JP6807044B2 - Sheet loading device and image forming device - Google Patents

Description

The present invention relates to a sheet loading device and an image forming device.

Conventionally, there is known a sheet loading device provided with a sheet reversing portion for reversing the sheet conveying direction above the sheet loading portion for loading the sheet.

In Patent Document 1, the sheet loading device is provided with a paper reversing part having a reversing tray for guiding the lower surface of the paper above the sheet discharging part which is a sheet loading part for loading sheets. Is described.

However, if the length of the reversing tray in the paper transport direction is shorter than the length of the paper in the paper transport direction, the tip end side of the paper pops out from the reversing tray and hangs down. When the tip side of the hanging paper comes into contact with the paper loaded on the paper ejection loading section, the alignment of the paper loaded on the paper ejection loading section may be disturbed, or the paper may be pushed out from the paper ejection loading section and dropped. There is a problem of doing so. On the other hand, if the length of the reversing tray in the paper transport direction is too long, the range in which the paper loaded on the paper ejection loading unit is covered by the reversing tray becomes large. Therefore, when the paper discharge loading section is viewed from above the reversing tray when using relatively small size paper, the paper loaded on the reversing tray is hidden by the reversing tray for visibility and removal. The problem arises that it gets worse.

In order to solve the above problems, the present invention forms a sheet loading section on which a sheet is loaded and a sheet transport path provided above the sheet loading section to reverse the transport direction of the fed sheet and deliver it. In the sheet loading device including the sheet reversing portion, the sheet reversing portion is downstream of the first guide member that guides the lower surface of the sheet and the first guide member in the direction in which the sheet is fed into the sheet reversing portion. A second guide member that guides the lower surface of the seat on the side and is detachably provided to the device body, a first guide cover member that covers the first guide member, and a second that is detachably provided to the device body. It is characterized by having a second guide cover member that covers the guide member .

As described above, according to the present invention, there is an excellent effect that it is possible to prevent the seats loaded on the seat loading portion from being disturbed or the seats being pushed out from the seat loading portion and dropped. ..

The schematic block diagram of the printer which concerns on embodiment. External perspective view of the printer. Explanatory drawing about the width of the paper transport path in a reversing part. Explanatory drawing about the height of the paper reversal path in a reversing part. The external perspective view of the printer with the inverting extension tray and the inverting extension top cover removed from the main body of the device. The figure which shows the state which the paper of a predetermined length or more is passed through the reversing part without the reversing extension tray and the reversing extension upper cover in the reversing part. The figure which shows the state which the paper of a predetermined length or more is passed through the reversing part with the reversing extension tray and the reversing extension upper cover in the reversing part. The schematic diagram of the attachment part of the inversion extension tray and the inversion extension upper cover with respect to the apparatus main body. The figure which showed the cross-sectional shape of the engaging part of the inverted engaging member of the inverted extension tray, and the engaged member of a device body. The figure which showed the method of attaching the inverting extension tray and the inverting extension top cover to the apparatus main body. The figure which showed the 2nd engaging part with respect to the apparatus main body of a reversing extension tray and a reversing extension upper cover. The schematic block diagram of the printer of the modification 1. The schematic block diagram of the printer of the modification 1 in the state where the inverting extension tray and the inverting extension top cover are removed. FIG. 3 is a cross-sectional view of the inverted portion of the printer and its vicinity in the state shown in FIG. FIG. 3 is a perspective view of the inverted portion of the printer and its vicinity in the state shown in FIG. FIG. 3 is a cross-sectional view of the reversing part of the printer of Modification 1 and its vicinity in a state where only the tip of the auxiliary tray is pulled out from the reversing tray. FIG. 6 is a perspective view of the inverted portion of the printer and its vicinity in the state shown in FIG. FIG. 3 is a cross-sectional view of the inverted portion of the printer of Modification 1 and its vicinity in a state where the tip portion of the auxiliary tray and the base portion of the auxiliary tray are pulled out from the inverted tray. A perspective view of the inverted portion of the printer and its vicinity in the state shown in FIG. The perspective view of the reversing part of the printer of the modification 1 and the vicinity thereof in the state before attaching the auxiliary tray. FIG. 3 is a cross-sectional view of the inverted portion of the printer of Modification 1 and its vicinity in a state where paper having a predetermined length or more is passed through the inverted portion in a state where the auxiliary tray is most retracted. FIG. 3 is a cross-sectional view of the inverted portion of the printer of Modification 1 and its vicinity in a state where paper P having a predetermined length or more is passed through the inverted portion in a state where the auxiliary tray is most extended. FIG. 2 is a perspective view of the inverted portion of the printer and its vicinity in the state shown in FIG. FIG. 3 is a cross-sectional view of the inverted portion of the printer of Modification 1 and its vicinity in a state where paper is passed through the inverted portion with the inverted extension tray and the inverted extension upper cover attached. FIG. 5 is a cross-sectional view of the inverted portion and its vicinity in a state where image formation is completed with the auxiliary tray extended most in the printer of the first modification. The perspective explanatory view which added the range covered with the inverting extension tray and the inverting extension cover to the perspective view of the printer of the modification 1 in the state where the auxiliary tray is most extended. The schematic block diagram of the printer of the modification 2. FIG. 3 is a cross-sectional view of the reversing part of the printer of Modification 2 and its vicinity in a state where only the reversing extension tray and the reversing extension upper cover are removed and only the tip of the auxiliary tray is pulled out from the reversing tray. FIG. 2 is a perspective view of the inverted portion of the printer and its vicinity in a state where the inverted upper cover is opened from the state shown in FIG. 28. FIG. 3 is a cross-sectional view of the inverted portion of the printer of Modification 2 and its vicinity in a state where the inverted extension tray and the inverted extension upper cover are attached. FIG. 30 is a perspective view of the inverted portion of the printer and its vicinity in a state where the inverted upper cover is opened from the state shown in FIG. The flowchart which shows the control flow of the printer of the modification 2 based on the detection result of the open / close sensor.

Hereinafter, embodiments in which the present invention is applied to a printer which is an electrophotographic image forming apparatus will be described. First, the basic configuration of the printer according to this embodiment will be described. FIG. 1 is a schematic configuration diagram showing a printer 100 which is an example of an image forming apparatus according to the present embodiment. The printer 100 includes photoconductor drums 10Y, 10M, 10C, and 10Bk as four image carriers arranged in the apparatus main body 1. A yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are formed on each of the photoconductor drums 10Y, 10M, 10C, and 10Bk, respectively. An intermediate transfer belt 25, which is an intermediate transfer body, is arranged so as to face the photoconductor drums 10Y, 10M, 10C, 10Bk, and each photoconductor drum 10Y, 10M, 10C, 10Bk comes into contact with the surface of the intermediate transfer belt 25. ing. The intermediate transfer belt 25 in this embodiment is rotatably stretched by a drive roller 31, a driven roller 33, and a tension roller 34.

The formation of the toner image on the photoconductor drums 10Y, 10M, 10C, 10Bk and the transfer of each toner image on the intermediate transfer belt 25 are substantially the same in each photoconductor drum 10Y, 10M, 10C, 10Bk. Yes, only the color of each toner image formed is different. Therefore, of the four photoconductor drums 10Y, 10M, 10C, and 10Bk, a configuration and an operation of forming a black toner image on the photoconductor drum 10Bk and transferring the black toner image onto the intermediate transfer belt 25 will be described.

The photoconductor drum 10Bk is rotationally driven in the clockwise direction in the drawing, and the surface of the photoconductor drum 10Bk is uniformly charged by the charging device 8Bk to a negative polarity which is a predetermined polarity. The surface of the photoconductor drum 10Bk charged in this way is irradiated with writing light from the exposure device 9 to form an electrostatic latent image corresponding to the image information. With the rotation of the photoconductor drum 10Bk, when the surface portion of the photoconductor drum 10Bk on which the electrostatic latent image is formed passes through the developing region facing the developing device 7Bk, the black toner in the developing device 7Bk The electrostatic latent image is developed and visualized as a black toner image. On the other hand, inside the intermediate transfer belt 25, the primary transfer roller 20Bk is arranged at a position facing the photoconductor drum 10Bk with the intermediate transfer belt 25 interposed therebetween. The primary transfer roller 20Bk abuts on the back surface of the intermediate transfer belt 25 to ensure an appropriate primary transfer nip between the photoconductor drum 10Bk and the intermediate transfer belt 25.

