JP6067076B2 - Medium conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a medium conveying apparatus and an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction machine, for example, a printer, includes an image forming unit, an LED head, a transfer roller, a fixing device, a paper cassette, and the like. In addition, a charging roller, a developing roller, a developing blade, a toner supply roller, a cleaning blade, a toner cartridge, and the like are arranged.

  In the image forming unit, the surface of the photosensitive drum uniformly charged by the charging roller is exposed by the LED head to form an electrostatic latent image. The toner supplied from the toner cartridge to the main body of the image forming unit, that is, the image forming unit main body, is supplied to the developing roller by the toner supply roller, and the toner on the developing roller is thinned by the developing blade. Then, the toner on the developing roller is attached to the electrostatic latent image on the photosensitive drum, the electrostatic latent image is developed, and a toner image is formed on the photosensitive drum.

  The sheet as the medium fed out from the sheet cassette is sent to a transfer unit formed between the photosensitive drum and the transfer roller. After the toner image is transferred by the transfer roller in the transfer unit, the sheet is transferred to the fixing unit. Sent. Then, the toner image is fixed on the paper in the fixing device, and an image is formed on the paper.

  By the way, printers equipped with a double-sided printing unit as a standard are provided so that images can be formed on both sides of paper and double-sided printing can be performed.

  In this type of printer, a medium transport device for transporting paper has a reversing unit for reversing the paper above the paper cassette and in the vicinity of the fixing unit, and above the paper cassette and fixing. A reversing medium transport unit for sending the reversed paper to the transfer unit again is provided on the side opposite to the container (see, for example, Patent Document 1).

JP 2010-2222085 A

  However, in the above-described conventional printer, when paper is jammed in the reversal medium transport unit of the duplex printing unit, that is, when paper jam occurs, the work for taking out the paper is troublesome.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional printer and to provide a medium conveying apparatus and an image forming apparatus that can easily take out a medium when the medium is jammed.

  For this purpose, the medium conveying apparatus of the present invention comprises an apparatus main body, a drive roller disposed rotatably with respect to the apparatus main body, a first guide member for guiding the medium, and a driven roller, A second guide member is provided to face the first guide member and to be swingable about the swing shaft with respect to the first guide member and to guide the medium.

  The first and second guide members are arranged as medium guide units so that they can be pulled out in a direction parallel to the medium guiding direction with respect to the apparatus main body.

Further, in a state where the medium guide unit is mounted on the apparatus main body, the driving roller is protruded from the first guide member toward the second guide member and is brought into contact with the driven roller.
Then, the medium guide unit is pulled out from the surface of the apparatus main body on the side where the medium enters between the first and second guide members while being attached to the apparatus main body.
Further, when the medium guiding unit is pulled out from the apparatus main body, the first guide member is moved in the protruding direction by a moving amount larger than the protruding amount of the driving roller in a state where the medium guiding unit is mounted on the apparatus main body. It is done.
The swing shaft extends in a direction perpendicular to the medium guiding direction in the vicinity of the front end portion of the medium guiding unit in the direction in which the medium guiding unit is inserted into the apparatus main body.

  According to the present invention, the medium conveying apparatus includes an apparatus main body, a driving roller rotatably disposed with respect to the apparatus main body, a first guide member for guiding the medium, and a driven roller. A second guide member is provided to face the first guide member and to be swingable about the swing shaft with respect to the first guide member and to guide the medium.

  The first and second guide members are arranged as medium guide units so that they can be pulled out in a direction parallel to the medium guiding direction with respect to the apparatus main body.

Further, in a state where the medium guide unit is mounted on the apparatus main body, the driving roller is protruded from the first guide member toward the second guide member and is brought into contact with the driven roller.
Then, the medium guide unit is pulled out from the surface of the apparatus main body on the side where the medium enters between the first and second guide members while being attached to the apparatus main body.
Further, when the medium guiding unit is pulled out from the apparatus main body, the first guide member is moved in the protruding direction by a moving amount larger than the protruding amount of the driving roller in a state where the medium guiding unit is mounted on the apparatus main body. It is done.
The swing shaft extends in a direction perpendicular to the medium guiding direction in the vicinity of the front end portion of the medium guiding unit in the direction in which the medium guiding unit is inserted into the apparatus main body.

  In this case, the medium can be easily taken out between the first and second guide members.

FIG. 2 is a first schematic diagram of a printer for explaining a method of taking out a sheet from a reversal medium transport unit according to the first embodiment of the present invention. 1 is a perspective view showing an external appearance of a printer according to a first embodiment of the present invention. 1 is a schematic diagram of a printer according to a first embodiment of the present invention. It is a figure for demonstrating the double-sided printing unit in the 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the printer in the case of performing single-sided printing in the 1st Embodiment of this invention. FIG. 6 is a first diagram for explaining the operation of the printer when performing duplex printing in the first embodiment of the present invention. FIG. 7 is a second diagram for explaining the operation of the printer when performing duplex printing in the first embodiment of the present invention. FIG. 9 is a third diagram for explaining the operation of the printer when performing duplex printing in the first embodiment of the present invention. FIG. 2 is a schematic diagram of a printer for explaining a method of taking out a sheet from a medium reversing unit according to the first embodiment of the present invention. FIG. 3 is a first perspective view of a printer for explaining a method of taking out a sheet from a medium reversing unit according to the first embodiment of the present invention. FIG. 6 is a second perspective view of the printer for explaining a method of taking out a sheet from the medium reversing unit according to the first embodiment of the present invention. FIG. 6 is a second schematic diagram of the printer for explaining a method of taking out a sheet from the reversal medium conveyance unit according to the first embodiment of the present invention. FIG. 6 is a second schematic diagram of the printer for explaining a method of taking out a sheet from the reversal medium conveyance unit according to the first embodiment of the present invention. FIG. 3 is a first perspective view of a printer for explaining a method of taking out a sheet from a reversing medium conveyance unit according to the first embodiment of the present invention. FIG. 6 is a second perspective view of the printer for explaining a method of taking out a sheet from the reversing medium conveyance unit according to the first embodiment of the present invention. FIG. 6 is a third perspective view of the printer for explaining a method of taking out a sheet from the reversing medium transport unit according to the first embodiment of the present invention. It is a perspective view of the drawer unit in the 1st Embodiment of this invention. It is a perspective view of the horizontal conveyance plate in the 1st Embodiment of this invention. It is a perspective view of the horizontal conveyance frame in the 1st Embodiment of this invention. It is a top view which shows the arrangement | positioning state of the pinch roller in the 1st Embodiment of this invention. It is XX sectional drawing of FIG. It is a figure which shows the state of the drawer unit and sensor lever when the drawer unit in the 1st Embodiment of this invention is arrange | positioned in the apparatus main body. It is a figure which shows the state of a drawer unit and a sensor lever when the drawer unit in the 1st Embodiment of this invention is pulled out only the predetermined amount from the apparatus main body. FIG. 10 is a first schematic diagram of a printer for explaining a method of taking out a sheet from a reversal medium transport unit according to a second embodiment of the present invention. FIG. 10 is a second schematic diagram of a printer for describing a method for taking out a sheet from a reversal medium conveyance unit according to a second embodiment of the present invention. FIG. 10 is a first perspective view of a printer for explaining a method of taking out a sheet from a reversing medium conveyance unit according to a second embodiment of the present invention. FIG. 10 is a second perspective view of a printer for explaining a method of taking out a sheet from a reversal medium transport unit according to the second embodiment of the present invention. It is a perspective view of the drawer unit in the 2nd Embodiment of this invention. It is a perspective view of the horizontal conveyance plate in the 2nd Embodiment of this invention. It is a figure which shows the state of the drawer unit and sensor lever when the drawer unit in the 2nd Embodiment of this invention is arrange | positioned in the apparatus main body. It is a figure which shows the state of the drawer unit and sensor lever when the drawer unit in the 2nd Embodiment of this invention is pulled out only the predetermined amount from the apparatus main body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a printer as an image forming apparatus will be described.

  2 is a perspective view showing an appearance of the printer according to the first embodiment of the present invention, FIG. 3 is a schematic view of the printer according to the first embodiment of the present invention, and FIG. 4 is a first embodiment of the present invention. FIG. 5 is a diagram for explaining the operation of the printer when performing single-sided printing in the first embodiment of the present invention, and FIG. 6 is a diagram for explaining the operation of the printer in the first embodiment of the present invention. FIG. 7 is a first diagram for explaining the operation of the printer when performing duplex printing in the embodiment, and FIG. 7 is a diagram for explaining the operation of the printer when performing duplex printing in the first embodiment of the present invention. FIG. 2 and FIG. 8 are third diagrams for explaining the operation of the printer when performing duplex printing in the first embodiment of the present invention.

  In the figure, 10 is a printer, Cs1 is a housing of the printer 10, and the housing Cs1 is a central housing portion Cn as a first housing portion disposed in the center of the printer 10, and the central housing. In front of the body part Cn, a front housing part Cf as a second housing part disposed so as to be swingable and openable with respect to the central housing part Cn, and the central housing part Cn A rear housing portion Cr is provided as a third housing portion that is detachably disposed on the rear side of the central housing portion Cn.

