JP2003295545A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a phenomenon such as the rubbing, the stripe or the sticking of special paper whose heat capacity is large such as cardboard or OHT by using a fan to suck air from the outside of a product and making the air from the outside of the product blow off to cool transfer material, and further to reduce apparatus cost and make the apparatus small-sized by providing a switching mechanism making the air blow off only a paper ejection port ejecting paper out of a plurality of paper ejection ports by one fan. <P>SOLUTION: The image forming apparatus is provided with a duct mechanism switched to make the air from the outside of the product sent from a cooling device blow off only the paper ejection port ejecting transfer material interlocked with a flapper for switching a paper carrying path, whereby the air is efficiently directly blown on the transfer material. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming a toner image by electrophotography and transferring the image onto a transfer material to obtain an image. 2. Description of the Related Art Conventionally, in a printer of a monochrome / color image forming apparatus, a sheet is generally discharged by face-down discharge (FD discharge) in which a print surface is discharged downward. In addition, face-up discharge (F
Many products also have a mechanism for discharging paper in U-paper discharge. FIG. 6 is a sectional view showing the structure of a conventional image forming apparatus. 130 is a paper feeder, 120 is an intermediate transfer belt unit, 150 is a paper transport unit, and 140 is a fixing unit. The transfer material P is sent to the paper transport unit 150 via the feed roller 131, the retard roller 132, and the transport roller 133. The toner image is formed by irradiating the surface of a photosensitive drum of each color provided in an image forming station provided with a developer (toner) of each color in the order of yellow, magenta, cyan, and black with laser scanner devices 100Y and 100M corresponding to the respective colors. , 100C,
It is formed by being exposed and developed by a laser beam emitted from 100Bk. A photosensitive drum 101Y on which a toner image is formed,
101M, 101C and 101Bk are driving rollers 122
The intermediate transfer belt 121 is rotated clockwise by the
First transfer is performed. Then, the secondary transfer of the toner image onto the transfer material P carried by the paper transport unit 150 is performed by the secondary transfer roller 151. Transfer material P on which toner image has been transferred
Is fixed as it is through the fixing unit 140, and in the case of FU discharge, the discharge port switching flapper 55 is switched, and the transfer material passes through the lower surface of the discharge port switching flapper 55, and is transferred to the FU discharge tray by the FU discharge rollers 153. 155 is discharged. In the case of FD discharge, the discharge port switching flapper 55 is switched, the transfer material passes through the upper surface of the discharge port switching flapper 55, and the transfer material is carried to the upper part of the product by the transport roller 152, and the product is transported by the FD discharge roller 154. The paper is discharged to the upper FD tray 156. [0005] Conventional products are provided with several cooling devices such as FAN for the purpose of lowering the temperature inside the product body. Fixing unit 140 that emits a large amount of heat due to its configuration
In order to cool the vicinity of the optical system unit 100 that dislikes high heat, a fan (exhaust) 170 is attached so as to exhaust heated air. FAN (exhaust)
Numeral 170 simultaneously cools the transfer material by blowing the air in the exhaust to the transfer material in the body in addition to the exhaust air for cooling the inside of the product body. [0006] In recent years, even in image forming apparatuses such as printers and copiers, media flexibility has been improved and print speed has been increased.
