, an empty discharge receiving member 125 is provided.

  Further, as shown in FIG. 2, in the non-printing area on the other side of the carriage 23 in the scanning direction, droplets that do not contribute to recording (image formation) (empty discharge) are discharged from the five recording heads 24. An empty discharge receiving member 126 is provided. The empty discharge receiving member 126 has five openings 127k2, 127k1, 127c, 127m, and 127y corresponding to the recording head 24 (referred to as “openings 127” when colors are not distinguished).

  As shown in FIG. 3, the sub-scanning conveyance unit 3 is a driving roller for conveying the paper 5 fed from below by changing the conveyance direction by approximately 90 degrees and facing the image forming unit 2. An endless transport belt 31 laid between the transport roller 32 and a driven roller 33 which is a tension roller, and a charging means to which a high voltage as an alternating voltage is applied from a high voltage power source in order to charge the surface of the transport belt 31 A charging roller 34, a guide member 35 that guides the conveyance belt 31 in a region opposite to the image forming unit 2, and two pressing rollers (additions) that press the paper 5 against the conveyance belt 31 at a position facing the conveyance roller 32. Pressure roller 36, two spur rollers 37 that press the top surface of the sheet 5 on which the image is formed by the image forming unit 2, and the sheet 5 on which the image is formed is separated from the conveyance belt 31. And a separation claw 38.

  The transport belt 31 of the sub-scan transport unit 3 is rotated in the paper transport direction (sub-scan direction) in FIG. 2 by rotating the transport roller 32 from the sub-scan motor 131 through the timing belt 132 and the timing roller 133. It is configured to do. The transport belt 31 includes, for example, a surface layer that is a sheet adsorption surface formed of a pure resin material that is not subjected to resistance control, such as ETFE pure material, and a back layer that is subjected to resistance control using carbon with the same material as the surface layer. Although a two-layer structure (medium resistance layer, earth layer) is used, the present invention is not limited to this, and a one-layer structure or a structure of three or more layers may be used.

  In addition, a cleaning unit (mylar is used here) 135 for removing paper dust and the like adhering to the surface of the conveyor belt 31 between the driven roller 33 and the charging roller 34, and the surface of the conveyor belt 31. And a static elimination brush 136 for removing electric charges.

  In addition, a cleaning unit (mylar is used here) 135 for removing paper dust and the like adhering to the surface of the conveyor belt 31 between the driven roller 33 and the charging roller 34, and the surface of the conveyor belt 31. And a static elimination brush 136 for removing electric charges.

  Further, a high-resolution code hole 137 is attached to the shaft 32 a of the transport roller 32, and a transmissive photosensor 138 that detects a slit (not shown) formed in the codewheel 137 is provided, and the codewheel 137 and the photosensor 138 are provided. The rotary encoder is constituted by the above.

  Further, a linear scale (not shown) is formed on the back surface of the conveyor belt 31 (a surface in contact with the outer circumferential surface of the conveyor roller 32), and a reflective photosensor 139 for reading the linear scale is provided. The scale and the photosensor 139 constitute a linear encoder. The linear scale may be formed in a striped pattern by depositing aluminum on the back surface side of the conveyor belt 31 and then flying with a laser beam. Further, the linear scale is provided at a portion where reading by the reflective photosensor 139 is not disturbed by the guide member 35. Further, a joint sensor 140 is provided adjacent to the sensor 139 for detecting a joint of a linear scale provided on the front surface of the transport belt 32.

  The paper feed unit 4 can be inserted / removed from the front side of the apparatus main body 1. The paper feed cassette 41 that stacks and stores a large number of sheets 5 and the sheets 5 in the sheet feed cassette 41 are separated and sent out one by one. A sheet feeding roller 42 and a friction pad 43 are provided, and a registration roller 44 that registers the fed sheet 5 is provided. The paper feed unit 4 includes a manual feed tray 46 for stacking and storing a large number of sheets 5, a manual feed roller 47 for feeding the sheets 5 from the manual feed tray 46 one by one, and the apparatus main body 1. On the lower side, a paper feed cassette that is optionally mounted and a transport roller 48 for transporting paper 5 fed from a duplex unit 10 described later are provided. A member for feeding the paper 5 to the sub-scanning conveyance unit 3 such as the paper feed roller 42, the registration roller 44, the manual feed roller 47, and the conveyance roller 48 is a paper feed motor including an HB type stepping motor via an electromagnetic clutch (not shown). (Drive means) 49 is rotationally driven.

