JP2012180153A - Sheet conveying device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact device having a same-edge reversal mechanism for receiving a sheet from its front end, turning it over, and outputting it from the same front end which has been received first.SOLUTION: This device includes: the same-edge reversal mechanism 21 which comprises a reversal conveyance path 24 provided with a paper conveying structure having a U-shaped cross section in a direction substantially perpendicular to a predetermined paper conveyance direction, and a paper conveyance path for conveying the paper in the horizontal direction to turn over the paper; and a paper feed tray 1c arranged in a space area formed by the paper conveying structure having the U-shaped cross section of the same-edge reversal mechanism 21, to store the paper. The space are formed by the sheet conveying structure having the U-shaped cross section can be effectively used as an area for storing the paper. Thus, an image forming device 100 with the same-edge reversal mechanism 21 mounted thereon can be made compact without enlarging it.

Description

  This invention is provided with a same edge reversing mechanism that receives from the front end side of the sheet member and reverses the front and back, and outputs the sheet member from the same front end side as when pulling in, and based on the duplex printing mode, images are printed on both sides of a predetermined sheet of paper. The present invention relates to a sheet conveying device and an image forming apparatus which can be applied to a monochrome printer or a color printer for forming the image forming apparatus, a copying machine, a multifunction machine, a printing apparatus, or the like.

  In recent years, monochrome printers and color printers, copiers, multifunction peripherals, printing apparatuses and the like (hereinafter referred to as image forming apparatuses) are often used. Among image forming apparatuses, a paper reversing device is provided, and an image is formed on one side of a predetermined paper based on the duplex printing mode, and then the front and back sides of the paper are reversed by the paper reversing device to form an image on the other side. A device equipped with is used.

  A monochrome image forming apparatus having a duplex printing function includes a paper feed tray, an image forming unit, a fixing unit, and an automatic paper reversing / conveying unit (hereinafter referred to as an ADU reversing unit). The ADU reversing unit has a function of automatically reversing the paper after image formation in a paper conveyance direction different from the paper conveyance direction during image formation.

  For example, when the double-sided printing mode is set in the image forming apparatus, the image forming unit forms a black toner image on one side of the paper fed from the paper feed tray based on the image data. In the image forming unit, an electrostatic latent image based on monochrome image data is formed on a photosensitive drum uniformly charged by a charger by a scanning exposure unit using a polygon mirror or the like.

  The electrostatic latent image on the photosensitive drum is developed by a developing device. Such charging, exposure, and development are performed, and the toner image formed on the photosensitive drum is transferred onto a desired sheet by the transfer unit. The toner image transferred onto a predetermined sheet is fixed by the fixing unit. The sheet after fixing is turned upside down by the ADU inversion unit, and the sheet after turning upside down is fed again to the image forming unit. In the image forming unit, a black toner image is formed on the other side of the re-fed paper based on the image data. The sheet on which the toner image is formed on the other side is fixed by the fixing unit. The fixed sheet is discharged. As a result, black and white images based on the image data can be formed on the front and back of a predetermined sheet.

  By the way, regarding the ADU reversing unit, there is also disclosed an image forming apparatus provided with a same edge reversing mechanism that receives from the front end side of the sheet member, reverses the front and back, and outputs the sheet member from the same front end side as when retracted.

  In relation to an image forming apparatus having this type of edge reversal function, Patent Document 1 discloses an image forming apparatus. The image forming apparatus includes a paper feeding unit, a paper discharge unit, a main conveyance path, an image forming unit, a refeed conveyance path, and a front / back conversion unit. The main transport path transports the paper fed from the paper feed unit to the paper discharge unit. The image forming unit is provided in the middle of the main conveyance path and forms an image on one side of the sheet. The re-feed conveyance path re-feeds the paper on which the image is formed on one side by the image forming unit to the image forming unit again. On the premise of this, the front / back conversion means is provided on the refeed conveyance path, and the front / back conversion means converts the front and back of the paper by reversing the left and right sides of the paper with respect to the paper transport direction. I made it. If the image forming apparatus is configured in this way, the configuration of the front / back conversion means can be simplified and the space can be saved.

Japanese Patent Application Laid-Open No. Sho 61-111244 (Page 4 FIG. 2)

According to the image forming apparatus provided with the paper reversing mechanism as found in Patent Document 1, there are the following problems.
i. According to the image forming apparatus of Patent Document 1, the front / back conversion unit includes the first stacking unit, and accommodates a sheet on which an image is formed on one side. A second stacking unit is provided below the front / back conversion unit, and a sheet (hereinafter also referred to as a sheet member) that is turned upside down by the front / back conversion unit is stored for refeeding to the image forming unit. For this reason, since the first and second stacking units must be provided in addition to the cassette for storing paper on which images are not formed, there is a problem that the image forming apparatus itself is increased in size.

  ii. According to the image forming apparatus of Patent Document 1, the first and second stacking units are arranged in the vertical direction with reference to the horizontal direction of the end of the U-shaped refeed path branched from the main conveyance path of the image forming unit. Therefore, there is a problem that the first and second stacking units occupy a lot in the height direction of the image forming apparatus.

  Accordingly, the present invention solves the above-described problems, and includes an apparatus equipped with a same edge reversing mechanism that receives the sheet member from the front end side and reverses the front and back and outputs the sheet member from the same front end side as when retracted. It is an object to provide a sheet conveying apparatus and an image forming apparatus that can be made compact.

  In order to solve the above-described problem, the sheet conveying apparatus according to claim 1 is a sheet conveying apparatus that outputs a sheet member that is received from a predetermined sheet conveying direction by reversing the front and back, and is substantially orthogonal to the sheet conveying direction. A reversal conveying path provided with a sheet conveying structure having a U-shaped cross section in the direction, and a sheet edge reversing mechanism for reversing the sheet member by having a paper conveying path for conveying the sheet member in the horizontal direction; And a sheet storage member that is provided in a space region defined by the U-shaped sheet conveyance structure of the same edge reversing mechanism and stores the sheet member.

  According to the sheet conveying apparatus of the first aspect, when a sheet member received from a predetermined sheet conveying direction is reversed and output, the same edge reversing mechanism and a sheet storage member are provided. The same edge reversing mechanism has a reversing conveyance path provided with a U-shaped sheet conveying structure in a direction substantially orthogonal to the sheet conveying direction, and has a paper conveying path for conveying the sheet member in the horizontal direction. Yes.

  The sheet storage member is provided in a space region defined by a sheet conveying structure having a U-shaped cross section of the same edge reversing mechanism. A sheet member is stored in the sheet storage member. Based on these assumptions, when a sheet storage member is selected, the same edge reversing mechanism reverses the sheet member fed out from the sheet storage member.

  With this structure, the space area defined by the sheet conveying structure having a U-shaped cross section can be effectively used as an area for storing the sheet member. As a result, the enlargement of the image forming apparatus equipped with the same edge reversing mechanism is hindered, and the compactness can be achieved.

  A sheet conveying apparatus according to a second aspect of the present invention includes the conveyance driving unit according to the first aspect, further comprising a conveyance driving unit that pulls the sheet member into the same edge reversing mechanism and sends out the sheet member that has been reversed upside down in the reversal conveying path. The driving unit pulls the sheet member received from the sheet conveying direction into the same edge reversing mechanism and sends the sheet member in a direction substantially orthogonal to the sheet conveying direction to convey the first sheet into the reversing conveying path. A second sheet conveying unit that pulls out the sheet member from the reversing conveyance path and sends out the sheet member that has been turned upside down from the inside of the same edge reversing mechanism to convey the sheet member in a predetermined sheet conveying direction; And a driving unit that drives the second sheet conveying unit.

  A sheet conveying apparatus according to a third aspect is the sheet conveying apparatus according to the second aspect, wherein the same edge reversing mechanism includes a sliding member that slidably holds the sheet storage member.

  According to a fourth aspect of the present invention, in the third aspect, the sheet storage member is provided with a detection member that detects the sheet member at a predetermined position.

  According to a fifth aspect of the present invention, there is provided the sheet conveying apparatus according to the fourth aspect, further comprising a movement restriction member that restricts movement of the sheet storage member in a predetermined direction.

  A sheet conveying apparatus according to a sixth aspect of the present invention is the sheet conveying apparatus according to the first aspect, wherein the same edge reversing mechanism is provided with a detection member that detects the sheet member at a predetermined position of the reversing conveying path and the sheet conveying path. It is a feature.

