JP3414896B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus for placing curled curled recording paper with good mountability.

[0002]

2. Description of the Related Art An image forming apparatus having an electrophotographic recording apparatus such as a facsimile machine, a copying machine and a laser printer generally has a fixing section for fixing the toner adhered to the recording paper to the recording paper. The recording paper fixed by the fixing unit is discharged and placed on the stacker unit provided outside the image forming apparatus.

In the image forming apparatus having such a fixing unit, the toner is fixed by heating the recording paper at the fixing unit. Therefore, some recording paper is curled, and the curled recording paper is The curled leading edge of the recording paper that is ejected and placed on the stacker with the curl direction facing the stacker is the curled recording paper that was placed on the stacker first. When the recording paper is ejected from the recording paper, a certain resistance is applied to the recording paper in the discharging direction as a reaction against the pressing of the recording paper.

In this case, if the recording paper is a relatively thick recording paper, the leading edge of the recording paper to be discharged later is
When the curled recording paper placed on the stacker section first comes into contact with it, the curled recording paper is discharged against the resistance received from the peak section, and is discharged on the recording paper previously placed on the stacker section. However, if the recording paper is a relatively thin recording paper, the leading edge of the recording paper that will be ejected later will be the curled recording that was previously placed on the stacker section. When it comes into contact with the mountain portion of the paper, it loses the resistance received from the mountain portion and cannot proceed further, so that it curls up as a whole and causes stacking failure.

Therefore, conventionally, a paper discharge tray having an improved stacking property has been proposed (see Japanese Patent Laid-Open No. 4-182260).

This conventional paper discharge tray is a paper discharge tray for holding paper discharged through a paper discharge device provided under the fixing device, and the paper passes through the fixing device on its free end side. It is characterized in that it is configured so that it can be bent in a curling direction when it is moved.

According to this paper discharge tray, the stacking property is improved by bending the free end side of the paper discharge tray in the curl direction of the recording paper and placing the recording paper in a mountain shape on the paper discharge tray. I am letting you.

[0008]

However, in the above-mentioned conventional paper discharge tray, since the free end side of the paper discharge tray is bent in the curl direction of the recording paper, the size of the recording paper changes. When the recording paper is curled, the angle at which the leading edge of the recording paper discharged onto the discharge tray contacts the discharge tray becomes an obtuse angle. The recording paper is likely to be curled in the curl direction, and there is a possibility that the recording paper cannot be sufficiently placed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image forming apparatus which improves the placement of curled recording paper regardless of the size of the recording paper.

[0010]

According to another aspect of the present invention, there is provided an image forming apparatus in which a recording sheet on which an image is recorded and which has a curl in a predetermined direction is placed, and the curl winding direction is directed toward the stacker surface side. An image forming apparatus that discharges and mounts on a stacker unit, wherein the stacker unit has a predetermined height higher than the stacker surface on the stacker surface, and a substantially central portion of the recording paper in the discharge direction has a predetermined length. auxiliary stacker part is provided to be placed over of the auxiliary stacker unit
It may be placed on the recording paper located on the stacker face
Loading position and how to eject the recording paper in the stacker section
Facing toward the front end of the recording paper discharged.
It is possible to move between the restriction position that restricts falling and both positions.
By being formed , the above object is achieved.

Here, the curl of the recording paper is applied in a state in which the front and rear directions of the recording paper in the discharge direction are rounded to one side of the recording paper, and the recording paper has its longitudinal direction in the discharge direction. it good, its shorter side direction may be a discharge direction.

The predetermined length at which the central portion of the auxiliary stacker portion in the sheet discharge direction is placed is a sufficient length for placing the recording sheet on the auxiliary stacker portion in a substantially flat state. Is.

Therefore, the recording paper is placed in a flat state on the auxiliary stacker portion which is higher than the stacker surface, and the leading edge of the recording paper to be ejected next is the recording ejected and placed first. Recording is performed by sliding on the flat surface of the previously ejected and placed recording paper without overlapping the curls of the paper and placing it on top of the previously ejected and placed recording paper. It is possible to improve the mountability of the paper on the stacker unit.