A positive polarity primary transfer voltage, which is opposite to the toner charging polarity of the black toner image formed on the surface of the photoconductor drum 10Bk, is applied to the primary transfer roller 20Bk. As a result, a transfer electric field is formed between the photoconductor drum 10Bk and the intermediate transfer belt 25, and a black toner image on the photoconductor drum 10Bk is formed on the intermediate transfer belt 25 which is rotationally driven in synchronization with the photoconductor drum 10Bk. Is electrostatically transferred. The transfer residual toner adhering to the surface of the photoconductor drum 10Bk after the black toner image is transferred onto the intermediate transfer belt 25 is removed by the cleaning device 11Bk, and the surface of the photoconductor drum 10Bk is cleaned.

Similarly, a yellow toner image, a magenta toner image, and a cyan toner image are formed on the other photoconductor drums 10Y, 10M, and 10C, and the toner image of each color is an intermediate transfer belt to which the black toner image is transferred. It is transferred on top of 25.

A paper cassette 400 that houses the paper P and a paper feed device 40 that feeds the paper P stored in the paper cassette 400 are arranged in the lower part of the main body 1. Then, by rotating the paper feed roller 41 provided in the paper feed device 40, the uppermost paper P housed in the paper feed cassette 400 is fed out. The paper P sent out from the paper feed cassette 400 in this way is sent to the resist roller pair 43 by the transport roller pair 42. Then, a resist roller pair 43 is formed between the portion of the intermediate transfer belt 25 wound around the drive roller 31 at a predetermined timing and the secondary transfer roller 32 of the secondary transfer device 30 arranged to face the intermediate transfer belt 25. It is sent to the secondary transfer nip. At this time, by applying a predetermined secondary transfer voltage to the secondary transfer roller 32, a transfer electric field is formed between the intermediate transfer belt 25 and the secondary transfer roller 32, and the toner image on the intermediate transfer belt 25 is displayed. Secondary transfer is performed on paper P.

The paper P on which the toner image is transferred is conveyed toward the fixing device 50 arranged above the secondary transfer nip. The fixing device 50 has a fixing roller 51 and a heating roller 52 that are in contact with each other, and when the paper P passes through the fixing nip formed by the fixing roller 51 and the heating roller 52, heat and pressure are applied. The toner image on the paper P is fixed on the paper P.

After that, the paper P on which the toner image is fixed is discharged to the discharge path provided in the upper part of the apparatus main body 1. At the time of forming a single-sided image in which an image is formed on only one side of the paper P, the paper transport path is switched by the switching claw 60 so that the paper P is sent to the paper ejection unit 70. The paper ejection unit 70 has a paper ejection roller pair 71 and a paper ejection tray 72, and the paper P sent to the paper ejection unit 70 is ejected to the paper ejection tray 72 by the paper ejection roller pair 71 and ejected. It is sequentially loaded on the paper tray 72.

An inversion tray 82 and an inversion extension tray 84 are installed above the output tray 72. The reversing tray 82 and the reversing extension tray 84 guide the lower surface of the paper P that is reversed by the reversing roller pair 81. The distance b from the reversing roller pair 81 to the end face of the reversing extension tray 84 in the paper transport direction in the reversing section 80 shown in FIG. 1 is longer than the length a in the paper transport direction of the paper feed cassette 400. The end surface of the reversing extension tray 84 coincides with the end surface of the apparatus main body in the vertical direction, and it is not necessary to move the apparatus main body 1 when the end direction is narrow in the installation space. An inverted upper cover 83 that covers the inverted tray 82 is provided above the inverted tray 82, and an inverted extension upper cover 85 that covers the inverted extension tray 84 is provided above the inverted extension tray 84. The reversing extension tray 84 and the reversing extension upper cover 85 are provided on the downstream side in the paper transport direction when the reversing tray enters, with respect to the reversing tray 82 and the reversing upper cover 83, respectively. The reversing extension tray 84 and the reversing extension upper cover 85 are parallel to the paper ejection direction in the paper ejection portion 70 of the apparatus main body 1 and are right side plate 1a with respect to the paper ejection direction, and the paper of the reversing tray 82 and the reversing upper cover 83. It is in contact with two L-shaped surfaces formed by the end surface on the downstream side in the transport direction. The reversing tray 82 and the reversing upper cover 83 are fixed to the device main body 1, and the reversing extension tray 84 and the reversing extension upper cover 85 are detachable from the device main body 1.

As shown in FIG. 2, the inversion upper cover 83 and the inversion extension upper cover 85 of the inversion portion 80 are configured to be flush with other upper surface portions of the printer 100 in the height direction of the printer 100. The size of the printer 100 can be reduced, and the size of the printer 100 can be reduced.

FIG. 3 is an explanatory diagram of the width of the paper reversing path in the reversing section 80. “Α” in FIG. 3 indicates the paper transport direction, and “β” in FIG. 3 indicates the paper width direction. The same applies to "α" and "β" in other drawings described later. The paper reversal path in the reversing section 80 is an upstream reversing path R1 formed by the reversing tray 82 and the reversing upper cover 83, and a downstream reversing path R2 formed by the reversing extension tray 84 and the reversing extension upper cover 85. It is composed of and. The width W1 of the upstream reversing path R1 in the paper width direction is the distance between the side plates 821 and the side plates 822 provided on both sides of the reversing tray 82 in the paper width direction in the paper width direction, and is used by the printer 100. It is larger than the width W0 of the maximum size paper P possible. The width W2 of the downstream reversing path R2 in the paper width direction is the distance between the inner wall surfaces of the side plates 841 and the side plates 842 provided on both sides of the reversing extension tray 84 in the paper width direction, and is upstream. It is larger than the width W1 of the side inversion path R1. As a result, the tip of the paper P entering the downstream reversing path R1 from the upstream reversing path R1 abuts against the paper transport direction end surface 841a of the side plate 841 or the paper transport direction end surface 842a of the side plate 842, resulting in a transport defect. Can be suppressed. The width of the paper reversing path may be gradually widened at the connecting portion between the upstream reversing path R1 and the downstream reversing path R2 toward the downstream reversing path R2.

FIG. 4 is an explanatory diagram of the height of the paper reversing path in the reversing section 80. “Γ” in FIG. 4 indicates the height direction of the inverted portion. The height H1 of the upstream reversing path R1 which is the distance between the facing surface 823a of the guide plate 823 of the reversing tray 82 with the paper P and the facing surface 833a of the upper plate 833 of the reversing upper cover 83 with the paper P is , It is larger than the thickness t of the maximum thickness paper P that can be used in the printer 100. Further, the distance H2 between the facing surface 843a of the guide plate 843 of the reversing extension tray 84 with the paper P and the facing surface 853a of the upper plate 853 of the reversing extension upper cover 85 with the paper P is the distance of the upstream reversing path R1. Larger than H1. The facing surface 843a of the guide plate 843 is located lower than the facing surface 823a of the guide plate 823, and the facing surface 853a of the upper plate 853 is located higher than the facing surface 833a of the upper plate 833. There is. As a result, the tip of the paper P entering the downstream reversal path R1 from the upstream reversal path R1 abuts against the paper transport direction end face 843b of the guide plate 843, the paper transport direction end face 853b of the upper plate 853, and the like, resulting in poor transport. It can be suppressed from occurring.

In each of the reversing tray 82, the reversing upper cover 83, the reversing extension tray 84, and the reversing extension upper cover 85, the concavo-convex shape may be provided on the surfaces 823a, 833a, 843a, 853a facing the paper P. As the uneven shape, for example, as shown in FIG. 4, ribs 862, 863, 864, 865 extending in the paper transport direction are provided on the facing surfaces 823a, 833a, 843a, 853a, respectively, with a paper width orthogonal to the paper transport direction. It may be configured by arranging a plurality of them in the direction. As a result, the contact area of each of the reversing tray 82, the reversing upper cover 83, the reversing extension tray 84, and the reversing extension upper cover 85 with the paper P is made smaller than that in the case where the ribs 862, 863, 864, 865 are not provided, and the transport resistance is reduced. Can be reduced to improve paper transportability.

When the ribs 862, 863, 864, 865 are provided in this way, the height h1 of the upstream reversing path R1, which is the distance between the upper end of the rib of the reversing tray 82 and the lower end of the rib of the reversing upper cover 83, is set to the printer 100. It is made larger than the thickness t of the maximum thickness paper P that can be used in. Further, the height h2 of the downstream reversing path R2, which is the distance between the upper end of the rib of the reversing extension tray 84 and the lower end of the rib of the reversing extension upper cover 85, is made larger than the height h1 of the upstream reversing path R1. Then, the upper end of the rib of the reverse extension tray 84 is positioned below the upper end of the rib of the reverse tray 82, and the lower end of the rib of the reverse extension upper cover 85 is positioned higher than the lower end of the rib of the reverse upper cover 83. As a result, the tip of the paper P entering the downstream reversal path R1 from the upstream reversal path R1 abuts against the paper transport direction end face of the rib 864, the paper transport direction end face of the rib 865, and the like, causing a transport defect. Can be suppressed.