  The paper discharge transport unit 7 includes three transport rollers 71a, 71b, and 71c that transport the paper 5 separated by the separation claw 38 of the sub-scan transport unit 3 (referred to as “transport roller 71” when not distinguished). Spurs 72a, 72b, 72c (also referred to as “spurs 72”), a lower guide portion 73 and an upper guide portion 74 for guiding the paper 5 conveyed between the paper discharge roller 71 and the spur 72, and a lower guide. A reversing roller pair 77 and a reversing discharge for reversing the sheet 5 fed from between the section 73 and the upper guide section 74 through the reversing sheet discharging path 81 which is the first transport path and sending it to the sheet discharging tray 8 face down. A pair of paper rollers 78. A conveyance path for conveying the sheet 5 between the lower guide portion 73 and the upper guide portion 74 is referred to as a conveyance path 70.

  Note that, on the exit side of the conveyance path 70, a first discharge path 81 for reverse discharge to the discharge tray 8, a second discharge path 82 for discharging to a straight discharge tray 181 described later, and both sides A branch mechanism 60 is provided for switching to the transport path for any of the units 10.

  The duplex unit 10 transports the fed paper 5 from the side surface of the apparatus main body 1 and transports it in the horizontal direction following the vertical duplex transport path 90c that constitutes the vertical duplex transport path 90c that transports it downward. A horizontal conveyance unit 101b that forms a horizontal take-in conveyance path 90a and a switchback conveyance path 90b is integrally provided.

  The vertical double-sided conveyance path 90c is provided with a double-sided entrance roller pair 91 for conveying the fed paper 5 downward and a conveyance roller pair 92 for sending it out to the horizontal taking-in conveyance path 90a. 93, and the switchback conveyance path 90b includes a double-sided exit roller 94 composed of a reverse roller for reversing and refeeding the sheet 5 fed from the take-in conveyance path 90a and three double-sided conveyance roller pairs 95. Yes.

  Further, the branch plate 96 for switching between the conveyance path of the sheet 5 from the take-in conveyance path 90a to the switchback conveyance path 90b and the conveyance path for refeeding from the switchback conveyance path 90b to the conveyance roller pair 48 can be swung. Provided. The branch plate 96 can swing between a switchback side position shown by a solid line in FIG. 1 and a refeeding side position shown by a broken line.

  The sheet 5 sent out from the duplex unit 10 is sent into the above-described transport roller 48 and sent to the registration roller 44.

  When the sheet 5 fed from the sheet feeding cassette 41, the manual sheet feeding tray 46, and the duplex unit 10 described above is conveyed by the registration roller 44, the conveyance roller 32 of the sub-scanning conveyance unit 3 and As shown in FIG. 1, the opening / closing guide plate 110 can be swung to form a loop (slack) on the paper 5 between the presser rollers 36 and the registration roller 44 to prevent back tension on the paper 5. Provided.

  When the sheet 5 is sent from the registration roller 44 to the sub-scanning conveyance unit 3, the open / close guide plate 110 swings in the direction indicated by the arrow to guide the sheet 5. At the timing reached, the state returns to the state shown in FIG.

  Further, in this image forming apparatus, in order to perform manual sheet feeding, a single sheet feeding tray 141 is provided on one side of the apparatus body 1 with respect to the apparatus body 1 as shown in FIG. In order to manually feed one sheet, the one-sheet manual feed tray 141 is folded to the position shown in the phantom line. The manually fed paper 5 from the single manual paper feed tray 141 is guided by the upper surface of the open / close guide plate 110 and linearly between the transport roller 32 and the pressing roller 36 of the sub-scanning transport unit 3 as it is. Can be plugged in.

  On the other hand, a straight discharge tray 181 is provided on the other side of the apparatus main body 1 so as to be openable and closable (can be opened and lowered) in order to discharge the sheet 5 on which the image has been formed straight up face up. By opening (opening) the straight paper discharge tray 181, the paper 5 fed from the lower guide portion 73 and the upper guide portion 74 to the paper discharge conveyance portion 7 is discharged linearly to the straight paper discharge tray 181. A straight paper discharge path 82 as a second paper discharge path is formed.

