JP4798766B2 - Paper relay conveying apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet relay and transport device of simple structure capable of preventing occurrence of malfunction such as a curl of a paper sheet by discharging the heat so as to prevent over-heating. <P>SOLUTION: The top surface of a paper delivery tray part 8a and the top surface of a projecting part 8c of a relay and transport unit 8 are formed with a plurality of air discharging through holes 40 for communicating the inside of the relay and transport unit 8 with the outside thereof. The air discharging through holes 40 are parallely extended in the paper delivering direction on the top surface of the paper delivery tray part 8a and the projecting part 8c of the relay and transport unit 8, and formed inside a plurality of recessed grooves 41 provided in a direction orthogonal to the paper delivery direction. With this structure, curl of the conveyed paper sheet P is prevented, and deformation and damage of a unit case of the relay and transport unit 8 as a resin molding are also prevented. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention relates to an image forming apparatus having a relay conveyance unit that conveys a sheet ejected by a sheet ejection unit from the sheet ejection unit to one side of an image forming apparatus main body.

  Conventionally, when a post-processing device such as a sorter or a stapler is disposed on the side of an image forming apparatus such as a copying machine or a printer, a paper discharge unit that discharges paper on which an image is formed in the image forming device, A relay conveyance unit for conveying the discharged paper to the post-processing apparatus is attached. There are various types of relay transport units, and many techniques have been proposed and implemented (see, for example, Patent Documents 1 and 2).

  In a conventional general electrophotographic image forming apparatus, a sheet on which a toner image is transferred in an image forming unit is pressed / heated in a fixing processing unit for fixing the toner image, and the fixed sheet is discharged. The sheet is discharged out of the apparatus. Then, the discharged paper is received by the relay conveyance unit and conveyed to the post-processing apparatus.

The relay conveyance unit is provided with a conveyance roller and a guide plate for conveying paper in a resin unit case, and passes the paper through the inside of the unit case and conveys the paper from the paper discharge unit of the image forming apparatus to the post-processing apparatus. It has become.
JP-A-9-301602 JP-A-10-152241

  In the conventional relay transport unit, since the paper that has been heated after receiving the fixing process passes through the unit case, the heat and moisture of the paper are put in the unit case to make the inside high temperature and high humidity, Furthermore, the transfer of heat generated by driving each part in the image forming apparatus also causes the inside of the unit case to become a high temperature.

  Due to heat and moisture in the unit case, the paper is likely to be curled, causing trouble in transporting the paper to the post-processing device, causing condensation, and heat. The unit case sometimes deformed. Occasionally, the temperature could be high enough that it did not satisfy the highest temperature standard of safety standards.

  For this reason, conventionally, in consideration of the adverse effects of heat and humidity, a fan and a fan drive motor are installed to discharge the accumulated heat and humidity to the outside. However, the installation of fans causes an increase in cost, noise during rotation drive, increase in power consumption, and increase in size.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to enable heat exhaustion with a simple configuration, to prevent overheating, and to prevent occurrence of problems such as paper curl and the like. It is to provide a forming apparatus.