  Further, 12 is arranged at the lower part of the printer 10 so as to extend from the front housing part Cf side of the printer 10, that is, from the front side to the rear housing part Cr side, that is, the back side. A paper cassette 38 serving as a medium containing portion for containing the paper P is formed on the top wall Wct of the central housing portion Cn, an image is formed, and the paper discharged outside the main body of the printer 10, that is, the apparatus main body. A stacker 67 for loading P is an operation panel as a display unit formed on the top wall Wft of the front casing Cf, and 68 is formed adjacent to the operation panel 67 on the top wall Wft. A control panel 69 serving as an operation unit is swingably formed at the center of the front wall Wf of the front casing Cf, so that various sizes of paper P can be manually fed. An MPT tray 66 serving as a medium stacking portion is formed on the right side wall Wfs of the front housing portion Cf, and is a lock as an opening operation portion for releasing the lock when the front housing portion Cf is opened. It is a lever.

  At the front end of the paper cassette 12, the paper cassette 12 is rotatably arranged, and feeds paper P stacked on the medium stacking plate 101 in the paper cassette 12 one by one, adjacent to the paper feed roller 13. The sheet feeding sub-roller 14 as a first discriminating roller disposed rotatably and separated as a second discriminating roller disposed opposite to the sheet feeding sub-roller 14 so as to rotate freely. A roller 15 is disposed. The paper feed sub-roller 14 and the separation roller 15 separate the paper P fed by the paper feed roller 13 one by one and supply it to the medium transport path Rt1 to constitute a discrimination device.

  In the medium transport path Rt1, an intermediate transport roller 16 and a pinch roller 17 serving as a first transport member for transporting the paper P are disposed on the downstream side of the paper feed sub-roller 14 and the separation roller 15, and the intermediate transport roller 16 A sensor lever 22 serving as a first medium detecting unit for detecting the front end of the paper P is disposed on the downstream side of the conveying roller 16 and the pinch roller 17, and the oblique side of the paper P is disposed on the downstream side of the sensor lever 22. A registration roller 18 and a pressure roller 19 are provided as a second conveyance member for correcting the line, and a third conveyance member as a third conveyance member for conveying the paper P to the downstream side of the registration roller 18 and the pressure roller 19 is provided. An intermediate conveyance roller 20 and a pressure roller 21 are disposed, and the front end of the sheet P is disposed downstream of the intermediate conveyance roller 20 and the pressure roller 21. Second sensor lever 23 as a medium detecting unit for output will be provided.

  The sensor lever 22 detects the paper P by being tilted with the passage of the paper P, and represents the position of the paper P from a sensor (not shown) that is disposed adjacent to the sensor lever 22. A position signal is sent to a control unit (not shown). In addition, the sensor lever 23 detects the paper P by being tilted as the paper P passes, and a writing signal is output from a sensor (not shown) as a detection output unit disposed adjacent to the sensor lever 23. Sent to. Upon receiving the writing signal, the control unit sends an instruction to form an image on the paper P to the image forming unit 103.

  The image forming unit 103 that forms a toner image as a developer image on the paper P is disposed on the downstream side of the sensor lever 23 in the medium conveyance path Rt1. The image forming unit 103 includes an image forming unit 24 and an LED head as an exposure device disposed above the photoconductive drum 26 as an image carrier in the image forming unit 24 so as to face the photoconductive drum 26. 27, a transfer roller 25 as a transfer member disposed below the photoconductive drum 26 so as to face the photoconductive drum 26 across the medium transport path Rt1. A transfer portion p1 is formed between the photosensitive drum 26 and the transfer roller 25.

  The image forming unit 24 includes, in addition to the photosensitive drum 26 and a toner cartridge 29 as a developer accommodating portion for accommodating toner as a developer, a charging roller and a developer as a charging device (not shown). A developing roller as a carrier, a developing blade as a developer regulating member, a toner supply roller as a developer supplying member, a cleaning blade as a cleaning member, and the like are provided.

  In the image forming unit 24, the surface of the photosensitive drum 26 uniformly charged by the charging roller is exposed by the LED head 27 to form an electrostatic latent image as a latent image. The toner supplied from the toner cartridge 29 is supplied to the developing roller by the toner supply roller, and the toner on the developing roller is thinned by the developing blade. The toner on the developing roller is attached to the electrostatic latent image on the photosensitive drum 26, and the electrostatic latent image is developed to form a toner image on the photosensitive drum 26. The toner image thus formed is transferred onto the paper P by the transfer roller 25.

  A fixing device 28 as a fixing device is disposed on the downstream side of the image forming unit 103 in the medium conveyance path Rt1. The fixing device 28 includes a heating roller 28a serving as a first fixing roller having a heating element (not shown) such as a halogen lamp therein, and a second fixing roller disposed to face the heating roller 28a. The toner image on the paper P is heated by the heating roller 28a and the pressure roller 28b, and is pressed and fixed on the paper P to form an image.

  A sensor lever 30 serving as a third medium detecting unit for detecting the front end of the paper P is disposed on the downstream side of the fixing device 28 in the medium transport path Rt1, and on the downstream side of the sensor lever 30. A transport roller 31 and a pinch roller 32 are disposed as a fourth transport member for transporting the paper P, and the medium transport path Rt1 and the paper P are disposed on the downstream side of the transport roller 31 and the pinch roller 32. By selectively connecting the medium discharge path Rt2 for discharging to the outside and the medium reversing path Rt3 for reversing the paper P, a switching guide 33 is provided as a switching member for switching the transport path of the paper P. Is done. The sensor lever 30 is tilted with the passage of the paper P to detect the front end of the paper P, and the paper P is detected from a sensor (not shown) as a detection output unit disposed adjacent to the sensor lever 30. A discharge signal indicating discharge from the medium transport path Rt1 is sent to the control unit.

  The switching guide 33 is switched by driving a solenoid (not shown) as a switching drive unit to take the first and second positions e and f. When the switching guide 33 is placed at the first position e, the medium transport path Rt1 and the medium discharge path Rt2 are connected, and when it is placed at the second position f, the medium transport path Rt1 and the medium reversing path Rt3 are connected. .

  In the medium discharge path Rt 2, a conveyance roller 34 and a pinch roller 35 as a fifth conveyance member that conveys the paper P are disposed on the downstream side of the switching guide 33, and downstream of the conveyance roller 34 and the pinch roller 35. On the side, a discharge roller 36 and a pinch roller 37 are disposed as discharge members for discharging the paper P.

  Further, on the medium reversing path Rt3, a reversing roller 42 and a pinch roller 43 as a first reversing member for reversing the paper P are disposed on the downstream side of the switching guide 33. The reversing roller 42 and the pinch A reversing roller 44 and a pinch roller 45 as a second reversing member for reversing the paper P are disposed on the downstream side of the roller 43. The medium reversing path Rt3, the reversing rollers 42 and 44, and the pinch rollers 43 and 45 constitute a medium reversing portion AR1 for reversing the paper P.

  A reversing guide 41 as a reversing medium guide member is disposed at the lower end of the medium reversing path Rt3, and the reversing guide 41 selectively connects the medium reversing path Rt3 with the reversing medium transport path Rt4. The fed paper P is supplied to the reverse medium conveyance path Rt4.

  The reversing guide 41 takes the first and second positions g and h, is urged by a predetermined urging force by a spring (not shown) as an urging member, and is normally placed at the first position g. When the reversing guide 41 is placed at the first position g, the medium reversing path Rt3 and the medium transporting path Rt1 are connected, and when the reversing guide 41 is placed at the second position h against the urging force of the spring, the medium reversing path Rt3 is reversed. The medium conveyance path Rt4 is connected.

  A sensor as a fourth medium detection unit for detecting the paper P that is reversed downstream of the reversing guide 41 in the reversing medium transport path Rt4 and supplied from the medium reversing path Rt3 to the reversing medium transport path Rt4. A lever 52 is disposed, and a transport roller 46 and a pinch roller 47 as a first reverse medium transport member for transporting the paper P are disposed on the downstream side of the sensor lever 52, and the transport roller 46 and the pinch roller A transport roller 48 and a pinch roller 49 as second reverse medium transport members that transport the paper P are disposed downstream of the transport roller 47, and a reverse medium transport path is disposed downstream of the transport roller 48 and the pinch roller 49. A sensor lever 53 serving as a fifth medium detection unit for detecting the paper P transported by Rt 4 is provided, and the paper P is placed downstream of the sensor lever 53. As a third reversed medium carrying member, the conveying roller 50 and the pinch roller 51 is arranged to feed.

  In this case, the transport rollers 48 and 50 are rotated by a reversing medium motor (not shown) serving as a reversing medium transport driving unit, and the pinch rollers 49 and 51 are rotated by the transport rollers 48 and 50. Rotated. The conveying rollers 48 and 50 constitute first and second driving rollers, and the pinch rollers 49 and 51 constitute first and second driven rollers.

  The sensor levers 52 and 53 detect the sheet P by being tilted as the sheet P passes, and are detected from respective sensors (not shown) as detection output units disposed adjacent to the sensor levers 52 and 53. A signal is sent to the controller.

  The reversal medium transport path Rt4 is a medium guide unit and a drawer as an insertion / removal member that can be inserted into and removed from the apparatus main body and can be moved in the horizontal direction on the front casing Cf side. A unit 60 is provided, and the drawer unit 60 is a horizontal transport plate 61 as a first guide member, and can be moved to and away from the horizontal transport plate above the horizontal transport plate 61 and swingable. A horizontal conveyance frame 62 as a second guide member provided, and the pinch rollers 49 and 51 supported rotatably with respect to the horizontal conveyance frame 62 are provided. The horizontal transport plate 61 is disposed below the reverse medium transport path Rt4, that is, on the transport rollers 48 and 50 side, and the horizontal transport frame 62 is disposed above the reverse medium transport path Rt4, that is, on the pinch rollers 49 and 51 side. Then, the paper P is conveyed on the reverse medium conveyance path Rt4 by the horizontal conveyance plate 61 and the horizontal conveyance frame 62.

