JP3387759B2 - Sheet discharging device and 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 a sheet discharging apparatus having a function of discharging sheets to a tray such as a sorter and a finisher.

[0002]

2. Description of the Related Art Conventionally, in order to stably discharge and stack a sheet in a tray, a discharge roller is provided with a brim portion or a guide plate of the sheet is provided with unevenness, so that the sheet is discharged in a sheet discharge direction. This was done to prevent buckling or popping-out of the sheet during sheet discharge.

Further, a discharging needle is provided in the vicinity of the downstream side of the discharging roller to sufficiently remove static electricity on the surface of the sheet, thereby preventing stacking failure and jamming due to sticking of the sheet in the tray.

[0004]

However, as the functions of the image forming apparatus are speeded up, colorized, diversified such as double-sided, multiplexed, etc., the number of times the sheets are charged up increases, and per unit time. Since the amount of static electricity carried by the sheet as a medium on the tray increases,
There is a need to improve the performance of the static eliminator that neutralizes the sheet. Therefore, conventionally, by increasing the contact amount of the static eliminator with respect to the sheet, increasing the density of the static eliminator needles of the static eliminator, or making the pitch finer, it has been dealt with, but in any of the above directions, the sheet The sliding resistance of the static eliminator with respect to is increased.

As shown in FIG. 7, generally, in a sheet discharging device, a sheet static eliminator 403 is provided on the downstream side of the most downstream discharging roller pair 401, 402, and a tray 404 is further provided on the downstream side. The rear end is a pair of discharge rollers
After passing through the sheets 1, 402, the sheet P is discharged to the tray 404 in the unrestrained area while receiving the sliding resistance of the static eliminator 403. Therefore, when the sliding resistance increases, the sheet P ₀
However, there was a case where the tray 404 could not be completely pushed out, resulting in poor stacking or a jam due to it. In particular, in the bin-moving sorter and the like, since the bin moves vertically with respect to the discharge port, it is necessary to keep a distance between the bin and the discharge roller, which tends to cause the above-mentioned problems.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and its object is to reduce the sliding resistance of the static eliminator with respect to the sheet, and to improve the sheet discharging property and stacking property. To improve.

[0007]

In order to achieve the above object, the first invention is to provide at least one tray for storing sheets, sheet discharging means for discharging sheets to the tray, and a sheet to be discharged. A sheet stiffening unit that bends in a substantially wavy shape in a direction intersecting with the discharging direction, and a static eliminating unit that is provided on the downstream side of the sheet discharging unit and abuts the surface of the sheet discharged from the sheet discharging unit to neutralize the surface of the sheet. In the sheet discharging apparatus having the above-mentioned, the static eliminating means is provided with an abutting portion arranged in a shape substantially corresponding to the curved shape of the sheet.

With this configuration, the sliding resistance between the sheet and the discharging means when the sheet is discharged can be reduced, and the trailing edge of the sheet easily occurs in the free space after passing through the discharge roller. It is possible to solve problems such as defective feeding.

Since the contact portion of the charge eliminating means is arranged in correspondence with the curved shape of the sheet, it is possible to greatly bend the sheet and strengthen the rigidity of the sheet, thereby improving the dischargeability and stackability of the sheet. it can.

In particular, with respect to a sorter or the like in which the sheet discharging means and the tray move relative to each other to sort the sheets, the discharging means can be set to view the free space distance of the tray, so that the latitude against mutual interference can be improved and
The latitude of the layout at the time of design can also be improved.

The contact portion of the charge eliminating means is not limited to the one arranged in a shape substantially corresponding to the curved shape of the sheet over the entire length in the direction orthogonal to the sheet discharging direction, and a part of the contact portion of the sheet is provided. It may be arranged in a shape substantially corresponding to the curved shape.

A second aspect of the present invention is an image forming apparatus including an image forming section for forming an image on a sheet and a sheet discharging section for discharging the sheet on which the image is formed in the image forming section. A sheet discharge device according to claim 1 is provided in the section.

By doing so, it is possible to provide an image forming apparatus which is excellent in sheet dischargeability and stackability.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described based on the illustrated embodiments.

(First Embodiment) FIG. 1 is a sectional view showing a schematic structure of a part of an image forming apparatus provided with a sheet discharging apparatus according to the first embodiment.

As shown in FIG. 1, on the upper surface of the image forming apparatus 200, an automatic document feeder 300 for automatically circulating a document.
Is installed. The automatic document feeder 300 conveys the lowermost document of the document stack D on the document table 303 in the conveyance path 301.
In accordance with the above, the document is conveyed onto the platen glass 208, the document read here is conveyed along the conveyance path 302,
It is discharged above and stacked.

The image forming apparatus 200 uses a well-known electrophotographic method, and a detailed description thereof will be omitted here.
An original document positioned on the platen glass 208 is imaged on the photosensitive drum 201 by an optical system (not shown), and the developing device 202 and the transfer electrode 2 provided around the photosensitive drum 201 are formed.
The image is transferred to a sheet by 03 and is fixed by a fixing device. Here, the image forming unit includes a photosensitive drum 201, a developing device 202, and a transfer electrode 203.

FIG. 2 is a sectional view showing a schematic structure of the sheet discharging portion of the image forming apparatus 200, and FIG. 3 is a view of the vicinity of the sheet discharging needle 211 of the sheet discharging portion as viewed from the downstream side in the sheet discharging direction.

