JPH0891665A - Paper discharging device - Google Patents

Abstract

PURPOSE: To provide a paper discharging device suppressing the occurrence of a paper discharge mistake even when the paper discharging speed of an image forming device is increased. CONSTITUTION: This paper discharging device is provided with a paper discharge base 1 constituted of a front plate 1a arranged on the downstream side in the conveying direction of the printed paper and having a butt plate 1f with which the tip of the printed paper is brought into contact at the upper section, a rear plate 1b arranged on the upstream side in the conveying direction of the printed paper, the right and left side plates 1c, 1d, and a bottom plate 1e and jump bases 3 arranged on a paper discharge passage 2 connecting the image forming device and the paper discharge base 1 and straightening the printed paper. The paper discharge base 1 is provided with a negative pressure means 4 setting the inside of the paper discharge base 1 to the negative pressure at the lower section on the upstream side in the conveying direction of the printed paper of the right and left side plates 1c, 1d and/or on the rear plate 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device for stacking printed paper discharged from an image forming apparatus.

[0002]

2. Description of the Related Art The demand for image forming apparatuses such as printing machines and copying machines used in offices and the like has increased year by year, and is now indispensable. Along with this, competition for cost reduction, high functionality, noise prevention, and high speed is intensifying. Especially regarding speeding up, there is a strong demand from users because it is directly related to work efficiency. Currently, many printing machines used in offices are stencil printing machines because of their ease of use. The greatest feature of this printing machine is that it can print at a higher speed and at a lower cost than a copying machine. However, the higher the speed, the more difficult it becomes to accurately feed and discharge the sheet, and thus increase the probability of feeding a large number of sheets at the time of sheet feeding and a discharge error.

Conventionally, as shown in FIG. 16, a sheet discharging device used in an image forming apparatus conveys a print sheet from an image forming section in a sheet ejecting direction by a conveying means such as a conveyer belt (not shown) and jumps on a jump table. After passing through 53, the paper is sent to the paper ejection tray 51. The jump base 53 curls the printing paper having a weak stiffness from both ends thereof, and makes the printing paper have a U-shaped cross-section so that the entire printing paper has a stiffness, and the printing paper is ejected to the paper ejection base 51. At this time, the printing paper is raised so that the printing paper does not fall from the front end and is lifted away. However, the condition of the discharged printing paper changes depending on the conditions such as the size and thickness of the printing paper, the discharging speed, and so on. Remains in the vicinity of the jump base 53, there is a risk that the leading edge of the printing paper that will be ejected later collides with this and a paper ejection error occurs. In this conventional paper discharge device, the occurrence of a paper discharge error is prevented by adjusting the angle, direction, etc. of the jump base 53.

[0004]

However, as described above, the image forming apparatus tends to be further speeded up in the future, and the prevention of a paper discharge error cannot be coped with only by adjusting the jump base 53. . This is because the discharged printing paper 55 has a larger kinetic energy and tends to fly further as the discharging speed becomes faster even if the degree of curling at both ends is reduced, and the air resistance at the lower surface is increased. The printing paper 55 itself rises by receiving the
The trailing edge of the printing paper 55 collides with the leading edge of the next printing paper 55 ′, causing a paper ejection error (see FIG. 17). On the other hand, if the printing paper 55 is not curled at all, the stiffness of the printing paper 55 is weak, and the leading edge of the printing paper falls first, causing a paper ejection error as described above (see FIG. 18).

The present invention solves the above-mentioned problems and provides a paper discharge device which suppresses the occurrence of paper discharge errors even when the paper discharge speed of the image forming apparatus is increased (130 sheets / minute or more). To aim.

[0006]

According to the first aspect of the present invention,
A paper discharge device that is connected to an image forming apparatus and stacks printed paper sheets, and is disposed on the downstream side in the printed paper sheet conveyance direction, and has a front plate having an abutting plate on the upper part of which a tip of the printed paper sheet comes into contact. And a paper ejection tray including a rear surface plate disposed on the upstream side in the printed sheet conveyance direction, left and right side plates, and a bottom plate, and a paper ejection passage that connects the image forming apparatus and the paper ejection tray. In a paper discharge device provided with a jump base for supporting the printed paper, the paper discharge base is a lower part of the left and right side plates on the upstream side in the printed paper conveyance direction and / or the rear plate. In addition, negative pressure means for making a negative pressure inside the discharge table is provided.