  Paper P reversed by the reverse medium transport path Rt4, the reverse guide 41, the horizontal transport plate 61, the horizontal transport frame 62, the sensor levers 52, 53, the transport rollers 46, 48, 50 and the pinch rollers 47, 49, 51. Is formed, that is, a reversing medium transport unit AR2. Then, the reverse medium conveyance path Rt4 and the medium conveyance path Rt1 are merged on the downstream side of the conveyance roller 50 and the pinch roller 51.

  The medium reversing unit AR1 and the reversing medium transport unit AR2 constitute a double-sided printing unit as a medium transport device. The medium reversing unit AR1 constitutes the vertical part of the duplex printing unit, and the reversing medium transport unit AR2 constitutes the horizontal part of the duplex printing unit.

  Next, the operation of the printer 10 when an image is formed on one side of the paper P and single-sided printing is performed will be described.

  First, when print data and a print command are received from a host computer (not shown) as a host device, the printer 10 starts printing.

  When single-sided printing is specified for the paper P stored in the paper cassette 12 in the printing command, the control unit drives a paper feeding motor (not shown) as a paper feeding driving unit, The paper P is rotated, the paper P in the paper cassette 12 is fed out, separated one by one by the paper feed sub roller 14 and the separation roller 15, and supplied to the medium transport path Rt1. The sheet P is transported by the intermediate transport roller 16 and the pinch roller 17, sent to the registration roller 18 and the pressure roller 19, and the front end is detected by the sensor lever 22. At this time, the registration roller 18 and the pressure roller 19 are stopped by an electromagnetic clutch (not shown), and the sheet P abuts against the registration roller 18 and the pressure roller 19 by the conveyance force of the intermediate conveyance roller 16 and the pinch roller 17, and the predetermined roller When time passes, it is rotated. Accordingly, the skew of the paper P is corrected, and the paper P is transported by the intermediate transport roller 20 and the pressure roller 21 and sent to the transfer portion p1.

  Further, as described above, when the front end of the paper P is detected by the sensor lever 23, a writing signal is sent to the control unit, and the control unit instructs the image forming unit 103 to form an image on the paper P. send.

  As a result, when the LED head 27 is caused to emit light corresponding to the print data and the photosensitive drum 26 is exposed, an electrostatic latent image is formed on the photosensitive drum 26. The toner supplied from the toner cartridge 29 is supplied to the developing roller by the toner supply roller, the toner on the developing roller is attached to the electrostatic latent image on the photosensitive drum 26, and the electrostatic latent image is developed. Thus, a toner image is formed.

  Subsequently, the toner image on the photosensitive drum 26 is transferred to the paper P by the transfer roller 25, and then the paper P is sent to the fixing device 28, in which the heating roller 28a and the pressure roller 28b are used. The toner image on the paper P is heated, pressurized and fixed on the paper P, and an image is formed.

  In this case, as shown in FIG. 5, since the switching guide 33 is placed at the first position e, the paper P discharged from the fixing device 28 is detected by the sensor lever 30, and then the conveyance roller. 31 and the pinch roller 32, supplied to the medium discharge path Rt 2, transported by the transport roller 34 and the pinch roller 35 in the medium discharge path Rt 2, and then discharged outside the apparatus main body by the discharge roller 36 and the pinch roller 37. And loaded on the stacker 38.

  Next, the operation of the printer 10 when performing double-sided printing by forming images on both sides of the paper P will be described.

  First, upon receiving print data and a print command from the host computer, the printer 10 starts printing.

  When double-sided printing is designated for the paper P stored in the paper cassette 12 in the print command, the control unit drives the paper feed motor and rotates the paper feed roller 13 to thereby feed the paper P in the paper cassette 12. Are separated one by one by the paper feed sub-roller 14 and the separation roller 15 and supplied to the medium conveyance path Rt1. The sheet P is transported by the intermediate transport roller 16 and the pinch roller 17, sent to the registration roller 18 and the pressure roller 19, the skew is corrected, further transported by the intermediate transport roller 20 and the pressure roller 21, and transferred to the transfer portion p <b> 1. Sent.

  When the front end of the paper P is detected by the sensor lever 23, a writing signal is sent to the control unit, and the control unit instructs the image forming unit 103 to form an image on one surface (front surface) of the paper P. Send to.

  As a result, when the LED head 27 is caused to emit light corresponding to the print data and the photosensitive drum 26 is exposed, an electrostatic latent image is formed on the photosensitive drum 26, and the toner on the developing roller is transferred to the photosensitive drum 26. A toner image is formed on the electrostatic latent image.

  Subsequently, the toner image on the photosensitive drum 26 is transferred to the paper P by the transfer roller 25, and then the paper P is sent to the fixing device 28, and the toner image on the paper P is transferred to the paper P in the fixing device 28. It is fixed. In this way, an image is formed on one side of the paper P.

  In this case, when the paper P discharged from the fixing device 28 is detected by the sensor lever 30, the solenoid is driven, and the switching guide 33 is placed at the second position f as shown in FIG. The reversing guide 41 is urged by the urging force of the spring and is placed at the second position h.

  When the front end of the sheet P conveyed by the conveying roller 31 and the pinch roller 32 abuts against the switching guide 33, as shown in FIG. 7, the reversing guide 41 is in the first position g against the urging force of the spring. The paper P is supplied to the medium reversing path Rt3, conveyed by the reversing roller 42 and the pinch roller 43, and further conveyed by the reversing roller 44 and the pinch roller 45. When the trailing edge of the sheet P passes through the reversing guide 41, the reversing guide 41 is urged by the urging force of the spring and is again placed at the second position h.

  The reversing guide 41 has a function of a sensor lever as a medium detecting unit, detects the rear end of the paper P by being placed again at the second position h, and is disposed adjacent to the reversing guide 41. A rear end detection signal is sent to the control unit from a sensor (not shown) as an output unit.

  When a rear end detection signal is sent from the reversing guide 41, the control unit stops the reversing rollers 42 and 44 and the pinch rollers 43 and 45, and then rotates them in the reverse direction. Thus, the paper P is stopped in the medium reversing path Rt3, then reversed, and supplied to the reversing medium transport path Rt4.

  Subsequently, as shown in FIG. 8, the paper P is detected by the sensor lever 52, and the one surface on which the toner image is formed is directed upward by the conveying rollers 46 and 48 and the pinch rollers 47 and 49. The reversal medium conveyance path Rt4 is conveyed. After that, it is detected by the sensor lever 53, is transported by the transport roller 50 and the pinch roller 51, and is supplied to the medium transport path Rt1.

  Then, the sheet P has its one surface opposed to the intermediate conveyance roller 16 and the other surface (back surface) opposed to the pinch roller 17, and the medium conveyance path Rt 1 is moved by the intermediate conveyance roller 16 and the pinch roller 17. After being conveyed and sent to the registration roller 18 and the pressure roller 19 to correct the skew of the paper P, it is conveyed by the intermediate conveyance roller 20 and the pressure roller 21 and sent to the transfer portion p1.

  When the front end of the paper P is detected by the sensor lever 23, a writing signal is sent to the control unit, and the control unit sends an instruction to form an image on the other side of the paper P to the image forming unit 103. .

  As a result, when the LED head 27 is caused to emit light corresponding to the print data and the photosensitive drum 26 is exposed, an electrostatic latent image is formed on the photosensitive drum 26, and the toner on the developing roller is transferred to the photosensitive drum 26. A toner image is formed on the electrostatic latent image.

  Subsequently, the toner image on the photosensitive drum 26 is transferred to the paper P by the transfer roller 25, and then the paper P is sent to the fixing device 28, and the toner image on the paper P is transferred to the paper P in the fixing device 28. It is fixed. In this way, an image is formed on the other side of the paper P.

  When the paper P discharged from the fixing device 28 is detected again by the sensor lever 30, the solenoid is driven and the switching guide 33 is placed at the first position e as shown in FIG. Accordingly, the sheet P is transported by the transport roller 31 and the pinch roller 32 in a state where images are formed on both sides, and is supplied to the medium discharge path Rt2, and the transport roller 34 and the pinch roller 35 in the medium discharge path Rt2. After being conveyed, the sheet is discharged out of the apparatus main body by the discharge roller 36 and the pinch roller 37 and is stacked on the stacker 38.

  Next, a method for detecting a paper jam when the paper P is jammed, that is, a paper jam has occurred in the duplex printing unit will be described.

  After the reversing rollers 42 and 44 and the pinch rollers 43 and 45 are stopped and subsequently rotated in the reverse direction, a detection signal is sent from the sensor arranged adjacent to the sensor lever 52 to the control unit. If no detection signal is continuously sent from the sensor to the control unit, the control unit determines that a paper jam has occurred in the medium reversing unit AR1, and the operation panel 67 (FIG. 2) displays the paper in the medium reversing unit AR1. A message indicating that a jam has occurred is displayed and the operator is notified.