[0014]

[0015] In addition, recording paper, or curl is not applied, weak curl be granted only or even one that is not granted, even if Carl is given, of the recording paper that has been released and placed before the mountain of When the recording paper is thick enough not to be curled up due to resistance, the auxiliary stacker unit can be moved to the regulation position so that a larger amount of recording paper can be placed on the stacker unit at the same time. It is possible to improve the usability of the recording sheet, and by setting the auxiliary stacker portion to the regulation position, the recording paper can be properly placed on the stacker portion.

Further, for example, as described in claim 2 , the auxiliary stacker portion may be formed such that the length of the auxiliary stacker portion in the discharging direction of the recording paper is variable.

In this way, by adjusting the length of the auxiliary stacker portion according to the change in the size of the recording paper, the recording papers of various sizes are appropriately placed on the auxiliary stacker portion without curling. Therefore, it is possible to further improve the mountability.

Further, for example, as described in claim 3 , in the auxiliary stacker section, the length of the auxiliary stacker section in the direction orthogonal to the discharge direction of the recording paper is the maximum size of the discharged recording. It may be formed to be a predetermined length longer than the length of the paper in the direction.

By doing so, curling of the recording paper on the auxiliary stacker portion due to the four end portions of the recording paper placed on the auxiliary stacker portion hanging from the auxiliary stacker portion is prevented, and the recording paper is prevented. It is possible to make the flattened state on the auxiliary stacker portion, and it is possible to further improve the mountability of the recording paper.

Further, for example, as described in claim 4 , the stacker portion is formed lower than the stacker surface by a predetermined height on the leading end side of the discharged recording paper than the stacker surface. An extension stacker unit may be provided on which the leading end portion of the recording paper, which is longer than the length of the stacker surface in the recording paper discharge direction, is placed.

In this way, the stacker surface is formed into a frequently used medium size recording sheet, for example, A4 size recording sheet, and the recording sheet larger than the medium size recording sheet is stacked. The image forming apparatus can be downsized by using the expansion stacker section only when the sheet is discharged and placed on the sheet.

Further, when the recording paper of a size larger than the stacker surface is ejected and placed, the expansion stacker portion is formed lower than the stacker surface, so that the recording paper extends from the auxiliary stacker portion to the stacker surface and the expansion stacker portion. Can be placed with its front end in the discharging direction inclined downward, and the front end of the next recording paper to be discharged can be slid on the surface of the inclined recording paper and discharged.

As a result, it is possible to further improve the mountability of the recording paper having a size larger than the stacker surface.

[0024]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The examples described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are given thereto. However, the scope of the present invention is particularly limited in the following description. The present invention is not limited to these modes unless there is a statement to limit the above.

1 to 5 are views showing an embodiment of the image forming apparatus of the present invention.

1 to 3 are overall side sectional views of a laser printer 1 to which an embodiment of the image forming apparatus of the present invention is applied.

1 to 3, the laser printer 1 is shown.
Is provided with a photoconductor 3 in a substantially central portion on the front side (right direction in FIGS. 1 to 3) in the main body case 2, and around the photoconductor 3, a charging unit 4, a developing unit 5, a transfer unit, and a transfer unit. A section 6, a cleaning section 7 and the like are provided.

Below the photoconductor 3, a paper feed cassette 9 containing a plurality of recording papers 8 and the recording papers 8 in the paper feed cassette 9 are provided.
A sheet feeding roller 10 for feeding the sheets one by one, a registration roller 11 for feeding the recording sheet 8 conveyed by the sheet feeding roller 10 to the transfer portion 6 at a predetermined timing, and the like are provided. A fixing unit 12 for heating and fixing the recording paper 8 to which the toner is transferred in 6 is provided.

On the rear side (on the left side in FIG. 1) of the main body case 2, an electrical equipment section 14 housed in a metal case 13 is arranged. The electrical equipment section 14 includes a controller board 15 and a controller board. It is formed by various adjustment switches (not shown), control unit, and the like, which are mounted on the unit 15.