  As a result, for example, when using paper that is difficult to convey in a curved line, such as OHP or thick paper, one sheet can be manually fed from the single sheet feed tray 141 and the sheet 5 can be conveyed linearly to the straight discharge tray 181. become able to. Of course, even normal paper such as plain paper can be fed from the single manual feed tray 141 and discharged linearly to the straight discharge tray 181.

  Here, the arrangement of various sensors will be described with reference to FIG. 4. In order to detect the paper 5, the conveyance registration sensor 201 is disposed upstream of the registration roller 44, the conveyance roller 32, the upstream pressing roller 36, and the like. The image registration sensor 203 for registering the image writing position is provided on the downstream side of the presser roller 36 on the downstream side (inlet of the image forming unit 2). A print unit exit sensor 204 is disposed at the exit (on the front side of the transport roller 71a), a branch sensor 205 is disposed on the branch mechanism 60, and a paper discharge sensor 206 is disposed on the front side of the paper discharge roller pair 78. .

  Further, a manual tray opening detection sensor 211 for detecting opening / closing of the single manual feeding tray 141 and a paper discharge tray opening detection sensor 212 for detecting opening / closing of the straight paper discharge tray 181 are arranged. Although not shown in FIG. 4, a double-sided inlet sensor is provided on the inlet side of the horizontal take-in conveyance path 90a of the duplex unit 10, and between the outlet side of the horizontal take-up conveyance path 90a and the inlet side of the switchback conveyance path 90b. Each reversal sensor is arranged.

Next, the configuration of the one-sheet manual sheet feeding unit will be described with reference to FIGS. 5 is an explanatory perspective view of the single sheet manual feeding unit, and FIG. 6 is an explanatory side view.
First, the opening / closing guide plate 110 and its swinging mechanism will be described. The opening / closing guide plate 110 serving as the opening / closing guide member is disposed so as to be swingable by the support shaft 111, and the tension roller 112 and the registration roller 44 are sub-scan transported. It is held at the loop formation position (position in FIG. 6) withdrawn from the conveyance path with the section 3.

  The guide surface 110 a curved in the vertical direction of the open / close guide plate 110 is a guide surface for guiding the paper 5 fed from the registration roller 44, and the horizontal guide surface 110 b is a paper manually fed from the single manual paper feed tray 141. 5 is a guide surface for guiding 5. By using the upper surface of the open / close guide plate 110 also as a manual guide surface for one sheet, the configuration is simplified.

  On the other hand, in order to swing the opening / closing guide plate 110, an opening / closing guide plate solenoid 113 as driving means is arranged, and a swing arm 114 is attached to a plunger 113a of the opening / closing guide plate solenoid 113, and the tip of the swing arm 114 is placed. When the opening / closing guide plate solenoid 113 is driven by bringing the portion into contact with the contact portion 115 formed integrally with the opening / closing guide plate 110, the plunger 113a is pulled and the swing arm 114 swings in the direction of the arrow in FIG. Then, the open / close guide plate 110 is swung in the direction of the arrow in the same figure against the urging force of the tension spring 112.

  In this case, when the paper 5 fed from the registration roller 44 is guided to the sub-scanning conveyance unit 3, the opening / closing guide plate solenoid 113 is driven to guide the paper 5 fed out, and the opening / closing guide plate solenoid 113 is driven at a predetermined timing. 6 is returned to the initial position shown in FIG. 6 so that a slack (loop) can be formed on the paper 5 between the registration roller 44 and the sub-scanning conveyance unit 3.

  Next, as described above, the single manual paper feed tray 141 is attached to the apparatus main body 1 by the support shaft 142 so as to be openable and closable. A shutter member 144 that opens and closes the manual feed port 143 is provided inside the single manual feed tray 141 so as to be swingable by a support shaft 145.

  The shutter member 144 includes an arm portion 144 a provided with a stopper portion 146 at the front end portion that can shield the paper 5 manually fed from the single manual paper feed tray 141, and an arm portion for interlocking with the opening / closing guide plate 110. 144b, and an engagement roller 147 that engages with an engagement portion 116 that is integrally formed with the opening / closing guide plate 110 is rotatably provided at the distal end portion of the arm portion 144b. The shutter member 144 is in the state of FIG. 6 in which the arm portion 144b does not engage with the open / close guide plate 110 in a steady state, that is, does not interlock with the swinging of the open / close guide plate 110.