According to a second aspect of the present invention, in the paper discharge device according to the first aspect, the negative pressure means is further provided so as to be movable in the vertical direction.

According to a third aspect of the present invention, in the sheet discharge device according to the first or second aspect, the sheet discharge tray is further provided on the upper portion of the left and right side plates on the downstream side in the printed sheet conveying direction or the front plate. It is characterized in that it is provided with a blowing means for blowing air toward the inside of the.

According to a fourth aspect of the present invention, in the paper discharge device according to the first, second or third aspect, the abutting plate has a contact surface with the leading end of the printed paper. The front end is formed in an arc shape that faces upward.

According to a fifth aspect of the present invention, in a paper discharge device which is connected to an image forming apparatus and stacks printed sheets, the sheet is arranged on the downstream side in the printed sheet conveying direction, and the tip of the printed sheets is provided on the upper side thereof. A paper ejection table including a front panel having an abutting plate that abuts, a rear panel disposed on the upstream side in the printed sheet conveying direction, left and right side panels, and a bottom panel, the image forming apparatus and the paper ejection table. And a jump table that is disposed on the paper discharge carriage and that supports the printed paper. The paper discharge tray is for printing the left and right side plates. Blower means disposed on the lower side of the downstream side of the printed sheet transport direction or on the front plate, and blower means for blowing air toward the inside of the paper discharge tray, and on the upper part of the left and right side plates near the downstream side of the printed sheet transport direction. The printed sheet on top of it And a stop member for stopping the front end of the printed sheet so that the front end of the printed sheet does not get over the end plate. Characterize.

According to a sixth aspect of the present invention, in the paper discharge device according to the fifth aspect, the contact surface of the retaining member with the printed sheet is a circle in which the printed sheet is directed upward. It is characterized in that it is formed in an arc shape.

According to a seventh aspect of the present invention, in the heat-sensitive stencil plate making apparatus according to the fifth aspect, further, the retaining members are provided on the left and right side plates near the downstream side end and the upstream side end in the printed sheet conveying direction. In between, it is movably provided in synchronization with the conveying speed of the printed paper.

[0013]

According to the first aspect of the present invention, since the negative pressure means arranged upstream in the conveying direction of the printed sheet makes the inside of the sheet discharge table a negative pressure, the printed sheet has its rear end downward. Attracted.

According to the second aspect of the present invention, the negative pressure means moves in correspondence with the amount of the printed sheets stacked inside the discharge tray.

According to the third aspect of the present invention, the negative pressure means arranged on the upstream side in the printed sheet conveying direction makes the inside of the discharge tray a negative pressure and is arranged on the downstream side in the printed sheet conveying direction. Since the blown air means blows air toward the inside of the paper ejection tray, the printed sheet is attracted downward at its rear end,
The tip is sent upward.

According to the fourth aspect of the present invention, the leading edge of the printed sheet that abuts against the abutting plate is directed upward along the abutting surface of the abutting plate formed in an arc shape.

According to the fifth aspect of the present invention, since the air blowing means disposed on the downstream side in the printed sheet conveying direction blows air toward the inside of the sheet discharge tray, the printed sheet has its leading end upward. To the abutment plate, and the substantially central portion of the abutment plate is retained on the retaining member, and then dropped from the rear end into the paper ejection tray.

According to the sixth aspect of the present invention, since the air blowing means disposed on the downstream side in the conveying direction of the printed paper blows the air toward the inside of the paper discharge tray, the printed paper has its leading end upward. Sent to the abutting plate and stopped at the substantially central portion on the arc-shaped stop member,
It falls from the rear edge into the output tray.

According to the invention as set forth in claim 7, since the air blowing means disposed on the downstream side in the printed sheet conveying direction blows air toward the inside of the paper discharge tray, the printed sheet has its front end upward. Sent to the abutment plate, and the substantially central portion is retained on a retaining member that moves in synchronization with the conveyance speed of the printed sheet, and then falls from the rear end into the discharge tray. .

[0020]

1 is a schematic view of a paper discharge device showing a first embodiment of the present invention. In the figure, the paper discharge device is mainly composed of a paper discharge base 1, a paper transport base 2, a jump base 3, negative pressure means 4, and the like.

