JP2020148867A - Ejection device and image forming apparatus - Google Patents

Abstract

To provide an ejection device including a cooling mechanism that can certainly cool a sheet.SOLUTION: The ejection device is an ejection device that ejects a sheet to which an image is fixed by heating, and comprises a cooling mechanism 23 that brings a turbulent flow generated by causing air currents sent from directions different from each other to collide, into contact with the sheet to cool the sheet.SELECTED DRAWING: Figure 4

Description

The present invention relates to an image forming apparatus including an ejection device and an ejection device for ejecting paper on which a toner image is fixed by heating.

In the electrophotographic image forming apparatus, the paper on which the toner image is formed is heated by the fixing device, the toner image is fixed on the paper, and then the paper is ejected to the ejection tray by the ejection device. At this time, if the paper is ejected from the ejection device at a high temperature, the papers tend to stick to each other or the toner image melts. Therefore, the discharge device is provided with a convection generator that cools the paper by applying an air flow to the paper.

For example, Patent Document 1 describes a recording medium discharging device provided with a blowing means for blowing air in parallel with the discharging direction on the upper surface side of the recording medium (paper) discharged from the discharging means.

Japanese Unexamined Patent Publication No. 2013-184809

However, when convection is forcibly generated in only one direction as in the recording medium discharging device described in Patent Document 1, if the image forming speed becomes high, the recording medium may not be sufficiently cooled.

In consideration of the above circumstances, an object of the present invention is to provide a discharge device and an image forming device provided with a cooling mechanism capable of reliably cooling paper.

In order to solve the above problems, the discharge device of the present invention is a discharge device that discharges paper on which an image is fixed by heating, and discharges turbulent flow generated by colliding airflows blown from different directions. It is characterized in that it is provided with a cooling mechanism for cooling the paper in contact with the paper.

In the discharge device of the present invention, the cooling mechanism has a casing in which a transport path for transporting paper along a predetermined transport direction is formed inside, and the transport path along a width direction intersecting the transport direction. It may be characterized by including a pair of air blowing means for generating airflows in directions facing each other, and an exhaust port provided at the center of the casing in the width direction.

In the discharge device of the present invention, the pair of blower means may be provided so as to blow airflow along both sides of the paper in the casing.

The image forming apparatus of the present invention is characterized by including a fixing device that heats a toner image and fixes it on paper, and an ejection device that discharges the paper on which the toner image is fixed by the fixing device.

According to the present invention, the heated paper is mainly cooled by the turbulent flow generated by the cooling mechanism, so that the cooling effect can be enhanced.

It is a front view which shows typically the internal structure of the image forming apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the discharge device which concerns on one Embodiment of this invention. It is a top view which shows the discharge device which concerns on one Embodiment of this invention. FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG.

Hereinafter, the image forming apparatus and the discharging apparatus according to the embodiment of the present invention will be described with reference to the accompanying drawings.

First, the overall configuration of the color printer 1 as an image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic diagram showing an outline of a color printer. In the following description, the front side of the paper surface of FIG. 1 is the front side (front side) of the color printer 1, and the left-right direction is based on the direction in which the color printer 1 is viewed from the front side. Fr and Rr in each figure indicate the front side and the rear side of the color printer 1.

The device main body 3 of the color printer 1 forms a paper feed cassette 5 in which paper is stored, a paper feed device 7 for feeding paper from the paper feed cassette 5, and a full-color toner image on the fed paper. An image forming unit 9, a fixing device 11 for fixing the toner image on the paper, an ejection device 13 for ejecting the paper on which the toner image is fixed, and an ejection tray 15 on which the ejected paper is loaded are provided. There is. Further, the apparatus main body 3 is formed with a paper transport path 17 from the paper feed device 7 to the discharge device 13 through the image forming unit 9 and the fixing device 11.

The paper is fed from the paper feed cassette 5 to the transport path 17 by the paper feed device 7, and after the toner image is transferred to one side of the paper in the image forming unit 9, the toner image is fixed in the fixing device 11. Then, it is discharged by the discharge device 13 and loaded on the discharge tray 15.

Next, the discharge device 13 will be described with reference to FIGS. 2 to 5. FIG. 2 is a perspective view of the discharge device, FIG. 3 is a plan view of the discharge device, and FIGS. 4 and 5 are sectional views of the discharge device.