  In order to switch the shutter member 144 to a position interlocked with the swinging of the opening / closing guide plate 110 by engaging the arm portion 144b of the shutter member 144 with the opening / closing guide plate 110, an electrical driving unit as a switching unit is used. A certain shutter switching solenoid 150 is arranged, and one end of a swing arm 152 that swingably supports a support shaft 151 is connected to a plunger 150a of the shutter switch solenoid 150, and the other end of the swing arm 152 is connected to a shutter. It arrange | positions so that the arm part 144b of the member 144 can contact | abut. By driving the shutter switching solenoid 150, the shutter member 144 swings in the direction of the arrow in FIG. 6, the arm 144b engages with the engaging portion 116 of the opening / closing guide plate 110, and the shutter member 144 moves to the opening / closing guide. The position is switched to the position interlocked with the swing of the plate 110.

Next, the operation of the one-sheet manual sheet feeding unit will be described with reference to FIGS. Each figure is an explanatory side view similar to FIG.
First, from the state shown in FIG. 6, the single manual paper feed tray 141 is opened in the direction of arrow A, and the single manual paper feed tray 141 is made usable as shown in FIG. Thereafter, the shutter switching solenoid 150 is driven (turned on) at a required timing, so that the swing arm 152 is swung in the arrow B direction and the shutter member 144 is swung in the arrow C direction. 8, the stopper portion 146 of the shutter member 144 swings to a position where the one-sheet manual feeding path 160 is opened, and in this state, the arm portion 141b of the shutter member 144 is engaged with the opening / closing guide plate 110. The shutter 116 can be engaged with the portion 116, that is, the shutter member 144 is in a position interlocked with the opening / closing guide plate 100.

  Prior to this state, the stopper portion 146 of the shutter member 144 is positioned on the one-sheet manual feed path 160 and the manual feed port 143 is closed, and the sheet 5 is manually fed from the one-sheet manual feed tray 141. Even if paper is to be fed, the paper is not fed because it is restricted by the stopper 146.

  Therefore, by driving the open / close guide plate solenoid 113, the swing arm 114 swings in the direction indicated by the arrow D, thereby swinging the open / close guide plate 110 in the direction indicated by the arrow E. At this time, as shown in FIG. Since the engaging portion 116 of the opening / closing guide plate 110 is engaged with the roller 147 of the arm portion 144b of the shutter member 144, the shutter member 144 and the opening / closing guide plate 110 can be interlocked, and the upper surface 110b of the opening / closing guide plate 110 is It is possible to guide the manually fed paper.

  As a result, the manual sheet feeding port 143 is opened and the one-sheet manual sheet feeding path 160 is opened, and the sheet 5 is manually fed to the sub-scanning conveyance unit 3 using the one-sheet manual sheet feeding tray 141. Will be able to.

  After the arm portion 144b of the shutter member 144 is engaged with the open / close guide plate 110, the shutter member 144 is opened even if the swing arm 152 is returned to the initial position by the shutter switching solenoid 150. Does not affect operation.

  That is, when the shutter switching solenoid 150 is ON, the shutter member 144 itself swings to the open position, but since the solenoid 150 is small, the plunger 150a is sucked (the shutter member 144 is open). Since the shutter member 144 swings to the open position shown in FIG. 9, the shutter member 144 is held open by the solenoid 114 in conjunction with the open / close guide plate 110, while the shutter switching solenoid 150 Is turned off.

  In this way, by providing a swingable shutter member that opens and closes the manual paper feed port from the single manual paper feed tray, the single manual paper feed tray can be manually fed when paper remains in the apparatus. Even when the paper is ready (use state), the manual feed port can be closed, and jamming can be prevented from being manually fed. In particular, even when manual sheet feeding can be performed without using registration rollers or sheet feeding rollers as in the above embodiment, manual sheet feeding is surely performed while the sheet remains in the apparatus. It can be blocked.