At the time of forming a double-sided image, the paper transport path is switched by the switching claw 60 as shown in FIG. 1, and the single-sided printed paper P is the reverse tray 82, the reverse upper cover 83, the reverse extension tray 84, and the reverse extension upper cover. It is conveyed to the reversing portion 80 formed by the 85. On the other hand, the double-sided printed paper P is conveyed to the paper ejection unit 70. That is, the paper P conveyed to the reversing section 80 is once discharged onto the reversing tray 82 and the reversing extension tray 84 with the rear end sandwiched by the reversing roller pair 81 as the reversing means. After that, the paper P is fed to the re-feeding path unit 90 by controlling the drive motor that rotationally drives the reversing roller pair 81 to rotate the reversing roller pair 81 in the reverse direction. Then, the paper P is fed to the transfer unit by the resist roller pair 43 in sequence via the transport roller pairs 91, 92, 93, 94, and the image is secondary from the intermediate transfer belt 25 on the back surface, which is the second surface of the paper P. Transcribed.

In this way, the reversing unit 80 can guide the lower surface of the paper and cover the upper surface of the paper in the entire length of the paper even when reversing the long paper P such as A3 size or DLT size (double letter size). Has a length. At the same time, by removing the reverse extension tray 84 and the reverse extension upper cover 85 with respect to the apparatus main body 1, the guide on the lower surface of the paper and the length that can cover the upper surface of the paper can be adjusted.

FIG. 5 is an external perspective view of the printer 100 in a state where the reverse extension tray 84 and the reverse extension upper cover 85 are removed from the apparatus main body 1. A hook hole 87a for hooking the reverse extension tray 84 and the reverse extension upper cover 85 is provided on the side plate 1a located parallel to the paper discharge direction in the paper discharge portion 70 of the apparatus main body 1 and located on the right side with respect to the paper discharge direction. It also has a through hole 87b below it. FIG. 6 is an enlarged cross-sectional view of the reversing portion 80 and its vicinity in a state where the reversing extension tray 84 and the reversing extension upper cover 85 are removed from the apparatus main body 1. As shown in FIG. 6, when the reverse extension tray 84 and the reverse extension upper cover 85 are removed from the apparatus main body 1, if the length of the reverse paper P2 in the transport direction is longer than the length of the reverse tray 82 in the paper transport direction, the reverse is reversed. The tip end side of the reversing paper P2 hangs down from the tray 82. Therefore, as shown in the area D surrounded by the broken line in FIG. 6, the tip of the reversing paper P2 may be in contact with the discharged paper P1 on the paper ejection tray 72. In the state where the reversing paper P2 can come into contact with the ejected paper P1 in this way, the paper alignment state of the ejected paper P1 is disturbed, or the ejected paper P1 is pushed out from the paper ejection tray 72 and dropped. Paper alignment failure occurs.

FIG. 7 is an enlarged view of the reversing portion 80 and its vicinity in a state where the reversing extension tray 84 and the reversing extension upper cover 85 are attached to the apparatus main body 1. It is a figure which shows the state which the paper P of a predetermined length or more which is longer than the reversing tray 82 in the paper transport direction is passed through the reversing part 80. As shown in FIG. 7, when the reversing extension tray 84 and the reversing extension upper cover 85 are attached to the apparatus main body 1, the length of the reversing portion 80 in the paper transport direction is extended as compared with FIG. Therefore, the lower surface of the paper can be guided by the reversing tray 82 and the reversing extension tray 84 in the entire length of the reversing paper P2 in the paper transport direction, and the tip end side of the reversing paper P2 does not hang down on the paper ejection tray 72. It is possible to prevent misalignment.

Further, in FIG. 6, the tip side of the reversing paper P2 is completely exposed from the reversing tray 82 and the reversing upper cover 83. Therefore, there is a possibility that the user pulls out the reversing paper P2 being reversed by the reversing unit 80. If the user pulls out the reversing paper P2 being reversed by the reversing unit 80, the image forming apparatus determines that a paper misconduct such as a paper jam has occurred in the reversing path, which causes an unexpected jam. Further, if the image forming apparatus has high productivity in which the number of images formed per unit time is large, the paper transport speed at the time of reversal is also increased. Therefore, there is a possibility that the user who sees the reversing paper P2 that protrudes from the reversing tray 82 and the reversing upper cover 83 at high speed and is exposed may feel uncomfortable.

On the other hand, by attaching the reverse extension tray 84 and the reverse extension upper cover 85 to the apparatus main body 1 as shown in FIG. 7, the reverse paper P2 being reversed by the reverse portion 80 is hidden from the user. Therefore, it is impossible for the user to pull out the paper during reversing by the reversing unit 80, and it is possible to prevent jams that may occur when the reversing paper P2 is pulled out. Further, since the tip end side of the reversing paper P2 does not protrude from the reversing portion 80 and is not exposed, it is possible to prevent the user from feeling uncomfortable when the reversing paper P2 pops out at high speed.

On the other hand, in the configuration of FIG. 6, the ejected paper P1 ejected to the output tray 72 can be visually recognized and taken out from any of the directions of arrow A, arrow B, and arrow C in the drawing. It is possible. On the other hand, by attaching the reversing extension tray 84 and the reversing extension upper cover 85 to the apparatus main body 1, as shown in FIG. 7, the paper is ejected on the paper ejection tray 72 from the direction of arrow A'in the drawing above the reversing portion 80. The visibility of the finished paper P1 deteriorates, and it becomes difficult to take out the ejected paper P1. Further, as shown in FIG. 7, when the total length of the ejected paper P1 is shorter than that of the inverted extension tray 84 that covers the upper part of the ejection tray 72, from the direction of arrow B'in the figure and the direction of arrow C'in the figure. Paper take-out property is also lowered.

On the other hand, when the relatively long paper P such as A3 size or DLT size (double letter size) is not passed, the reverse extension tray 84 and the reverse extension upper cover 85 are removed from the apparatus main body 1. As a result, the area covered by the paper ejection tray 72 by the reversing portion 80 becomes smaller than when the reversing extension tray 84 and the reversing extension upper cover 85 are attached to the apparatus main body 1. Therefore, the visibility and take-out property of the ejected paper P1 loaded on the output tray 72 can be improved accordingly. When the reverse extension tray 84 and the reverse extension upper cover 85 are attached to the apparatus main body 1, the attachment is detected by the sensor member that detects the attached state, and A3 size or DLT size paper is supplied from the paper feed cassette 400. The device main body 1 controls what can be printed on paper, and a display panel of the device main body 1 or a display device connected to the device main body 1 by a communication means displays a display that can be operated. When the reverse extension tray 84 and the reverse extension upper cover 85 are removed from the device main body 1, control is performed so that paper cannot be fed from the paper feed cassette 400, and the display device indicates that the operation is inoperable.

FIG. 8 is a schematic view of a mounting portion of the reverse extension tray 84 and the reverse extension upper cover 85 with respect to the device main body 1. The reversing extension tray 84 and the reversing extension upper cover 85 are fixed to each other with fastening screws and integrally configured, and are provided with two reversing engaging members 86 provided on the reversing extension tray 84 in the paper transport direction. ing. The reverse engagement member 86 may be provided on the reverse extension upper cover 85. Further, the number of the inverting engaging members 86 is not limited to two, and three or more may be provided. When two or more inverting engaging members 86 are provided on the inverting extension tray 84 or the inverting extension upper cover 85. It is desirable to position each reverse engagement member 86 on the same straight line in the paper transport direction. The side plate 1a parallel to the paper ejection direction in the paper ejection portion 70 of the apparatus main body 1 and located on the right side with respect to the paper ejection direction engages with each reversing engaging member 86 provided in the reversing extension tray 84. Engagement members 87 are provided at two locations in the paper ejection direction. Then, when each of the inverted engaging members 86 and each of the engaged members 87 engage with each other, the inverted extension tray 84 and the inverted extension upper cover 85 are attached to the device main body 1.

Further, in the present embodiment, the thickness of one end side of the reverse extension upper cover 85 provided with the reverse engagement member 86 in the paper width direction is thicker than the thickness of the other end side in the paper width direction. As a result, the rigidity of the inverting extension upper cover 85 at the one end side, which is the base portion when the inverting extension tray 84 and the inverting extension upper cover 85 are attached to the apparatus main body 1, becomes higher than that at the other end side, and the inverting extension tray 84. It is possible to prevent the 84 and the reverse extension upper cover 85 from bending.