Various kinds of materials such as T, thin paper, and thick paper are used as transfer materials, and high-speed printing is performed. When the user prints using thick paper or OHT as the transfer material in the configuration as shown in FIG. 6, the heat capacity of the thick paper or OHT is large, and the transfer material is discharged while being extremely hot by the heat of the fixing device. The paper is discharged without the toner being completely fixed, and phenomena such as rubbing and streaks on the printed image and a phenomenon such as sticking at the paper discharge port may rarely appear. [0007] Current image forming apparatuses are mainly provided with a cooling device such as a fan. For cooling a transfer material, a product having a plurality of paper outlets is provided with a fan at each paper outlet. This not only increases the product cost but also increases the size of the product. In addition to the above, the transfer material is cooled by using the exhaust air in the product body in the product body using the fan for cooling the body and blowing the air in the exhaust gas onto the transfer material. However, since the warm air inside the product is blown against the transfer material, the transfer material cannot be sufficiently cooled. Therefore, the present invention uses a FAN to suck air from outside of a product and blows the air outside of the product onto a transfer material to cool the transfer material, so that special paper having a large heat capacity such as cardboard or OHT is rubbed. The purpose is to prevent phenomena such as streaks and sticking. Furthermore, one FA
It is an object of the present invention to reduce the product cost and reduce the size of the product by having a switching mechanism that blows air only to the discharge port that discharges paper among the plurality of discharge ports at N. In order to achieve the above object, the invention according to the present application is directed to cooling only a discharge port for discharging a transfer material in conjunction with a flapper for switching a paper transport path. By having a duct mechanism that switches so as to blow out the air outside the product sent from the apparatus, it is possible to efficiently directly apply air to the transfer material. Also,
The occurrence of sticking, rubbing, streaks, and the like of the transfer material immediately after paper ejection can be suppressed. Further, since the paper transport path switching flapper and the duct are linked, it is not necessary to attach a cooling device to each of the plurality of paper discharge ports, so that not only can the cost be reduced, but also the product can be downsized. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic diagram of the entire structure of the present invention. In the configuration of the product, the same parts as those in the conventional example are denoted by the same reference numerals, and the description is omitted. The switching mechanism 50 is connected to the FU discharge port 10 and the F
This is a device for switching the transport path to the D paper discharge port 11. When the user selects the FU discharge port 10 or the FD discharge port 11, the solenoid, which is a driving unit (not shown), rotates the paper transport switching flapper 55 to switch the paper transport path. I have. First, the case where the transfer material is discharged to the FU discharge port 10 will be described. FIG. 2 shows a configuration diagram of the paper transport switching flapper. When the user selects the FU discharge, a current flows from a circuit (not shown) to the solenoid 51 as the driving means in a direction to push the solenoid core 51F in the direction of arrow a. By driving the solenoid 51, the left side 52L of the solenoid seesaw 52 is lifted by lowering the right side 52R of the solenoid seesaw 52 about the solenoid seesaw rotation axis 52S of the solenoid seesaw 52, and the solenoid pin 53 contacting the solenoid seesaw 52 is lifted. Arrow b
Lift in the direction. By rotating the link member 54 in contact with the solenoid pin 53 in the direction of arrow c, the paper transport switching flapper 55 is rotated to switch the paper transport path. At the same time, the solenoid pin 53 is connected to the slider 33 pressed by the slider spring 34 in the direction of the arrow d, and the slider spring 3
4 and slide in the direction of arrow e.
The lower opening / closing lid 36 is connected to the slider 33. When the slider 33 slides upward, the lower opening / closing lid 36 is turned around the lower opening / closing lid turning center 38 in the direction of arrow f. FIG. 3 shows a configuration of a duct when the sheet is discharged to the FU sheet discharge port 10. As shown in FIG. FIG. 3A is a diagram of the cooling device unit viewed from the left side of FIG. 1, and FIG. 3B is a cross-sectional view. The movements of the slider 33 and the lower cover 36 are as described above.
The air outside the product taken in by the FAN 171 is blown to the slider 33. At that time, the slider 33 is sliding upward, and the phases of the slider hole 35 and the duct hole 32 formed in the duct 31 are out of phase.
Air is not blown to the paper passing area 40 of the FD discharge. The lower opening / closing lid 36 connected to the slider 33 rotates in the direction of the arrow m about the lower opening / closing lid rotation center 38 in accordance with the movement of the slider 33, and the transfer sheet discharged onto the FU discharge tray 155 is transferred. The material P is sprayed, and FAN1
The air outside the product taken in by 71 is blown onto the transfer material P discharged on the FU discharge tray 155 along the arrow z direction. Next, a case where the paper is discharged to the FD paper outlet 11 will be described. FIG. 4 shows a configuration diagram of the paper transport switching flapper. When the user selects the FD sheet discharge, a current flows from a circuit (not shown) to the solenoid 51 as a driving unit in a direction in which the solenoid core 51F is pulled back in the direction of arrow g. As described above, the right side 5 of the solenoid seesaw 52 around the solenoid seesaw rotation axis 52S of the solenoid seesaw 52
By raising 2R, the left side of solenoid seesaw 52 5
To lower 2L, the solenoid pin 53 in contact with the solenoid seesaw 52 is lowered in the direction of arrow h. By rotating the link member 54 in contact with the solenoid pin 53 in the direction of arrow i, the paper transport switching flapper 55 is rotated to switch the paper transport path. At the same time, the solenoid pin 53 is connected to the slider 33 pressed in the direction of arrow j by the slider spring 34, and slides in the direction of arrow k. The lower opening / closing lid 36 is connected to the slider 33. When the slider 33 slides downward, the lower opening / closing lid 36 rotates about the lower opening / closing lid rotation center 38 in the direction of the arrow l. FIG. 5 shows the configuration of a duct when the paper is discharged to the FD paper discharge port 11. FIG. 5A is a view of the cooling device unit as viewed from the left side in FIG. 1, and FIG. 5B is a cross-sectional view. The movements of the slider 33 and the lower cover 36 are as described above.
