JP2018049234A - Image forming apparatus and relay conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus configured to prevent increase in temperature of a paper discharge tray even when sheets are stacked on the paper discharge tray.SOLUTION: On a top face of a relay conveyance unit 100, a paper discharge tray 101 is provided where sheets discharged from a printer are stacked. The paper discharge tray 101 includes a tray base surface 101a, and a projection 101b having a flat top face and projecting beyond the tray base surface 101a. The projection 101b is hollow. The projection 101b is provided at the center of the tray 101 in a width direction (Y direction) of a sheet, which is orthogonal to a sheet conveyance direction. The projection 101b has three side faces (101ba, 101bb, 101bc). Each of the side faces has a vent hole 103 for dissipating heat in the relay conveyance unit 100.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet such as a printer or a copying machine, and a relay conveying apparatus that conveys a sheet image formed by the image forming apparatus to a post-processing apparatus connected to the image forming apparatus. Is.

  Some recent electrophotographic printers are capable of connecting post-processing devices such as a sorter and a stapler. Some of them require a relay transport device (relay transport unit) that transports the sheet discharged from the printer to the post-processing device. Some relay conveyance devices have a discharge tray for receiving sheets discharged from the printer at the top.

  By the way, in the relay conveyance unit having the paper discharge tray at the upper part, the sheet heated by the heat fixing device in the printer passes. For this reason, the temperature of the relay conveyance unit is easily increased. When the temperature in the unit rises, the sheet discharge tray of the relay conveyance unit and the sheet on the sheet discharge tray are also warmed, and the toner of the toner image formed on the sheet may be softened and stuck to the tray.

  In view of this, it is considered to provide a vent in the paper discharge tray of the relay conveyance unit to suppress the temperature rise on the tray surface (Patent Documents 1 and 2).

JP 2007-145529 A JP 2008-247611 A

  However, since sheets are stacked on the paper discharge tray, there is a problem in that a part of the vent hole is blocked with the sheets and cooling efficiency is lowered.

  SUMMARY An advantage of some aspects of the invention is to provide an apparatus capable of suppressing the temperature rise of a paper discharge tray even when sheets are stacked on the paper discharge tray.

  In order to solve the above-described problems, the present invention provides an image forming unit that forms an image on a sheet, a discharge unit that discharges an image formed by the image forming unit to the outside of the apparatus, and the discharge unit In an image forming apparatus comprising: a tray that receives sheets; and a transport unit that is disposed directly below the tray and transports a sheet on which an image is formed by the image forming unit. A convex portion protruding from the tray base surface, and a vent hole is provided on a side surface of the convex portion.

  According to another aspect of the present invention, a tray that receives an image formed by the image forming apparatus and that is discharged from the image forming apparatus is disposed immediately below the tray, and conveys the sheet formed by the image forming apparatus. A relay unit for transporting a sheet image-formed by the image forming apparatus to a post-processing apparatus connected to the image forming apparatus, wherein the tray includes a tray base surface, A convex portion protruding from the tray base surface, and a vent is provided on a side surface of the convex portion.

  According to the present invention, it is possible to provide an apparatus capable of suppressing the temperature rise of the paper discharge tray even when sheets are stacked on the paper discharge tray.

1 is a cross-sectional view of an image forming apparatus. The perspective view of a relay conveyance apparatus. Sectional drawing of a relay conveyance apparatus. FIG. 5 is a diagram when sheets with a small paper width are stacked on a paper discharge tray. FIG. 6 is a diagram when a sheet having a large paper width is stacked on a paper discharge tray. FIG. 4 is a cross-sectional view of an image forming apparatus according to a second embodiment.

Example 1
DETAILED DESCRIPTION Exemplary embodiments for carrying out the present invention will be described in detail below with reference to the drawings. However, the dimensions, shapes, and relative arrangements of the components described in this embodiment should be changed as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions. The present invention is not intended to be limited to the following embodiments.