Below the case 13, a case 18 accommodating a power source 16 and an electric board 17 and an optical device 19 for writing an image on the photoconductor 3 are arranged.

The fixing section 12 is provided with a fixing roller 12a and a fixing roller 12b. The recording paper 8 on which the toner is transferred by the transfer section 6 is fixed to the fixing roller 12a and the fixing roller 1b.
It is conveyed to the contact portion 2b.

The fixing unit 12 conveys the recording paper 8 conveyed from the transfer unit 6 while pressing it against the fixing roller 12a by the fixing roller 12b, and heats the conveyed recording paper 8 by the fixing roller 12a, thereby recording. The toner transferred to the paper 8 is fixed on the recording paper 8.

At this time, the recording paper 8 is fixed on the fixing roller 12a.
Since the recording paper 8 is heated by the curl, the curl crease curls in the direction of the fixing roller 12a depending on the recording paper 8.

The fixing section 12 conveys the recording paper 8 to the discharge roller 20 while performing the fixing process on the recording paper 8,
A paper discharge roller 21 is in contact with the paper discharge roller 20.

The recording paper 8 conveyed to the paper discharge roller 20 is
The sheet is discharged and placed on a stacker portion 22 formed on the upper side of the rear (in the left direction in FIGS. 1 to 3) of the main body case 2 by the sheet discharge roller 20 and the sheet discharge roller 21.

The stacker section 22 is provided with a stacker plate 23 at the upper rear part of the main body case 2, and the auxiliary stacker section 24 is slidable on the stacker plate 23 in the discharging direction of the recording paper 8 by a predetermined amount. It is attached.

The auxiliary stacker section 24 is composed of the stacker plate 2
The stacker plates 23 are arranged in a pair so as to sandwich both sides of the stacker plate 23.
A slide plate 24a slidably attached to
L-shaped auxiliary stacker plate 24c rotatably attached to the rear end of the slide plate 24a via a shaft 24b.
As shown in FIG. 1, the auxiliary stacker plate 24c is substantially upright on the rear side of the laser printer 1 and the recording paper 8 discharged to the stacker unit 22 falls behind the stacker unit 22. 2 and 3, in a state substantially parallel to the stacker plate 23, a substantially central portion of the recording paper 8 positioned a predetermined distance above the stacker plate 23 and ejected is placed. It rotates about the shaft 24b between the placed position where it is placed.

That is, the auxiliary stacker plate 24c is connected to the slide plate 24a via the shaft 24b and the arm portion 2 is connected.
4d, and the length of the arm portion 24d is, as shown in FIG. 2, the auxiliary stacker plate 24c is set to the above-mentioned mounting position, and the curled recording paper 8 is at the center of the curled recording paper 8. Auxiliary stacker plate 2
The curled front end portion and rear end portion of the recording paper 8 are formed to have a length slightly separated from the stacker plate 23 when the recording paper 8 is placed on the stacker 4c.

Further, as shown in FIGS. 2 and 3, the auxiliary stacker plate 24c has a double structure which is slidable in the discharging direction of the recording paper 8 and is arranged in accordance with the size of the recording paper 8 to be discharged. The length of the auxiliary stacker plate 24c in the discharge direction of the recording paper 8 can be adjusted.

The width of the auxiliary stacker plate 24c in the width direction is formed to be longer than the width of the maximum size recordable recording paper 8 of the laser printer 1 by a predetermined length. Even when the recording paper 8 is ejected to the stacker unit 22, both end portions in the width direction of the recording paper 8 have a predetermined portion at the center in the ejection direction of the auxiliary stacker plate 24c.
Placed on top.

Further, an extension stacker section 25 is disposed behind the stacker section 22, and the extension stacker section 2 is provided.
Reference numeral 5 denotes a slide plate 2 attached to the main body case 2 of the laser printer 1 so as to be slidable in the discharging direction of the recording paper 8.
5a, and a support plate 25b that is formed at a substantially right angle to the slide plate 25a and restricts the recording paper 8 placed on the stacker unit 22 from falling.

The slide plate 25a is slidably attached to the main body case 2 at a position lower than the stacker plate 23, and its surface is arranged at a position lower than the surface of the stacker plate 23 by a predetermined height. .