In order to achieve the above object, an invention according to claim 1 is directed to an image forming unit that forms an image on paper, a paper discharge unit that discharges paper after image formation, and a paper discharge unit that discharges paper. A relay conveyance unit that conveys the paper sheet from the paper discharge unit to one side of the image forming apparatus main body, a circuit board provided in the image forming apparatus main body, and heat released from the circuit board. A discharge fan for discharging to the outside of the image forming apparatus main body, and the image forming apparatus main body includes a discharge air flow path generated in the image forming apparatus main body by the operation of the discharge fan and a side of the relay conveyance unit. In the image forming apparatus having an inner wall portion for partitioning, an exhaust through hole for exhausting from the inside of the relay transport unit to the outside thereof is formed in the upper portion of the relay transport unit, and the inner wall portion Relay transfer facing A first air flow path hole is formed in the knitted portion, and a second air flow path hole is formed in the portion of the inner wall portion facing the relay transport unit portion, and the inside of the relay transport unit is The flow path of the air flow that is discharged through the first air flow path hole and then flows through the second air flow path hole is the flow path of the discharged air flow generated in the image forming apparatus main body by the operation of the discharge fan. This configuration makes it possible to discharge the heat and moisture in the sheet relay conveyance device body to the outside through the exhaust through-hole without installing any special member.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the relay conveyance unit portion facing the inner wall portion and the inner wall portion portion facing the relay conveyance unit portion include the discharge fan. It protrudes to the flow path side of the exhaust air flow generated in the image forming apparatus main body by the operation of No. 1.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the image forming apparatus further includes a bin tray that is disposed above the relay conveyance unit and receives the paper ejected by the paper ejection unit. The bin tray is formed with an exhaust through hole corresponding to an exhaust through hole formed in the upper part of the relay transport unit.

A fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, further comprising an image reading unit, and the image forming unit receives image data from the image reading unit and receives paper. A sheet discharge space is formed between the image reading unit and the image forming unit, and a sheet discharged from the sheet discharge unit is discharged between the image reading unit and the image forming unit. The relay transport unit is arranged. With this configuration, even if the relay transport unit is mounted in a paper discharge space formed between an image reading unit such as a scanner and an image forming unit, By eliminating the influence of heat and moisture as described above, the sheet is smoothly conveyed from the sheet discharge unit to one side of the image forming apparatus main body.

According to the present invention, by providing the exhaust through hole in the upper part of the relay transport unit, the heat and moisture in the relay transport unit can be discharged to the outside through the exhaust through hole without installing a special member. Therefore, with a simple configuration, the temperature and humidity of the relay transport unit can be prevented from rising, and problems such as device deformation and paper curl can be prevented. The practical effect of enabling conveyance and good post-processing is significant.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an image forming apparatus for explaining an embodiment of the present invention. An apparatus main body 1 of the image forming apparatus is provided with an image forming unit 2 for forming an image on a sheet. A paper feed unit 3 is provided below the image forming unit 2, and a paper discharge unit 4 that discharges paper after image formation is provided above the image forming unit 2. A scanner 5 is installed. A post-processing device 6 such as a sorter, a stapler, or a finisher is installed on one side (left side in the figure) of the device main body 1.

In a sheet discharge space 7 formed on the lateral upper surface of the sheet discharge unit 4 and below the scanner 5 in the apparatus main body 1, a sheet relay transfer device that transfers sheets from the sheet discharge unit 4 to the post-processing device 6. A relay transfer unit 8 is provided. In this manner, a paper discharge space 7 for discharging the paper discharged from the paper discharge unit 4 is formed between the image reading unit composed of a scanner and the image forming unit 2, and relayed and conveyed to the paper discharge space 7. A unit 8 is arranged, and this relay conveyance unit 8 serves to convey the paper discharged from the paper discharge unit 4 from the paper discharge unit 4 to one side of the image forming apparatus main body 1.

  The paper feed unit 3 is loaded with a plurality of paper feed cassettes 9, each of which contains paper P of a different paper type. The paper P is fed / conveyed by a paper feed roller 11, a transport roller 12, and the like through a transport path 10 extending in a substantially vertical direction from the paper feed unit 3 to the paper discharge unit 4. After the fixing process, the paper is discharged to the relay transport unit 8 by the paper discharge roller 13 as will be described later.

  The image forming unit 2 is of an electrophotographic type in this example, and includes a photoconductor 15 that is rotated counterclockwise and an optical writing device 16 that forms an electrostatic latent image on the photoconductor 15. Further, around the photoconductor 15, a charger 17 that uniformly charges the photoconductor 15, a developing device 18 that visualizes an electrostatic latent image (toner image), and a developing device 18 are formed. A transfer device 19 for transferring the transferred toner image onto the conveyed paper P, a cleaning unit 20 for removing the toner remaining on the photoconductor 15 after the transfer, and cleaning the photoconductor 15 are disposed. A fixing device 21 is provided between the transfer device 19 and the paper discharge unit 4 to heat and press the toner image transferred onto the paper P by the transfer device 19 and fix it.