  FIG. 1 is a cross-sectional view of an image forming apparatus (electrophotographic recording type printer) in which a relay conveyance unit 100 is mounted.

  Reference numeral 1 denotes a main body of the image forming apparatus, which includes four drum-shaped photoreceptors 2 (2a, 2b, 2c, and 2d). An image forming unit for forming an image on a sheet is provided in the main body of the image forming apparatus. The image forming unit is composed of a photoconductor shown below. The photoreceptor 2 is driven to rotate clockwise in the figure by a driving unit (not shown). In addition, a charging unit (not shown) that uniformly charges the surface of the photoconductor 2 and a scanner unit 4 that forms an electrostatic latent image on each photoconductor 2 with a laser beam based on image information are provided. Further, a developing unit (not shown) that supplies toner to the electrostatic latent image to develop the electrostatic latent image, and a cleaner (not shown) that removes transfer residual toner remaining on the surface of the photoreceptor 2 after transfer are provided. ing. The photosensitive member 2, the charging unit, the developing unit, and the cleaner are integrated as a cartridge 3 (3a, 3b, 3c, 3d). Each of the cartridges 3 is detachable from the image forming apparatus main body.

  A primary transfer roller 5 (5a, 5b, 5c, 5d) as a transfer portion is in contact with the photosensitive member 2 via the intermediate transfer belt 6, and the toner image on the photosensitive member 2 is transferred to the intermediate transfer belt 6. Is done. The intermediate transfer belt 6 is stretched between a driving roller 7, a tension roller 8, and a secondary transfer counter roller 9, and rotates counterclockwise by driving the driving roller 7. A secondary transfer roller 10 provided at a position facing the secondary transfer counter roller 9 via the intermediate transfer belt 6 transfers the toner image transferred to the intermediate transfer belt 6 to a sheet S such as plain paper. A cleaner 11 for the intermediate transfer belt 6 is provided at a position facing the tension roller 8 with the intermediate transfer belt 6 interposed therebetween.

  The sheet S is fed by a sheet feeding cassette 12, a sheet feeding roller 13 for feeding the uppermost sheet in the sheet feeding cassette 12, and a sheet feeding roller 13 as a sheet feeding and conveying unit. A separation roller 14 is provided to separate and convey the sheets one by one. Further, the apparatus 1 is provided with a registration roller pair 15 that corrects the skew of the sheet S and a conveyance roller 16 provided between the separation roller 14 and the registration roller pair 15. The sheet S on which the unfixed toner image is formed via the intermediate transfer belt 6 is conveyed to the fixing unit 20 and heated. As a result, the unfixed toner image is fixed on the sheet S. The sheet S that has passed through the fixing unit 20 is sorted and transported by the transport path switching unit 21 to either the path toward the relay transport unit 100 or the path toward the paper discharge reverse roller pair (discharge section) 22 disposed downstream. Is done. The sheet conveyed on the path toward the relay conveyance unit 100 is conveyed by the discharge roller 23. Further, the sheet S is conveyed by rollers (conveyance units) 150, 151, 152 provided in the relay conveyance unit 100, and is delivered to a post-processing apparatus (not shown) disposed downstream thereof. The sheet conveyed to the path toward the discharge reversing roller pair 22 is discharged out of the apparatus by the discharge reversing roller pair 22 during single-sided printing, and discharged onto a discharge tray 101 provided on the relay transfer unit 100. Is done. The rollers (conveying units) 150, 151, and 152 described above are disposed directly below the paper discharge tray 101 as shown in FIG. During double-sided printing, the sheet S is conveyed again into the image forming apparatus main body 1 by stopping and reversely rotating the discharge reversing roller pair 22. Then, the sheet is conveyed again to the intermediate transfer belt 6 through the duplex conveying path 24, and image formation is performed on the second surface.

  FIG. 2 is a perspective view of the relay conveyance unit 100. As described above, the paper discharge tray 101 that receives the sheets discharged by the paper discharge reverse roller pair 22 is provided on the upper surface of the relay conveyance unit 100. The sheets discharged from the printer by the discharge reversing roller pair 22 are stacked on the discharge tray 101.