The extended stacker section 25 is used by sliding it backward as shown in FIG. 3 when stacking the recording papers 8 having a long length in the discharge direction of the recording papers 8 on the stacker plate 23. The support plate 25b holds the leading end of the large-sized recording paper 8 and holds the recording paper 8 in the stacker unit 2
The recording paper 8 having a large size is placed on the slide plate 25a which is lower than the stacker plate 23 while being placed on the slide plate 25a.

Next, the operation of this embodiment will be described.

In the laser printer 1 of this embodiment, the recording paper 8 which is curled by the fixing unit 12 and discharged from the paper discharge roller 20 to the stacker unit 22 is appropriately placed without curling the recording paper 8. There is a feature in doing it.

The operation of placing the recording paper 8 will be described below.
explain.

The laser printer 1 forms an electrostatic latent image on the photoconductor 3 uniformly charged by the charging unit 4 based on the image data by the optical device 19, and the photoconductor on which the electrostatic latent image is formed. Toner 3 is made to adhere to the developing unit 5 to form a visible image (development). The toner attached to the photoconductor 3 is transferred by the transfer unit 6 to the recording paper 8 conveyed from the paper feeding cassette 9, and the recording paper 8 on which the toner is transferred is conveyed to the fixing unit 12.

The cleaning unit 7 removes the residual toner from the photoconductor 3 whose transfer of the toner image has been completed by the transfer unit 6 and is charged again by the charging unit 4 to form the next electrostatic latent image. Be served.

The recording paper 8 conveyed to the fixing unit 12 is heated by the fixing roller 12a while being brought into close contact with the fixing roller 12a by the fixing roller 12b, so that the toner on the recording paper 8 is fixed on the recording paper 8 and the fixing roller 12a. 12a and fixing roller 12
It is conveyed in the direction of the paper discharge roller 20 by the rotation of b.

The recording paper 8 conveyed to the paper discharge roller 20 is
The sheet is pressed against the sheet discharge roller 20 by the sheet discharge roller 21, and is discharged onto the stacker unit 22 outside the laser printer 1 by the rotation of the sheet discharge roller 20.

At this time, when the recording sheet 8 is not curled by the fixing section 12, the recording sheet 8 is placed on the stacker section 22 in a state where the auxiliary stacker section 24 is set at the above-mentioned restriction position where the auxiliary stacker plate 24c is substantially upright. The recording papers 8 can be properly stacked even if they are stacked in
When the recording paper 8 is curled, as shown in FIG. 1, the stacker portion 2 is placed on the stacking portion of the recording paper 8 which is first placed on the stacker portion 22 and curled.
The leading edge of the recording paper 8 discharged onto the sheet 2 collides.

At this time, when the recording paper 8 is a relatively thick recording paper 8, the leading end of the recording paper 8 discharged later is discharged earlier and is curled. It slides on the mountain portion of the stack and is properly placed on the stacker unit 22.

However, in the case where the recording paper 8 is a relatively thin recording paper 8, as shown in FIG. 1, the leading end of the recording paper 8 ejected later is ejected first. The curled mountain portion of the recording paper 8 is crushed, and the leading end of the recording paper 8 ejected afterward is curled, so that the entire recording paper 8 curls and is properly placed on the stacker unit 22. Not done.

Therefore, in the laser printer 1 of the present embodiment, a relatively thin recording paper 8 having such a curl.
2 is placed on the stacker unit 22, the auxiliary stacker plate 24 of the auxiliary stacker unit 24 is placed as shown in FIG.
The auxiliary stacker plate 24c is moved to a position suitable for the size of the recording paper 8 to be ejected, by rotating c from the regulation position to the placement position described above and sliding the slide plate 24a.

That is, the auxiliary stacker plate 24c is disposed such that the substantially central portion of the recording paper 8 to be discharged is the auxiliary stacker plate 24c.
Set it to the position to be placed on top.

Further, the auxiliary stacker plate 24c is expanded and contracted in the front-rear direction of the recording paper 8 so that at least one side end of the leading end and the rear end of the recording paper 8 discharged onto the auxiliary stacker plate 24c is a stacker plate. Set the length so that it slightly floats away from 23.