FIG. 9 is a view showing a cross-sectional shape of a first engaging portion between the inverted engaging member 86 of the inverted extension tray 84 and the engaged member 87 of the apparatus main body 1. The inverting engaging member 86 has a hook-shaped portion 86a, and is screwed to the inverting extension upper cover 85 in a state where the hook-shaped portion 86a protrudes from the side surface of the inverting extension upper cover 85 on one end side in the paper width direction. .. Further, below the hook-shaped portion 86a of the reverse extension upper cover 85, a positioning convex portion 85a protruding from the side surface on one end side in the paper width direction is provided. On the other hand, the engaged member 87 provided on the side plate 1a of the apparatus main body 1 has a hook hole 87a for hooking the hook-shaped portion 86a, and has a through hole 87b below which the positioning convex portion 85a is inserted. doing.

FIG. 10 is a diagram showing a method of attaching the reverse extension tray 84 and the reverse extension upper cover 85 to the device main body 1. As a method of mounting the reversing extension tray 84 and the reversing extension upper cover 85, the hook shape portion 86a of the reversing engaging member 86 is inserted into the hook hole 87a of the engaged member 87, and the reversing extension tray 84 and the reversing extension upper cover are directly attached. Rotate 85 downwards. Then, the positioning convex portion 85a of the inverted extension upper cover 85 is inserted into the through hole 87b of the engaged member 87, and the hook-shaped portion of the inverted engaging member 86 is inserted into the edge of the hook hole 87a in the engaged member 87. Hook 86a. As a result, the mounting of the reverse extension tray 84 and the reverse extension upper cover 85 on the device main body 1 is completed. Therefore, the inversion extension tray 84 and the inversion extension upper cover 85 can be easily attached to the apparatus main body 1 without using a tool. By inserting the positioning convex portion 85a into the through hole 87b, the reverse extension upper cover 85 is positioned with respect to the apparatus main body 1. Further, in this configuration, a sliding member 88 for improving sliding of the positioning convex portion 85a with respect to the through hole 87b is attached so as to cover the edge of the through hole 87b to improve the detachability. .. As the material of the sliding member 88, for example, a resin such as polyacetal (POM) can be used.

When removing the reversing extension tray 84 and the reversing extension upper cover 85 from the apparatus main body 1, the reverse operation at the time of mounting described above is performed. Thereby, the reversing extension tray 84 and the reversing extension upper cover 85 can be easily removed from the apparatus main body 1 without using a tool. It is desirable that the inverting extension tray 84 and the inverting extension upper cover 85 removed from the apparatus main body 1 are stored as close to the printer 100 as possible. Therefore, for example, the exterior cover of the apparatus main body 1 is provided with a hook hole for hooking the hook-shaped portion 86a as described above and a through hole into which the positioning convex portion 85a is inserted. Alternatively, the paper is stored in the paper cassette 400 in which A3 size or DLT size paper is stored among the plurality of paper cassettes 400. As a result, the reversing extension tray 84 and the reversing extension upper cover 85 removed from the device main body 1 can be held by the outer cover of the device main body 1 or stored in the device main body 1.

FIG. 11 is a diagram showing a second engaging portion of the reverse extension tray 84 and the reverse extension upper cover 85 with respect to the device main body 1. An insertion hole provided in the reversing tray 82 or the reversing upper cover 83 fixed to the apparatus main body 1 at the opposite end of the reversing extension upper cover 85 opposite to the side where the reversing engaging member 86 is located in the paper width direction. A positioning member 89 that can be engaged with and disengaged is provided. The positioning member 89 of the reverse extension upper cover 85 is a surface (the surface provided with the engaged member 87) orthogonal to the paper transport direction of the apparatus main body 1 (paper transport of the reverse tray 82 or the reverse upper cover 83). It engages with the insertion hole provided on the downstream end face in the direction). The positioning member 89 may be provided at the opposite end of the reversing extension tray 84. The positioning member 89 provided on the reverse extension upper cover 85 is a moving member capable of advancing and retreating with respect to the insertion hole provided on the reverse tray 82 or the reverse upper cover 83, and is in the arrow direction (paper transport direction) in the drawing and its It is configured to be movable in the opposite direction. Further, the reverse extension upper cover 85 is provided with an operation window 85b for the user to pick the knob portion 89a provided on the positioning member 89 and slide the positioning member 89. Then, the user picks the knob portion 89a from the operation window 85b and slides the positioning member 89 to move the positioning member 89 forward and backward with respect to the insertion hole. The positioning member 89 inserted into the insertion hole is positioned in contact with the inner wall surface at least above the insertion hole so that the position of the reversing extension upper cover 85 with respect to the reversing tray 82 or the reversing upper cover 83 comes out. ing.

[Modification 1]
Next, a first modification of the image forming apparatus to which the present invention is applied (hereinafter, referred to as “modification example 1”) will be described.
FIG. 12 is a schematic configuration diagram of the printer 100 of the first modification.
Similar to the printer 100 of the above-described embodiment, the printer 100 of the first modification has a discharge port in which the paper discharge roller pair 71 is arranged and an inversion port provided above the discharge port and in which the reversing roller pair 81 is arranged. It is an image forming apparatus having. Further, it has an inversion tray 82 that guides the lower surface of the inversion paper P2, and an inversion upper cover 83 that is provided so as to cover the inversion tray 82.

The printer 100 of the first modification is different from the printer 100 of the above-described embodiment in that it has an auxiliary tray 500 built in the reversing tray 82, and has the same configuration except for the printer 100. Hereinafter, the same configuration as that of the embodiment will be omitted as appropriate, and the differences will be described.
The auxiliary tray 500 includes an auxiliary tray base 501 and an auxiliary tray tip 502, and is configured to expand and contract with respect to the reversing tray 82 on the downstream side in the paper transport direction when the reversing tray enters.

FIG. 13 is a schematic configuration diagram of the printer 100 in a state where the inverting extension tray 84 and the inverting extension upper cover 85 are removed from the apparatus main body 1 in the state shown in FIG. FIG. 14 is a cross-sectional view of the inverted portion 80 of the printer 100 and its vicinity in the state shown in FIG. 13, and FIG. 15 is a perspective view of the inverted portion 80 of the printer 100 and its vicinity in the state shown in FIG.

FIG. 16 is a cross-sectional view of the reversing portion 80 of the printer 100 and its vicinity in a state where only the auxiliary tray tip portion 502 of the auxiliary tray 500 is pulled out from the reversing tray 82, and FIG. 17 is a cross-sectional view of the printer 100 in the state shown in FIG. It is a perspective view of the reversing part 80 and the vicinity thereof. FIG. 18 is a cross-sectional view of the reversing portion 80 of the printer 100 and its vicinity in a state where the auxiliary tray tip portion 502 and the auxiliary tray base portion 501 of the auxiliary tray 500 are pulled out from the reversing tray 82. Further, FIG. 19 is a perspective view of the reversing portion 80 of the printer 100 and its vicinity in the state shown in FIG.

The auxiliary tray tip portion 502 and the auxiliary tray base portion 501 of the auxiliary tray 500 may be configured to have an uneven shape on the upper surface which is a surface facing the paper P. As the uneven shape, a plurality of ribs extending in the paper transport direction may be provided on each of the upper surfaces of the auxiliary tray tip portion 502 and the auxiliary tray base portion 501 side by side in the paper width direction orthogonal to the paper transport direction. As a result, the contact area of the auxiliary tray 500 with the paper P can be made smaller than that in the case where the ribs are not provided, the transport resistance can be reduced, and the paper transportability can be improved.

Even in the printer 100 of the first modification, the reversing tray 82 guides the lower surface of the paper P to be reversed by the reversing roller pair 81. An inversion upper cover 83 is provided above the inversion tray 82, and the inversion tray 82 and the inversion upper cover 83 are fixedly provided to the apparatus main body 1.

When image formation is performed with the inverting extension tray 84 and the inverting extension upper cover 85 removed from the printer 100 of the first modification, the paper P sent to the paper ejection unit 70 in the same manner as in the above-described embodiment when forming a single-sided image. Is ejected to the output tray 72 by the output roller pair 71. Then, the paper is sequentially loaded on the output tray 72. On the other hand, at the time of forming the double-sided image, the auxiliary tray 500 is pulled out from the state shown in FIG. 13 with respect to the reversing tray 82 to the downstream side in the paper transport direction at the time of entering the reversing tray before forming the image. Then, at the time of image formation, the paper transport path is switched by the switching claw 60, and the single-sided printed paper P is transported to the reversing portion 80 formed by the reversing tray 82, the reversing upper cover 83, and the auxiliary tray 500. .. The double-sided printed paper P is conveyed to the paper ejection unit 70.