The paper discharge tray 1 includes a front plate 1a located on the downstream side in the paper discharge direction, which is the printed paper conveyance direction, a rear plate 1b located on the upstream side in the paper discharge direction, a left side plate 1c, a right side plate 1d, and a bottom plate 1e. It has a box shape mainly composed of. An abutting plate 1f is integrally provided on the upper end of the front plate 1a. Protruding members 1g, 1g projecting toward the inside of the paper ejection tray 1 are provided integrally with the respective side plates 1c, 1d at a position slightly upstream of the central portion of the left right plates 1c, 1d in the paper ejection direction. The rear plate 1b and the bottom plate 1e are fixed to each other at their end portions in contact with each other, and the front plate 1a is movable in the paper ejection direction at the end portion in contact with the bottom plate 1e and the paper ejection tray 1
Is rotatably attached to the outside of the. The left and right side plates 1c and 1d are attached at their end portions in contact with the bottom plate 1e so as to be movable in the direction orthogonal to the paper discharge direction and rotatable toward the outside of the paper discharge tray 1.

At the upper end of the rear plate 1b, there is attached a paper carrying table 2 which forms a paper discharge passage. The sheet conveying table 2 is a plate material and guides printed sheets conveyed from an image forming apparatus (not shown) to the sheet discharging table 1. A transport means (not shown) such as a belt conveyor may be provided on the upstream side of the sheet transport table 2 in the sheet discharge direction.

On the upper surface of the paper transport table 2, the jump table 3,
3 is attached. The jump table 3 deforms the printed paper that is conveyed so that the cross-sectional shape thereof is a substantially U-shape, and allows the printed paper to have a waist. It has a well-known structure for ejecting toward the paper ejection tray 1 so as to face toward.

Fans 4 and 4 as negative pressure means are attached to the lower portions of the left and right side plates 1c and 1d near the upstream end in the sheet discharge direction. The fans 4 and 4 are rotationally driven by a drive device (not shown), and discharge the air inside the paper ejection tray 1 to the outside to generate a negative pressure inside the paper ejection tray 1.

The operation of the first embodiment will be described below with reference to FIG. When the printed sheet 5 conveyed from the image forming apparatus passes through the jump table 3 on the sheet discharge conveyor table 2,
The paper is conveyed from the both ends to the paper ejection tray 1 while being curled and stiffened (see FIG. 2A). At this time, the fan 4 is operating, but the printed paper 5 is not strongly attracted downward because the printed paper 5 is strongly conveyed while being strongly supported. Rather, due to the interaction between the jump table 3 and the high-speed transport speed, the wind pressure is received from below in the traveling direction, and the wind pressure rises (see FIG. 2B). Then, when the front end of the printed paper 5 approaches the front plate 1a (abutting plate 1f), the printed paper 5 closes the upper part of the paper output tray 1, so that the fan 4 acts to cause the paper output tray 1 to move. The inside becomes negative pressure, and the printed paper 5 starts to be attracted downward (see FIG. 2C). At this time, since the printed paper 5 still maintains a certain transport speed, wind pressure acts on the front end of the printed paper 5, and the rear end of the printed paper 5 is lower than the front end. . When the front end of the printed paper 5 comes into contact with the front plate 1a (abutting plate 1f), the printed paper 5 is moved by its own weight and the action of the fan 4.
The paper is accommodated inside the paper ejection tray 1 from its rear end (FIG. 2D).
reference). The next printed sheet 5 ′ is conveyed immediately after the printed sheet 5, but since the rear end of the printed sheet 5 is forcibly attracted downward by the fan 4, the printed sheet 5 ′ is conveyed. Collision between the rear end and the front end of the printed paper 5 ′ is avoided, and good paper discharge can be performed.

The printed sheet 5 discharged is a front plate 1a, a rear plate 1b, and projecting members 1g, 1g inside the discharge tray 1.
The items are sequentially loaded in the space surrounded by. The operator is
After tilting the front plate 1a toward the outside of the paper ejection tray 1, the side plate 1
The printed paper 5 can be easily taken out by inserting a hand between c and the protruding member 1g or between the side plate 1d and the protruding member 1g (see FIG. 3).