  The sheet conveying device according to claim 7 is the sheet conveying device according to claim 1, wherein the same edge reversing mechanism pulls in the sheet member from the leading end side to reverse the sheet member, and reverses the sheet member from the leading end side same as when the sheet is pulled in. The sheet member is discharged.

  The image forming apparatus according to claim 8, further comprising: an image forming unit that forms an image on a predetermined surface of the sheet member; and a sheet conveying unit that conveys the sheet member to the image forming unit. Is composed of any one of the sheet conveying apparatuses according to claims 1 to 7, or a combination of these sheet conveying apparatuses.

  According to the image forming apparatus of the eighth aspect, the sheet conveying apparatus according to the present invention having the same edge reversing mechanism is provided. With this structure, an image can be formed on the front and back surfaces of the sheet member supplied from the sheet storage member provided in the space area defined by the sheet conveyance structure having a U-shaped cross section.

  An image forming apparatus according to a ninth aspect is the image forming apparatus according to the eighth aspect, further comprising an apparatus main body portion on which the image forming section and the sheet conveying apparatus are mounted, wherein the sheet conveying apparatus is unitized, and the apparatus main body portion is a unit And a sliding member that slidably holds the sheet conveying device.

  According to a tenth aspect of the present invention, there is provided a movement restricting member for restricting the movement of the sheet conveying device in a predetermined direction.

  According to the sheet conveying apparatus of the first aspect, the sheet storage member is provided in a space region defined by the sheet conveying structure having a U-shaped cross section of the same edge reversing mechanism.

  With this configuration, the space area defined by the sheet conveying structure having a U-shaped cross section can be effectively used as an area for storing the sheet member. As a result, the enlargement of the image forming apparatus equipped with the same edge reversing mechanism is hindered, and the compactness can be achieved.

  According to the sheet conveying apparatus of the second aspect, the sheet member is pulled out from the reversing conveyance path and the sheet member after reversing the front and back from the same edge reversing mechanism is conveyed and conveyed in a predetermined sheet conveying direction. When an image is formed, the image can be written from the front end side on both the front and back sides of the sheet member.

  According to the sheet conveying apparatus of the third aspect, the sheet member can be replenished in the sheet storage member pulled out in the predetermined direction from the same edge reversing mechanism. In addition, when another sheet storage member is selected and a printing operation is performed, the printing operation can be continued.

  According to the sheet conveying apparatus of the fourth aspect, since the presence / absence of the sheet member in the sheet storage member can be detected at a predetermined position, it is possible to determine whether or not the sheet member needs to be replenished.

  According to the sheet conveying apparatus of the fifth aspect, the sheet storage member is pulled out from the same edge reversing mechanism in a predetermined direction in response to the presence / absence of the remaining detection of the sheet member in the sheet storage member or the abnormal stop of the jam occurrence. You can limit it. Therefore, even when the remaining sheet member is detected, the withdrawal of the sheet storage member can be restricted when jamming abnormally stops.

  According to the sheet conveying apparatus of the sixth aspect, the presence / absence of the sheet member passing through the reverse conveying path and the sheet conveying path can be detected at a predetermined position, so that the occurrence of jamming of the sheet member can be determined.

  According to the sheet conveying apparatus of the seventh aspect, when images are formed on the front and back sides of the sheet member, the images can be written from the front end side on both the front and back sides of the sheet member. Therefore, compared with an image forming apparatus provided with a switchback type sheet reversing mechanism, the image writing position can be aligned on the front and back surfaces of the sheet member so that they cannot be distinguished from each other, so that the image forming quality can be improved.

  According to the image forming apparatus of the eighth aspect, the sheet conveying apparatus according to the present invention having the same edge reversing mechanism is provided. With this configuration, it becomes possible to form images on the front and back surfaces of the sheet member supplied from the sheet storage member provided in the space area defined by the sheet conveyance structure having a U-shaped cross section. As a result, a compact image forming apparatus equipped with the same edge reversing mechanism can be provided.

  According to the image forming apparatus of the ninth aspect, it is possible to inspect and maintain the same edge reversing mechanism and the like in the sheet conveying apparatus pulled out in a predetermined direction from the apparatus main body.

  According to the image forming apparatus of the tenth aspect, in response to presence / absence of residual detection of the sheet member in the sheet conveying apparatus, abnormal stoppage of jam occurrence, etc., the sheet conveying apparatus is pulled out in a predetermined direction from the apparatus main body, Alternatively, the drawer of the sheet storage member can be restricted. Therefore, even when there is no detection of the remaining sheet member, when the jam occurrence is abnormally stopped, the sheet conveying device can be allowed to be pulled out while restricting the pulling out of the sheet storage member, and the same edge reversing mechanism and the like can be inspected and maintained.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus 100 as a first embodiment according to the present invention. 4 is a schematic side view showing an example of the internal configuration of the same edge reversing unit 201. FIG. 6 is a perspective view showing an example of mounting a paper feed tray 1c in the same edge reversing mechanism 21. FIG. 5 is a perspective view showing an example of pulling out a paper feed tray 1c in the same edge reversing mechanism 21. FIG. FIG. 3 is a perspective view illustrating an example of pulling out the same edge reversing unit 201 in the image forming apparatus 100. FIG. 5 is a conceptual diagram illustrating a configuration example (part 1) of a transport driving unit 23 in the same edge reversing mechanism 21 as viewed from the front. FIG. 6 is a conceptual diagram viewed from a side surface illustrating a configuration example (No. 2) of a conveyance driving unit 23 in the same edge reversing mechanism 21; 5 is a perspective view illustrating an example of paper conveyance in the same edge reversing unit 201. FIG. FIG. 6 is a schematic view seen from the bottom showing an operation example (No. 1) of the same edge reversing unit. (A) And (B) is the schematic seen from the side surface which shows the operation example (the 2) of the same edge inversion unit 201. FIG. FIG. 6 is a schematic view seen from the upper surface showing an operation example (No. 3) of the same edge reversing unit. FIG. 6 is a perspective view showing an arrangement example of paper detection sensors # 1 to # 6 in the same edge reversing unit 201. 3 is a block diagram illustrating a configuration example of a control system in the same edge reversing unit 201. FIG. 5 is a flowchart showing an example of control in the same edge reversing unit 201. FIG. 6 is a schematic diagram of a front side illustrating a configuration example of an image forming apparatus 200 as a second embodiment. FIG. 5 is a perspective view showing a configuration example of the same edge reversing unit 202. 4 is a schematic side view illustrating an example of mounting a same edge reversing unit 202 in the image forming apparatus 200. FIG. 5 is a schematic side view showing an example of drawing out a paper feed tray 1c in the same edge reversing unit 202. FIG. 3 is a schematic side view illustrating an example of drawing out a same edge reversing unit 202 in the image forming apparatus 200. FIG.

  Hereinafter, a sheet conveying apparatus and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  A configuration example of an image forming apparatus 100 as a first embodiment according to the present invention will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 1 includes a sheet conveying apparatus according to the present invention, and is a monochrome or color printer that forms an image on both sides of a predetermined sheet member (hereinafter referred to as paper) based on a duplex printing mode. The present invention can be applied to these copying machines and multifunction machines. The sheet member includes plain paper, cardboard, thin resin sheets, sealed letters, labels, postcards, and the like (hereinafter simply referred to as paper).

  The image forming apparatus 100 includes an apparatus main body 101. In the center of the apparatus main body 101, there is provided a same edge reversing unit 201 that constitutes an example of a sheet reversing unit, and operates to reverse the paper P after image formation. Further, in the same edge reversing unit 201, a paper feed tray 1c constituting an example of a sheet storage member is mounted, and a paper P of a predetermined size is stored and operates to feed the paper P. The paper feed tray 1c has a feeding roller 2c. The same edge reversing unit 201 uses the sheet conveying apparatus according to the present invention.

  Around the same edge reversing unit 201, a paper feed unit 1, an image forming unit 6, a fixing unit 8, a paper feed path 10, a paper discharge path 18, a circulation re-feed path 26, and a re-feed path 27 are provided. The sheet feeding unit 1 has sheet feeding trays 1 a and 1 b and is disposed below the same edge reversing unit 201. The paper feed tray 1a has a feeding roller 2a for storing paper P of a predetermined size. The paper feed tray 1b has a feeding roller 2b, and stores paper P of a predetermined size. For example, when the paper feed tray 1 a is selected, the feeding roller 2 a rotates and operates to feed the paper P from the paper feed tray 1 a to the paper feed path 10. When the paper feed tray 1c is selected, the feeding roller 2c rotates and operates to feed the paper P from the paper feed tray 1c to the paper feed path 10.