  Further, the reversing rollers 42 and 44 and the pinch rollers 43 and 45 are stopped and subsequently rotated in the reverse direction, and a detection signal is sent from the sensor disposed adjacent to the sensor lever 52 to the control unit. Thereafter, when a detection signal is not sent from the sensor disposed adjacent to the sensor lever 53 to the control unit, or when a detection signal is continuously sent from the sensor to the control unit, the control unit performs the reverse medium conveyance unit AR2. The operation panel 67 displays a message indicating that a paper jam has occurred in the reversing medium transport unit AR2, and notifies the operator.

  Next, a method of taking out a sheet from the medium reversing unit AR1 when a paper jam occurs in the medium reversing unit AR1 will be described.

  FIG. 9 is a schematic diagram of a printer for explaining a method of taking out a sheet from the medium reversing unit according to the first embodiment of the present invention, and FIG. FIG. 11 is a second perspective view of the printer for explaining a method of taking out a sheet from the medium reversing unit according to the first embodiment of the present invention. .

  In the figure, Cs1 is a housing of the printer 10, Cn is a central housing portion, Cf is a front housing portion, Cr is a rear housing portion, and a medium reversing portion AR1 on the rear wall Wr of the rear housing portion Cr. A rear cover 55 as a rear opening / closing member is disposed at an opposing position so as to be swingable about the swing shaft 56 and to be openable / closable.

  In the present embodiment, an opening / closing knob 57 is disposed in the vicinity of the upper end of the rear cover 55 as an operating portion for opening and closing the rear cover 55.

  When a paper jam occurs in the medium reversing unit AR1, a message indicating that a paper jam has occurred in the medium reversing unit AR1 is displayed on the operation panel 67 and notified to the operator. Thus, when the operator pulls the opening / closing knob 57 in the direction of arrow A, the engagement between the lock member 58 disposed at the upper end of the rear cover 55 and the main body of the rear housing portion Cr is released, as shown in FIG. Thus, the rear cover 55 is opened.

  In this case, the reverse rollers 42 and 44 are disposed on the rear cover 55, and the pinch rollers 43 and 45 are disposed on the apparatus main body, and the reverse rollers 42 and 44 and the pinch rollers 43 and 45 are separated as the rear cover 55 is opened. Therefore, the paper P can be easily taken out. Therefore, paper jam can be eliminated.

  Next, a method for taking out a sheet from the reversing medium transport unit AR2 when a paper jam occurs in the reversing medium transport unit AR2 will be described.

  FIG. 1 is a first schematic diagram of a printer for explaining a method of taking out a sheet from a reversing medium transport unit according to the first embodiment of the present invention, and FIG. 12 is a reversing medium according to the first embodiment of the present invention. FIG. 13 is a second schematic diagram of the printer for explaining a method for taking out the paper from the transport unit, and FIG. 13 is a second schematic diagram of the printer for explaining the method for taking out the paper from the reversing medium transport unit in the first embodiment of the present invention. FIG. 14 is a first perspective view of a printer for explaining a method of taking out a sheet from a reversing medium transport unit according to the first embodiment of the present invention, and FIG. 15 is a first embodiment of the present invention. FIG. 16 is a second perspective view of the printer for explaining a method of taking out the paper from the reversing medium transport unit in the embodiment, and FIG. 16 explains a method of taking out the paper from the reversing medium transport unit in the first embodiment of the present invention. The It is a third perspective view of the printer.

  In the figure, Cn is a central housing portion, Cf is a front housing portion, Cr is a rear housing portion, and the front housing portion Cf swings about a swing shaft sh2 disposed in the apparatus main body. A lock lever 66 is provided that is freely arranged and for releasing the lock of the front housing part Cf. Further, AR2 is a reversing medium transport unit, Rt4 is a reversing medium transport path, and 60 is a drawer unit.

  When a paper jam occurs in the reverse medium transport unit AR2, a message indicating that a paper jam has occurred in the reverse medium transport unit AR2 is displayed on the operation panel 67, and the operator is notified. As a result, the operator operates the lock lever 66 disposed in the front housing portion Cf to open the front housing portion Cf and is formed at the front end of the drawer unit 60 as shown in FIGS. By pulling the handle 70, the drawer unit 60 can be pulled out from the apparatus main body as shown in FIGS.

  In this case, since the pinch rollers 49 and 51 are disposed in the drawer unit 60 and the transport rollers 48 and 50 and the sensor lever 53 are disposed in the apparatus main body, the transport roller 48 is extracted as the drawer unit 60 is pulled out from the apparatus main body. , 50 and the pinch rollers 49 and 51 are separated, and the paper P is pulled out from the apparatus main body together with the pull-out unit 60.

  Accordingly, as shown in FIGS. 13 and 16, the operator can open the horizontal conveyance frame 62 by rotating it around the swing shaft sh1 and take out the paper P.

  Next, the drawer unit 60 will be described.

  FIG. 17 is a perspective view of the drawer unit in the first embodiment of the present invention, FIG. 18 is a perspective view of the horizontal transport plate in the first embodiment of the present invention, and FIG. 19 is the first embodiment of the present invention. FIG. 20 is a plan view showing the arrangement state of the pinch rollers in the first embodiment of the present invention, and FIG. 21 is a sectional view taken along line XX in FIG.

  In the figure, 60 is a drawer unit, 61 is a horizontal transport plate as a first guide member, and 62 is a horizontal transport frame as a second guide member.

  The horizontal transport plate 61 has a rectangular shape, and includes a guide portion 111 having a guide surface Sa that guides the paper P below the paper P (FIG. 1) passing through the drawer unit 60, and the guide portion 111. Side edges 112 and 113 are formed so as to rise and protrude from the guide surface Sa at both edges so as to form wall surfaces. The horizontal conveyance frame 62 has a rectangular shape, and has a guide portion 121 provided with a guide surface Sb for guiding the paper P above the paper P, and the guide surface Sb at both edges of the guide portion 121. The side edges 122 and 123 are formed so as to protrude substantially orthogonally and form wall surfaces.

  The drawer unit 60 is inserted and removed in a direction substantially parallel to the direction in which the guide surfaces Sa and Sb extend, in the present embodiment, within a range of ± 20 °.

  In the horizontal transport plate 61, the guide part 111 is formed by extending a main body part 114 extending in the horizontal direction, obliquely upward from the front end of the main body part 114, and pulling out the drawer unit 60. An inclined portion 115 for guiding the passing paper P to the intermediate transport roller 16 and the pinch roller 17, a plurality of ribs 117 extending in the transport direction of the paper P and spaced from each other by a predetermined distance, etc. Is provided. In the present embodiment, a plurality of three openings 61d, 61e, 61f are formed at predetermined intervals from the rear end to the front end of the guide portion 111 in the central flat portion where the rib 117 is not formed. An opening 61g is formed adjacent to the opening 61f. The openings 61e and 61f are formed at positions corresponding to the pinch rollers 49 and 51 disposed on the horizontal transport frame 62, and in the reversing medium transport path Rt4 with the drawer unit 60 disposed in the apparatus main body. The conveying roller 48 and the pinch roller 49 are brought into contact with each other, and the conveying roller 50 and the pinch roller 51 are brought into contact with each other. Then, in a state where the drawer unit 60 is disposed in the apparatus main body, the sensor lever 53 is projected to the reverse medium transport path Rt4 through the opening 61g.

  Further, in the horizontal conveyance frame 62, the guide part 121 is formed by extending the body part 124 extending in the horizontal direction, obliquely upward from the front end of the body part 124, and the inclined part. 115, and an inclined portion 125 for guiding the paper P passing through the drawing unit 60 to the intermediate conveyance roller 16 and the pinch roller 17, and extending in the conveyance direction of the paper P, and at a predetermined distance from each other. The plurality of ribs 127, the plurality of ribs 128 formed in the direction perpendicular to the conveyance direction of the paper P, that is, extending in the width direction of the guide portion 121 and spaced apart from each other by a predetermined distance, etc. Is provided.

  Then, at the center portion in the width direction of the guide portion 121, the pinch rollers 49 and 51 are respectively urged toward the horizontal conveyance plate 61 by springs sp1 and sp2 as urging members made of rod-shaped bodies. It is supported rotatably in the state.

  For this purpose, a roller holding portion Q1 for holding the pinch rollers 49 and 51 is urged to hold the springs sp1 and sp2 adjacent to the roller holding portion Q1 at predetermined positions in the guide portion 121. A member holding part Q2 is formed.

  Further, in order to allow the paper P to pass between the horizontal transport plate 61 and the horizontal transport frame 62, the drawer unit 60 is disposed in the main body of the apparatus, so that the sheet P is interposed between the horizontal transport plate 61 and the horizontal transport frame 62. A predetermined gap is formed. In order to prevent the drawer unit 60 from interfering with the transport rollers 48 and 50 (FIG. 1), the sensor lever 53 and the like when the drawer unit 60 is pulled out from the apparatus body or inserted into the apparatus body. The horizontal transport plate 61 is moved toward the horizontal transport frame 62 and is brought into contact with the horizontal transport frame 62 via the paper P so that the gap is eliminated (set to 0).

  Further, in the drawer unit 60 pulled out from the apparatus main body, the horizontal conveyance frame 62 is disposed with respect to the horizontal conveyance plate 61 so that the paper P jammed between the horizontal conveyance plate 61 and the horizontal conveyance frame 62 can be taken out. It is swingably supported.