  In this case, a swingable opening / closing guide member for forming a slack in the sheet is provided in the sheet conveyance path from the sheet feeding unit to the image forming unit, and one sheet is manually fed downstream of the opening / closing guide member. An electric drive means (for example, the above-described operation) is used to perform the opening / closing operation of the shutter member by arranging the manual feed port of the tray so that the swinging of the opening / closing guide member and the opening / closing of the shutter member are interlocked. Even when a solenoid is used, it is sufficient to swing the shutter member to a state where it engages with the opening / closing guide member (interlocking position). Therefore, a small and small capacity driving means can be used, and the cost can be reduced. Can be reduced.

  Further, as described above, the shutter member is disposed so that it can be switched between a position not interlocked with the opening / closing guide member and a position interlocked with the shutter opening / closing guide member. Even if it is swung, the shutter member is not swung, and noise and useless movement of the shutter member can be eliminated.

Next, the shape and action of the stopper portion 146 of the shutter member 144 will be described with reference to FIG.
The stopper portion 146 of the shutter member 144 includes a restricting portion 146a that extends obliquely upward in the manual feed direction, and an upper restricting portion 146b that faces from the upper end of the restricting portion 146a in the direction opposite to the manual feed direction. . Accordingly, even when the paper 5 is manually inserted while the shutter member 144 is in the closed state, the paper 5 can be guided obliquely upward by the restricting portion 146a and reliably stopped by the upper restricting portion 146b.

  On the other hand, for example, as shown in FIG. 12, when the stopper portion 146 of the shutter member 144 is a restricting portion 146a ′ in a direction orthogonal to the manual paper feeding direction, the paper 5 is manually fed. In addition, the sheet 5 may be fed through the lower end of the restricting portion 146a ′. Therefore, it is preferable that the stopper portion 146 has a restricting portion 146a as shown in FIG.

Next, an outline of the control unit of the image forming apparatus will be described with reference to the block diagram of FIG.
The control unit 300 retains data even when the power of the apparatus is shut off, the CPU 301, the ROM 302 that stores programs executed by the CPU 301 and other fixed data, the RAM 303 that temporarily stores image data and the like. Control of the entire apparatus, including a non-volatile memory (NVRAM) 304 and an ASIC 305 that processes input / output signals for performing various signal processing and rearrangement on image data and other input / output signals for controlling the entire apparatus. A main control unit 310 is provided.

  The control unit 300 is interposed between the host side and the main control unit 310, and includes an external I / F 311 for transmitting and receiving data and signals, and a head driver for driving and controlling the recording head 24. Sub-scanning based on the detection results of the head drive control unit 312 including the main scanning drive unit (motor driver) 313 for driving the main scanning motor 27 that moves and scans the carriage 23, the rotary encoder 138A, and the linear encoder 139A. A sub-scanning drive unit 314 for driving the motor 131, a paper feed drive unit 315 for driving the paper feed motor 49, and a discharge motor for driving each roller of the paper discharge unit 7 are driven. A paper drive unit 316, a double-sided drive unit 317 for driving a double-sided paper refeed motor 99 that drives each roller of the double-sided unit 10, and the maintenance and recovery mechanism 12 Includes a recovery system driving portion 318 for driving the maintenance and recovery motor 129 for driving, and AC bias supply unit 319 which co subjected AC bias to the charging belt 34.

  Further, the control unit 300 includes a solenoid driving unit (driver) 322 for driving various solenoids (SOL) 321 including the opening / closing guide plate solenoid 113 and the shutter solenoid 150 described above, and an electromagnetic cracking 323 related to sheet feeding. And a scanner control unit 325 for controlling the image reading unit 11.

  The main control unit 310 includes various sensors 201 to 206 that detect the above-described paper, a sensor 211 that detects opening and closing of the one-sheet manual feed tray 141, a sensor 212 that detects opening and closing of the straight discharge tray 181, and Various detection signals from sensors 326 including other sensors are input, and keys necessary for operation / display unit 327 including various keys such as a numeric keypad and a print start key provided on apparatus main body 1 and various displays are provided. Captures input and outputs display information.

  The control of the image forming operation by the control unit 300 will be briefly described. By applying a high voltage of a positive and negative rectangular wave, which is an alternating voltage, from the AC bias supply unit 319 to the charging roller 34, the charging roller 34 is moved to the conveying belt. Since it is in contact with the insulating layer (surface layer) 31, positive and negative charges are alternately applied to the surface layer of the conveying belt 31 in a band shape in the conveying direction of the conveying belt 31, and the predetermined amount is applied on the conveying belt 31. The charging is performed with the charging width of 1 to generate an unequal electric field.