The optical writing device 16 performs exposure by performing optical writing on the photosensitive member 15 based on image data from the scanner 5 or optical writing on the photosensitive member 15 based on image information input from a personal computer or the like. An electrostatic latent image is formed. The image forming unit 2 receives the image data from the image reading unit and forms an image on the paper P.

  When the paper P is fed from the paper feed cassette 9 by the paper feed roller 11, the paper P is separated one by one by the separation roller pair 22, and is transported in the transport path 10 by the transport roller 12. Further, the paper P is fed between the nip between the transfer device 19 and the photosensitive member 15 at a predetermined timing by a registration roller pair 23 provided on the upstream side of the transfer device 19 and receives the transfer of the toner image. .

  The scanner 5 includes a contact glass 25 on which an original is placed, a white pressure plate 26 that holds the original, an illumination lamp 27 that irradiates light on the original placed on the contact glass 25, and reflected light from the surface of the original. Is composed of a scanning mirror 28 that reflects the light beam, an optical path folding mirror pair 29a and 29b that moves at half the speed of the scanning mirror 28, an imaging lens 30 and a CCD 31.

  The relay conveyance unit 8 has a discharge tray portion 8a formed on the upper surface thereof, and a roller conveyance portion 8b for conveying the paper discharged to the post-processing device 6 therein.

  Further, the relay transport unit 8 includes a first transport unit 32 that transports the paper P from the paper discharge unit 4, a second transport unit 33 that transports the paper P from the paper discharge unit 4 to the roller transport unit 8b, and a paper discharge unit. 4 includes a branching claw member 34 that switches the path of the paper P discharged from the first transport unit 32 or the second transport unit 33.

  The first transport unit 32 is provided with a first transport unit and a discharge roller 35 for discharging the paper P to the paper discharge tray unit 8a. The roller transport unit 8b communicating with the second transport unit 33 is relayed and transported. In the unit 8, a paper path 36 that leads to the post-processing device 6, a plurality of transport rollers 37, and a second transport unit that is disposed downstream of the paper path 36 and discharges the paper P to the post-processing device 6. A roller 38 is provided.

  Next, the image forming operation and the operation of the relay conveyance unit in the present embodiment will be described.

  Optical writing is performed by the optical writing device 16 on the surface of the photoconductor 15 whose surface is uniformly charged by the charger 17 to form an electrostatic latent image. The electrostatic latent image on the photoreceptor 15 is developed with toner by the developing device 18 to form a toner visible image.

  On the other hand, the paper P is fed from any of the paper feed cassettes 9 of the paper feed unit 3 by the paper feed roller 11, separated and conveyed one by one by the separation roller 22, and sent into the conveyance path 10. The sheet P is transported by the transport roller 12, the transfer timing of the toner visible image on the photoconductor 15 is captured by the registration roller pair 23, and is transported to the nip between the photoconductor 15 and the transfer device 19. The paper P on which the toner image has been transferred is sent to the fixing device 21 where the toner image is heated / pressurized and fixed on the paper P. After fixing, the paper P is discharged from the paper discharge unit 4.

  Here, when a mode that does not require post-processing in the post-processing device 6 is selected, as shown in FIG. 2, the branching claw member 34 rotates downward under the control of a control unit (not shown). As a result, only the first transport unit 32 is opened, and the paper P is stacked on the paper discharge tray unit 8 a by the first transport unit and the paper discharge roller 35.