  Therefore, in the horizontal transport plate 61, a predetermined position on the side edge portions 112 and 113, in the present embodiment, a predetermined shape La in front of the rear end of the guide portion 111 by a predetermined distance La1. In the form, the long hole 61a as the first support portion having an O-shaped shape has a predetermined shape behind the front end of the guide portion 111 by a predetermined distance Lb1, and in the present embodiment, U A long hole 61b as a second support portion having a letter shape and having an open upper end is formed by a long groove.

  Further, in the horizontal conveyance frame 62, a predetermined shape at the side edge portions 122 and 123, in the present embodiment, at the rear end of the guide portion 121, a cylindrical shape in the present embodiment. A post portion 62a as a first supported portion having a second shape having a predetermined shape, in this embodiment, a prismatic shape, behind the front end of the guide portion 121 by a predetermined distance Lc. The post part 62b as a supported part is formed so as to protrude toward the outside of both edges of the guide part 121.

  Accordingly, by inserting the post portion 62a into the long hole 61a and rotating the horizontal transport frame 62 with the post portion 62a serving as the swing shaft sh1 (FIG. 16) in the drawer unit 60 pulled out from the apparatus main body, The paper P jammed between the transport plate 61 and the horizontal transport frame 62 can be taken out.

Further, when the dimension of the long hole 61a in the horizontal direction (conveying direction of the paper P), that is, the width is zw1, the dimension in the vertical direction, that is, the height is zh1, and the diameter of the post portion 62a is zd1. The width zw1 is slightly larger than the diameter zd1, and the height zh1 is larger than the diameter zd1 by a predetermined dimension L1. Further, when the width of the elongated hole 61b is zw2, the height is zh2, and the diameter of the post portion 62b is zd2, the width zw2 is slightly larger than the diameter zd2, and the height zh2 is a predetermined dimension L2 from the diameter sd2. Will only be enlarged. In the present embodiment, the dimensions L1 and L2 are
L1 = L2
To be.

  Therefore, the horizontal conveying plate 61 is formed by inserting the post portions 62a into the respective long holes 61a so as to be movable in the vertical direction (free fitting) and inserting the post portions 62b into the respective long holes 61b so as to be movable in the vertical direction. And the horizontal conveyance frame 62 can be relatively moved in the vertical direction. That is, in a state where the drawer unit 60 is disposed in the apparatus main body, the horizontal transport plate 61 is placed at the lower position in the vertical direction as the first position so that the paper P can pass therethrough, A predetermined gap is formed between the plate 61 and the horizontal conveyance frame 62. Further, when the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the horizontal transport plate 61 is placed at the upper position in the vertical direction as the second position and contacts the horizontal transport frame 62. And the gap disappears (becomes 0).

  In the state where the drawer unit 60 is disposed in the apparatus main body, the amount by which the transport rollers 48 and 50 project from the openings 61e and 61f toward the horizontal transport frame 62, that is, the projecting amount is Lr. The amount of movement of the horizontal transport plate 61 from the lower position in the vertical direction to the upper position in the vertical direction when it is pulled out from the apparatus main body, that is, when the movement amount is Lp, the movement amount Lp is larger than the protrusion amount Lr. .

  Therefore, when the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the drawer unit 60 does not interfere with the transport rollers 48 and 50, the sensor lever 53, and the like.

  In the present embodiment, when the gap is d, the gap d is made equal to the dimensions L1 and L2.

  Next, the roller holding part Q1 and the urging member holding part Q2 will be described. Since the roller holding portion Q1 and the urging member holding portion Q2 of the pinch roller 49 and the roller holding portion Q1 and the urging member holding portion Q2 of the pinch roller 51 have the same structure, the pinch roller in FIGS. Only 49 roller holding portions Q1 and biasing member holding portions Q2 are shown.

  The pinch rollers 49 and 51 include roller portions 49a and 51a and roller shaft portions 49b and 51b formed to protrude from both ends of the roller portions 49a and 51a, respectively.

  In the roller holding portion Q1, a rectangular frame portion Fr1 is formed by a predetermined rib 128, pinch rollers 49 and 51 are accommodated in the frame portion Fr1, and shaft holding formed at both ends in the frame portion Fr1. The roller shaft portions 49b and 51b are held by a roller restricting portion 62g as a portion. The roller restricting portion 62g is formed so as to protrude from the bottom wall 131 of the guide portion 121, the roller shaft portions 49b and 51b across the bottom wall 131, and substantially perpendicular to the guide surface Sb. It consists of two wall bodies w1 and w2. The roller shaft portions 49b and 51b are slidably disposed with respect to the wall bodies w1 and w2 between the wall bodies w1 and w2.

  In the urging member holding portion Q2, a rectangular frame portion Fr2 is formed adjacent to the frame portion Fr1 by a predetermined rib 128, and springs sp1 and sp2 are accommodated in the frame portion Fr2. Each of the springs sp1 and sp2 has a U-shape, and includes two arms am1 and am2 and a connecting portion k1 for connecting the arms am1 and am2, and each roller shaft portion near the tip of the arms am1 and am2. 49b and 51b are brought into contact, and the vicinity of the central part of the arms am1 and am2 is locked to a hook-like engagement part 62i formed on the frame part Fr2 with the connecting part k1 in contact with the bottom wall 131. By attaching, it is attached to the urging member holding part Q2. Accordingly, the arms am1 and am2 urge the roller shaft portions 49b and 51b toward the bottom wall 131, and press the roller shaft portions 49b and 51b against the abutting surface Sp formed on the bottom wall 131. As a result, the springs sp1 and sp2 bias the pinch rollers 49 and 51 toward the bottom wall 131 with a predetermined biasing force.

In each frame portion Fr1, an opening 62k is formed in a portion of the bottom wall 131 inside the roller restricting portion 62g, and the pinch rollers 49 and 51 are biased by the biasing force of the springs sp1 and sp2. , And projecting from the guide surface Sb toward the transport rollers 48 and 50 through the opening 62k. Then, with the drawer unit 60 disposed in the apparatus main body, the transport roller 48 and the pinch roller 49 are in contact with each other through the openings 61e and 62k, and the transport roller 50 and the pinch roller 51 are in contact with each other through the openings 61f and 62k. In the state where the drawer unit 60 is pulled out from the apparatus main body, the roller portions 49a and 51b of the pinch rollers 49 and 51 are projected downward from the bottom wall 131. When the radius of the roller portions 49a and 51a is r1, the radius of the roller shaft portions 49b and 51b is r2, and the thickness of the bottom wall 131 is δ1, the amount of protrusion ε from the openings 61e and 62k of the roller portions 49a and 51a ε Is
ε = r1− (r2 + δ1)
become.

  Moreover, it is a rear end of the side edge parts 112 and 113, and the boss | hub part 63 as a 1st to-be-engaged element faces outward from the rear end of the guide part 111 by the predetermined distance Ld1 (<La1). It is formed by protruding. The lower edge of each of the side edges 112 and 113 extends along the side edges 112 and 113 and protrudes outward to form a belt-like protrusion as a second engaged element. 61h is formed. The projecting edge 61h includes a main body portion 61i formed to extend horizontally and a valley portion 61j as a step forming portion that forms a step at the front end of the main body portion 61i.

  Next, operations of the drawer unit 60 and the sensor lever 53 when the drawer unit 60 is pulled out from the apparatus main body will be described.

  FIG. 22 is a diagram showing the state of the drawer unit and the sensor lever when the drawer unit according to the first embodiment of the present invention is disposed in the apparatus main body, and FIG. 23 is the first embodiment of the present invention. It is a figure which shows the state of a drawer unit and a sensor lever when the drawer unit in is pulled out by the predetermined amount from the apparatus main body. The transport roller 50 and the pinch roller 51 are not shown because they have the same structure as the transport roller 48 and the pinch roller 50.

  In the figure, 48 is a conveyance roller, 49 is a pinch roller, 53 is a sensor lever, 60 is a drawer unit, 61 is a horizontal conveyance plate, 62 is a horizontal conveyance frame, 111 and 121 are guide portions, and 83 is adjacent to the sensor lever 53. And a sensor that generates a detection signal and sends it to the control unit when the paper P is detected by the sensor lever 53. In the present embodiment, an optical sensor is used as the sensor 83.

  Each of the transport rollers 48 and 50 (FIG. 1) is disposed so as to be rotatable with respect to the apparatus body in a state where the rotation shaft sh11 is fixed at a predetermined position, and is rotated by receiving rotation from a reversing medium motor. It is done.

  The pinch rollers 49 and 51 are both arranged such that the rotation shaft sh12 of the roller shaft portions 49b and 51b is movable in the vertical direction with respect to the guide portion 121 and is rotatable, and the drawer unit 60 is an apparatus. In the state where it is disposed in the main body, it is rotated (driven rotation) by receiving the rotation of the transport rollers 48 and 50. Therefore, as described above, the transport roller 48 and the pinch roller 49 are brought into contact with each other through the openings 61e and 62k, and the transport roller 50 and the pinch roller 51 are brought into contact with each other through the openings 61f and 62k. The openings 61e and 61f are formed in such a shape that the horizontal transport plate 61 and the transport rollers 48 and 50 do not interfere when the horizontal transport plate 61 moves between the vertical lower position and the vertical upper position. The

  The sensor lever 53 is swingably disposed with respect to the apparatus main body with the swing shaft sh13 fixed at a predetermined position, and the drawer unit 60 is disposed in the apparatus main body. The sheet P is projected to the reversal medium conveyance path Rt4 through the opening 61g, pressed against the guide 121, and pushed down by the sheet P when the sheet P passes between the horizontal conveyance plate 61 and the horizontal conveyance frame 62. It is. The sensor lever 53 is pushed down by the guide portion 111 when the drawer unit 60 is pulled out from the apparatus main body in the arrow direction (drawing direction) or inserted into the apparatus main body.