In the conventional paper discharge method, the maximum amount of paper that can be discharged is 130 sheets / minute, and when the paper discharge speed is higher than this, the next printed sheet is printed at the trailing edge of the discharged printed sheet. Although the leading edge of the paper collided to cause a paper ejection error, as a result of an experiment using the paper ejection apparatus of the present invention, 200 sheets /
It was confirmed that the paper was discharged well up to the minute.

In the above embodiment, the fan 4 is installed on the left and right side plates 1.
The fan 4 may be provided on the rear face plate 1b, or may be provided on both the left and right side plates 1c, 1d and the rear face plate 1b. It may be.

FIG. 4 shows a second embodiment of the present invention. Compared to the first embodiment, this embodiment is different from the first embodiment in that the left and right side plates 1c and 1d are provided with vertically movable fans 6 and 6, and the fans 6 and 6 are vertically moved. It differs from the first embodiment in that the driving means 7 is provided.

The left and right side plates 1c, 1d have cutouts 1h, 1
h are respectively formed, and fans 6 and 6 are attached to the notches 1h and 1h so as to be vertically movable.
Further, a bellows 8 for maintaining airtightness inside the paper ejection tray 1 is attached to a gap between the fan 6 and the cutout portion 1h. A bracket 6a is attached to one side surface of the fan 6.

A drive means 7 is disposed on the side of the fan 6 on the side where the bracket 6a is attached.
The drive means 7 includes drive pulleys 7a, 7a, driven pulleys 7b, 7b, endless belts 7c, 7c, drive shaft 7
d, mainly composed of a drive motor (not shown).
The drive pulleys 7a, 7a are rotatably attached to the left and right side plates 1c, 1d, respectively. Drive shaft 7d
Is rotatably supported by a non-moving member (not shown) of the main body of the paper discharge device, and driven pulleys 7b, 7b are provided at both ends thereof.
b is attached. A pinion (not shown) is attached to the center of the drive shaft 7d, and the drive shaft 7d is rotationally driven by transmitting a rotational force from a drive means (not shown) provided in the main body of the paper discharge device via the pinion. It The drive pulley 7a and the driven pulley 7b are connected by an endless belt 7c.
b is rotated in synchronization with the drive pulley 7a. Also,
A bracket 6a is attached to the endless belt 7c, and the fan 6 is configured to move up and down as the endless belt 7c moves. Although only the drive pulley 7a, the driven pulley 7b, and the endless belt 7c on the left side plate 1c side are shown in FIG. 4, the right side plate 1d has the same configuration as the left side plate 1c.

The operation of the second embodiment will be described below with reference to FIG. As with the first embodiment, the printed paper 5 is placed on the paper ejection tray 1 while being supported by the jump tray 3.
Be transported to. Then, the pressure rises from below the traveling direction (see FIG. 5A), and when the front end of the printed paper 5 approaches the front plate 1a (abutting plate 1f), the fan 6 acts to discharge the paper 1 The printed sheet 5 starts to be attracted downward (see FIG. 5B) due to negative pressure inside the sheet, and the printed sheet 5 is moved from its rear end to the discharge tray 1 by the action of its own weight and the fan 6. It is housed inside (see FIG. 5D). Immediately after the printed paper 5, the next printed paper 5'is being conveyed.
Since the trailing edge of the printed sheet 5 is forcibly pulled downward by the fan 6, the trailing edge of the printed sheet 5 and the printed sheet 5 '
Collision with the tip of is avoided. After that, printed paper 5
Since the fan 6 rises due to the operation of the driving means (not shown) as the stacking amount of the paper is increased (see FIG. 5D), the fan 6 is not covered by the printed paper 5, and the fan 6 always ejects the paper. Since the inside of the table 1 is in a negative pressure state, good paper discharge can always be performed.

FIG. 6 shows a third embodiment of the present invention. Compared to the first embodiment, this embodiment is different from the first embodiment in that the left and right side plates 1c and 1d are provided with blower fans 9 and 9 as blower means.

Blower fans 9 and 9 are attached to the upper portions of the left and right side plates 1c and 1d, which are close to the ends on the downstream side in the sheet discharge direction. The blower fans 9 and 9 are rotationally driven by a driving device (not shown), and blow outside air into the inside of the paper ejection tray 1.