That is, the paper P conveyed to the reversing section 80 is once discharged onto the reversing tray 82 and the auxiliary tray 500 with the rear end sandwiched by the reversing roller pair 81 as the reversing means. After that, the paper P is fed to the re-feeding path unit 90 by controlling the drive motor that rotationally drives the reversing roller pair 81 to rotate the reversing roller pair 81 in the reverse direction. Then, the paper P is fed to the transfer unit by the resist roller pair 43 in sequence via the transport roller pairs 91, 92, 93, 94, and the image is secondary from the intermediate transfer belt 25 on the back surface, which is the second surface of the paper P. Transcribed.
As shown in FIGS. 14 to 19, the expandable and contractible auxiliary tray 500 can be expanded and contracted to an arbitrary length, and when forming a double-sided image, the auxiliary tray 500 can be moved from the reversing tray 82 as necessary before the start of image formation. Pull it out and adjust it to the appropriate length.

FIG. 20 is a perspective view of the reversing portion 80 of the printer 100 and its vicinity in a state before the auxiliary tray 500 is attached to the reversing tray 82. As shown in FIG. 20, the auxiliary tray 500 is inserted into the reversing tray 82 as shown by an arrow E in FIG. 20 in an assembled state in which the auxiliary tray tip portion 502 is assembled to the auxiliary tray base portion 501. The state shown in FIG. 15 is obtained. In the state shown in FIG. 15, the auxiliary tray 500 is configured to be snap-fitted to the reversing tray 82 to prevent it from coming off. The auxiliary tray 500 does not come off from the reversing tray 82 in a normal pull-out operation, but is detachable from the reversing tray 82 when maintenance or the like is required.

As shown in FIGS. 14 and 15, when the auxiliary tray 500 is in the most contracted (stored) state, the auxiliary tray 500 is completely stored inside the reversing tray 82. Therefore, in the states of FIGS. 14 and 15, the visibility and removal of the paper P ejected to the output tray 72 can be seen from any of the directions of arrow A, arrow B, and arrow C in FIG. Sex is ensured.

FIG. 21 shows the reversing section 80 and the reversing section 80 of the printer 100 in a state where the auxiliary tray 500 shown in FIGS. 14 and 15 is in the most contracted state and paper P having a predetermined length or more such as A3 size is passed through the reversing section 80. It is a cross-sectional view of the vicinity.
As shown in FIG. 21, when a long paper P such as A3 size is passed, the length of the paper P is longer than the length that can guide the lower surface by the reversing tray 82, so that the tip of the reversing paper P2 is formed. It hangs down. Therefore, as shown in the area D surrounded by the broken line in FIG. 21, the tip of the reversing paper P2 may be in contact with the discharged paper P1 on the paper ejection tray 72. In the state where the reversing paper P2 can come into contact with the ejected paper P1 in this way, the paper alignment state of the ejected paper P1 is disturbed, or the ejected paper P1 is pushed out from the paper ejection tray 72 and dropped. Poor paper alignment may occur.

FIG. 22 shows the reversing section 80 and the reversing section 80 of the printer 100 in a state where the auxiliary tray 500 shown in FIGS. 18 and 19 is most extended and paper P having a predetermined length or more such as A3 size is passed through the reversing section 80. It is a cross-sectional view of the vicinity.
In the state shown in FIGS. 18 and 19, the extendable auxiliary tray 500 is pulled out as compared with the state shown in FIGS. 14 and 15. However, regarding the width and length of the auxiliary tray 500, the tip of the reversing paper P2 (“P2a” in FIG. 22) becomes the ejected paper P1 even when the long paper P such as A3 size is passed. It is set to the minimum necessary to prevent contact. Therefore, the visibility and take-out property of the paper P discharged to the paper ejection tray 72 are not impaired.

16 and 17 show a state in which the auxiliary tray 500 is pulled out to a length intermediate between the state shown in FIGS. 14 and 15 and the state shown in FIGS. 18 and 19. When passing paper P that is longer than A4 size but shorter than A3 size, the visibility of the paper P ejected to the output tray 72 and the visibility of the ejected paper P while preventing contact between the reversing paper P2 and the ejected paper P1. It can also be set as shown in FIGS. 16 and 17 in order to ensure the ease of taking out.
In the first modification, the auxiliary tray 500 is composed of two parts, the auxiliary tray base portion 501 and the auxiliary tray tip portion 502, and the configuration in which the auxiliary tray 500 is expanded and contracted stepwise has been described. The auxiliary tray 500 is not limited to the configuration of two parts, and may be composed of only one component or three or more components.

The auxiliary tray 500 of the first modification has a first position housed in the reversing tray 72 as shown in FIGS. 14 and 15, and a second position pulled out from the reversing tray 72 as shown in FIGS. 18 and 19. It is a configuration that can be moved to and from the position. The auxiliary tray 500 guides the lower surface of the reversing paper P2 at the second position.
Further, in the printer 100 of the modified example 1, when the auxiliary tray 500 is in the first position, the reverse extension tray 84, which is the second guide member, can be attached to and detached from the apparatus main body 1.

The auxiliary tray 500 of the first modification is composed of two parts, and as a position between the first position and the second position, only the auxiliary tray tip portion 502 is inverted as shown in FIGS. 16 and 17. It can be a position pulled out from 82. The auxiliary tray 500 is not limited to the configuration of pulling out in two stages as in the first modification, and can be moved to the first position stored in the reversing tray 82 and at least one or more positions pulled out from the reversing tray 82. It may be configured. Further, two or more auxiliary trays 500 may be arranged.

Next, the state shown in FIG. 12 in which the reverse extension tray 84 and the reverse extension upper cover 85 are attached to the printer 100 of the first modification will be described. FIG. 23 is a perspective view of the reversing portion 80 of the printer 100 and its vicinity in the state shown in FIG. FIG. 24 shows a cross section of the reversing portion 80 of the printer 100 and its vicinity in a state where the paper P is passed through the reversing portion 80 with the reversing extension tray 84 and the reversing extension upper cover 85 shown in FIGS. 12 and 23 attached. It is a figure.
The auxiliary tray 500 of the printer 100 of the first modification 1 is expandable and contractible, and is further stored in the reversing tray 82 without popping out from the appearance of the reversing tray 82 as shown in FIGS. 14 and 15. Therefore, in the printer 100 of the modified example 1, in a state where the auxiliary tray 500 is housed in the reversing tray 82, the reversing extension tray 84 and the reversing extension upper cover 85 similar to the printer 100 of the above-described embodiment are attached to the apparatus main body 1. Can be installed.

Since the tip side of the reversing paper P2 shown in FIGS. 21 and 22 is completely exposed to the user from the reversing tray 82 and the reversing upper cover 83, the user pulls out the reversing paper P2 being reversed by the reversing portion 80. There is a possibility that it will end up. If the user pulls out the reversing paper P2 being reversed by the reversing unit 80, it is determined that a paper jam or other paper misconduct has occurred in the transport path in the printer 100, which causes an unexpected jam for the printer 100. It becomes. Further, in the case of the highly productive printer 100 in which the number of images formed per unit time is large, the paper transport speed at the time of reversal is also increased. Therefore, there is a possibility that the user who sees the reversing paper P2 that protrudes from the reversing tray 82 and the reversing upper cover 83 at high speed and is exposed may feel uncomfortable.

On the other hand, in the printer 100 of the first modification, the auxiliary tray 500 is housed in the reversing tray 82 as shown in FIGS. 13 to 15, and the reversing extension tray is stored as shown in FIGS. 12, 23 and 24. The 84 and the reverse extension upper cover 85 are attached to the device main body 1. As a result, the reversing paper P2 being reversed by the reversing unit 80 is hidden from the user, so that the user cannot pull out the reversing paper P2 by the reversing unit 80, and it is possible to prevent jams that may occur when the reversing paper P2 is pulled out. Can be done. Further, since the tip end side of the reversing paper P2 does not protrude from the reversing portion 80 and is not exposed, it is possible to prevent the user from feeling uncomfortable when the reversing paper P2 pops out at high speed.

In the printer 100 of the embodiment described with reference to FIGS. 1 to 11, when the paper P having a predetermined length or more such as A3 size is passed through the reversing section 80, the reversing extension tray 84 and the reversing extension cover 85 are used. To wear. When the reverse extension tray 84 and the reverse extension cover 85 are attached, the paper P is in a state of covering the upper part of the output tray 72, so that the visibility and take-out property of the paper P discharged to the output tray 72 are lowered.
Further, in the configuration of the embodiment, when the printer 100 is switched between a state in which the paper P having a predetermined length or longer is passed through the reversing section 80 and a state in which the paper P is not passed through the reversing section 80, the reversing extension is performed. It is necessary to attach / detach the tray 84 and the reversing extension cover 85. Therefore, for a user who only needs to avoid disturbing the paper alignment state of the ejected paper P1 or pushing out the ejected paper P1 from the output tray 72, the reversing paper P2 is replaced with a replacement time longer than necessary. Man-hours are required.