  In this example, the paper feed path 10 is arranged on the upstream side of the image forming unit 6 and along the right wall surface inside the apparatus main body 101. The paper feed path 10 includes transport rollers 3 a, 3 b, 3 c, a transport roller 4 and a registration roller 5. The paper P fed out from the paper feed tray 1 a to the paper feed path 10 is transported by the transport rollers 3 a, 3 b, 3 c and the transport roller 4 and reaches the registration roller 5. The sheet P waits at the position of the registration roller 5 and is fed to the image forming unit 6 at a predetermined timing.

  The image forming unit 6 is disposed between the registration roller 5 and the fixing unit 8. The image forming unit 6 forms an image on the paper P at a predetermined timing. Although not shown, the image forming unit 6 includes a photosensitive drum, a developing device, a transfer device, a writing unit, a cleaning unit, and the like. For example, when the image forming apparatus 100 forms a color printer, a tandem electrophotographic color printer engine is used for the image forming unit 6. When configuring a monochrome printer, an electrophotographic monochrome printer engine is used.

  The paper discharge path 18 includes the conveyance belt 7 and the paper discharge roller 9, and is disposed on the downstream side of the image forming unit 6. The conveyance belt 7 is disposed on the downstream side of the image forming unit 6 and conveys the paper P after image formation from the image forming unit to the fixing unit 8. The fixing unit 8 is disposed between the conveyance belt 7 and the paper discharge roller 9 and fixes the paper P after image formation. The fixing unit 8 is provided with a heating roller, and heats and fixes the toner image transferred to the paper P after image formation. The sheet P after the fixing process is heated. The paper discharge roller 9 is disposed on the downstream side of the fixing unit 8 and discharges the fixed paper P to the outside.

  The circulation refeed path 26 is branched from the paper discharge path 18 and is disposed at a position along the left wall surface inside the apparatus main body 101. The circulation refeeding path 26 has conveying rollers 11 and 12 and is connected to the same edge reversing unit 201. When the double-sided printing mode is set in the circulation refeed path 26, the fixed sheet P branched from the paper discharge path 18 is guided to the same edge reversing unit 201 via the transport rollers 11 and 12. To work.

  The same edge reversing unit 201 operates to reverse the paper P after image formation (fixing) received from the circulation refeed path 26 (predetermined paper transport direction). The same edge reversing unit 201 has a same edge reversing mechanism 21 and a transport driving unit 23. A transport drive unit 23 is provided inside the same edge reversing mechanism 21. The conveyance drive unit 23 includes pull-in rollers 13 and 14 that constitute an example of a sheet conveyance unit, pull-out rollers 15 and 16, a feed roller 31, a reception roller 32, and the like, and conveys the sheet in the horizontal direction. To work. The conveyance drive unit 23 operates to pull the paper P into the same edge reversing mechanism 21 and to send out the paper P that has been reversed in the reverse conveyance path 24. In the figure, Y and Z are the sheet conveying directions.

  A re-feed path 27 having a loop roller 17 is connected to the same edge reversing unit 201. The re-feeding path 27 is connected to the feeding path 10 in a time-sharing manner so that the paper P that has been turned upside down by the same edge reversing unit 201 is re-fed to the image forming unit 6 via the loop roller 17. Operate. These constitute the image forming apparatus 100.

  Next, an example of the internal configuration of the same edge reversing unit 201 will be described with reference to FIGS. 2 and 3. The same edge reversing unit 201 shown in FIG. 2 reverses the paper P after image formation received from the circulation refeed path 26 (sheet transport direction; hereinafter referred to as paper transport direction Y) shown in FIG. It operates to output to 6. X and Z in the figure are the sheet conveyance direction (hereinafter referred to as the sheet conveyance direction).

  The same edge reversing unit 201 includes a same edge reversing mechanism 21, a transport driving unit 23, and a reversing transport path 24. The reverse conveyance path 24 has a sheet conveyance structure having a U-shaped cross section. The same edge reversing mechanism 21 has a housing shape (box shape) including a U-shaped side surface portion along the sheet conveying structure of the reversing conveying path 24. The same edge reversing mechanism 21 has a reverse conveyance path 24 in the paper conveyance direction X substantially orthogonal to the paper conveyance direction Y and reverses the paper P.

  As shown in FIG. 3, the paper feed tray 1 c is provided in a space region defined by a sheet conveying structure having a U-shaped cross section of the same edge reversing mechanism 21 and stores the paper P. The same edge reversing mechanism 21 shown in FIG. 3 is provided with U-shaped side portions (hereinafter referred to as side frames 21 a and 21 b) on both sides of the reversing conveyance path 24.

  Inside the side frames 21a and 21b, fixing rail members 22a and 22b constituting an example of a sliding member are attached correspondingly. The rail members 22a and 22b are configured to slidably hold the paper feed tray 1c. A slide rail is used as the sliding member. A rectangular portion of the side frame 21b is a window portion from which the paper P is discharged.

  Roller members (not shown) are rotatably attached to both outer sides of the paper feed tray 1c. The roller members are engaged with the corresponding movable rail members 42a and 42b on both outer sides of the paper feed tray 1c, and the rail members 42a and 42b are respectively connected to the rail members 22a and 22b of the side frames 21a and 21b. Each is engaged and movably engaged. The rail members 42a and 42b constitute another example of the sliding member.

  Further, a stopper 41 constituting an example of a movement limiting member is provided on one outer side of the paper feed tray 1c (see FIG. 4). The stopper 41 restricts the movement of the paper feed tray 1c in a predetermined direction, in this example, the front side (predetermined direction) of the apparatus main body 101. In this example, a release mechanism 43 that releases the function of the stopper 41 is provided. The release mechanism 43 is provided on the back side of the rail member 22a for fixing the same edge reversing mechanism 21, for example. When the stopper 41 is provided on the other side of the paper feed tray 1c, a release mechanism 43 is also provided on the back side of the rail member 22b for fixing the same edge reversing mechanism 21 (not shown).

  For the release mechanism 43, for example, a solenoid (electromagnet) is used. The solenoid is controlled to lock the stopper 41 and open the stopper 41 based on the tray control signal. When such a release mechanism 43 is provided, paper is fed from the same edge reversing mechanism 21 to the front side of the apparatus main body 101 in response to the presence / absence of the remaining detection of the paper P in the paper feed tray 1c, abnormal occurrence of jamming, or the like. The drawer of the tray 1c can be restricted. Accordingly, it is possible to limit the pull-out of the paper feed tray 1c when there is a residual detection of the paper P and the jam occurrence abnormally stops.

  This restriction is based on a configuration in which the same edge reversing mechanism 21 can be pulled out. Therefore, when the same edge reversing mechanism 21 is pulled out from the apparatus main body 101 and the paper feeding tray 1c is further pulled out from this state, the same edge is obtained. This is to reduce the load applied to the rail members 44a, 44b and the like (see FIG. 5) that support the reversing mechanism 21. It is possible to prevent the apparatus body 101 from falling to the near side.

  Here, with reference to FIG. 4, an example of pulling out the paper feed tray 1c in the same edge reversing mechanism 21 will be described. According to the same edge reversing mechanism 21 shown in FIG. 4, a handle 81 is provided on the paper feed tray 1c. In the release mechanism 43 shown in FIG. 3, when the stopper 41 is opened and the handle 81 of the paper feed tray 1c is pulled forward, the paper feed tray 1c held by the rail members 22a and 22b is slidable. It can be pulled out to the near side of the part 101.

  According to the same edge reversing unit 201, the paper P can be replenished in the paper feed tray 1c pulled out from the same edge reversing mechanism 21 in a predetermined direction. In addition, when another sheet feeding tray 1a, 1b, etc. is selected and the printing operation is executed, the printing operation can be continued.

  Next, an example of pulling out the same edge reversing mechanism 21 in the image forming apparatus 100 will be described with reference to FIG. In this example, the image forming unit 6 is provided in the apparatus main body 101 and the same edge reversing unit 201 is mounted. The same edge reversing mechanism 21 is unitized, and a frame member (not shown) of the apparatus main body 101 is provided. ) Are fixedly attached to fixing rail members 44a and 44b constituting an example of the sliding member. The rail members 44a and 44b are configured to hold the same edge reversing unit 201 slidably. A slide rail is used as the sliding member.

  A roller member (not shown) is rotatably attached to both outer sides of the same edge reversing unit 201. The roller members are engaged with the corresponding movable rail members 45a and 45b on both outer sides of the same edge reversing unit 201, and the rail members 45a and 45b respectively correspond to the rail members 44a and 44b of the apparatus main body. And are movably engaged. Rail members 45a and 45b constitute another example of a sliding member.