In this state, the recording paper 8 is ejected from the paper ejection roller 20.
When the paper is discharged onto the stacker unit 22, the first recording paper 8
The front end of the recording paper 8 slides down on the stacker plate 23 and advances to the rear of the stacker unit 22 to slide down the rear end of the auxiliary stacker plate 24c.
The discharge of the recording paper 8 is completed before the contact with the surface.

At this time, the recording paper 8 has a predetermined portion in the middle portion in the discharging direction, in the present embodiment, most of it rides on the auxiliary stacker plate 24c and hangs from the auxiliary stacker plate 24c to the stacker plate 23 side. 8 is placed on the auxiliary stacker plate 24c in a state where at least one side end portion of the front end portion and the rear end portion of 8 is slightly floated.

At this time, as shown in FIG. 4, when the width of the auxiliary stacker plate 24c is formed to be narrower than the width of the recording paper 8, both end portions in the width direction of the recording paper 8 and both end portions in the front-rear direction are formed. It will hang from the auxiliary stacker plate 24c,
The curl of the recording paper 8 is increased, and the auxiliary stacker plate 24c
A mountain may be formed in the central portion of the upper recording paper 8, and the recording paper 8 to be ejected next may collide with the mountain and curl up, so that the recording paper 8 may not be ejected properly.

However, as described above, the auxiliary stacker plate 24c of this embodiment has a width wider than that of the recording paper 8 as shown in FIG. As shown in FIG.
It is placed with the upper surface of the portion placed on top being flat.

In this state, when the recording paper 8 is next ejected from the paper ejection roller 20, the leading end of the recording paper 8 comes into contact with the upper surface of the previously ejected recording paper 8. At this time, As described above, the recording paper 8 ejected earlier is placed on the auxiliary stacker plate 24c with its upper surface flat, so that the leading edge of the recording paper 8 is ejected onto the stack of the recording paper 8 ejected earlier. Instead of rolling due to resistance, the upper surface of the previously ejected recording paper 8 is slid, and the recording paper 8 is placed so as to overlap with the previously ejected recording paper 8.

Thereafter, the recording papers 8 which are sequentially ejected are mounted so that the leading end thereof slides on the upper surface of the previously ejected recording papers 8 and overlaps with the previously ejected recording papers 8 in the same manner as described above. Placed.

Therefore, the curled recording paper 8 is appropriately slid at the position of the auxiliary stacker plate 24c according to the size of the recording paper 8, and the auxiliary stacker plate 24 is also moved.
By adjusting the length of c itself by expanding and contracting, the recording paper 8
Irrespective of the size, the recording paper 8 can be appropriately placed without curling, and the placement property of the recording paper 8 can be improved.

When the size of the recording paper 8 is such that the recording paper 8 does not fit on the stacker plate 23,
As shown in FIG. 3, the expansion stacker unit 25 is slid rearward according to the size of the recording paper 8, that is, the length of the recording paper 8 in the discharge direction, and is adjusted to the size of the recording paper 8. Then, the set position of the auxiliary stacker plate 24c and the length of the auxiliary stacker plate 24c are adjusted in the same manner as above.

In this state, the recording paper 8 is ejected from the paper ejection roller 20.
When the recording paper 8 is discharged, the leading end of the recording paper 8 slides on the auxiliary stacker plate 24c and comes into contact with the stacker plate 23, and further slides on the stacker plate 23 to slide the expansion stacker unit 25. Abut on 25a.

When the recording paper 8 is further discharged, the leading end of the recording paper 8 slides on the slide plate 25a.

Thereafter, the trailing edge of the recording paper 8 is ejected by the paper ejection roller 2.
When discharged from 0, the slide plate 2 at the leading end of the recording paper 8
The movement of the recording paper 8 on the stacker unit 22 is stopped, the recording paper 8 is mostly placed on the auxiliary stacker plate 24c, and the leading end of the recording paper 8 is positioned on the slide plate 25a of the expansion stacker unit 25. Placed on.