As shown in FIG. 2, the discharging device 13 is arranged on the downstream side of the fixing device 11 in the paper transport direction and adjacent to the fixing device 11. The discharge device 13 includes two pairs of discharge rollers 21, a cooling mechanism 23, and a discharge guide 25.

The two pairs of discharge rollers 21 each have a drive roller and a driven roller. The two pairs of discharge rollers 21 are arranged at predetermined intervals in the transport direction, and are rotatably supported by the casing 31 of the cooling mechanism 23 described later. The drive roller is driven by a motor and rotates in the clockwise direction of FIG. The driven roller is driven by the drive roller and rotates in a direction opposite to the rotation direction of the drive roller.

The cooling mechanism 23 includes a casing 31 and a pair of sirocco fans 33 as ventilation means.

The casing 31 has a top plate 31a and a bottom plate 31b, a left side plate 31c and a right side plate 31d, and a front side plate 31e and a rear side plate 31f. 31 g of the hollow portion of the above is formed. An inlet 35 of the paper S is formed along the width direction on the right side plate 31d facing the fixing device 11. A paper outlet 37 is formed along the width direction on the left side plate 31c opposite to the fixing device 11. In the hollow portion 31g, a transport path 17 for the paper S is formed between the inlet 35 and the outlet 37.

Each roller of the two pairs of discharge rollers 21 is rotatably supported by the left and right side plates 31c and 31d, respectively. As the two pairs of discharge rollers 21 rotate, the paper S entering from the inlet 35 is discharged from the outlet 37 through the transport path 17 in the casing 31.

Exhaust ports 39 and 41 are formed at the centers of the top plate 31a and the bottom plate 31b in the front-rear direction and the left-right direction, respectively. The exhaust ports 39 and 41 are formed by a plurality of rectangular openings (three in this example) along the front-rear direction.

Further, vents 43 and 45 are formed on the front and rear side plates 31e and 31f, respectively. The vents 43 and 45 are arranged so as to cross the transport path 17 (the nip between the drive roller and the driven roller of the discharge roller 21) in the vertical direction. In this example, the vents 43 and 45 are formed so that their centers in the vertical direction substantially coincide with the transport path 17. Further, the vents 43 and 45 are arranged between the two pairs of discharge rollers 21 in the left-right direction.

The pair of sirocco fans 33 have the same configuration. Each sirocco fan 33 is supported by the front and rear side plates 31e and 31f so that the air vents communicate with the vents 43 and 45 of the front and rear side plates 31e and 31f. As the ventilation means, a propeller fan may be used instead of the sirocco fan.

The discharge guide 25 is supported below the outlet 45 of the left side plate 31c of the casing 31 so as to extend downstream in the transport direction.

The paper ejection operation in the ejection device 13 having the above configuration will be described. The paper S on which the toner image has been fixed by the fixing device 11 enters the hollow portion 31 g (transport path 17) from the inlet 35 of the casing 31, is conveyed by the rotation of the discharge roller 21, and is discharged from the outlet 37. While the paper S passes through the hollow portion 31 g of the casing 31, both sirocco fans 33 are driven to generate an air flow at the same wind speed. Specifically, when the discharge roller 21 starts rotating, both sirocco fans 33 are driven, and when the rotation is stopped, the drive is stopped.

Then, the airflow blown from both the vents 43 and 45 to the hollow portion 31g of the casing 31 collides with each other at the central portion in the front-rear direction, and a turbulent flow is generated as shown in FIG. The turbulent flow is bounced inward by the top plate 31a and the bottom plate 31b of the casing 31, and the left and right side plates 31c and 31d. The paper S is cooled by being in contact with the air blown from both fans 44 and the generated turbulent flow. As shown in FIG. 4, such a turbulent flow comes into contact with the paper S not only from the original blowing direction (front-back direction) of the sirocco fan 33 but also from the upward or downward direction, so that the generated airflow comes into contact with the paper S. The frequency of contact with the paper S increases, and the effect of cooling the paper S can be enhanced.

The warm air that has taken the heat of the paper S and a part of the air flow sent from the sirocco fan 33 are exhausted from the exhaust ports 39 and 41 of the top plate 31a and the bottom plate 31b of the casing 31 and the outlet 37 of the left side plate 31c. Ru.