  Further, a stopper 51 constituting an example of a movement limiting member is provided on one outer side of the same edge reversing unit 201. The stopper 51 restricts the movement of the same edge reversing unit 201 in the predetermined direction, in this example, the front side (predetermined direction) of the apparatus main body 101. Also, a release mechanism 53 that releases the function of the stopper 51 is provided. The release mechanism 53 is provided on the back side of the rail member 44a for fixing the apparatus main body 101, for example. When the stopper 51 is provided on the other side of the same edge reversing unit 201, a release mechanism 53 is also provided on the inner side of the fixing rail member 44b of the apparatus main body 101 (not shown).

  For the release mechanism 53, for example, a solenoid (electromagnet) is used. The solenoid is controlled so as to lock the stopper 51 and open the stopper 51 based on the tray control signal. When the same edge reversing mechanism 21 needs to be pulled out, the same edge reversing mechanism 21 + paper feed tray 1c can be pulled out from the apparatus main body 101 as shown in FIG.

  In the hatched area in FIG. 5, mechanical parts constituting the circulation refeeding path 26 are arranged. However, in order to make the explanation of the same edge reversing mechanism 21 easy to understand, the description of the part is omitted. . When such a release mechanism 53 is provided, in response to the presence / absence of the remaining detection of the paper P in the same edge reversing unit 201, the abnormal occurrence stoppage of the jam, etc., the same end reversing unit 201 is moved to the front side from the apparatus main body 101. It will be possible to limit the drawer.

  Accordingly, the withdrawal of the same edge reversing unit 201 can be restricted except when jamming abnormally stops. In the same edge reversing unit 201 that is independently pulled out from the apparatus main body 101 to the front side, the same edge reversing mechanism 21 and the like can be inspected and maintained.

  Next, configuration examples (Nos. 1 and 2) of the transport driving unit 23 in the same edge reversing mechanism 21 will be described with reference to FIGS. 6 and 7. The transport driving unit 23 shown in FIG. 6 operates to pull the paper P into the same edge reversing mechanism 21 and to send out the paper P that has been turned upside down in the reverse transport path 24. In the same edge reversing mechanism 21, in addition to the drawing rollers 13 and 14 and the drawing rollers 15 and 16 constituting the conveyance driving unit 23, a belt driving mechanism 305 having a motor 33 and a predetermined belt or pulley is disposed. .

  In this example, the drawing roller 13 includes a driving roller 13 a and a driven roller 13 b for drawing the paper P received from the circulation refeeding path 26 into the same edge reversing mechanism 21. The driving roller 13 a is provided with a rotating shaft 301, and a driving pulley 302 is attached to the rotating shaft 301. The motor 33 is attached to the side facing the reverse conveyance path 24 side. For example, a DC motor is used as the motor 33.

  The motor 33 has a rotating shaft 303, and a motor pulley 304 is attached to the rotating shaft 303. The motor pulley 304 is engaged with the belt drive mechanism 305. The belt driving mechanism 305 is engaged with the driving pulley 302 of the driving roller 13a. When the motor 33 rotates in a predetermined direction, the rotational force of the motor 33 rotates the drive roller 13a via the belt drive mechanism 305. Thereby, the drawing roller 13 can be driven in a predetermined direction. The drawing roller 14 is configured in the same manner as the drawing roller 13.

  Further, the drawing roller 15 is composed of a driving roller 15a and a driven roller 15b to send out the paper P after being reversed from the inside of the same edge reversing mechanism 21 and transport it to the refeed path 27. Since the mechanism and method for transmitting to the drive roller 15a are configured in the same manner as the pull-in roller 13, the description thereof is omitted. The drawing roller 16 is configured in the same manner as the drawing roller 15.

  When the drawing rollers 13 and 14 and the drawing rollers 15 and 16 are independently driven, three other motors corresponding to the motor 33 are provided inside the same edge reversing mechanism 21. When the two drawing rollers 13 and 14 are simultaneously driven and the two drawing rollers 15 and 16 are simultaneously driven, two motors are reduced. When driving the drawing rollers 13 and 14 and the drawing rollers 15 and 16 simultaneously, the number of motors is reduced to one.

  7 is provided in an internal area defined by the side frames 21a and 21b by the same edge reversing mechanism 21, and in this internal area, a feed roller 31 and a receiving roller 32 constituting the transport drive section 23 are provided. In addition, motors 34 and 35 are arranged.

  In this example, the feed roller 31 is composed of a driving roller 31a and a driven roller 31b, and feeds the paper P in the paper transport direction X substantially orthogonal to the paper transport direction Y and transports it into the reverse transport path 24 (see FIG. 6). To be made. The driving roller 31 a is provided with a rotating shaft 311, and a driving gear 312 is attached to the rotating shaft 311. The motor 34 is attached inside the same edge reversing mechanism 21 along the reversing conveyance path 24. For example, a DC motor is used as the motor 34.

  The motor 34 has a rotation shaft 313, and a motor gear 314 is attached to the rotation shaft 313. The motor gear 314 is engaged with the drive gear 312. When the motor 34 rotates in a predetermined direction, the rotational force of the motor 34 is transmitted to the drive gear 312 to rotate the drive roller 13a. The motor 34 can drive the feed roller 31 in a predetermined direction.

  The receiving roller 32 includes a driving roller 32a and a driven roller 32b for receiving the paper P that is reversed from the reverse conveying path 24. The receiving roller 32 transmits the motor rotational force of the motor 35 to the driving roller 32a. Since the mechanism and the method thereof are configured in the same manner as the delivery roller 31, description thereof is omitted. The drawing rollers 13 and 14 and the delivery roller 31 described above constitute a first sheet conveying unit, and the receiving roller 32 and the drawing rollers 15 and 16 constitute a second sheet conveying unit. Thus, a conveyance driving unit 23 that drives the first and second sheet conveying units is configured.

  Next, an example of paper conveyance in the same edge reversing unit 201 will be described with reference to FIG. According to the example of paper conveyance in the same edge reversing unit 201 shown in FIG. 8, when paper is fed from the paper feed tray 1c to the image forming unit 6 shown in FIG. 1, the feed roller 2c shown in FIG. The sheet P is fed out from 1c in the direction of the black arrow Ia shown in FIG.

  The paper P fed out from the paper feed tray 1c joins the paper feed path 10 shown in FIG. Thereafter, the sheet P is conveyed upward in the vertical portion of the sheet feeding path 10, that is, in the direction of the black arrow Ib in the drawing, and reaches the uppermost sheet conveying path 28. The paper transport path 28 is composed of a horizontal portion of the paper feed path 10 and a paper discharge path 18. When paper is fed to the image forming unit 6 from an external large-capacity paper feeder or the like, the paper P is transported to the paper transport path 28 from the direction of the black arrow Ic in the drawing.

  In addition, the paper transport direction of the paper P differs depending on the image forming mode. For example, when the single-sided printing mode is set, the paper P that has reached the paper transport path 28 is transported in the direction of white arrows (1) → (2) → (3) in the drawing. During this time, an image is formed by the image forming unit 6, and thereafter, fixing processing is performed, and the paper reaches the paper discharge path 18 and is discharged. This conveying method is the same as in the conventional example.

  In this image forming apparatus 100, when the double-sided printing mode is set, the paper P that has reached the paper transport path 28 forms an image on the first surface (front surface) of the paper P in the same manner as the single-sided printing mode. Then, it is conveyed in the direction of the white arrow (1) → (2) → (3). In the double-sided printing mode, the paper P after the fixing process is not discharged and is guided to the circulation refeed path 26 in the figure, and the white arrows (4) → (5) → (6) → (7) → (8) → (2) → (3) In the direction of (conveyance) is conveyed.

  A portion indicated by a white arrow (4) is a sheet conveyance path in a vertical portion of the circulation refeed path 26. A white arrow (5) indicates a horizontal sheet conveyance path of the circulation refeed path 26 and reaches the entrance of the same edge reversing mechanism 21. The white arrow (6) indicates the reverse conveyance path 24 of the same edge reverse mechanism 21. The same edge reversing mechanism 21 pulls in the paper P from the front end side, reverses the paper P, and discharges the paper P from the same front end side as that at the time of drawing.

  A white arrow (7) indicates a sheet conveyance path in a horizontal portion of the refeed path 27, and starts from the exit of the same edge reversing mechanism 21. A portion indicated by a white arrow (8) is a sheet conveyance path in a vertical portion of the refeed path 27. The re-feeding path 27 joins the feeding path 10. In the same edge reversing unit 201, the paper P is conveyed by the above-described path.