  Further, when a mode to be processed in the post-processing device 6, for example, a staple mode, is selected, as shown in FIG. 3, the branch claw member 34 is rotated upward to open only the second transport unit 33, The paper P is transported by a plurality of transport rollers 37 in the paper path 36 of the roller transport unit 8b, and is sent to the post-processing device 6 by the second transport unit / discharge roller 38. The paper P is stacked on the stack unit 6a after a predetermined job such as stapling (not shown) is completed in the post-processing device 6.

  By the way, inside the relay conveyance unit 8, the paper P after being heated by receiving the fixing process in the fixing device 21 is fed from the paper discharge unit 4, and the heat and humidity of the paper P are generated. This can cause the paper P to curl easily, and the unit case of the relay transport unit 8 that is a resin molded product may be deformed or damaged due to high temperatures.

Therefore, in the present embodiment, as shown in the entire perspective view of the relay transport unit in FIG. 4, the first transport is performed on the upper surface of the paper discharge tray 8a in the relay transport unit 8 and the paper transport path as shown in FIG. A plurality of exhaust through holes 40 are formed on the upper surface of the protruding portion 8c of the relay transport unit 8 where the branching claw member 34 to be switched to the section 32 or the second transport section 33 is installed. . An exhaust hole 40 for exhausting air from inside the relay transport unit 8 to the outside thereof is formed in the upper part of the relay transport unit 8. Thereby, curling of the paper P to be transported can be prevented, and deformation and damage of the unit case of the relay transport unit 8 which is a resin molded product can be prevented.

  As shown in FIG. 5, the exhaust hole 40 extends in parallel to the paper discharge direction on the upper surface of the paper discharge tray portion 8 a and the protruding portion 8 c of the relay transport unit 8 and is orthogonal to the paper discharge direction. It is formed in the concave groove 41 provided with a plurality of strips in the direction. In this way, when the exhaust holes 40 and the concave grooves 41 are randomly formed by extending the concave grooves 41 in the paper discharge tray portion 8a in parallel with the paper discharge direction, the discharged paper P Can be prevented from being caught in the exhaust through hole 40 or the concave groove 41.

  Further, by providing the exhaust through hole 40 over the entire interior of the relay transfer unit 8, the internal heat and moisture can be released to the outside, and the exhaust is performed well. Further, by providing the exhaust through hole 40 in the protruding portion 8c, as shown in FIGS. 6 and 7, even if the sheet P is discharged and placed on the discharge tray portion 8a, the exhaust is exhausted. Is possible.

  FIG. 6 shows a case where the paper P is horizontally fed and discharged, and FIG. 7 shows a case where the paper P is vertically fed and discharged. As shown in FIGS. 6 and 7, the installation position of the groove 41 is designed so that the side portions Pa and Pb of the paper P of various sizes to be discharged are not caught by the groove 41. Therefore, it is possible to prevent troubles during transportation.

As shown in FIG. 8, the image forming unit 2 of the image forming apparatus according to the present embodiment is fixed by heating / pressurizing the circuit image 42 of various control / drive systems and the toner image transferred onto the paper P. A heating unit such as the fixing device 21 is disposed, and a discharge fan 43 for discharging the heat to the outside of the apparatus main body 1 is provided. As described above, the image forming apparatus of this example includes the discharge fan 43 that discharges the heat released from the circuit board 42 provided inside the image forming apparatus main body 1 to the outside of the image forming apparatus main body 1. The image forming apparatus main body 1 has an inner wall portion 45 that partitions the flow path of the discharged air flow (arrow A) generated in the image forming apparatus main body by the operation of the discharge fan 43 and the relay conveyance unit 8 side. ing.