At this time, since the surface of the slide plate 25a of the expansion stacker unit 25 is lower than the surface of the stacker plate 23 by a predetermined height, the leading end of the recording paper 8 has the stacker plate 23. Slide plate 2 from the rear end
Since it falls on 5a and slides on the slide plate 25a, the load on the recording paper 8 is small, it is possible to prevent the leading end of the recording paper 8 from curling, and the recording paper 8 does not curl.
The recording paper 8 is properly flat on the auxiliary stacker plate 24c, the stacker plate 23, and the slide plate 25a, and
The auxiliary stacker plate 24c can be placed in a state of being inclined downward from the slide plate 25a to the slide plate 25a.

In this way, when the next recording paper 8 is ejected onto the stacker section after the first recording paper 8 is placed, the next recording paper 8 will be the previously ejected recording paper. As described above, 8 is properly placed on the auxiliary stacker plate 24c, the stacker plate 23, and the slide plate 25a in a flat state, and is inclined downward from the auxiliary stacker plate 24c to the slide plate 25a. Therefore, the leading end of the recording paper 8 slides on the upper surface of the recording paper 8 placed first, and is placed so as to overlap the recording paper 8 placed first.

Since the support plate 25b, which is substantially perpendicular to the slide plate 25a, is formed in the expansion stacker unit 25, the large size recording paper 8 can be prevented from falling behind the laser printer 1. , Stacker section 2
It can be mounted appropriately on the second.

As described above, according to this embodiment, the recording paper 8
The stacking position of the auxiliary stacker plate 24c and the length of the auxiliary stacker plate 24c are adjusted in accordance with the size of the recording paper 8 and the extension stacker portion 25 is slid rearward, regardless of the size of the recording paper 8. The recording paper 8 can be placed properly without curling.
The mountability of can be improved.

Further, in this embodiment, since the auxiliary stacker plate 24c of the auxiliary stacker portion 24 can be moved between the regulating position and the mounting position, when the recording paper 8 is hard to curl, the auxiliary stacker plate 24c is used. By setting 24c to the regulation position, a larger amount of recording paper 8 can be placed on the stacker unit 22 at the same time.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the auxiliary stacker plate 24c of the auxiliary stacker portion 24 is replaced by the arm portion 24.
Although it is fixed at a right angle to d, it is not limited to this, and for example, some angle adjustment may be possible.

[0076]

According to the image forming apparatus of the present invention, the recording paper is placed flat on the auxiliary stacker portion higher than the stacker surface, and the recording paper to be discharged next is placed. , Its tip slides on the flat surface of the previously ejected / loaded recording paper without ejecting the resistance of the curls of the previously ejected / loaded recording paper, It is possible to place the recording paper so as to overlap the placed recording paper, and it is possible to improve the mountability of the recording paper on the stacker unit.

Further , the auxiliary stacker portion is positioned on the stacker surface to place the recording paper, and the stacker portion is located on the leading end side of the recording paper in the discharging direction of the recording paper and the leading end of the discharged recording paper. If it is formed so as to be movable between both positions of the regulation position that regulates the falling in the direction, and the curl is not imparted to the recording paper, or even if it is imparted, only a weak curl is imparted, Even if curl is applied, if the recording paper is thick enough not to be curled up due to the resistance of the pile of recording paper that has been ejected / placed first, move the auxiliary stacker section to the regulation position A larger amount of recording paper can be placed on the unit at the same time,
The usability of the image forming apparatus can be improved, and the recording paper can be appropriately placed on the stacker unit by setting the auxiliary stacker unit at the regulation position.

Further, as described in claim 2 , when the auxiliary stacker portion is formed so that the length of the auxiliary stacker portion with respect to the recording paper discharge direction is variable, the auxiliary stacker portion may be changed in accordance with the change in the size of the recording paper. By adjusting the length of the auxiliary stacker unit, recording sheets of various sizes can be appropriately placed on the auxiliary stacker unit without curling up, and the placement property can be further improved.