  For this purpose, the sensor lever 53 swings above the swinging shaft sh13 (on the drawer unit 60 side), below the swinging shaft sh13, and on the passive portion 53a that comes into contact with the conveyed paper P and the guide unit 111. Accordingly, a detection operation unit 53b that selectively shields between the light emitting side and the light receiving side of the sensor 83 is provided. The passive portion 53a abuts the front end of the paper P when the paper P passes through, and the upstream side in the drawing direction of the drawing unit 60 at the inner peripheral edge of the opening 61g when the drawing unit 60 is drawn from the apparatus main body. And a contact surface 53d that contacts the rear end of the guide portion 111 when the drawer unit 60 is inserted into the apparatus main body.

  Further, the sensor lever 53 is provided with a torsion spring 80 as a biasing member that biases the passive portion 53a toward the guide portion 121 and makes contact with the back surface of the guide portion 121. The torsion spring 80 includes a winding portion 80a and first and second arms 80b and 80c extending from the winding portion 80a, and the winding portion 80a is externally fitted to the shaft portion of the swing shaft sh13. The tip of the arm 80b is brought into contact with a contact portion 85 formed at a predetermined position of the apparatus main body, and the tip of the second arm 80c is brought into contact with a contact portion 86 formed in the detection actuating portion 53b. To be attached to the apparatus main body.

  Therefore, the sensor lever 53 is pressed against the guide portion 121 by the urging force of the torsion spring 80.

  In addition, when the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the contact surface is in a state in which the passive portion 53a is in contact with the guide portion 111 so that the sensor lever 53 is smoothly tilted. 53c is inclined so as to form an obtuse angle with respect to the direction in which the drawer unit 60 is pulled out from the apparatus main body, and the contact surface 53d is inclined so as to form an obtuse angle with respect to the direction in which the drawer unit 60 is inserted into the apparatus main body. It is done.

  Further, no other opening is formed on the upstream side and the downstream side from the opening 61g in the drawing direction of the drawing unit 60. Therefore, while the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the sensor lever 53 is not protruded into the reversing medium conveyance path Rt4 via the opening other than the opening 61g.

  By the way, the wall 64 adjacent to the drawer unit 60 in the apparatus main body is extended along the insertion / removal direction of the drawer unit 60 to form a groove 64 as a first engagement element. The groove 64 and the boss portion 63 is engaged.

  Further, a guide post 82 as a second engagement element is formed on the wall surface of the apparatus main body adjacent to the drawer unit 60 so as to project toward the drawer unit 60 side and engage with the protruding edge 61h. The

  The groove 64 is formed to extend horizontally in order to move the horizontal transport plate 61 in the vertical direction in accordance with the insertion / removal of the drawer unit 60, and the rear of the main body 64a. An eccentric portion 64b is formed as a step forming portion that is formed to be slightly decentered downward from the main body portion 64a at the end and forms a step. A first guide surface Sg <b> 1 for moving the horizontal transport plate 61 in the vertical direction is formed on the lower surface of the groove 64 as the drawer unit 60 is inserted and removed. The first guide surface Sg1 is a lower guide formed below the upper guide portion SU1 by a step amount ρ1 represented by a predetermined distance in the upper guide portion SU1 and the eccentric portion 64b formed in the main body portion 64a. It consists of part SL1, and upper guide part SU1 and lower guide part SL1 are connected by the inclination part extended diagonally.

  Further, as described above, the main body portion 61i formed on the projecting edge 61h extends horizontally in order to move the horizontal transport plate 61 in the vertical direction as the drawer unit 60 is inserted and removed. And a trough portion 61j formed at the front end of the main body portion 61i. A second guide surface Sg2 for moving the horizontal transport plate 61 in the vertical direction is formed on the lower surface of the projecting edge 61h as the drawer unit 60 is inserted and removed. The second guide surface Sg2 is formed by an upper guide formed above the lower guide portion SL2 by a step amount ρ2 represented by a predetermined distance in the lower guide portion SL2 and the valley portion 61j formed in the main body portion 61i. It consists of part SU2, and lower guide part SL2 and upper guide part SU2 are connected by the inclination part extended diagonally.

The steps ρ1 and ρ2 are
ρ1 = ρ2
To be.

  By the way, in the present embodiment, with the drawer unit 60 disposed in the apparatus main body, the transport roller 48 and the pinch roller 49 are connected to each other via the openings 61e and 62k. The conveyance rollers 48 and 50 are disposed in the apparatus main body with the rotation shafts sh11 being rotatably fixed at predetermined positions, so that the pinch rollers 49 and 50 are brought into contact with each other through the openings 61f and 62k. 51 is placed on the transport rollers 48 and 50.

Further, the boss portion 63 is placed on the eccentric portion 64b, the guide post 82 is placed on the valley portion 61j, and the horizontal transport plate 61 is placed on the lower position in the vertical direction. At this time, Fs is a resultant force of the spring sp1 that biases the pinch roller 49 toward the bottom wall 131 and the resultant force of the spring sp2 that biases the pinch roller 51 toward the bottom wall 131. When the force generated by the weight of 62 to separate the pinch rollers 49 and 51 from the bottom wall 131 is Fm,
Fs = Fm
To be. At this time, the springs sp1 and sp2 are deflected by a predetermined amount, and the roller shaft portion 49b is separated from the abutting surface Sp of the bottom wall 131 by a predetermined distance S. Accordingly, the weight of the horizontal transport frame 62 is supported by the springs sp1 and sp2. Then, in a state where the drawer unit 60 is mounted on the apparatus main body and placed at the position shown in FIG. 22, the distance S becomes smaller than the protrusion amount ε, and the distance between the horizontal transport plate 61 and the horizontal transport frame 62 is increased. A gap d is formed.

  When the drawer unit 60 is pulled out from the apparatus main body, as shown in FIG. 23, the boss part 63 is moved from the eccentric part 64b to the main body part 64a as the drawer unit 60 moves in the horizontal direction. The first guide surface Sg1 is brought into contact with the upper guide portion SU1, and the guide post 82 is moved from the valley portion 61j to the main body portion 61i, and the second guide surface Sg2 is brought into contact with the lower guide portion SL2. It is done.

  Along with this, the horizontal transport plate 61 is moved upward and placed at the upper position in the vertical direction. As a result, the paper P is sandwiched between the guide 111 of the horizontal transport plate 61 and the guide portion 121 of the horizontal transport frame 62, and the gap d is eliminated. Therefore, when a paper jam occurs in the reversing medium transport unit AR2 (FIG. 1), the drawer unit 60 is pulled out from the apparatus main body with the paper P sandwiched between the horizontal transport plate 61 and the horizontal transport frame 62. be able to.

  In this case, the eccentric portion 64b and the trough portion 61j are arranged so that the timing at which the boss portion 63 is brought into contact with the upper guide portion SU1 and the timing at which the guide post 82 is brought into contact with the lower guide portion SL2 are substantially the same. The position is set. The amount of drawer of the drawer unit 60 is set based on the length of the main body portions 64a and 61i.

  In the present embodiment, the step amounts ρ1 and ρ2, the gap d, and the dimensions L1 and L2 are equal to each other, but the step amounts ρ1 and ρ2 are set to be equal to or larger than the gap d, and the dimensions L1 and L2 are set to the step amount ρ1. , Ρ2 or more. By setting the step amounts ρ1 and ρ2 to the gap d or more and the dimensions L1 and L2 to the step amounts ρ1 and ρ2 or more, when a paper jam occurs in the reversing medium transport unit AR2, the horizontal transport plate 61 is sufficiently moved upward. The drawer unit 60 can be pulled out from the apparatus main body with the paper P securely sandwiched between the horizontal transport plate 61 and the horizontal transport frame 62.

  Further, when the drawer unit 60 is inserted into the apparatus main body, the boss part 63 is moved from the main body part 64a to the eccentric part 64b, and the guide post 82 is moved from the main body part 61i to the valley part 61j. A gap d is formed between the horizontal transport plate 61 and the horizontal transport frame 62.

  Thus, in the present embodiment, the drawer unit 60 is detachably disposed with respect to the apparatus main body, and when pulling out the drawer unit 60 from the apparatus main body, the pinch rollers 49 and 51 and the transport rollers 48 and 50 are provided. Therefore, when a paper jam occurs between the horizontal transport plate 61 and the horizontal transport frame 62, the paper P can be easily taken out simply by pulling out the drawer unit 60 from the apparatus main body. Moreover, since the drawer unit 60 is small in size and light, the operation of taking out the paper P from between the horizontal transport plate 61 and the horizontal transport frame 62 can be easily performed.

  Furthermore, since the drawer unit 60 is detachably disposed on the front casing Cf side of the printer 10 (FIG. 2), that is, on the front side, it can be inserted into and removed from the apparatus main body. It can be carried out.

  In the present embodiment, since the long holes 61a and 61b are formed to extend vertically, the horizontal transport plate 61 is moved in the vertical direction between the lower position in the vertical direction and the upper position in the vertical direction. . Therefore, the direction in which the horizontal transport plate 61 is moved toward the horizontal transport frame 62 as the drawer unit 60 is pulled out from the apparatus main body is substantially the same as the direction in which the drawer unit 60 is pulled out from the apparatus main body. Be vertical. That is, the direction in which the horizontal transport plate 61 moves between the lower position in the vertical direction and the upper position in the vertical direction is substantially perpendicular to the direction in which the drawer unit 60 is inserted into and removed from the apparatus body, that is, 80 [°. ] And an angle of 100 [°] or less.