  The paper discharge tray 101 has a tray base surface 101a and a convex portion 101b whose top surface is a flat surface and protrudes from the tray base surface 101a. The inside of the convex portion 101b is a space. In the sheet width direction (Y-axis direction), which is a direction orthogonal to the sheet conveyance direction, the width of the convex portion 101b is narrower than the width of the tray base surface 101a. Moreover, the convex part 101b is provided in the center part of the tray 101 regarding the Y-axis direction. The convex portion 101b is provided with three side surfaces (101ba, 101bb, 101bc). The side surface 101ba is a front end surface provided at the front end of the convex portion 101b in the sheet conveyance direction (−X direction). The side surface 101bb and the side surface 101bc are two surfaces that intersect the tip surface 101ba. The three side surfaces are each provided with a vent 103 for releasing the heat inside the relay conveyance unit 100. In this example, the vent 103 is provided on all three side surfaces. However, in consideration of the device design, the ventilation port on the side visible to the user may be closed, and the ventilation port may be provided only on the other two side surfaces not visible to the user. It is only necessary that a vent is provided on at least one of the three side surfaces. Above the discharge tray 101, a full load detection flag 102 for detecting the full load of sheets stacked on the discharge tray 101 is provided. Reference numeral 101ac denotes a handle held by a user for opening a guide 104a, which will be described later, with respect to the guide 104b and processing a jammed sheet in a sheet conveyance path in which rollers 150, 151, and 152 are disposed. When the user holds the handle and lifts the guide 104a around an axis (not shown) at the back of the relay conveyance unit 100 in the arrow-Y direction, the guide 104a is opened with respect to the guide 104b, and jamming can be performed. .

  FIG. 3 is a cross-sectional perspective view of the relay conveyance unit 100. A guide 104a that is an upper surface guide and a guide 104b that is a lower surface guide are provided in the sheet conveyance path in which the rollers 150, 151, and 152 are disposed. The guide 104a is provided with a large number of vent holes 104ah so that heat from the sheet S passing between the guides 104a and 104b is released from the vent holes 104ah. In addition, a large number of vents 101ah are also provided in the tray base surface 101a disposed on the upper portion of the guide 104a. Therefore, as indicated by the arrows in FIG. 3, the heat from the sheet S rises by natural convection and is discharged to the outside of the apparatus via the vent 104 ah, vent 101 ah, and vent 103.

  FIG. 4 is a view showing a state where sheets S (letter size: width 279.4 mm) are stacked on the paper discharge tray 101. FIG. The discharged sheets S are stacked along the upper surface shape (flat surface) of the convex portion 101b, and the end portions in the direction (Y-axis direction) orthogonal to the conveying direction of the sheet S are respectively from the end portions of the convex portions 101b. Is also projected and loaded. In this case, since the end portion in the width direction (Y-axis direction) of the sheet is kept lifted by the waist of the sheet S, the sheet S does not block the vent hole 103. Therefore, the heat of the sheets S can be efficiently radiated regardless of the number of stacked sheets on the tray 101.

  By the way, the standard paper having the largest width that can be used in the printer of this example is the SR A3 size (the width is 320 mm). In the width direction of the sheet, which is a direction orthogonal to the sheet conveyance direction, the width (240 mm) of the convex portion 101 b is the width (320 mm) of the standard paper (SR A3 size) having the largest width available in the apparatus. It is narrower than.

  When a sheet S having a wide paper width as shown in FIG. 5 (FIG. 5 shows the SRA3 size as an example) is stacked, the both ends of the paper cannot be lifted by the waist of the sheet S, and the sheet bends downward. Is also possible. However, since the vent 103 is provided on the side surface of the convex portion 101 b, the space SP can be secured between the sheet S and the tray 101, and the sheet S does not block the vent 103. Therefore, the heat of the sheets S can be efficiently radiated regardless of the number of stacked sheets on the tray 101.