  Next, with reference to FIGS. 9 to 11, an operation example (Nos. 1 to 3) of the same edge reversing unit 201 will be described. In this example, after the image is formed on the surface of the paper P by the image forming unit 6, the fixing process is performed, and the fixed paper P is conveyed to the circulation refeeding path 26 and is transferred from the circulation refeeding path 26 to the same edge reversing unit. It is assumed that the paper P is pulled into the 201 and the paper P that has been turned upside down by the reversing conveyance path 24 is sent out to the refeed path 27 and an image is formed on the paper P that has been turned upside down by the image forming unit 6. I will explain. In the figure, the white arrow is the conveyance direction of the paper P.

  Under these operating conditions, in the same edge reversing mechanism 21 viewed from the bottom side of the same edge reversing unit 201 shown in FIG. 9, the paper P conveyed from the circulation refeed path 26 (paper conveying direction Y) It is taken into the same edge reversing mechanism 21 from the bottom side of the unit 201.

  At this time, in the same edge reversing mechanism 21, the nip between the driving roller 31a and the driven roller 31b constituting the feeding roller 31 is released. The nip is formed, for example, by pressing the driven roller 31b against the driving roller 31a by a lift mechanism (not shown) and coming into contact with the driving roller 31a. The nip is released by, for example, pushing up the driven roller 31b by a motor-driven lift mechanism.

  In this state, a nip between the driving roller 13a and the driven roller 13b constituting the pulling roller 13 is formed, and similarly, a nip of the pulling roller 14 is formed and driven and conveyed from the circulation refeed path 26. The sheet P in the face-down state after image formation (fixing) is taken into the bottom side of the same edge reversing mechanism 21.

  Thereafter, in the same edge reversing unit 201 viewed from the side surface side of the same edge reversing mechanism 21 shown in FIG. 10A, the paper P taken into the bottom surface side of the same edge reversing mechanism 21 is sent to the reversing conveyance path 24. At this time, the nip between the driving roller 13a and the driven roller 13b constituting the drawing roller 13 is released, and similarly, the driving of the drawing roller 14 is released and the feeding roller 31 is driven, so that the conveyance direction of the paper P Is switched from the paper transport direction Y to the paper transport direction X.

  At this time, the feed roller 31 forms a nip between the driving roller 31a and the driven roller 31b, and the motor 34 rotates to feed the paper P in the paper transport direction X that is substantially orthogonal to the paper transport direction Y, and the reverse transport path. It is made to convey in 24 (refer FIG. 10A).

  In the reverse conveyance path 24, the conveyance direction of the paper P is gradually changed from the paper conveyance direction X to the paper conveyance direction Z, and after passing through the intermediate point, the conveyance direction of the paper P is gradually conveyed from the paper conveyance direction Z. The direction is changed to X.

  Then, in the same edge reversing unit 201 viewed from the side of the same edge reversing mechanism 21 shown in FIG. 10B, the paper P received from the reversing conveyance path 24 moves to the top surface side of the same edge reversing mechanism 21. At this time, in the same edge reversing mechanism 21, the nip between the driving roller 15a and the driven roller 15b constituting the drawing roller 15 is released, and similarly, the driving of the drawing roller 15 is also released.

  At this time, the receiving roller 32 forms a nip between the driving roller 32a and the driven roller 32b, and the motor 35 rotates, so that the sheet P is directed from the sheet conveying direction Z to the sheet conveying direction X at the exit of the reverse conveying path 24. Will be returned, but it will be in an inverted state (face-up state). The paper P is discharged from the same front end side as that at the time of drawing.

  After that, in the same edge reversing unit 201 viewed from the top plate surface side of the same edge reversing mechanism 21 shown in FIG. 11, the paper P moves in the paper transport direction Y, that is, from the top surface side of the same edge reversing mechanism 21 to the refeed path 27. Discharged. At this time, in the same edge reversing unit 201, the nip of the receiving roller 32 is released, the nip of the driving roller 15a and the driven roller 15b constituting the pulling roller 15 is formed, and similarly, the nip of the pulling roller 16 is formed. The driven paper P in the face-up state after being turned upside down is conveyed from the same edge reversing unit 201 to the refeed path 27.

  The paper P in the face-up state after the front and back is reversed is fed again to the paper feed path 10 via the loop roller 17 shown in FIG. At this time, the face-up paper P is transported from the paper transport direction Y in the paper transport direction Z, and is transported again in the paper transport direction Y, so that the back surface of the image P is below the image forming unit 6. The paper P is set in the image forming unit 6 in the face-down state. In the image forming unit 6, an image is formed on the paper P in the face-down state. As a result, an image can be formed from the front end side of the second surface, which is the same as when the first surface image is formed, and an image can be formed on both sides of the paper P.

  As described above, according to the same edge reversing unit 201, when images are formed on the front and back sides of the paper P, the images can be written on the front and back sides of the paper P from the leading end side. Therefore, as compared with an image forming apparatus having a switchback type sheet reversing mechanism, the image writing position can be aligned on the front and back surfaces of the paper P so that they cannot be distinguished from each other, so that the image forming quality can be improved.

  Next, an example of the arrangement of the sheet detection sensors # 1 to # 6 in the same edge reversing unit 201 will be described with reference to FIG. In this example, five paper detection sensors # 1 to # 5 constituting an example of the detection member are used for jam detection, and the remaining one is used for detection of the presence of the paper P in the paper feed tray 1c.

  According to the same edge reversing unit 201 shown in FIG. 12, the paper detection sensor # 1 is arranged in the paper feed path 10 shown in FIG. 1, and is conveyed in the direction of the black arrow Ib shown in FIG. Detected paper P is detected. The paper detection sensor # 2 is arranged in the circulation refeed path 26 shown in the figure, and the fixed paper P is conveyed from the paper discharge path 18 to the circulation refeed path 26, and the whiteness shown in FIG. The paper P conveyed in the direction of the arrow (4) is detected.

  The paper detection sensor # 3 is disposed below the reversal conveyance path 24 of the same edge reversing mechanism 21, detects the paper P that has been conveyed to the same edge reversing mechanism 21 and arrives, and whether or not the paper P remains after the reversal of the paper starts. Is detected. The paper detection sensor # 4 is disposed above the reversal conveyance path 24, detects the paper P discharged from the same edge reversing mechanism 21, and detects whether or not the paper P remains after the paper discharge starts (FIG. The white arrow (7) vicinity shown in FIG. 8).

  The paper detection sensor # 5 is disposed between the paper refeed path 27 and the paper feed path 10, and detects the paper P that joins from the paper refeed path 27 to the paper feed path 10 (the white arrow shown in FIG. 8). (8) Near). The arrangement positions of the paper detection sensors # 1 to # 5 are not limited to these, and may be any place (position) where the jam in the same edge reversing mechanism 21 can be accurately determined.

  The paper detection sensor # 6 is arranged in the paper feed tray 1c or in the outer periphery of the paper feed tray 1c, and detects the presence or absence of the paper P stored in the paper feed tray 1c. As the sheet detection sensors # 1 to # 6, an optical sensor such as a reflection type or a transmission type is used. As a result, the six paper detection sensors # 1 to # 6 are arranged, and the presence / absence of the paper P in the same edge reversing unit 201 can be detected at a predetermined position. Since the presence / absence of the sheet P passing through the reverse conveyance path 24 and the sheet conveyance path 28 can be detected at a predetermined position, it is possible to determine the occurrence of the jam of the sheet P.

  Next, a configuration example of a control system in the same edge reversing unit 201 will be described with reference to FIG. The control system in the same edge reversing unit 201 shown in FIG. 13 includes six sheet detection sensors # 1 to # 6, a motor drive unit 38, a tray lock drive unit 48, a control unit 55, and a unit lock drive unit 58. Configured.

  The paper detection sensor # 1 is connected to the control unit 55, detects the paper P stagnated in the refeed path 27, the paper feed path 10 and the like, and generates a paper detection signal S1. The paper detection signal S1 is output from the paper detection sensor # 1 to the control unit 55. The sheet detection sensor # 2 is connected to the control unit 55, detects the sheet P stagnated in the circulation refeed path 26, and generates a sheet detection signal S2. The paper detection signal S2 is output from the paper detection sensor # 2 to the control unit 55.