  Next, a description will be given of a second embodiment of the present invention in which the drawer unit 60 is disposed so as to be detachable with respect to the apparatus main body on the rear housing portion Cr side. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  FIG. 24 is a first schematic diagram of a printer for explaining a method of taking out a sheet from a reversing medium transport unit according to the second embodiment of the present invention, and FIG. 25 is a reversing medium according to the second embodiment of the present invention. FIG. 26 is a second schematic diagram of a printer for explaining a method of taking out a sheet from the conveyance unit, and FIG. FIG. 27 is a second perspective view of the printer for explaining a method of taking out a sheet from the reversing medium transport unit according to the second embodiment of the present invention.

  In the figure, 10 is a printer as an image forming apparatus, Cs1 is a casing of the printer 10, and the casing Cs1 is a central casing as a first casing disposed in the center of the printer 10. Cn, a front housing portion Cf as a second housing portion that is swingably and openably openable with respect to the central housing portion Cn in front of the central housing portion Cn; and A rear housing portion Cr is provided as a third housing portion that is detachably disposed on the central housing portion Cn behind the central housing portion Cn.

  Reference numeral 55 denotes a rear cover as a rear opening / closing member that is swingably and openably disposed at a central portion of the rear wall Wr of the rear housing portion Cr, and 60 is below the rear cover 55 on the rear wall Wr. In addition, a drawer unit 59 as a medium guide unit that is detachably inserted in the apparatus main body and is movable in the horizontal direction, and 59 is a panel of the drawer unit 60. Is a knob as an operation portion for pulling out the drawer unit 60 provided at a predetermined portion of the panel 59, in the present embodiment, at the lower end of the panel 59.

  Next, a method for taking out a sheet from the reversing medium transport unit AR2 when a paper jam occurs in the reversing medium transport unit AR2 will be described.

  When a paper jam occurs in the reverse medium transport unit AR2, a message indicating that a paper jam has occurred in the reverse medium transport unit AR2 is displayed on the operation panel 67 serving as a display unit, and the operator is notified. As a result, when the operator operates and pulls the knob 71 provided on the panel 59, the drawer unit 60 can be pulled out from the apparatus main body as shown in FIGS.

  At this time, the pinch rollers 49 and 51 as the first and second driven rollers are supplied to the drawer unit 60, the conveying rollers 48 and 50 as the first and second driving rollers, and the sensor lever as the fifth medium detecting unit. 53 is disposed in the apparatus main body, so that the transport rollers 48 and 50 and the pinch rollers 49 and 51 are separated as the drawer unit 60 is pulled out from the apparatus main body, and the paper P as a medium is also used. It is pulled out from the apparatus main body together with the drawing unit 60.

  Then, as shown in FIGS. 25 and 27, the operator can open the horizontal conveyance frame 62 as the second guide member by rotating it around the swing shaft sh21 and take out the paper P.

  Next, the drawer unit 60 will be described.

  FIG. 28 is a perspective view of a drawer unit according to the second embodiment of the present invention, and FIG. 29 is a perspective view of a horizontal transport plate according to the second embodiment of the present invention.

  In the figure, 60 is a drawer unit, 61 is a horizontal transport plate as a first guide member, and 62 is a horizontal transport frame.

  The horizontal transport plate 61 includes a guide portion 111 that guides the paper P, and side edges 112 and 113 that are raised at both edges of the guide portion 111, and the horizontal transport frame 62 The guide part 121 to guide and the side edge parts 122 and 123 which are formed by being raised at both edges of the guide part 121 are provided.

  In order to allow the paper P to pass between the horizontal transport plate 61 and the horizontal transport frame 62, a predetermined amount is provided between the horizontal transport plate 61 and the horizontal transport frame 62 in a state where the drawer unit 60 is disposed in the apparatus main body. When the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the drawer unit 60 is connected to the transport rollers 48 and 50 (FIG. 24), the sensor lever 53, and the like. In order not to interfere, the horizontal transport plate 61 is moved toward the horizontal transport frame 62 and brought into contact with the horizontal transport frame 62 via the paper P, thereby eliminating the gap d ( 0).

  Further, in the drawer unit 60 pulled out from the apparatus main body, the horizontal conveyance frame 62 is disposed with respect to the horizontal conveyance plate 61 so that the paper P jammed between the horizontal conveyance plate 61 and the horizontal conveyance frame 62 can be taken out. It is swingably supported.

  Therefore, in the horizontal transport plate 61, a predetermined position on the side edge portions 112 and 113, in this embodiment, a predetermined shape La2 behind the front end of the guide portion 111, a predetermined shape, this embodiment. In the present embodiment, the long hole 161a as the first support portion having an O-shape is formed in a predetermined shape, in the present embodiment, U in front of the rear end of the guide portion 111 by a predetermined distance Lb2. A long hole 161b as a second support portion having a letter shape and having an open upper end is formed by a long groove.

  In the horizontal conveyance frame 62, a predetermined shape at the side edge portions 122 and 123, in this embodiment, the front end of the guide portion 121, and a cylindrical shape in this embodiment. A post part 162a as a first supported part having a post part as a second supported part having a predetermined shape, in this embodiment, a prismatic shape, at the rear end of the guide part 121 162b is formed to protrude toward the outside of both edges of the guide portion 121.

Then, when the dimension in the horizontal direction (the transport direction of the paper P) of the long hole 161a, that is, the width is zw1, the dimension in the vertical direction, that is, the height is zh1, and the diameter of the post portion 162a is zd1. The width zw1 is slightly larger than the diameter zd1, and the height zh1 is larger than the diameter zd1 by a predetermined dimension L1 (FIG. 17). Further, when the width of the long hole 161b is zw2, the height is zh2, and the diameter of the post portion 162b is zd2, the width zw2 is slightly larger than the diameter zd2, and the height zh2 is a predetermined dimension L2 from the diameter sd2. Will only be enlarged. In the present embodiment, the dimensions L1 and L2 are
L1 = L2
To be.

  Therefore, the horizontal conveying plate 61 is formed by inserting the post portions 162a into the respective long holes 161a so as to be movable in the vertical direction (free fitting) and inserting the post portions 162b into the respective long holes 161b so as to be movable in the vertical direction. And the horizontal conveyance frame 62 can be relatively moved in the vertical direction. That is, in a state where the drawer unit 60 is disposed in the apparatus main body, the horizontal transport plate 61 is placed at the lower position in the vertical direction as the first position so that the paper P can pass therethrough, A predetermined gap d is formed between the frame 62 and the frame 62. Further, when the drawer unit 60 is pulled out from the apparatus main body or inserted into the apparatus main body, the horizontal transport plate 61 is placed at the upper position in the vertical direction as the second position and contacts the horizontal transport frame 62. The gap is eliminated (set to 0). As a result, the drawer unit 60 does not interfere with the transport rollers 48 and 50, the sensor lever 53, and the like when the drawer unit 60 is pulled out of the apparatus body or inserted into the apparatus body.

  Further, since the post portion 162a is fitted into the long hole 161a, in the drawer unit 60 pulled out from the apparatus main body, by rotating the horizontal transport frame 62 with the post portion 162a serving as the swing shaft sh21 (FIG. 27). The paper P jammed between the horizontal transport plate 61 and the horizontal transport frame 62 can be taken out.

  In the horizontal transport plate 61, the guide part 111 is formed by extending a main body part 114 extending in the horizontal direction, obliquely upward from the front end of the main body part 114, and pulling out the drawer unit 60. An inclined portion 115 for guiding the passing paper P to the intermediate transport roller 16 and the pinch roller 17 as a first transport member, extending in the transport direction of the paper P, and at a predetermined distance from each other. A plurality of formed ribs 117 and the like are provided. In the present embodiment, a plurality of three openings 61d, 61e, 61f are formed at predetermined intervals from the rear end to the front end of the guide portion 111 in the central flat portion where the rib 117 is not formed. An opening 61g is formed adjacent to the opening 61f. The openings 61e and 61f are formed at positions corresponding to the pinch rollers 49 and 51 disposed on the horizontal transport frame 62, and in the reversing medium transport path Rt4 with the drawer unit 60 disposed in the apparatus main body. The conveying roller 48 and the pinch roller 49 are brought into contact with each other, and the conveying roller 50 and the pinch roller 51 are brought into contact with each other. Then, in a state where the drawer unit 60 is disposed in the apparatus main body, the sensor lever 53 is projected to the reverse medium transport path Rt4 through the opening 61g.

  Further, in the horizontal conveyance frame 62, the guide part 121 is formed by extending the body part 124 extending in the horizontal direction, obliquely upward from the front end of the body part 124, and the inclined part. 115, and an inclined portion 125 for guiding the paper P passing through the drawing unit 60 to the intermediate conveyance roller 16 and the pinch roller 17, and extending in the conveyance direction of the paper P, and at a predetermined distance from each other. The plurality of ribs 127, the plurality of ribs 128 formed in the direction perpendicular to the conveyance direction of the paper P, that is, extending in the width direction of the guide portion 121 and spaced apart from each other by a predetermined distance, etc. Is provided.