Here, the relay transport unit is projected so as to protrude into the area of the flow path of the exhaust air flow (arrow A) formed by the exhaust fan 43 inside the apparatus main body 1 of the image forming apparatus in which the relay transport unit 8 is installed. 8 by integrally forming a protruding portion 44 on the lateral side portion, and forming first and second air flow passage holes 44a and 45a in the protruding portion 44 and the inner wall portion 45 of the apparatus main body 1, respectively. It becomes possible to forcibly exhaust heat, moisture, and the like inside the relay conveyance unit 8 to the outside using the discharge fan 43. More specifically, the first air flow path hole 44a is formed in the relay conveyance unit portion facing the inner wall portion 45 of the image forming apparatus main body 1, and the portion of the inner wall portion 45 facing the relay conveyance unit portion. Is formed with a second air passage hole 45a, which is discharged from the inside of the relay transport unit 8 through the first air passage hole 44a and then flows through the second air passage hole 45a. The path merges with the flow path of the discharge air flow generated in the image forming apparatus main body 1 by the operation of the discharge fan 43, and faces the relay transport unit portion facing the inner wall portion 45 and the relay transport unit portion. The portion of the inner wall portion 45 protrudes toward the flow path of the exhaust air flow generated in the image forming apparatus main body 1 by the operation of the exhaust fan 43.

FIG. 9 illustrates a bin tray 46 that receives paper P discharged from a paper discharge port (not shown) different from the paper discharge port corresponding to the paper discharge roller 13 in the paper discharge space 7 of the paper discharge unit 4. In addition, a planar state is shown when the bin tray 46 is disposed above the relay transport unit 8 and the upstream side in the paper discharge direction of the bin tray 46 is placed on the protruding portion 8c of the relay transport unit 8. In this case, the bin tray 46 is shown. In this example, the exhaust from the relay transport unit 8 located below is hindered by the presence of air, so that in the present example, the exhaust is also exhausted to the bin tray 46 in correspondence with the exhaust hole 40 in the protrusion 8c of the relay transport unit 8. A through-hole 47 is formed. As described above, the exhaust hole 47 corresponding to the exhaust hole 40 formed in the upper portion of the relay conveyance unit 8 is formed in the bin tray 46.

  FIGS. 10A to 10C are explanatory views of the configuration and operation of a modified example of the relay transport unit, showing a part of the relay transport unit 8 on the downstream side in the paper discharge direction (the post-processing device 6 side). .

  An extension tray 51 is slidable at the end of the case side portion 50 of the relay conveyance unit 8, and is provided so as to be able to move in and out and to be rotatable, and a split pin protruding from the side of the extension tray 51. 52 is arranged so as to be movable through a horizontally elongated hole 53 provided in the case side portion 50.

  10A, the split pin 52 is positioned in the concave portion 53a on the upstream side in the paper discharge direction of the horizontally long hole 53, and the extension tray 51 is in a fixed state due to the elasticity of the split pin 52. 10B, the split pin 52 is positioned in the concave portion 53b on the downstream side in the paper discharge direction of the laterally long hole 53, and the split pin 52 is in the retracted state accommodated in the relay transport unit 8. As shown in FIG. The state of being in a fixed state by the elasticity of 52 is an extended state in which the extension tray 51 is protruding from the relay transport unit 8. Furthermore, as shown in FIG. 10C, the extension tray 51 has the split pin 52 positioned in the concave portion 53 b on the downstream side in the paper discharge direction of the laterally long hole 53, and rotates upward about the split pin 52. Can be fixed.

  Therefore, as shown in FIG. 11A, when a normal size sheet such as A4 or B5 is discharged, the extension tray 51 is set at the retracted position, as shown in FIG. As described above, when a long sheet such as A3 or DLT is discharged, the leading end of the sheet hangs down from the relay conveyance unit 8 onto the post-processing device 6, so that the extension tray 51 is extended. By supporting and guiding the leading edge of the paper P, drooping is prevented.

  Further, when an opening / closing cover body 54 or the like is installed on the upper portion of the post-processing device 6 for jam processing, as shown in FIG. 11 (c), the opening / closing cover body 54 that is opened during the jam processing is extended. Since the tray 51 can be rotated upward, the opening / closing cover body 54 can be opened without hindrance.