The operation of the third embodiment will be described below with reference to FIG. As with the first embodiment, the printed paper 5 is placed on the paper ejection tray 1 while being supported by the jump tray 3.
(See FIG. 7A). Then, it receives wind pressure from below in the traveling direction and rises up (see FIG. 7B), and further receives air from the blower fan 9 and rises up further, so that the front end of the printed paper 5 comes to the front plate 1a.
When the printed sheet 5 approaches the (abutting plate 1f) and moves away from the jump base 3, the fan 4 acts to eject the paper 1.
The inside of the sheet becomes negative pressure and the printed sheet 5 starts to be attracted downward. At this time, the angle θ formed between the front end and the rear end of the printed paper 5 becomes smaller than that in the first embodiment (see FIG. 7C), and the force that the printed paper 5 tends to expand. Is larger than that in the first embodiment, the trailing edge of the printed paper 5 is lower than that in the first embodiment (see FIG. 7D), and the printed paper 5 collides with the next printed paper 5 ′. The possibility of occurrence of the above is further reduced, and better paper discharge can be performed.

In the above embodiment, the blower fan 9 is arranged above the left and right side plates 1c, 1d near the downstream end in the sheet discharge direction, but the blower fan 9 may be provided on the front plate 1a. Further, a configuration may be adopted in which the blower fan 9 is provided on the paper ejection tray 1 shown in FIG. Further, as the air blowing means, instead of the air blowing fan 9, a duct or the like for sending the air from another air blowing device into the inside of the paper ejection tray 1 may be provided.

FIG. 8 shows a fourth embodiment of the present invention. Compared to the first embodiment, this embodiment is different from the first embodiment in that an abutting plate 1i is provided instead of the abutting plate 1f so that the contact surface with the printed paper 5 has an arc shape. , Different from the first embodiment.

As shown in FIG. 8, the abutting plate 1i has a contact surface with the printed paper 5 formed in an arc shape in which the front end of the printed paper 5 is directed upward.
The front end of the printed paper 5 is bent at a substantially right angle toward the inside of the paper ejection tray 1 so that the front end of the printed paper 5 does not get over the abutting plate 1i.

The operation of the fourth embodiment will be described below with reference to FIG. As with the first embodiment, the printed paper 5 is placed on the paper ejection tray 1 while being supported by the jump tray 3.
(See FIG. 9A). Then, it receives wind pressure from below in the traveling direction and rises up (see FIG. 9B), and the leading end of the printed paper 5 contacts the abutting plate 1i. The front end of the printed paper 5 moves upward along the shape of the butting plate 1i, and its tip comes into contact with the bent portion formed at the tip of the butting plate 1i (see FIG. 9C).
Then, the curl at both ends applied to the printed paper 5 when passing through the jump table 3 is released, and the printed paper 5 is
It becomes easy to bend from around the center, and printed paper 5
Causes the rear end to be lowered as compared with the first embodiment (see FIG. 9D). Therefore, the possibility of collision between the printed paper 5 and the next printed paper 5 ′ is further reduced, and more favorable paper discharge can be performed.

In each of the first, second, third and fourth embodiments,
Although the fan 4 or the fan 6 is used as the negative pressure means,
Instead of the fan 4 or the fan 6, a duct may be provided in the paper discharge tray 1, and air may be sucked from the inside of the paper discharge tray 1 by another suction device.

FIG. 10 shows a fifth embodiment of the present invention. In this embodiment, a paper discharge table 11 having a pin 10 as a retaining member is used. The paper ejection tray 11 includes a front plate 11a, a rear plate 11b, a left side plate 11c, a right side plate 11d,
The bottom plate 11e and the pins 10 are mainly included.

The paper ejection tray 11 has a box shape similar to that of the paper ejection tray 1 of the first embodiment, and the front plate 11a is movable in the paper ejection direction and faces the outside of the paper ejection tray 11. The left and right side plates 11c and 11d are configured to be movable in a direction orthogonal to the paper discharge direction and rotatable toward the outside of the paper discharge tray 11, respectively. Left and right side plate 11c,
Protruding members 11g, 11g that protrude toward the inside of the paper ejection tray 11 are located slightly upstream of the central portion of 11d in the paper ejection direction.
Is integrally provided with each of the side plates 11c and 11d.
The rear surface plate 11b and the left and right side plates 11c and 11d are provided with a single opening 11h or a plurality of openings 11h, and are configured to allow air to flow through the inside of the discharge tray 11 to the outside. At the upper end of the front plate 11a, an abutting plate 11f whose front end is bent substantially at a right angle toward the inside of the paper ejection tray 11
Are integrally provided with the front plate 11a. A blower fan 9 similar to that used in the third embodiment is attached to the front plate 11a, and the left and right side plates 11c, 1 are attached.
Pins 10 and 10 are provided on the upper part of the downstream side of 1d in the sheet discharge direction.
Are integrally provided with the side plates 11c and 11d.