  The paper detection sensor # 3 is connected to the control unit 55 and detects the paper P that has not reached the same edge reversing mechanism 21 or the paper P stagnating in the same edge reversing mechanism 21 and generates a paper detection signal S3. The paper detection signal S3 is output from the paper detection sensor # 3 to the control unit 55. The sheet detection sensor # 4 is connected to the control unit 55, detects the undischarged sheet P from the same edge reversing mechanism 21 to the refeed path 27, and generates a sheet detection signal S4. The paper detection signal S4 is output from the paper detection sensor # 4 to the control unit 55.

  The paper detection sensor # 5 is connected to the control unit 55 and detects the paper P stagnated in the refeed path 27 or at the junction between the refeed path 27 and the paper feed path 10 to detect the paper detection signal. S5 is generated. The paper detection signal S5 is output from the paper detection sensor # 5 to the control unit 55. The paper detection sensor # 6 is connected to the control unit 55, detects the presence or absence of the paper P stored in the paper feed tray 1c, and generates a paper detection signal S6. The paper detection signal S6 is output from the paper feed tray 1c to the control unit 55.

  The motor drive unit 38 is connected to the control unit 55, and controls the three motors 33 to 35 based on the motor drive data D38. The motor drive unit 38 decodes the motor drive data D38 and generates motor control signals S33, S34, and S35, respectively. The motor control signal S33 is output to the motor 33, the motor control signal S34 is output to the motor 34, and the motor control signal S35 is output to the motor 35.

  In this example, when the motor 33 rotates in a predetermined direction based on the motor control signal S33, the belt driving mechanism 305 shown in FIG. 6 rotates, and the drawing roller 13 (the driving roller 13a and the driven roller 13b) and the drawing roller are rotated. 15 (drive roller 15a, driven roller 15b) rotates. When the motor 34 rotates in a predetermined direction based on the motor control signal S34, the drive gear 312 meshed with the motor gear 314 shown in FIG. 7 rotates, and the delivery roller 31 (drive roller 31a and driven roller 31b) rotates. . When the motor 35 rotates in a predetermined direction based on the motor control signal S35, the receiving roller 32 (the driving roller 32a and the driven roller 32b) shown in FIG. 7 rotates.

  The tray lock drive unit 48 is connected to the control unit 55 and controls the release mechanism 43 based on the solenoid drive data D48. The tray lock drive unit 48 decodes the solenoid drive data D48 and generates a solenoid control signal S48. The solenoid control signal S48 is output to a solenoid (not shown) of the release mechanism 43.

  The unit lock drive unit 58 is connected to the control unit 55 and controls the release mechanism 53 based on the solenoid drive data D58. The unit lock drive unit 58 decodes the solenoid drive data D58 and generates a solenoid control signal S58. The solenoid control signal S58 is output to a solenoid (not shown) of the release mechanism 53.

  The control unit 55 outputs motor drive data D38 to the motor drive unit 38, outputs solenoid drive data D48 to the tray lock drive unit 48, outputs solenoid drive data D58 to the unit lock drive unit 58, and the same edge reversing mechanism 21. The input / output of the motor drive unit 38, the tray lock drive unit 48, and the unit lock drive unit 58 is controlled in accordance with the jam in the printer and the presence or absence of the paper P in the paper feed tray 1c. Thus, a control system of the same edge reversing unit 201 is configured.

  Next, a control example in the same edge reversing unit 201 will be described with reference to FIG. In this embodiment, in order to deal with the occurrence of a jam, the detection of the outputs of the six sheet detection sensors # 1 to # 6 is started in the normal operation mode, and the stagnation of the sheet P in the same edge reversing unit 201 is monitored. . In this example, an example is given in which control branches in response to the outputs of the paper detection sensors # 1 to # 6.

  Under these control conditions, the control unit 55 monitors the sensor output in step ST1 of the flowchart shown in FIG. This sensor output monitoring is for detecting an abnormality in the same edge reversing mechanism 21. In this example, the paper detection sensor # 1 arranged in the paper feed path 10 shown in FIG. 1 detects the paper P conveyed in the direction of the black arrow Ib shown in FIG. 12, and controls the paper detection signal S1. To the unit 55. The sheet detection sensor # 2 disposed in the circulation refeed path 26 detects the fixed sheet P conveyed from the sheet discharge path 18 to the circulation refeed path 26, and sends a sheet detection signal S2 to the control unit 55. Output to.

  The sheet detection sensor # 3 disposed below the reversal conveyance path 24 of the same edge reversing mechanism 21 shown in FIG. 12 detects the paper P that has been conveyed to the same edge reversing mechanism 21 and arrived, and after the reversal of the paper starts, The presence or absence of the remaining paper P is detected, and a paper detection signal S3 is output to the control unit 55. Further, the sheet detection sensor # 4 arranged at the upper portion of the reverse conveyance path 24 shown in FIG. 3 detects the sheet P discharged from the same edge reversing mechanism 21, and after the sheet discharge starts, the sheet P The sheet detection signal S4 is output to the control unit 55.

  Further, the sheet detection sensor # 5 disposed between the refeed path 27 and the sheet feed path 10 detects the sheet P that joins from the refeed path 27 to the sheet feed path 10, and detects a sheet detection signal S5. Is output to the control unit 55. The paper detection sensor # 6 arranged in the paper feed tray 1c or in the outer periphery of the paper feed tray 1c detects the presence or absence of the paper P stored in the paper feed tray 1c, and controls the paper detection signal S6. To the unit 55.

  In step ST2, the control unit 55 branches the control based on whether or not the stagnation of the paper P is detected in the same edge reversing mechanism 21. In this case, the determination criterion is to compare the signal levels of the sheet detection signals S1 to S5 output from the five sheet detection sensors # 1 to # 5 with the threshold level that is the determination criterion, and determine the threshold level of the determination criterion. It is recognized that the paper P is stagnant at any of the placement positions of the paper detection sensors # 1 to # 5 that output a signal level exceeding the signal level.

  None of the five paper detection sensors # 1 to # 5 outputs the paper detection signals S1 to S5 exceeding the threshold level of the judgment standard, and it is detected that the paper P is not stagnated in the same edge reversing mechanism 21. In step ST3, the control unit 55 permits the operation of pulling out the paper feed tray 1c.

  At this time, the control unit 55 outputs solenoid drive data D48 indicating release of the tray lock to the tray lock drive unit 48. The tray lock driving unit 48 decodes the solenoid driving data D48 and generates a solenoid control signal S48 indicating unlocking. The solenoid control signal S48 is output to a solenoid (not shown) of the release mechanism 43. The solenoid of the release mechanism 43 releases the lock of the stopper 41 based on the solenoid control signal S48. As a result, the paper feed tray 1c can be pulled out from the same edge reversing mechanism 21, and the paper P can be replenished.

  The control unit 55 outputs solenoid drive data D58 indicating that the unit lock is not released to the unit lock drive unit 58. The unit lock drive unit 58 controls the release mechanism 53 based on the solenoid drive data D58. The unit lock drive unit 58 decodes the solenoid drive data D58 and generates a solenoid control signal S58 indicating that lock is not released.

  The solenoid of the release mechanism 53 maintains the locked state of the stopper 51 based on the solenoid control signal S58. Accordingly, the withdrawal of the same edge reversing unit 201 is not permitted, and the state where the same edge reversing unit 201 cannot be pulled out from the apparatus main body 101 is maintained. Thereafter, the process proceeds to step ST5.

  When the paper P is detected in the same edge reversing mechanism 21 in the above-described step ST2, that is, any one of the five paper detection sensors # 1 to # 5 is a paper detection signal that exceeds the threshold level of the determination criterion. When S1 to S5 are output and it is detected that the paper P is stagnating in the same edge reversing mechanism 21, the drawer operation of the paper feed tray 1c + same edge reversing mechanism 21 is permitted in step ST4.

  The control unit 55 outputs solenoid drive data D58 indicating unit lock release to the unit lock drive unit 58. The unit lock drive unit 58 controls the release mechanism 53 based on the solenoid drive data D58. The unit lock driving unit 58 decodes the solenoid driving data D58 and generates a solenoid control signal S58 indicating unlocking. The solenoid of the release mechanism 53 releases the locked state of the stopper 51 based on the solenoid control signal S58. As a result, the same edge reversing unit 201 can be pulled out from the apparatus main body 101, and jam processing can be executed.

  The control unit 55 outputs solenoid drive data D48 indicating that the tray lock is not released to the tray lock drive unit 48. The tray lock drive unit 48 controls the release mechanism 43 based on the solenoid drive data D48. The tray lock drive unit 48 decodes the solenoid drive data D48 and generates a solenoid control signal S48 indicating that lock is not released.