Further, according to a third aspect of the present invention , the length of the auxiliary stacker portion in the direction orthogonal to the recording paper discharge direction of the auxiliary stacker portion is the length of the maximum size recording paper to be discharged in that direction. If it is formed a predetermined length longer than this, the curl of the recording paper on the auxiliary stacker part due to the four edges of the recording paper placed on the auxiliary stacker part hanging from the auxiliary stacker part is prevented. Further, the recording paper can be made flatter on the auxiliary stacker portion, and the mountability of the recording paper can be further improved.

Further, as described in claim 4 , the stacker portion is formed on the leading end side of the recording paper discharged from the stacker surface to be lower than the stacker surface by a predetermined height, and the stacker is formed in the recording paper discharge direction. If the stacker has an extended stacker section on which the leading end of the recording paper is placed that is longer than the length of the surface, the stacker surface has a medium size that is frequently used, for example, A4 size recording paper. The image forming apparatus can be downsized by using the expansion stacker unit only when the recording paper having a size larger than the medium size is discharged and placed on the stacker unit.

Further, when the recording paper having a size larger than the stacker surface is discharged and placed, the expansion stacker portion is formed lower than the stacker surface, so that the recording paper is extended from the auxiliary stacker portion to the stacker surface and the expansion stacker portion. Can be placed with its front end in the discharging direction inclined downward, and the front end of the next recording paper to be discharged can be slid on the surface of the inclined recording paper and discharged.

As a result, it is possible to further improve the mountability of recording paper of a size larger than the stacker surface.

[Brief description of drawings]

FIG. 1 is an overall side cross-sectional view of a laser printer to which an embodiment of an image forming apparatus of the present invention is applied when an auxiliary stacker plate is at a restriction position.

FIG. 2 is an overall side sectional view of the laser printer of FIG. 1 when an auxiliary stacker plate is in a mounting position.

FIG. 3 is an overall side sectional view of the laser printer of FIG. 1 with the auxiliary stacker plate in a mounting position and the extended stacker unit pulled out.

FIG. 4 is a perspective view of the auxiliary stacker plate for showing the problem when the auxiliary stacker plate of the laser printer of FIG. 1 is narrower than the recording paper width.

5 is a perspective view of the auxiliary stacker plate showing the stacking of the recording paper when the auxiliary stacker plate of the laser printer of FIG. 1 is wider than the recording paper width.

[Explanation of symbols]

1 laser printer 2 body case 8 recording paper 12 Fixing part 20 Paper ejection roller 21 Paper ejection roller 22 Stacker section 23 Stacker board 24 Auxiliary stacker section 24a slide plate 24b axis 24c Auxiliary stacker plate 24d arm part 25 Extended stacker section 25a slide plate 25b support plate

Claims (4)

(57) [Claims] 1. An image forming apparatus for ejecting a recording paper, on which an image is recorded and having a curl in a predetermined direction, onto a stacker part with the curl winding direction facing the stacker surface side and mounting the image. the stacker unit, on the stacker face, a predetermined height higher than the stacker face, the auxiliary stacker portion is provided where the discharge direction substantially central portion of the recording paper is placed over a predetermined length, the The auxiliary stacker unit is located on the stacker surface and mounts the recording paper.
Placement position and destination of the stacker section in the paper discharge direction
The ejected recording paper positioned at the end side falls toward the front end
It is formed so that it can move between the regulation position that regulates
An image forming apparatus characterized by being provided. 2. The auxiliary stacker unit is arranged in the discharge direction of the recording paper of the auxiliary stacker unit.
The length is variable and formed.
The image forming apparatus described. 3. The auxiliary stacker section is orthogonal to a direction in which the auxiliary stacker section discharges the recording paper.
The length in the direction of the
Be formed a predetermined length longer than the length in that direction
The image forming apparatus according to claim 1 or 2, characterized in that
Place 4. The stacker section discharges the recording paper discharged from the stacker surface.
Formed on the front end side with a predetermined height lower than the stacker surface
The stacker surface in the discharge direction of the recording paper.
Extension of the leading edge of the recording paper longer than the length of
The stacker section is provided, and the stacker section is provided.
The image forming apparatus according to claim 3 .