  As described above, with the relay conveyance device 100 of this example, the temperature rise of the paper discharge tray can be suppressed even when sheets are stacked on the paper discharge tray.

(Example 2)
In the apparatus according to the second embodiment illustrated in FIG. 6, the printer itself has a relay conveyance function.

  The sheet sorted to the relay roller 250 side by the conveyance path switching unit 21 is conveyed to the downstream discharge roller 253 via rollers 251 and 252 provided inside the apparatus main body. The sheets discharged out of the apparatus from the discharge roller 253 are stacked on a second discharge tray 254 provided in the apparatus. Even in the case of such an apparatus configuration, by providing the convex portion 101b on the paper discharge tray 101 and providing the vent 103 on the side surface, the temperature rise of the paper discharge tray can be achieved even when sheets are stacked on the paper discharge tray. Can be suppressed.

DESCRIPTION OF SYMBOLS 100 Relay conveyance unit 101 Paper discharge tray 101a Paper discharge tray base surface 101b Convex part 103 Vent

Claims (14)

An image forming unit for forming an image on a sheet;
A discharge unit that discharges the image-formed sheet to the outside of the apparatus;
A tray for receiving sheets discharged by the discharge unit;
A conveying unit that is disposed directly below the tray and conveys a sheet on which an image is formed by the image forming unit;
In an image forming apparatus having
The tray has a tray base surface and a convex portion protruding from the tray base surface,
An image forming apparatus, wherein a vent is provided on a side surface of the convex portion.   The image forming apparatus according to claim 1, wherein a width of the convex portion is narrower than a width of the tray base surface in a sheet width direction that is a direction orthogonal to a sheet conveyance direction.   The width of the convex portion is narrower than the width of the standard paper having the largest width available in the apparatus in the width direction of the sheet, which is a direction orthogonal to the conveyance direction of the sheet. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein a top surface of the convex portion is a flat surface.   The side surface is provided with at least three of a front end surface provided at the front end of the convex portion in the sheet conveying direction and two surfaces intersecting the front end surface, and at least one of the three side surfaces is provided. The image forming apparatus according to claim 1, wherein the ventilation hole is provided on one side surface.   The image forming apparatus according to claim 5, wherein the vent hole is provided on all of the three side surfaces.   The inside of the convex portion connected to the vent is a space, and the tray base that forms the space is provided with a vent for releasing heat from the transport unit to the space. The image forming apparatus according to claim 1, wherein: A tray that receives an image formed by the image forming apparatus and discharged from the image forming apparatus;
A conveying unit that is disposed directly below the tray and conveys a sheet on which an image is formed by the image forming apparatus;
A relay conveying apparatus for conveying a sheet image-formed by the image forming apparatus to a post-processing apparatus connected to the image forming apparatus,
The tray has a tray base surface and a convex portion protruding from the tray base surface,
A relay conveyance device, wherein a vent is provided on a side surface of the convex portion.   The relay conveyance device according to claim 8, wherein a width of the convex portion is narrower than a width of the tray base surface in a width direction of the sheet that is a direction orthogonal to a conveyance direction of the sheet.   The width of the convex portion is narrower than the width of the standard paper having the largest width available in the apparatus in the width direction of the sheet, which is a direction perpendicular to the sheet conveyance direction. The relay transfer device described.   The relay conveyance device according to any one of claims 8 to 10, wherein a top surface of the convex portion is a flat surface.   The side surface is provided with at least three of a front end surface provided at the front end of the convex portion in the sheet conveying direction and two surfaces intersecting the front end surface, and at least one of the three side surfaces is provided. The relay conveyance device according to any one of claims 8 to 11, wherein the vent hole is provided on one side surface.   The relay conveyance device according to claim 12, wherein the vent hole is provided on all of the three side surfaces.   The inside of the convex portion connected to the vent is a space, and the tray base that forms the space is provided with a vent for releasing heat from the transport unit to the space. The relay conveyance device according to any one of claims 8 to 13.

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