  The solenoid of the release mechanism 43 maintains the locked state of the stopper 41 as it is based on the solenoid control signal S48. Thereby, the drawer of the paper feed tray 1c is not permitted, and the state where the paper feed tray 1c cannot be pulled out from the same edge reversing mechanism 21 is maintained. Thereafter, the process proceeds to step ST5.

  Thereafter, in step ST5, the control unit 55 determines the end of the jam processing. The criterion for determining the end of the jam processing is based on the output of a return sensor (not shown). The return sensor detects, for example, whether or not the same edge reversing unit 201 has been stored in the apparatus main body 101. While the same edge reversing unit 201 is being pulled out from the apparatus main body 101, a high level return detection is performed. The signal is output to the control unit 55. When the same edge reversing unit 201 is housed (set) in the apparatus main body 101, a low level return detection signal is output to the control unit 55. The control unit 55 continues control based on the signal level of the return detection signal.

When the control unit 55 receives the low level return detection signal and recognizes the end of the jam processing, the control unit 55 returns to the normal operation mode in step ST6. In the normal operation mode, the paper P is fed out from the selected paper feed tray 1c and conveyed to the image forming unit 6. The image forming unit 6 forms an image on the paper P. Thereafter, processing such as fixing is performed.
As described above, according to the image forming apparatus 100 as the first embodiment, the same edge reversing unit 201 is provided, and the paper P received from the predetermined sheet conveying direction is reversed and output. When the paper feed tray 1c in the unit 201 is selected, the same edge reversing mechanism 21 reverses the paper P fed from the paper feed tray 1c.

  With this structure, the space area defined by the sheet conveying structure having a U-shaped cross section can be effectively used as an area for storing the paper P. Thereby, the enlargement of the image forming apparatus 100 equipped with the same edge reversing unit 201 is hindered, and the downsizing can be achieved.

  Next, a configuration example of the image forming apparatus 200 as the second embodiment will be described with reference to FIG. In this embodiment, not only one sheet feeding tray 1c but also a plurality of sheet feeding trays 1d and 1e together with the sheet feeding tray 1c are U-shaped sheet conveying structures of the same edge reversing unit 201 shown in FIG. Is provided in a space area defined by the above, and stores the paper P.

  An image forming apparatus 200 shown in FIG. 15 includes a sheet conveying apparatus according to the present invention, and forms a black and white or color printer that forms an image on both sides of a predetermined sheet P based on a double-sided printing mode. It can be applied to a multifunction machine or the like. The image forming apparatus 200 has an apparatus main body 102. In the center of the apparatus main body 102, there is provided a same edge reversing unit 202 that constitutes an example of a sheet reversing unit, and operates to reverse the paper-P after image formation.

  In the same edge reversing unit 202, a plurality of paper feed trays 1c to 1e constituting an example of a sheet storage member are mounted, and a paper P of a predetermined size is stored and operates to feed the paper P. . The paper feed tray 1c has a feed roller 2c, the paper feed tray 1d has a feed roller 2d, and the paper feed tray 1e has a feed roller 2e. The same edge reversing unit 202 uses the sheet conveying apparatus according to the present invention.

  As for the periphery of the same edge reversing unit 202, as in the first embodiment, a sheet feeding unit 1, an image forming unit 6, a fixing unit 8, a sheet feeding path 10, a sheet discharging path 18, a circulation re-feed (not shown). A paper path 26 and a refeed path 27 are provided, but the description thereof is omitted. Also in this example, the sheet P after fixing branched from the paper discharge path 18 shown in FIG. 1 operates so as to be guided to the same edge reversing unit 202 via the conveying rollers 11 and 12 shown in FIG.

  The same edge reversing unit 202 operates to reverse the paper P after image formation (fixing) received from the circulation refeed path 26 (predetermined paper transport direction). The same edge reversing unit 202 includes the same edge reversing mechanism 61 and the transport driving unit 23. The transport driving unit 23 has the same configuration as that of the first embodiment, and thus the description thereof is omitted. The same edge reversing unit 202 operates to re-feed the paper P that has been turned upside down to the image forming unit 6 via the loop roller 17 shown in FIG. These constitute the image forming apparatus 200.

  Next, an example of the internal configuration of the same edge reversing unit 202 and a mounting example of the same edge reversing unit 202 in the image forming apparatus 200 will be described with reference to FIGS. 16 and 17. The same edge reversing unit 202 shown in FIG. 16 is mounted below the apparatus main body 102 shown in FIG. 17, and is received from the circulation refeed path 26 (sheet transport direction; hereinafter referred to as paper transport direction Y) shown in FIG. It operates so that the paper P after image formation is reversed and output to the image forming unit 6.

  The same edge reversing unit 202 includes a same edge reversing mechanism 61, a transport driving unit 23, and a reversing transport path 64. The reverse conveyance path 64 has a sheet conveyance structure having a U-shaped cross section. Compared to the first embodiment, the same edge reversing mechanism 61 has a box-like shape including a U-shaped side portion along the sheet conveying structure of the reversing conveying path 64 in order to take a wider space area. Yes. The same edge reversing mechanism 61 has a reversal conveyance path 64 in the paper conveyance direction X substantially orthogonal to the paper conveyance direction Y and reverses the paper P.

  As shown in FIG. 16, the paper feed tray 1 c is provided in a space area defined by a sheet conveying structure having a U-shaped cross section of the same edge reversing mechanism 61 and stores the paper P. The paper feed tray 1d is provided below the paper feed tray 1c and in the space area shown in FIG. The paper feed tray 1e is provided below the paper feed tray 1d and in the space area shown in FIG.

  The same edge reversing mechanism 61 shown in FIG. 16 is provided with U-shaped side portions (hereinafter referred to as side frames 61 a and 61 b) on both sides of the reversing conveyance path 64. As shown in FIG. 17, fixing rail members 42 a and 42 b constituting an example of a sliding member are respectively attached to the inside of the side frames 61 a and 61 b. The rail members 42a and 42b are configured to slidably hold the paper feed tray 1c. A slide rail is used as the sliding member.

  Roller members (not shown) are rotatably attached to both outer sides of the paper feed tray 1c. The roller members are engaged with the corresponding movable rail members 42a and 42b on both outer sides of the paper feed tray 1c, and the rail members 42a and 42b are respectively connected to the rail members 42a and 22b of the side frames 61a and 61b. Each is engaged and movably engaged. The rail members 42a and 42b constitute another example of the sliding member. The other paper feed trays 1d and 1e are similarly configured.

  Moreover, a stopper 41 that constitutes an example of a movement limiting member is provided outside one of the paper feed trays 1c, although not shown. The stopper 41 restricts the movement of the paper feed tray 1c in a predetermined direction, in this example, the front side (predetermined direction) of the apparatus main body 102. In this example, a release mechanism 43 that releases the function of the stopper 41 is provided. The release mechanism 43 is provided, for example, on the back side of the rail member 42a for fixing the same edge reversing mechanism 61. When the stopper 41 is provided on the other side of the paper feed tray 1c, a release mechanism 43 is also provided on the back side of the rail member 42b for fixing the same edge reversing mechanism 61 (see FIG. 4). The other paper feed trays 1d and 1e are similarly configured.

  As in the first embodiment, a solenoid (electromagnet) is used for the release mechanism 43 of each of the paper feed trays 1c to 1e. The solenoid is controlled to lock the stopper 41 and open the stopper 41 based on the tray control signal. When such a release mechanism 43 is provided in each of the paper feed trays 1c to 1e, the same edge reversing mechanism 61 detects that the paper P in the paper feed trays 1c to 1e has been detected, jammed abnormally stopped, or the like. The drawers of the paper feed trays 1c to 1e to the front side of the apparatus main body 102 can be restricted. Accordingly, it is possible to limit the pull-out of the paper feed trays 1c to 1e when there is a residual detection of the paper P and jamming abnormally stops.

  This restriction is such that the same edge reversing mechanism 61 can be pulled out, so that the same edge reversing mechanism 61 is pulled out from the apparatus main body 102, and the paper feed tray 1c, 1d or 1e is further pulled out from this state. This is to reduce the load applied to the rail members 44a, 44b and the like (see FIG. 19) that support the same edge reversing mechanism 61. It is possible to prevent the apparatus main body 102 from falling to the near side.