The operation of the fifth embodiment will be described below with reference to FIG. The printed paper 5 is conveyed to the paper discharge base 11 while being stiffened by the jump base 3 as in the first embodiment (see FIG. 11A). Then, the printed paper sheet 5 is blown up from the lower side in the traveling direction and from the blower fan 9 and soars upward, and its leading end is brought into contact with the abutting plate 11f. At this time, the front end of the printed paper 5 stops at the bent front end of the abutting plate 11f, and the curl at both ends of the printed paper 5 provided by the jump table 3 is released. The curled sheet is released and the printed sheet 5 having lost its waist is retained on the pin 10 with its central portion protruding downward (see FIG. 11B). After that, the printed paper 5 falls below the rear end portion due to its own weight (see FIG. 11C), the rear end portion is first accommodated inside the paper ejection tray 11, and then the front end portion is pinned. The paper 10 drops while sliding on 10 and the printed paper 5 is completely stored in the paper discharge tray 11 (see FIG. 11D).

During the above-mentioned operation, in the state of FIG. 11C, the trailing edge of the printed sheet 5 collides with the leading edge of the next printed sheet 5'because it loses its waist and easily falls due to its own weight. By avoiding the above, it is possible to prevent a paper discharge error and perform good paper discharge.

In the above embodiment, the blower fan 9 is attached to the front plate 1.
1a, but the blower fan 9 includes the left and right side plates 11c, 1c.
It may be provided in the upper part near the downstream end of 1d in the sheet discharge direction. Further, as the air blowing means, instead of the air blowing fan 9, a duct or the like may be provided for sending air from another air blowing device into the inside of the paper ejection tray 1.

FIG. 12 shows a modification of the fifth embodiment of the present invention. Compared to the fifth embodiment, this modification is different from the pin 10 in that the block 12 serving as a retaining member is used.
Is different from the fifth embodiment in that The block 12 has a contact surface with the printed paper 5 for the printed paper 5
When the abutting contacts, the tip is formed in an arc shape that faces upward.

The operation of this modification will be described below with reference to FIG. The printed paper 5 is conveyed to the paper discharge base 11 while being stretched by the jump base 3 (FIG. 1).
3 (a)). At this time, since various kinds of paper are used as the printed paper 5, in the fifth embodiment, the tip of the printed paper 5 may come into contact with the pin 10. However, in this modification, since the contact surface of the block 12 with the front end of the printed paper 5 is formed in an arc shape, even if the front end of the printed paper 5 contacts (FIG. 13B).
(See), the tip faces upward and contacts the abutment plate 11f. At this time, the front end of the printed paper 5 stops at the bent front end of the abutting plate 11f, and the printed paper 5 ends.
On the other hand, the curl at both ends provided by the jump table 3 is released (see FIG. 13C). The curled sheet is released, and the stiff printed sheet 5 is retained on the block 12 and then falls below the rear end due to its own weight, and the rear end is first accommodated in the discharge tray 11. Then, the leading end falls while sliding on the block 12, and the storage of the printed paper 5 in the paper discharge tray 11 is completed (see FIG. 13D).

Also in this modification, the trailing edge of the printed sheet 5 loses its waist and is easily lowered due to its own weight, so that the collision with the leading edge of the next printed sheet 5'is avoided and a discharge error is prevented. As a result, good paper ejection is performed.

FIG. 14 shows a sixth embodiment of the present invention. In this embodiment, a paper discharge table 21 having a pin 20 as a movable stopping member is used. Paper ejection table 21
Is mainly composed of a front plate 21a, a rear plate 21b, a left side plate 21c, a right side plate 21d, a bottom plate 21e, pins 20 and the like.