  Therefore, the sheet 5 is fed from the sheet feeding unit 4, the manual sheet feeding unit 46, the duplex unit 10, the one-sheet manual sheet feeding tray 141, and the positive and negative charges between the transport roller 32 and the pressing roller 36 are generated. When the sheet 5 is fed onto the conveyor belt 31 where an unequal electric field is generated, the sheet 5 is instantly polarized according to the direction of the electric field, and is attracted onto the conveyor belt 31 by electrostatic adsorption force. It is transported as the transport belt 31 moves.

  Then, while the paper 5 is intermittently transported by the transport belt 31, an image is formed (printed) by ejecting recording liquid droplets from the recording head 24 on the paper 5 according to the print data. The front end side of the sheet 5 is separated from the conveyor belt 31 by the separation claw 38 and is discharged to the sheet discharge tray 8 and the straight sheet discharge tray 181 as appropriate by the sheet discharge conveyance unit 7 or sent to the duplex unit 10. Then, after the image on the other side is formed, it is discharged.

Next, a process until one image is manually fed using the one-sheet manual feed tray 141 to form an image will be described with reference to FIG.
When the one-sheet manual feed tray 141 is opened, it is determined whether or not there is an active job (JOB). If there is an active job (JOB), the paper 5 remains in the apparatus. Therefore, an operation is performed to interrupt the JOB during operation and to discharge the paper 5 being printed in the apparatus. At this time, since the shutter member 141 closes the manual paper feed port 143 as shown in FIG. 7 described above, the paper 5 cannot be fed manually.

  Then, after the discharge of the job in operation (JOB) is completed, or if there is no job in operation (JOB), the conveyance belt 31 is precharged as it is, and then the shutter switching solenoid 150 is driven (ON), and FIG. And wait for a predetermined time (for example, 500 msec). Thereafter, the open / close guide plate solenoid 113 is driven (ON), and the shutter member 141 opens the manual paper feed port 143 as shown in FIGS. 8 to 10 so that the open / close guide plate 110 can guide the manually fed paper. After a predetermined time (for example, 500 msec) has elapsed, the shutter switching solenoid 150 is not driven (OFF).

  As a result, the shutter member 141 is opened, and one sheet of paper 5 is manually fed (inserted) from the one-sheet manual feed tray 141, the entrance sensor 202 of the conveyor belt 31 is turned on, and image registration is performed. An image is formed on the manually fed sheet 5 fed based on the detection timing of the sensor 203. When the printing unit entrance sensor 202 detects passage of the rear end of the sheet 5 (when it is turned OFF), the open / close guide plate solenoid 113 is not driven (OFF). Paper is discharged onto a paper discharge tray 181.

Next, another configuration of the one-sheet manual sheet feeding unit will be described with reference to FIGS. In addition, each figure is a side explanatory drawing explaining a different state.
In this configuration, the above-described shutter member switching solenoid 150 is omitted, and the arm portion 144a of the shutter member 141 is engaged with the open / close guide plate 110 by opening and closing the single manual feed tray 141, thereby opening / closing guide plate 110. The position is switched to the position interlocked with the swing of the. That is, the single manual sheet feeding tray 141 constitutes a switching unit that switches between a position where the shutter member 141 is interlocked with the opening / closing guide plate 110 and a position where the shutter member 141 is not interlocked.

  A specific description will be given with reference to FIGS. 16 and 17 as well. A swing arm 141a is integrally provided at the lower end of the single manual feed tray 141, and a protrusion is formed at the lower end of the swing arm 141a. As shown in FIG. 16, when the one-sheet manual feed tray 141 is opened, the projection 141b of the swing arm 141a pushes up the arm 144a of the shutter member 141 so that the arm 144b is It moves to a position where it engages with the engaging portion 116 of the opening / closing guide plate 110.

  As a result, as shown in FIG. 16, the opening / closing guide plate solenoid 113 is driven to swing the opening / closing guide plate 110, whereby the roller 147 of the shutter member 141 is engaged with the engaging portion 116 of the opening / closing guide plate 110. Then, the shutter member 141 swings to the open position in conjunction with the swing of the open / close guide plate 110 to open the manual sheet feed port 143 from the one-sheet manual sheet feed tray 141 as shown in FIG. The manual sheet feed path 160 is opened, and a single sheet can be manually fed.