  A boss portion 163 as a first engaged element is formed to protrude outward at the front end of the guide portion 111 that is behind the front ends of the side edge portions 112 and 113 by a predetermined distance Ld2. Further, at the lower end of the side edge portions 112 and 113, a belt-like protruding edge as a second engaged element is extended along the side edge portions 112 and 113 and protrudes outward. 161h is formed. The projecting edge 161h includes a main body portion 161i formed to extend horizontally, and a valley portion 161j as a step forming portion that forms a step at the front end of the main body portion 161i.

  Next, operations of the drawer unit 60 and the sensor lever 53 when the drawer unit 60 is pulled out from the apparatus main body will be described.

  FIG. 30 is a diagram showing the state of the drawer unit and the sensor lever when the drawer unit according to the second embodiment of the present invention is disposed in the apparatus main body, and FIG. 31 is the second embodiment of the present invention. It is a figure which shows the state of a drawer unit and a sensor lever when the drawer unit in is pulled out by the predetermined amount from the apparatus main body. The conveyance roller 50 and the pinch roller 51 are not shown.

  In the figure, 48 is a conveyance roller, 49 is a pinch roller, 53 is a sensor lever, 60 is a drawer unit, 61 is a horizontal conveyance plate, 62 is a horizontal conveyance frame, 111 and 121 are guide portions, and 83 is adjacent to the sensor lever 53. And is a sensor that generates a detection signal and sends it to the control unit when the paper P is detected by the sensor lever 53. In the present embodiment, an optical sensor is used as the sensor 83.

  Each of the transport rollers 48 and 50 (FIG. 24) is disposed so as to be rotatable with respect to the apparatus main body in a state where the rotation shaft sh11 is fixed at a predetermined position, and is reversed as a drive unit for transporting the reverse medium. The rotation is received from the medium motor.

  Further, the pinch rollers 49 and 51 are both disposed such that the rotation shaft sh12 is movable in the vertical direction with respect to the guide portion 121 and is rotatable, and the drawer unit 60 is disposed in the apparatus main body. In this state, it is rotated (driven rotation) in response to the rotation of the transport rollers 48 and 50.

  The sensor lever 53 is swingably disposed with respect to the apparatus main body with the swing shaft sh13 fixed at a predetermined position, and the drawer unit 60 is disposed in the apparatus main body. The paper P is projected through the opening 61g to the reversing medium transport path Rt4 (FIG. 24), pressed against the guide 121, and passed by the paper P between the horizontal transport plate 61 and the horizontal transport frame 62. Pressed and defeated. The sensor lever 53 is pushed down by the guide portion 111 when the drawer unit 60 is pulled out of the apparatus main body or inserted into the apparatus main body.

  For this purpose, the sensor lever 53 swings above the swinging shaft sh13 (on the drawer unit 60 side), below the swinging shaft sh13, and on the passive portion 53a that comes into contact with the conveyed paper P and the guide unit 111. Accordingly, a detection operation unit 53b that selectively shields between the light emitting side and the light receiving side of the sensor 83 is provided. The passive portion 53a abuts the front end of the paper P when the paper P passes through, and the upstream side in the drawing direction of the drawing unit 60 at the inner peripheral edge of the opening 61g when the drawing unit 60 is drawn from the apparatus main body. And a contact surface 53d that contacts the rear end of the guide portion 111 when the drawer unit 60 is inserted into the apparatus main body.

  Further, the sensor lever 53 is provided with a torsion spring 80 (FIG. 22) as an urging member that urges the passive portion 53 a toward the guide portion 121 and makes contact with the back surface of the guide portion 121. Therefore, the sensor lever 53 is pressed against the guide portion 121 by the urging force of the torsion spring 80.

  By the way, a groove 164 as a first engagement element is formed on a wall surface of the apparatus main body adjacent to the drawer unit 60 along the insertion / removal direction of the drawer unit 60, and the groove 164 and the boss portion are formed. 163 is engaged.

  Further, as described above, the protruding edge 161h is formed at the lower end of the side edge portions 112 and 113 of the horizontal transport plate 61, and protrudes toward the drawer unit 60 side on the wall surface adjacent to the drawer unit 60 in the apparatus main body. In addition, a guide post (not shown) as a second engagement element is formed by engaging with the protruding edge 161h.

  The groove 164 includes a main body 164a that is formed to extend horizontally in order to move the horizontal transport plate 61 in the vertical direction as the drawer unit 60 is inserted and removed, and a front end of the main body 164a. Are provided with an eccentric portion 164b as a step forming portion that is formed to be slightly decentered downward from the main body portion 164a. A first guide surface Sg11 for moving the horizontal transport plate 61 in the vertical direction is formed on the lower surface of the groove 164 as the drawer unit 60 is inserted and removed. The first guide surface Sg11 includes an upper guide portion SU11 formed on the main body portion 164a and a lower guide portion SL11 formed below the upper guide portion SU11 by a predetermined distance in the eccentric portion 164b. The part SU11 and the lower guide part SL11 are connected by an inclined part extending obliquely.

  Further, as described above, the protruding edge 161h includes the main body portion 161i and the valley portion 161j in order to move the horizontal transport plate 61 in the vertical direction as the drawer unit 60 is inserted and removed. A second guide surface for moving the horizontal transport plate 61 in the vertical direction is formed on the lower surface of the projecting edge 161h as the drawer unit 60 is inserted and removed. The second guide surface includes a lower guide portion formed on the main body portion 161i and an upper guide portion formed at a predetermined distance above the lower guide portion in the valley portion 161j. The parts are connected by an inclined part extending obliquely.

  In each of the above embodiments, the printer 10 has been described. However, the present invention can be applied to a copying machine, a facsimile machine, a multifunction machine, and the like.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

49, 51 Follower roller 60 Drawer unit 61 Horizontal transport plate 62 Horizontal transport frame P Paper sh1 Swing shaft

Claims (10)

(A) the device body;
(B) a driving roller disposed rotatably with respect to the apparatus main body;
(C) a first guide member for guiding the medium;
(D) A second guide that includes a driven roller and is disposed so as to be swingable about the swing shaft with respect to the first guide member so as to face the first guide member and guide the medium. And having a member,
(E) The first and second guide members are arranged as media guide units so that they can be pulled out in the direction parallel to the direction of guiding the medium with respect to the apparatus main body.
(F) With the medium guide unit mounted on the apparatus main body, the drive roller is protruded from the first guide member toward the second guide member and is brought into contact with the driven roller.
(G) The medium guide unit is pulled out from the surface of the apparatus main body on the side where the medium enters between the first and second guide members while being attached to the apparatus main body, leaving a drive roller;
(H) When the medium guiding unit is pulled out from the apparatus main body, the first guide member moves in the protruding direction with a moving amount larger than the protruding amount of the driving roller in a state where the medium guiding unit is mounted on the apparatus main body. Let
(I) The swing shaft extends in a direction perpendicular to the medium guiding direction in the vicinity of the front end of the medium guiding unit in the direction in which the medium guiding unit is inserted into the apparatus main body. A medium conveying apparatus characterized by the above. (A) the device body;
(B) a driving roller disposed rotatably with respect to the apparatus main body;
(C) a first guide member for guiding the medium;
(D) A second guide that includes a driven roller and is disposed so as to be swingable about the swing shaft with respect to the first guide member so as to face the first guide member and guide the medium. And having a member,
(E) The first and second guide members are arranged as media guide units so that they can be pulled out in the direction parallel to the direction of guiding the medium with respect to the apparatus main body.
(F) With the medium guide unit mounted on the apparatus main body, the drive roller is protruded from the first guide member toward the second guide member and is brought into contact with the driven roller.
(G) The medium guide unit is pulled out from the surface of the apparatus main body on the side from which the medium is discharged from between the first and second guide members while being attached to the apparatus main body,
(H) When the medium guiding unit is pulled out from the apparatus main body, the first guide member moves in the protruding direction with a moving amount larger than the protruding amount of the driving roller in a state where the medium guiding unit is mounted on the apparatus main body. Let
(I) The swing shaft extends in a direction perpendicular to the medium guiding direction in the vicinity of the front end of the medium guiding unit in the direction in which the medium guiding unit is inserted into the apparatus main body. A medium conveying apparatus characterized by the above. The driven roller is urged by the urging member, the second medium feeding apparatus according to claim 1 or 2 through the opening formed in the guide member is protruded from said second guide member. (A) the first guide member includes a plurality of ribs;
(B) The medium carrying device according to any one of claims 1 to 3, wherein an opening is formed between adjacent ribs. Said second guide member, the medium conveying device according to any one of claims 1 to 4 having an opening exposing the first guide member. Said second guide member, the medium conveying device according to any one of claims 1 to 5, an opening in the vicinity of the driven roller. The said 1st guide member is made longer than a said 2nd guide member in the opposite side to the side in which the said rocking | fluctuation axis | shaft is formed in the said medium guide unit of any one of Claims 1-6 . Medium transport device. It said first guide member, the medium conveying device according to any one of claims 1 to 7 including an opening for protruding said driven roller and the counter is allowed to disposed a driving roller. (A) having a medium detecting unit for detecting a medium conveyed in the medium guiding unit;
(B) The medium conveyance device according to any one of claims 1 to 8 , wherein the medium detection unit includes a medium contact surface formed so as to form an obtuse angle with respect to the first guide member. The image forming apparatus in which the medium transport device is mounted according to any one of the claims 1-9.

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