The paper ejection tray 21 has a box shape similar to that of the paper ejection tray 1 of the first embodiment, and the front plate 21a is movable in the paper ejection direction and faces the outside of the paper ejection tray 21. The left and right side plates 21c, 21d are configured to be movable in a direction orthogonal to the paper discharge direction and rotatable toward the outside of the paper discharge table 21. Left and right side plate 21c,
Projecting members 21g, 21g projecting toward the inside of the paper discharge tray 21 are provided on the side plates 21 on the upstream side of 21d in the paper discharge direction.
It is provided integrally with c and 21d. An abutting plate 21f is integrally provided with the front plate 21a at the upper end of the front plate 21a. Further, the same blower fan 9 as that used in the third embodiment is attached to the front plate 21a.

Four rollers 22, 22, 22, 22 are rotatably attached to the upper portions of the left and right side plates 21c, 21d, which are located upstream of the sheet discharge direction and upstream of the sheet discharge direction. An endless belt 2 in which a pin 20 is planted between each roller 22 and 22 mounted on the same side plate.
3 has been passed over. Further, a driving means 23 for rotationally driving the roller 22 is connected to either one of the rollers 22, 22 attached to the same side plate. Roller 2 attached to each side plate 21c, 21d
The drive means 23, 23 for respectively driving 2, 22 are
They are synchronized with each other, and are also controlled so as to be synchronized with the discharge speed of the printed paper 5 from the image forming apparatus.

The operation of the sixth embodiment will be described below with reference to FIG. The printed paper 5 is conveyed to the paper discharge base 21 while being stiffened by the jump base 3 as in the first embodiment (see FIG. 15A). Then, the printed paper sheet 5 is blown up from the lower side in the traveling direction and from the blower fan 9 and soars upward, and its leading end is brought into contact with the abutting plate 21f. At this time, the front end of the printed paper 5 stops at the bent front end of the abutting plate 21f, and the curl at both ends given to the printed paper 5 by the jump table 3 is released. The curled paper is released and the printed paper sheet 5 that has lost its waist is retained on the pin 20 with its central portion protruding downward (see FIG. 15B). After that, the roller 2 is driven by the driving means 23, 23.
2 and 22 are driven to rotate, respectively, so that the pin 2
0 and 20 proceed to the downstream side in the paper discharge direction, and the pins 20 and 20 are retracted from below the printed paper 5 (see FIG. 15C). The printed paper 5 falls below the rear end due to its own weight, and the rear end is first accommodated inside the paper ejection tray 21, and then the front end drops and the paper ejection tray for the printed paper 5 is dropped. The storage in 21 is completed (see FIG. 15D).

With this configuration, the pin 2
Since 0 and 20 are always located rearward and downward with respect to the front end of the printed paper 5, collision of the front end of the printed paper 5 with the pin 20 is avoided, and a paper ejection error is prevented and good paper ejection is achieved. It can be carried out.

In the above embodiment, the blower fan 9 is installed on the front plate 2.
1a, but the blower fan 9 includes the left and right side plates 21c, 2
It may be provided in the upper part near the downstream end of 1d in the sheet discharge direction. Further, as the air blowing means, instead of the air blowing fan 9, a duct or the like may be provided for sending air from another air blowing device into the inside of the paper ejection tray 1.

[0055]

According to the first aspect of the present invention, the negative pressure means arranged upstream in the conveying direction of the printed sheet makes the inside of the discharge tray negative pressure, and the rear end of the printed sheet is downward. Since the paper is attracted and accommodated inside the paper discharge tray from the rear end, collision between the rear end of the printed paper and the front end of the next printed paper is avoided, and the paper can be discharged well.

According to the second aspect of the present invention, since the negative pressure means moves in accordance with the amount of the printed paper loaded inside the paper output tray, the printed paper loaded inside the paper output tray is printed. Since the negative pressure means is prevented from being covered by the negative pressure means and the negative pressure means always keeps the negative pressure inside the discharge tray, the printed paper is
Since the trailing edge is pulled downward and is stored inside the paper ejection tray from the trailing edge, collision between the trailing edge of the printed sheet and the leading edge of the next printed sheet is avoided, and the sheet is ejected well. be able to.