  An example of processing performed by the control unit 300 in this configuration is shown in FIG. The process in FIG. 14 is the same as the process in FIG. 14 except that the ON / OFF control of the shutter member switching solenoid 150 is eliminated.

  As described above, by switching the shutter member between the position not interlocked with the opening / closing guide member and the position interlocked with the opening / closing operation of the single manual sheet feeding tray, an electric driving means such as a solenoid becomes unnecessary. This further simplifies the configuration.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus according to the present invention. 2 is an explanatory plan view of an image forming unit and a sub-scanning conveyance unit of the apparatus. It is a side explanatory view similarly. It is explanatory drawing similarly used for description of a conveyance path | route. FIG. 6 is a perspective view for explaining the configuration of the single manual sheet feeding unit. It is a side explanatory view similarly. FIG. 6 is an explanatory side view illustrating a state in which the single manual sheet feeding tray is opened. It is side explanatory drawing when a shutter solenoid is similarly made into an ON state. It is a side explanatory view when the open / close guide plate solenoid is similarly driven. It is side explanatory drawing when a shutter solenoid is similarly made into an OFF state. It is a principal part explanatory drawing similarly used for description of the stopper part of a shutter member. It is a principal part explanatory drawing similarly used for description of the comparative example of the stopper part of a shutter member. 2 is a block diagram illustrating an overview of a control unit of the image forming apparatus. FIG. It is a flowchart with which it uses for description of the process at the time of one sheet manual feeding by the control part. FIG. 6 is an explanatory side view illustrating another configuration of the single manual sheet feeder. FIG. 6 is an explanatory side view illustrating a state in which the single manual sheet feeding tray is opened. It is side explanatory drawing of a state where the shutter member opened similarly. It is a flowchart with which it uses for description of the process at the time of one sheet manual feeding by the control part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 2 ... Image formation part 3 ... Sub-scanning conveyance part 4 ... Paper feed part 5 ... Paper (recording medium)
DESCRIPTION OF SYMBOLS 7 ... Paper discharge conveyance part 8 ... Paper discharge tray 10 ... Duplex unit 11 ... Image reading part 23 ... Carriage 24 ... Recording head 31 ... Conveyance belt 32 ... Conveyance roller 34 ... Charging roller 110 ... Opening / closing guide plate 113 ... Opening / closing guide plate solenoid 141: One-sheet manual feed tray 141 ... Manual feed port 144 ... Shutter member 150 ... Shutter solenoid

Claims (9)

  An image forming apparatus comprising: an image forming unit that forms an image on a recording medium; a paper feeding unit that feeds the recording medium; and a manual paper feeding unit that manually feeds the recording medium. An image forming apparatus, wherein a shutter member that opens and closes a manual paper feed port from the manual paper feed unit is swingably provided.   The swingable opening / closing guide member for forming a slack in the recording medium in a conveyance path of the recording medium from the paper feeding unit to the image forming unit. An image forming apparatus, wherein the manual feed port is disposed downstream of the opening / closing guide member, and the swinging of the opening / closing guide member and the opening / closing of the shutter member are interlocked.   4. The image forming apparatus according to claim 3, wherein the shutter member is disposed so as to be switchable between a position not interlocked with the opening / closing guide member and a position interlocked with the shutter member.   4. The image forming apparatus according to claim 3, further comprising switching means for displacing the shutter member from a position not interlocked with the opening / closing guide member to a position interlocked.   5. The image forming apparatus according to claim 4, wherein the switching unit is an electric drive unit.   5. The image forming apparatus according to claim 4, wherein the switching unit is a tray of the manual sheet feeding unit that is detachably attached to the apparatus main body.   7. The image forming apparatus according to claim 1, wherein the shutter member has an inclined portion that extends obliquely upward with respect to a paper feeding direction.   8. The image forming apparatus according to claim 1, wherein the opening / closing guide member also serves as a guide for a recording medium fed from the manual sheet feeding unit. 9. The image forming apparatus according to claim 1, wherein when the manual sheet feeding portion is set to a manually feedable position and the recording medium remains in the apparatus, the recording medium is discharged. The image forming apparatus is characterized in that the shutter member is placed in a closed position until the process is completed.

Images