On the other hand, in the printer 100 of the modification 1, when the paper P having a predetermined length or more is passed through the reversing portion 80, the work of pulling out the auxiliary tray 500 and the reversing extension tray 84 and the reversing extension cover 85 are attached. It is possible to select one of the tasks to be performed.
By pulling out the auxiliary tray 500, the auxiliary tray 500 guides the lower surface of the reversing paper P2 even when passing a large size paper P such as A3 size. As a result, the reversing paper P2 is prevented from coming into contact with the ejected paper P1 when the large-sized paper P is passed, and the reversing paper P2 disturbs the paper alignment state of the ejected paper P1 or the paper ejection tray 72. It is possible to prevent the ejected paper P1 from being pushed out from the paper.

Further, in the printer 100 of the modified example 1, the auxiliary tray 500 for guiding the lower surface of the reversing paper P2 has a minimum necessary length and area so that the reversing paper P2 does not come into contact with the ejected paper P1 on the ejection tray 72. ..
FIG. 25 is a cross-sectional view of the reversing portion 80 and its vicinity in a state where the image formation is completed in the state where the auxiliary tray 500 is most extended in the printer 100 of the modified example 1. FIG. 26 shows a range (area “G” surrounded by a broken line) covered with the inverting extension tray 84 and the inverting extension cover 85 attached to the perspective view of the printer 100 in the state where the auxiliary tray 500 is most extended. It is a perspective explanatory view added.

As shown in FIG. 26, even when the auxiliary tray 500 is in the most extended state, the range covered by the auxiliary tray 500 above the output tray 72 is when the reverse extension tray 84 and the reverse extension cover 85 are attached. It is sufficiently small compared to the area covered by these.
Therefore, even when the auxiliary tray 500 is in the most extended state, the paper P ejected to the output tray 72 can be viewed from any of the directions of arrow A, arrow B, and arrow C in FIG. 25. Visibility and take-out are ensured.
The visibility and take-out property of these sheets P are large when the auxiliary tray 500 shown in FIGS. 14 and 15 is stored in the reversing tray 82 and when the auxiliary tray 500 is most extended as shown in FIG. 25. There is no difference.
In the printer 100 of the first modification, by using the auxiliary tray 500, a large size paper P such as A3 size is passed through, and even in a state where the lower surface of the reversing paper P2 is guided, the paper is discharged to the output tray 72. The visibility and take-out property of the finished paper P are ensured.

Further, the printer 100 of the first modification has a built-in auxiliary tray 500 that can be expanded and contracted with respect to the reversing tray 82 corresponding to A4 size. When the auxiliary tray 500 is not required, as in the case of forming a single-sided image or forming a double-sided image up to A4 size, the auxiliary tray 500 is used in a state of being stored in the reversing tray 82. When reversing a long paper P such as A3 size, by pulling out the auxiliary tray 500, the ejected paper P1 discharged to the discharge tray 72 even when the long paper P is reversed. The reversing paper P2 does not come into contact with the paper bundle. As a result, it is possible to prevent the paper alignment state of the ejected paper P1 from being disturbed and the ejected paper P1 from being pushed out from the output tray 72.

Further, when a large size paper P such as A3 size is not passed, the auxiliary tray 500 can be quickly stored in the reversing tray 82. As a result, the configuration of the reversing portion 80 of the printer 100 can be easily switched between the case of passing the paper P up to A4 size and the case of passing the long paper P such as A3 size.

In the printer 100 of the first modification, for the user whose exposure of the reversing paper P2 is not a problem, the reversing extension tray 84 and the reversing extension cover 85 are not attached, and the pull-out amount of the auxiliary tray 500 is easily and quickly adjusted and used. Will be possible. Further, even when the auxiliary tray 500 is most pulled out, the visibility and take-out property of the paper P ejected to the output tray 72 are ensured.
On the other hand, for a user who has a problem of exposure of the reversing paper P2, the reversing extension tray 84 and the reversing extension cover 85 are attached with the auxiliary tray 500 stored in the reversing tray 82. As a result, it is possible to prevent the paper alignment state of the ejected paper P1 from being disturbed and the ejected paper P1 from being pushed out from the output tray 72, and to prevent the user from pulling out the inverted paper P2. Further, since the tip end side of the reversing paper P2 does not protrude from the reversing portion 80 and is not exposed, it is possible to prevent the user from feeling uncomfortable when the reversing paper P2 pops out at high speed.

In the printer 100 of the first modification, the reverse extension tray 84 and the reverse extension cover 85, which are reverse trays with a cover having a length that does not expose the entire length of the paper to the user, and the expandable auxiliary tray 500 are used in combination. To do. As a result, when the paper P having a predetermined length or longer is passed through the reversing section 80, the reversing section 80 determines which of the reversing extension tray 84, the reversing extension cover 85, and the expandable auxiliary tray 500 is used. It is possible to arbitrarily select the configuration of the above according to the convenience of the user.

[Modification 2]
Next, a second modification of the image forming apparatus to which the present invention is applied (hereinafter, referred to as “modification 2”) will be described.
FIG. 27 is a schematic configuration diagram of the printer 100 of the modified example 2.
The printer 100 of the second modification is different from the printer 100 of the embodiment in that the reversing upper cover 83 is configured to be openable and closable with respect to the reversing tray 82 and has an open / close sensor 600 for detecting the open / closed state of the reversing upper cover 83. , Others have the same configuration. Hereinafter, the same configuration as that of the first modification will be omitted as appropriate, and the differences will be described.

FIG. 28 is a cross-sectional view of the reversing portion 80 of the printer 100 and its vicinity in a state where the reversing extension tray 84 and the reversing extension upper cover 85 are removed and only the auxiliary tray tip portion 502 of the auxiliary tray 500 is pulled out from the reversing tray 82. .. FIG. 29 is a perspective view of the inverted portion 80 of the printer 100 and its vicinity in a state where the inverted upper cover 83 is opened from the state shown in FIG. 28.
FIG. 30 is a cross-sectional view of the reversing portion 80 of the printer 100 and its vicinity in a state where the reversing extension tray 84 and the reversing extension upper cover 85 are attached. FIG. 31 is a perspective view of the inverted portion 80 of the printer 100 and its vicinity in a state where the inverted upper cover 83 is opened from the state shown in FIG.

As shown in FIGS. 29 and 31, the reversing upper cover 83 is rotatable with respect to the reversing tray 82 about a rotation axis near the downstream end in the paper transport direction when the reversing tray enters the reversing tray 82. It is assembled. Further, as shown in FIGS. 28 and 30, an open / close sensor 600, which is a guide cover open / close state detecting means, is arranged in the open / close portion exposed by the opening operation of the reverse upper cover 83 in the reverse tray 82.

Next, the jam processing in the reversing portion 80 of the printer 100 of the modification 2 will be described.
In the printer 100 of the second modification, the inverted upper cover 83 can be opened and closed regardless of the expansion / contraction state and the stored state of the auxiliary tray 500. 28 and 29 show a state in which only the tip end portion 502 of the auxiliary tray is pulled out from the reversing tray 82. In the second modification, similarly to the state shown in FIGS. 14 and 18 of the first modification described above, the auxiliary tray 500 is inverted even when the auxiliary tray 500 is stored in the inverted tray 82 or the auxiliary tray 500 is most extended. The cover 83 can be opened and closed. Then, with respect to the jam in the reversing portion 80, the jam paper can be accessed from the direction of arrow H in FIG. 28 with the reversing upper cover 83 opened as shown in FIG. 29, and the jam paper can be easily removed. ..

Further, in the printer 100 of the second modification, as shown in FIGS. 30 and 31, the reversing cover 83 can be opened and closed in the same manner even when the reversing extension tray 84 and the reversing extension upper cover 85 are attached. Then, with respect to the jam in the reversing portion 80, the jam paper can be accessed from the direction of the arrow H'in FIG. 30 with the reversing upper cover 83 opened as shown in FIG. 31, and the jam paper can be easily removed. ..

Next, prevention of jams in the reversing portion 80 of the printer 100 of the second modification and avoidance of unnecessary printing stop will be described.
FIG. 32 is a flowchart showing a control flow of the printer 100 of the modification 2 based on the detection result of the open / close sensor 600.
The printer 100 of the second modification is provided with an open / close sensor 600 at the open / close portion of the reverse upper cover 83, and can detect the open / closed state of the reverse upper cover 83. By performing the printing operation according to the flowchart shown in FIG. 32 according to the open / closed state of the reversing upper cover 83, it is possible to prevent jams and to avoid unnecessary printing stoppages.