  Next, an example of pulling out the paper feed tray 1c in the same edge reversing unit 202 will be described with reference to FIG. According to the same edge reversing mechanism 61 shown in FIG. 18, the handle 81 is provided on the paper feed tray 1c and the like. In the release mechanism 43 as shown in FIG. 4, when the stopper 41 is opened and the handle 81 of the paper feed tray 1c is pulled forward, the paper feed tray 1c held by the rail members 42a and 42b is slidable. The main body 102 can be pulled out to the near side.

  According to the same edge reversing unit 202, the paper P can be replenished in the paper feed tray 1c or the like drawn out from the same edge reversing mechanism 61 in a predetermined direction. In addition, even when the other paper feed trays 1d and 1e are selected and the printing operation is executed, the printing operation can be continued.

  Next, with reference to FIG. 19, an example of pulling out the same edge reversing unit 202 in the image forming apparatus 200 will be described. In this example, the image forming unit 6 is provided in the apparatus main body 102 and the same edge reversing unit 202 is mounted. However, the same edge reversing mechanism 61 is unitized in the same manner as in the first embodiment, and the apparatus main body unit is provided. Fixing rail members 44a and 44b constituting an example of a sliding member are attached to a frame member 102 (not shown) correspondingly. The rail members 44a and 44b are configured to slidably hold the same edge reversing unit 202. A slide rail is used as the sliding member.

  A roller member (not shown) is rotatably attached to both outer sides of the same edge reversing unit 202. The roller members are engaged with the corresponding movable rail members 45 a and 45 b on both outer sides of the same edge reversing unit 202, and the rail members 45 a and 45 b are respectively connected to the rail members 44 a and 44 b of the apparatus main body 102. Corresponding and movably engaged. Rail members 45a and 45b constitute another example of a sliding member.

  Further, a stopper 51 constituting an example of a movement limiting member is provided on one outer side of the same edge reversing unit 202. The stopper 51 of the same edge reversing unit 202 restricts the movement of the same edge reversing unit 202 in a predetermined direction, in this example, the front side (predetermined direction) of the apparatus main body 102. Also, a release mechanism 53 that releases the function of the stopper 51 is provided. The release mechanism 53 is provided, for example, on the back side of the rail member 44a for fixing the apparatus main body 102 (see FIG. 5). When the stopper 51 is provided on the other side of the same edge reversing unit 202, a release mechanism 53 is also provided on the back side of the fixing rail member 44b of the apparatus main body 102 (not shown).

  For example, a solenoid (electromagnet) is also used for the release mechanism 53 of the same edge reversing unit 202. The solenoid is controlled so as to lock the stopper 51 and open the stopper 51 based on the tray control signal. When it is necessary to pull out the same edge reversing mechanism 61, the same edge reversing mechanism 61 + sheet feeding tray 1c + 1d + 1e can be pulled out from the apparatus main body 102 as shown in FIG.

  When such a release mechanism 53 is provided in the same edge reversing unit 202, the apparatus main body 102 moves from the apparatus main body 102 to the front side in response to the presence / absence of the remaining detection of the paper P in the same edge reversing unit 202, abnormal occurrence of jam, etc. The withdrawal of the same edge reversing unit 202 can be restricted. Accordingly, the withdrawal of the same edge reversing unit 202 can be restricted except when jamming abnormally stops. The same edge reversing mechanism 61 and the like can be inspected and maintained in the same edge reversing unit 202 pulled out from the apparatus main body 102 to the front side.

  As described above, according to the image forming apparatus 200 as the second embodiment, according to the image forming apparatus 200, the image forming unit 6 that forms an image on a predetermined surface of the paper P, and the paper P on the image forming unit 6. And the same edge reversing unit 202. The same edge reversing unit 202 is composed of any of the sheet conveying means according to the present invention, or a combination of these sheet conveying means.

  With this configuration, on the front and back surfaces of the paper P supplied from the paper feed tray 1c or the paper feed trays 1d and 1e provided in the space area defined by the sheet conveyance structure having a U-shaped cross section of the same edge reversing unit 202 An image can be formed. As a result, a compact image forming apparatus 200 equipped with the same edge reversing unit 202 can be provided.

  It should be noted that the above-described release mechanism 43, release mechanism 53, and the like have a pull-out amount adjustment function so that the pull-out amount of the paper feed trays 1c to 1e and the pull-out amount of the same edge reversing mechanism 202 + paper feed tray 1c + 1d + 1e can be varied. May be. In that case, the stopper 41, 51, etc. can be divided into several stages, and the withdrawal amount can be regulated in stages.

  This invention is provided with a same edge reversing mechanism that receives from the front end side of the sheet member and reverses the front and back, and outputs the sheet member from the same front end side as when pulling in, and based on the duplex printing mode, images are printed on both sides of a predetermined sheet of paper. The present invention is extremely suitable when applied to monochrome printers and color printers for forming the image forming apparatus, copying machines, multifunction machines, printing apparatuses, and the like.

# 1 to # 6 Paper detection sensor (detection member)
1 Paper Feed Unit 1c, 1d, 1e Paper Feed Tray (Sheet Storage Member)
2a, 2b, 2b, 2c, 2d, 2e Delivery rollers 3a, 3b, 3c, 4, 11, 12 Transport roller 5 Registration roller 6 Image forming unit 7 Transport belt 8 Fixing unit 9 Paper discharge roller 10 Paper feed path 11, 12 Conveyance roller 13, 14 Pull-in roller 15, 16 Pull-out roller 17 Loop roller 21, 61 Same edge reversing mechanism 22a, 22b, 44a, 44b, 45a, 45b Rail member (sliding member)
23 Conveyance Drive Units 24, 64 Reverse Conveyance Path 26 Circulation Refeed Path 27 Refeed Path 31 Feeding Roller (First Sheet Conveying Section)
32 Receiving roller (second sheet conveying unit)
33, 34, 35 Motor 41, 51 Stopper (movement limiting member)
43, 53 Release mechanism 100, 200 Image forming apparatus 101, 102 Apparatus main body 201, 202 Same edge reversing unit (sheet conveying means, sheet conveying apparatus)

Claims (10)

A sheet conveying apparatus that outputs a sheet member received from a predetermined sheet conveying direction by reversing the front and back,
The sheet member has a reverse conveyance path provided with a U-shaped sheet conveyance structure in a direction substantially orthogonal to the sheet conveyance direction, and a sheet conveyance path for conveying the sheet member in a horizontal direction. Same edge reversing mechanism to reverse
A sheet conveying apparatus comprising: a sheet storage member that is provided in a space region defined by the U-shaped sheet conveyance structure of the same edge reversing mechanism and that accommodates the sheet member. A transport drive unit that pulls the sheet member into the same edge reversing mechanism and sends out the sheet member after being reversed on the reverse transport path;
The transport driving unit is
A first sheet transport unit that pulls the sheet member received from the sheet transport direction into the same edge reversing mechanism and feeds the sheet member in a direction substantially perpendicular to the sheet transport direction and transports the sheet member into the reverse transport path;
A second sheet conveying unit that pulls out the sheet member from the reversing conveyance path and sends out the sheet member after reversing the front and back from within the same edge reversing mechanism,
The sheet conveying apparatus according to claim 1, further comprising a drive unit that drives the first and second sheet conveying units. The same edge reversing mechanism is
The sheet conveying apparatus according to claim 2, further comprising a sliding member that slidably holds the sheet storage member. In the sheet storage member,
The sheet conveying apparatus according to claim 3, wherein a detection member that detects the sheet member is provided at a predetermined position.   The sheet conveying apparatus according to claim 4, further comprising a movement restriction member that restricts movement of the sheet storage member in a predetermined direction. In the same edge reversing mechanism,
The sheet conveying apparatus according to claim 1, wherein a detection member that detects the sheet member is provided at a predetermined position in the reverse conveying path and the sheet conveying path. The same edge reversing mechanism is
The sheet conveying apparatus according to claim 6, wherein the sheet member is received from the leading end side of the sheet member, the sheet member is turned upside down, and the sheet member is output from the leading end side that is the same as that at the time of drawing. An image forming unit that forms an image on a predetermined surface of the sheet member;
Sheet conveying means for conveying the sheet member to the image forming unit,
8. The image forming apparatus according to claim 1, wherein the sheet conveying unit includes any one of the sheet conveying apparatuses according to claim 1 or a combination of these sheet conveying apparatuses. An apparatus main body for mounting the image forming unit and the sheet conveying apparatus;
The sheet conveying device is unitized,
The apparatus main body is
9. The image forming apparatus according to claim 8, further comprising a sliding member that slidably holds the unitized sheet conveying device.   The image forming apparatus according to claim 9, further comprising a movement restriction member that restricts movement of the sheet conveying apparatus in a predetermined direction.

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