The sheet P is discharged onto the tray 210 while being corrugated in the discharge direction by a pair of discharge rollers 212a and 212b serving as a sheet discharging means and a sheet loosening means. The sheet charge eliminating needle 211 as a charge eliminating means is attached to the housing 200a, and the tip as an abutting portion is formed so as to overlap a certain amount in accordance with the shape of the stiffened sheet. Therefore, the sheet charge elimination needle 211 is brought into sliding contact with the sheet P over the entire surface of the sheet, so that the charge removal performance can be maintained and the sliding resistance against the sheet P can be suppressed to a minimum.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a partially cutaway sectional view showing a schematic structure of the sorting apparatus 100 provided in the image forming apparatus 200, and FIG.
6 is a cross-sectional view showing a schematic configuration of a sheet discharging unit of the sorting apparatus 100, and FIG. 6 is a view of the vicinity of the sheet discharging needle 8 of the sheet discharging unit of the sorting apparatus 100 as viewed from the downstream side in the sheet discharging direction.

Sorting device 100 as a sheet discharging device
Is a so-called pin-moving sorter, and bin trays b that are vertically stacked are moved up or down one by one by one rotation of the spiral cams 4 provided on both sides.

The sheet on which the image is formed by the image forming apparatus 200 is sent to the sorting apparatus 100 via a pair of discharge rollers (not shown), and the flapper 1 sorts the sorting path 6a,
The direction to the non-sort path 6b is selected (see FIG. 4). At the time of non-sort without classifying sheets,
All the sheets pass through the non-sort path 6b (the flapper 1 is in the chain line position) and are ejected to the non-sort tray 10. When sorting sheets, the sheets pass through the sort path 6a (the flapper 1 is in the solid line position) and serve as ejection means. the discharge roller pair 7a, the sheets discharged by 7b, the bin trays b ₁ ~b ₂₀ to lift synchronously accommodates.

As shown in FIG. 6 , the seat back rib 9 as the seat back support means is fixed to the plate 10 at three places in the longitudinal direction. With respect to the plate 10, the ribs 9 for supporting the sheet are movable in the vertical direction through the elongated holes, and the tops of the ribs 6 are located above the nips of the discharge rollers 7a and 7b, which is optimal for discharging the sheet P. It is fixed at a position that conveys the waist.

Also in this embodiment, as in the first embodiment,
In accordance with the shape of the seated sheet P, the tip portion as the contact portion of the sheet charge eliminating needle 8 as the charge eliminating means is
It is formed so that it overlaps slightly. In the present embodiment, the sheet charge elimination needle 8 is screwed to the mounting portion 11 provided in the sorting apparatus 100 main body as shown in FIG.

As shown in FIG. 5 , since the sorting apparatus 100 according to this embodiment is a bin-moving sorter, the distance between the sheet stopper b _a of the bin b and the discharge rollers 7a and 7b is set to be considerably long. However, with the above-mentioned configuration, the sheet P does not receive an excessive sliding resistance from the sheet static elimination needle 8.
Can be stably discharged onto the bin b.

Further, it goes without saying that the present configuration is not limited to the image forming apparatus and the sorting apparatus, and can be applied to any sheet discharging apparatus having a function of discharging sheets onto the tray.

[0028]

As described above, according to the first aspect of the present invention, since the contact portion of the discharging means is arranged so as to substantially correspond to the curved shape of the discharged sheet, the discharged sheet and the discharging means. Since the sliding resistance between the sheet and the sheet can be reduced, it is possible to solve problems such as pop-out defects that tend to occur in the free space after the trailing edge of the sheet has passed through the discharge roller. Also, more aggressively,
It is also possible to greatly bend the seat and strengthen the waist of the seat, which improves the discharge and stackability of the seat.

Further, particularly in a sorter or the like in which the sheet discharging means and the tray move relatively to sort the sheets, the free space distance between the discharging means and the tray can be set to be long, so that the latitude against mutual interference can be improved. The latitude of the design layout can also be improved.

According to the second aspect of the present invention, it is possible to provide an image forming apparatus having a good sheet discharging property and stacking property.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a schematic configuration of a sheet discharging unit of the image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is an enlarged side view showing a schematic configuration of a sheet discharging unit of the image forming apparatus according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a schematic configuration of a sorting device according to a second embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view showing a schematic configuration of a sheet discharging unit of a sorting device according to a second embodiment of the present invention.

FIG. 6 is an enlarged side view showing a schematic configuration of a sheet discharging unit of a sorting device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a state of stacking failure of a conventional sheet discharging device.

[Explanation of symbols]

P, P ₀ sheets 210, 404 tray 10 non-sort tray b bin trays 7a, 7b, 212a, 212b, 401, 402 discharge rollers 8, 211, 403 sheet static elimination needles 9 sheet ribs 100 sorting apparatus 200 image forming apparatus

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 29/70 B65H 5/00 G03G 15/00 530

Claims (2)

(57) [Claims] 1. At least one tray for accommodating sheets, sheet ejection means for ejecting sheets to the tray, sheet stiffening means for curving the ejected sheets in a substantially wavy shape in a direction intersecting the ejection direction, A sheet discharging device provided downstream of the sheet discharging means for discharging electricity from the sheet surface by contacting the surface of the sheet discharged from the sheet discharging means; A sheet ejection device comprising a contact portion arranged in a shape substantially corresponding to the shape. 2. An image forming apparatus, comprising: an image forming section for forming an image on a sheet; and a sheet discharging section for discharging the sheet on which the image is formed in the image forming section, wherein the sheet discharging section comprises: An image forming apparatus comprising the sheet discharging device described in 1.