As shown in FIG. 32, when the print start instruction is input, it is determined whether or not the paper P is in the operation mode of passing through the reversing unit 80 (S1). In the operation mode such as single-sided printing in which the paper P does not pass through the reversing portion 80 (“No” in S1, in the reversing portion non-conveying mode), the open / close sensor 600 is used to detect the open / closed state of the reverse top cover 83. Printing is started without (S2). That is, in the operation mode in which the paper P does not pass through the reversing portion 80, the paper passing operation such as printing is started regardless of the open / closed state of the reversing upper cover 83.

Further, after printing is started, the open / close sensor 600 does not detect the open / closed state of the reversing upper cover until the print is completed. That is, in the operation mode in which the paper P does not pass through the reversing portion 80, the paper passing operation is performed even if the reversing upper cover 83 is opened during the paper passing operation of the paper P after the start of printing or the like. Do not stop. As a result, it is possible to avoid unnecessary printing stoppage in an operation mode unrelated to the reversing unit 80 such as single-sided printing.

On the other hand, in the case of the operation mode in which the paper P passes through the reversing unit 80 for double-sided printing or the like (S1), it is determined whether or not the paper P passes through the reversing unit 80 when the printing start instruction is input (S1). In S1, “Yes”, in the reverse unit transport mode), the open / close sensor 600 detects (S3). If it is detected that the reversing upper cover 83 is in the open state based on the detection result of the open / close sensor 600 (“No” in S3), printing is not started (S4). As a result, it is possible to prevent the occurrence of jam due to the paper being passed through the inverted upper cover 83 in the open state.

When it is detected that the reversing upper cover 83 is in the closed state based on the detection result of the open / close sensor 600 (“Yes” in S3), printing is started (S5). In the case of the operation mode in which the paper P passes through the reversing unit 80, after printing is started, the opening / closing sensor 600 continues the operation of detecting the open / closed state of the reversing upper cover 83 (S6 to S8). If the reverse top cover 83 is opened during the printing operation from the start of printing to the completion of printing, the paper P may be caught by the reverse portion 80 and jam may occur. Therefore, when it is detected that the reverse top cover 83 is in the open state by the detection operation of the open / close sensor 600 that continues until the printing is completed after the printing is started (“No” in S6), the printing is stopped. That is, if the reversing upper cover 83 is opened while the operation of passing the paper P to the reversing portion 80 is being executed, the operation of passing the paper P to the reversing portion 80 is performed by stopping printing. Stop. As a result, it is possible to prevent the occurrence of jam caused by the inverted upper cover 83 being opened in the middle of printing.

In a configuration including the reversing top cover 83 that covers the reversing tray 82 as in the printer 100 of the embodiment or the first modification, when a jam occurs in the reversing portion 80, the transport path of the paper P in the reversing portion 80 is reversed. Since it is covered with the cover 83, it is difficult to jam. On the other hand, in the printer 100 of the second modification, since the reversing upper cover 83 can be opened and closed with respect to the reversing tray 82, the jam processing property can be improved.
Further, in the configuration in which the reversing upper cover 83 can be opened and closed, when the paper P operates in a transport mode such as double-sided printing in which the reversing upper cover 83 is opened and the paper P passes through the reversing portion 80, a jam occurs due to the paper P being caught. There is a risk of On the other hand, in the printer 100 of the modification 2, when the open / close sensor 600 is provided and the paper P operates in the transport mode in which the paper P passes through the reversing portion 80, it detects that the reversing upper cover 83 is in the open state, and prints. To stop. As a result, it is possible to prevent the occurrence of jam caused by passing the paper in the inverted upper cover 83 in the open state.

In the second modification, the opening / closing sensor 600 for detecting the open / closed state of the inverted upper cover 83 is arranged so that the inverted upper cover 83 can be opened / closed with respect to the configuration of the printer 100 of the modified example 1. As a configuration in which the reversing upper cover 83 can be opened and closed and the open / close sensor 600 is arranged, it can be applied to a configuration not provided with the auxiliary tray 500 such as the printer 100 of the above-described embodiment.

What has been described above is an example, and each of the following aspects produces a unique effect.
(Aspect A)
A sheet loading section such as a paper output tray 72 on which sheets such as paper P are loaded, and an inversion that is provided above the sheet loading section and forms a sheet transport path to reverse the transport direction of the fed sheet and feed it out. In a sheet loading device including a sheet reversing part such as a portion 80, the sheet reversing part is a direction in which a first guide member such as a reversing tray 82 that guides the lower surface of the sheet and a sheet are fed to the sheet reversing part. It has a second guide member such as an inversion extension tray 84 that is detachably provided with respect to the main body of the apparatus and guides the lower surface of the seat on the downstream side of the first guide member.
In (Aspect A), when a sheet having a length longer in the sheet transport direction than the first guide member is used, the lower surface of the long sheet fed to the sheet reversing portion by attaching the second guide member to the apparatus main body. Is guided by the first guide member and the second guide member. As a result, it is possible to prevent the tip end side of the sheet fed to the sheet reversing portion from hanging down and coming into contact with the sheet loaded on the seat loading portion, as compared with the case where the second guide member is not attached to the apparatus main body. Therefore, it is possible to prevent the seats loaded on the seat loading portion from being disturbed or pushed out and dropped by the seats fed to the seat reversing portion. Further, when a sheet having a shorter sheet transport direction length than the first guide member is used, the second guide member is removed from the apparatus main body. As a result, the area covered by the seat loading portion is smaller than when the second guide member is attached to the main body of the device, so that the visibility and take-out of the seat loaded on the seat loading portion are improved. Can be made to.

(Aspect B)
In (Aspect A), the sheet reversing portion is provided detachably from a first guide cover member such as an reversing upper cover 83 that covers the first guide member and a reversing extension that covers the second guide member. It has a second guide cover member such as an upper cover 85. According to this, as described in the above-described embodiment, it is possible to suppress the user from pulling out the sheet during reversal. In addition, it is possible to prevent the user from feeling uncomfortable when the sheet pops out.

(Aspect C)
In (Aspect A) or (Aspect B), a concave-convex shape is provided on a surface of the first guide member, the second guide member, the first guide cover member, and the second guide cover member facing at least one sheet. It was. According to this, as described in the above-described embodiment, the transportability of the sheet can be improved.

(Aspect D)
In (Aspect C), the concave-convex shape is configured by arranging a plurality of ribs such as ribs 862, 863, 864, 865 extending in the sheet transport direction in the sheet width direction orthogonal to the sheet transport direction. According to this, as described in the above-described embodiment, the transportability of the sheet can be improved.

(Aspect E)
In any of (Aspect A) to (Aspect D), the second guide member or the second guide cover member engages and disengages with an engaged portion such as an engaged member 87 provided on the main body of the apparatus. It has an engaging portion such as a possible reversing engaging member 86, and one of the engaging portion and the engaged portion has a hole shape and the other has a hook shape. According to this, as described in the above embodiment, the second guide member and the second guide cover member can be easily attached to and detached from the apparatus main body without using a tool or the like.

(Aspect F)
In (Aspect E), the second guide member or the second guide cover member provided on the apparatus main body at the opposite end of the second guide member or the second guide cover member with respect to the engaging portion of the second guide cover member. (2) A second engaging portion that can be engaged and disengaged with the engaged portion is provided. According to this, as described in the above-described embodiment, it is possible to reduce the positional deviation of the first guide member with respect to the apparatus main body and suppress the occurrence of sheet transport defects.

(Aspect G)
In (Aspect F), the second engaged portion has a hole shape, and the second engaged portion is a moving member such as a positioning member 89 that can move forward and backward with respect to the second engaged portion. According to this, as described in the above embodiment, the second engaging portion and the second engaged portion can be easily engaged and disengaged without using a tool or the like.

(Aspect H)
In (Aspect G), the moving member moves into the second engaged portion and is positioned with respect to the device main body. According to this, as described in the above-described embodiment, the first guide member can be easily positioned with respect to the apparatus main body without using a tool such as a screw.

(Aspect I)
In any of the aspects (Aspect A) to (Aspect H), a sheet such as paper P is placed in the first position housed in the first guide member such as the reversing guide 82 and in the sheet reversing portion such as the reversing portion 80. An auxiliary guide member such as an auxiliary tray 500 that is configured to be movable to a second position on the downstream side of the downstream end of the first guide member in the feeding direction and guides the lower surface of the seat at the second position. Have.
In (Aspect I), when a sheet having a longer sheet transport direction length than the first guide member is used, the auxiliary guide member is moved to the second position to move the long sheet fed to the sheet reversing portion. The lower surface is guided by the first guide member and the auxiliary guide member. As a result, the tip end side of the sheet fed to the sheet reversing part hangs down from the state where the auxiliary guide member is housed in the first guide member, and comes into contact with the sheet loaded on the sheet loading part such as the paper output tray 72. Can be suppressed. Therefore, it is possible to prevent the seats loaded on the seat loading portion from being disturbed or pushed out and dropped by the seats fed to the seat reversing portion. Further, when a sheet having a shorter sheet transport direction length than the first guide member is used, the auxiliary guide member is housed in the first guide member. As a result, the area covered by the seat loading portion is smaller than that in the state where the auxiliary guide member is moved to the second position, so that the visibility and take-out of the seat loaded on the seat loading portion are improved. Can be improved.