  In the above-described embodiment, the example in which the scanner 5 serving as the image reading unit is installed above the apparatus main body 1 of the image forming apparatus has been described. However, as illustrated in FIG. The present invention can also be applied to a configuration in which a paper discharge unit 4 similar to that of the above embodiment is provided on the upper portion of the apparatus main body 1 without being installed. In FIG. 12, the members corresponding to the members described in FIG.

  The present invention is applied to a sheet relay conveyance device in an image forming apparatus such as a copying machine, a printer, and a facsimile machine in which post-processing devices such as a sorter, a stapler, and a finisher are arranged in parallel.

1 is a schematic configuration diagram of an image forming apparatus for describing an embodiment of the present invention. Explanatory drawing of the paper discharge operation when processing in the post-processing apparatus is not necessary in the present embodiment Explanatory drawing of the paper discharge operation when processing in the post-processing apparatus is necessary in this embodiment Overall perspective view of relay transfer unit in this embodiment Plan view of relay transfer unit in this embodiment The top view which shows the case where a paper is laterally fed and discharged to the relay conveyance unit in the present embodiment The top view which shows the case where a sheet is vertically fed and discharged to the relay conveyance unit in this embodiment Explanatory drawing of the exhaust by the fan of the image forming apparatus in this embodiment Explanatory drawing of the bin tray mounted in the relay conveyance unit in this embodiment (A)-(c) is explanatory drawing of a structure and operation | movement of the modification of the relay conveyance unit in this embodiment. (A)-(c) is explanatory drawing which shows the usage example of the extension tray of the relay conveyance unit in this embodiment. Front view showing an example of an image forming apparatus according to the present embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Image forming part 4 Paper discharge part 7 Paper discharge space 8 Relay conveyance unit 40 Exhaust through hole 42 Circuit board 43 Exhaust fan 44a, 45a Air flow path hole 46 Bin tray 47 Exhaust through hole P Paper

Claims (4)

An image forming unit that forms an image on paper;
A paper discharge unit for discharging paper after image formation;
A relay conveyance unit that conveys the paper ejected by the paper ejection unit from the paper ejection unit to one side of the image forming apparatus main body;
A circuit board provided inside the image forming apparatus main body;
A discharge fan for discharging the heat released from the circuit board to the outside of the image forming apparatus main body,
In the image forming apparatus, the image forming apparatus main body has an inner wall portion that partitions a flow path of a discharge air flow generated in the image forming apparatus main body by the operation of the discharge fan and the relay conveyance unit side.
An exhaust hole for exhausting air from inside the relay transport unit to the outside is formed in the upper portion of the relay transport unit, and a first air flow path is formed in the relay transport unit portion facing the inner wall portion. A hole is formed and a second air flow path hole is formed in the portion of the inner wall portion facing the relay transport unit portion, and the first air flow path hole is passed through the relay transport unit from the inside. The flow path of the air flow that is discharged and then flows through the second air flow path hole is joined to the flow path of the discharge air flow generated in the image forming apparatus main body by the operation of the discharge fan. Image forming apparatus.   The relay conveyance unit portion facing the inner wall portion and the inner wall portion portion facing the relay conveyance unit portion are on the side of the flow path of the exhaust air flow generated in the image forming apparatus main body by the operation of the discharge fan. The image forming apparatus according to claim 1, wherein the image forming apparatus projects on the surface.   A bin tray that is disposed above the relay conveyance unit and that receives the paper discharged from the paper discharge unit is provided, and the bin tray has an exhaust through hole formed in the upper portion of the relay conveyance unit. The image forming apparatus according to claim 1, wherein an exhaust through hole corresponding to the above is formed.   An image reading unit, wherein the image forming unit receives image data from the image reading unit and forms an image on a sheet, and the image forming unit is provided between the image reading unit and the image forming unit. The image forming apparatus according to claim 1, wherein a paper discharge space for discharging the paper discharged from the paper discharge unit is formed, and the relay conveyance unit is arranged in the paper discharge space.

Images