The paper S cooled by the hollow portion 31 g of the casing 31 is discharged to the discharge tray 15 along the discharge guide 25 through the outlet 37.

As described above, according to the discharge device 13 of the present invention, the paper heated by the fixing device 11 is mainly cooled by the turbulent flow generated by the cooling mechanism 23. As described above, since the cooling effect can be enhanced by the turbulent flow, the paper S can be cooled quickly. Since the turbulent flow is mainly generated in the central portion in the front-rear direction of the casing 31, the central portion in the width direction of the paper S is mainly cooled by this turbulent flow. On the other hand, turbulence is unlikely to occur at both ends of the paper S in the width direction, but the temperature of the airflow generated by the sirocco fan 33 remains low (a state in which the heat of the paper S is not taken away). Is also cooled quickly.

Further, the warm air that has taken away the heat of the paper is mainly exhausted from the exhaust ports 39 and 41 formed on the top plate 31a and the bottom plate 31b of the casing 31. Therefore, it is possible to release the pressure of the hollow portion 31 g of the casing 31 to activate the air flow, or to exhaust the warm air including the heat taken from the paper S. Therefore, the cooling efficiency can be further increased.

Further, as shown in FIG. 4, since the airflow and the turbulent flow come into contact with the front side surface and the back side surface of the paper S, the paper S can be cooled more efficiently. By changing the positions of the vents 43 and 45 with respect to the transport path 17 in the vertical direction, the air volume of the airflow flowing in the space above and below the transport path 17 can be changed. For example, if you want to cool the surface on which the toner is fixed (the back side in this example), you can move the vents 43 and 45 downward with respect to the transport path 17, and the airflow flowing into the space below the transport path 17 will flow. The air volume can be greater than the amount of airflow flowing into the space above the transport path 17. As a result, cooling of the surface on which the toner is fixed is promoted, so that melting of the toner can be suppressed.

Further, as shown in FIG. 5, since both vents 43 and 45 are arranged between the two pairs of discharge rollers 21, the airflow blown from both vents 43 and 45 is blocked by the discharge rollers 21. It collides in the central part in the front-back direction without being hit. That is, since the energy of the airflow at the time of collision is not significantly reduced, the turbulent flow can be activated more and the cooling capacity can be further increased. Further, since the paper S is sandwiched between the two pairs of discharge rollers 21, the posture of the paper S is not disturbed by the turbulent flow.

Further, the wind speed of the sirocco fan 33 may be changed. In this case, when it is necessary to increase the cooling capacity, the wind speed is changed to increase. As a result, the energy when the airflow collides is increased, and a more active turbulent flow can be generated, so that the cooling capacity can be increased.

Further, the cooling capacity can be increased by generating an air flow from the two sirocco fans 33. The number of fans is not limited to two, and may be three or more. For example, when three fans are used, each fan is arranged at the center of the paper S in the width direction so that the airflow generated from each fan collides with each other.

Further, since the above-described description of the embodiment of the present invention describes a preferred embodiment of the discharge device and the image forming device according to the present invention, various technically preferable limitations may be added. However, the technical scope of the present invention is not limited to these aspects unless otherwise specified to limit the present invention.

1 Color printer (image forming device)
11 Fixing device 13 Discharging device 17 Transport path 23 Cooling mechanism 31 Casing 33 Sirocco fan (blower means)
39, 41 Exhaust port

Claims (4)

It is a discharge device that discharges paper on which images are fixed by heating.
A discharge device including a cooling mechanism that cools the paper by bringing turbulent flow generated by colliding airflows blown from different directions into contact with the paper. The cooling mechanism
A casing in which a transport path for transporting paper along a predetermined transport direction is formed inside, and
A pair of blower means for generating airflows in the direction opposite to each other along the width direction intersecting the transfer direction in the transfer path.
The discharge device according to claim 1, further comprising an exhaust port provided at a central portion of the casing in the width direction. The discharge device according to claim 2, wherein the pair of blower means is provided so as to blow airflow along both sides of the paper in the casing. A fixing device that heats the toner image and fixes it on the paper,
An image forming apparatus including an ejection device for ejecting paper on which a toner image has been fixed by the fixing device.

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