(Aspect J)
In (Aspect I), the second guide member such as the reversing extension tray 84 is removable from the device main body when the auxiliary guide member such as the auxiliary tray 500 is in the first position. According to this, as described in the first modification, when a sheet having a longer sheet transport direction length than the first guide member is used, the second guide member is attached or the auxiliary guide member is second. It is possible to select one of the operations of moving to the position of.

(Aspect K)
In (Aspect I) or (Aspect J), an uneven shape such as a rib is provided on a surface such as an upper surface facing a sheet such as paper P of an auxiliary guide member such as an auxiliary tray 500. According to this, as described in the above-mentioned modification 1, the transportability of the sheet can be improved.

(Aspect L)
In any of the embodiments (A) to (K), the first guide cover member such as the reversible upper cover 83 which can be opened and closed and the first guide cover member which is provided so as to cover the first guide member such as the reversing tray 82. A guide cover open / closed state detecting means such as an open / close sensor 600 for detecting an open / closed state of the guide cover member is provided. According to this, as described in the above-described second modification, by releasing the first guide cover member, it is possible to improve the jam handling property in the sheet reversing portion such as the reversing portion 80. Further, by providing the guide cover open / closed state detecting means, when the released state of the first guide cover member is detected, it is possible to perform control not to execute the sheet transport operation such as not starting printing. As a result, it is possible to prevent the occurrence of jam caused by the sheet being conveyed to the sheet reversing portion while the first guide cover member is in the open state.

(Aspect M)
In (Aspect L), when the reversing part transport mode such as double-sided printing in which the sheet such as paper P is fed to the sheet reversing part such as the reversing part 80, the reversing upper cover 83 or the like is operated by the guide cover opening / closing state detecting means such as the opening / closing sensor 600. If the open / closed state of the first guide cover member is detected and the guide cover open / closed state detecting means detects the open state of the first guide cover member before the sheet is fed to the sheet reversing portion, printing is not started. Do not perform the transport operation of. According to this, as described in the second modification, it is possible to prevent the occurrence of jam due to the sheet being conveyed to the sheet reversing portion while the first guide cover member is in the open state.

(Aspect N)
In (Aspect L) or (Aspect M), in the reversing part non-conveying mode such as single-sided printing in which the sheet such as paper P is not fed to the sheet reversing part such as the reversing part 80, the first guide cover member such as the reversing upper cover 83 is used. The sheet transfer operation such as printing is executed regardless of the open / closed state of. According to this, as described in the above-described second modification, it is possible to avoid unnecessary stoppage of the transport operation in the operation mode unrelated to the sheet reversing portion.

(Aspect O)
In an image forming apparatus including an image forming means for forming an image on a sheet and a sheet loading means for loading a sheet on which an image is formed by the image forming means, the sheet loading means is (aspect A) to (aspect). One of the sheet loading devices of O) was used. According to this, as described in the above-described embodiment, it is possible to prevent the sheets loaded on the sheet loading portion from being disturbed or pushed out and dropped after the image is formed.

1 Device body 7 Developer 8 Charging device 9 Exposure device 10 Photoreceptor drum 11 Cleaning device 20 Primary transfer roller 25 Intermediate transfer belt 30 Secondary transfer device 31 Drive roller 32 Secondary transfer roller 33 Driven roller 34 Tension roller 40 Paper feed device 41 Paper feed roller 42 Conveyor roller vs. 43 Resist roller vs. 50 Fixing device 51 Fixing roller 52 Heating roller 60 Switching claw 70 Paper ejection part 71 Paper ejection roller vs. 72 Paper ejection tray 80 Inverting part 81 Inverting roller vs. 82 Inverting tray 83 Inverting top Cover 84 Inverted extension tray 85 Inverted extension upper cover 85a Convex part 85b Operation window 86 Inverted engaging member 86a Hook shape part 87 Engagement member 87a Hook hole 87b Through hole 88 Sliding member 89 Positioning member 89a Picking part 90 Re-feeding Route 91 Conveying roller vs. 92 Conveying roller vs. 93 Conveying roller vs. 94 Conveying roller vs. 100 Printer 400 Paper feed cassette 500 Auxiliary tray 600 Open / close sensor 821 Side plate 822 Side plate 823 Guide plate 823a Facing surface 833 Top plate 833a Facing surface 841 Transport direction end face 842 Side plate 842a Paper transport direction end face 843 Guide plate 843a Facing surface 843b Paper transport direction end face 853 Top plate 853a Facing surface 853b Paper transport direction end face 862 rib 863 rib 864 rib 865 rib

Japanese Patent No. 4890896

Claims (14)

The seat loading section where the seats are loaded and
In a sheet loading device provided above the sheet loading portion and provided with a sheet reversing portion that forms a sheet transport path for feeding the fed sheet by reversing the transport direction.
The sheet reversing part
The first guide member that guides the underside of the seat,
A second guide member detachably provided with respect to the apparatus main body, which guides the lower surface of the seat on the downstream side of the first guide member in the direction in which the sheet is fed into the sheet reversing portion ,
The first guide cover member that covers the first guide member and
A seat loading device characterized by having a second guide cover member that is detachably provided with respect to the device main body and covers the second guide member . In the sheet loading device according to claim 1 ,
A sheet loading device characterized in that an uneven shape is provided on a surface of the first guide member, the second guide member, the first guide cover member, and the second guide cover member facing at least one sheet. In the sheet loading device according to claim 2 ,
The uneven shape is a sheet loading device characterized in that a plurality of ribs extending in the sheet transport direction are arranged in a sheet width direction orthogonal to the sheet transport direction. In the sheet loading device according to any one of claims 1 to 3 .
The second guide member or the second guide cover member has an engaging portion that can be engaged and disengaged with respect to the engaged portion provided on the main body of the apparatus.
A seat loading device characterized in that one of the engaging portion and the engaged portion has a hole shape and the other has a hook shape. In the sheet loading device according to claim 4 ,
At the opposite end of the second guide member or the second guide cover member with respect to the engaging portion of the second guide member or the second guide cover member, a second engaged portion provided on the apparatus main body A seat loading device characterized by providing a second engaging portion that can be engaged and disengaged. In the sheet loading device according to claim 5 ,
A seat loading device characterized in that the second engaged portion has a hole shape, and the second engaged portion is a moving member capable of advancing and retreating with respect to the second engaged portion. In the sheet loading device according to claim 6 ,
A seat loading device characterized in that the moving member moves into the second engaged portion and is positioned with respect to the device main body. In the sheet loading device according to any one of claims 1 to 7 .
Movable to a first position housed in the first guide member and a second position downstream of the downstream end of the first guide member in the direction in which the sheet is fed into the sheet reversing portion. A seat loading device, characterized in that it has an auxiliary guide member for guiding the lower surface of the seat at the second position. In the sheet loading device of claim 8 ,
The second guide member is a seat loading device that is removable from the device main body when the auxiliary guide member is in the first position. In the sheet loading device of claim 8 or 9 .
A sheet loading device characterized in that an uneven shape is provided on a surface of the auxiliary guide member facing the sheet. In the sheet loading device according to any one of claims 1 to 10 .
An openable and closable first guide cover member provided so as to cover the first guide member,
A seat loading device including a guide cover open / closed state detecting means for detecting an open / closed state of the first guide cover member. In the sheet loading device of claim 11 ,
In the reversing section transport mode in which the sheet is fed to the sheet reversing section, the open / closed state of the first guide cover member is detected by the guide cover open / closed state detecting means.
A sheet loading device characterized in that if the guide cover open / closed state detecting means detects an open state of the first guide cover member before the sheet is fed into the sheet reversing portion, the sheet transport operation is not executed. In the sheet loading device of claim 11 or 12 ,
A sheet loading device characterized in that, in the reversing section non-conveying mode in which the sheet is not fed to the sheet reversing section, the sheet transport operation is executed regardless of the open / closed state of the first guide cover member. An image forming means for forming an image on a sheet and
In an image forming apparatus including a sheet loading means for loading a sheet on which an image is formed by the image forming means.
An image forming apparatus according to any one of claims 1 to 13 using the sheet loading device as the sheet loading means.

Images