The air outside the product taken in by the FAN 171 is blown to the slider 33. At this time, the slider 33 slides downward, the phase of the slider hole 35 matches the phase of the duct hole 32 formed in the duct 31, and the air is blown to the paper passing area 40 of the FD discharge.
The air taken into the product is rotated by the lower opening / closing lid 36 connected to the slider 33 in the direction of the arrow n around the lower opening / closing lid rotation center 38 in accordance with the movement of the slider 33, and the FU paper outlet. In order not to be sprayed in the eleven directions, all are sprayed on the paper passing area of the FD discharge. As described above, according to the present invention,
By using the cooling device to take in the outside air of the product and positively blow it onto the transfer material, the cooled transfer material can be discharged. Also, the occurrence of sticking, rubbing, streaks, and the like of the transfer material immediately after the discharge can be suppressed.
Further, by linking the paper transport path switching flapper and the duct, the outside air can be blown only to the paper transport path to be discharged, so that it is not necessary to attach a cooling device to each of the plurality of discharge ports, thereby reducing costs. Not only that, the product can be downsized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of an image forming apparatus of the present invention. FIG. 2 is a configuration diagram (FU) of a paper transport switching flapper. FIG. 3 is a schematic diagram (FU) of the cooling mechanism structure of the present invention. FIG. 4 is a configuration diagram (FD) of a paper transport switching flapper. FIG. 5 is a schematic diagram (FD) of a cooling mechanism structure according to the present invention. FIG. 6 is a sectional view of a conventional image forming apparatus. DESCRIPTION OF SYMBOLS 10 FU discharge port 11 FD discharge port 30 Cooling unit 31 Duct 32 Duct hole 33 Slider 34 Slider spring 35 Slider hole 36 Lower opening / closing lid 37 Joint member 38 Lower opening / closing lid rotation center 40 Paper passing area 50 Switching Mechanism 51 Solenoid 51F Solenoid Iron Core 52 Solenoid Seesaw 52S Solenoid Seesaw Rotating Axis 52R Right Side 52L From Solenoid Seesaw Rotation Center 52L Left From Solenoid Seesaw Rotation Center 53 Solenoid Pin 54 Link Member 55 Paper Exit Switching Flapper 100 Optical System Unit 101 Photosensitive drum 120 Intermediate transfer belt unit 121 Intermediate transfer belt 140 Fixing unit 151 Secondary transfer roller 152 Transport roller 153 FU discharge roller 154 FD discharge roller 155 FU discharge tray 156 FD Output tray 170 FAN (exhaust) 171 FAN P Transfer material

Claims (1)

Claims 1. An image forming apparatus including one or more image exposing means and one or more image carriers, and a toner on the image carrier formed by the image forming means. A transfer unit for transferring the image to the transfer material, a fixing unit for fixing the transfer material on which the toner image has been transferred, and a paper discharge unit for discharging the transfer material having the toner image fixed thereon, and at least two paper discharge units An image forming apparatus having a path, switching means for selecting the two or more discharge paths, and means for sucking air outside the main body and blowing the air to the discharge path; a switching means for selecting a discharge path for the transfer material; An image forming apparatus characterized in that air is blown only to a paper discharge path where a transfer material is discharged in conjunction with the image forming apparatus.