According to the third aspect of the present invention, the negative pressure means arranged upstream in the conveying direction of the printed sheet makes the inside of the discharge tray negative pressure and is arranged in the downstream side in the conveying direction of the printed sheet. Since the blown air blowing means blows the air toward the inside of the paper ejection tray, the printed paper is sent further upward at its leading end so that the trailing end is lowered and the trailing end is attracted further downward. Collision between the edge and the leading edge of the next printed sheet is further avoided, and better sheet discharge can be performed.

According to the fourth aspect of the present invention, since the leading edge of the printed sheet contacting the abutting plate is directed upward along the abutting surface of the abutting plate formed in an arc shape, the printing is performed. The trailing edge of the printed sheet is lowered because the leading edge of the printed sheet is fed further upward, and the trailing edge is pulled further downward, so that collision between the trailing edge and the leading edge of the next printed sheet is further avoided, and Good paper discharge can be performed.

According to the fifth aspect of the present invention, the air blowing means disposed on the downstream side in the conveying direction of the printed paper blows air toward the inside of the paper discharge tray, and the front end of the printed paper moves upward. After being sent and abutted against the abutment plate, its approximately central portion is retained on the retaining member and then falls from the rear end into the output tray, so that the rear end and the front end of the next printed sheet The collision can be avoided, and good paper discharge can be performed.

According to the sixth aspect of the present invention, the air blowing means disposed on the downstream side in the printed sheet conveying direction blows air toward the inside of the paper discharge tray, and the printed sheet has its leading end upward. After being sent and abutted against the abutting plate, the substantially central part of the abutment plate is retained on a retaining member formed in an arc shape, and then falls from the rear end into the discharge tray. Collision with the front end of the printed paper can be avoided, and good paper ejection can be performed. Further, collision between the front end of the printed paper and the retention member can be avoided, and thus even better paper ejection can be performed. .

According to the seventh aspect of the present invention, the air blowing means disposed on the downstream side in the conveying direction of the printed paper blows the air toward the inside of the paper discharge tray, and the printed paper has its leading end upward. Since it is sent and abutted against the abutment plate, its approximate center part is retained on a retaining member that moves in synchronization with the conveyance speed of the printed sheet, and then falls from the rear end into the delivery tray. , The rear edge and the leading edge of the next printed sheet can be avoided, and good ejection can be performed, and the collision between the leading edge of the printed sheet and the retaining member can be avoided, so that even better ejection is possible. You can do paper.

[Brief description of drawings]

FIG. 1 is a perspective view of a paper discharge device showing a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation in the first embodiment of the present invention.

FIG. 3 is a top view of the paper discharge device showing the first embodiment of the present invention.

FIG. 4 is a perspective view of a paper discharge device showing a second embodiment of the present invention.

FIG. 5 is a diagram illustrating an operation in the second embodiment of the present invention.

FIG. 6 is a perspective view of a paper discharge device showing a third embodiment of the present invention.

FIG. 7 is a diagram for explaining the operation in the third embodiment of the present invention.

FIG. 8 is a perspective view of a paper discharge device showing a fourth embodiment of the present invention.

FIG. 9 is a diagram for explaining the operation in the fourth embodiment of the present invention.

FIG. 10 is a perspective view of a paper discharge device showing a fifth embodiment of the present invention.

FIG. 11 is a diagram for explaining the operation in the fifth embodiment of the present invention.

FIG. 12 is a perspective view of a paper discharge device showing a modification of the fifth embodiment of the present invention.

FIG. 13 is a diagram for explaining an operation in a modified example of the fifth exemplary embodiment of the present invention.

FIG. 14 is a perspective view of a paper discharge device showing a sixth embodiment of the present invention.

FIG. 15 is a diagram for explaining the operation in the sixth embodiment of the present invention.

FIG. 16 is a perspective view of a conventional paper discharge device.

FIG. 17 is a diagram illustrating a paper discharge operation using a conventional paper discharge device.

FIG. 18 is a diagram illustrating a paper discharge operation using a conventional paper discharge device.

[Explanation of symbols]

 1, 11 and 21 Paper ejection table 1a, 11a, 21a Front plate 1b, 11b, 21b Rear plate 1c, 11c, 21c Left side plate 1d, 11d, 21d Right side plate 1e, 11e, 21e Bottom plate 1f, 1i, 11f, 21f Thrust Pad 2 Paper transport base 3 Jump base 4,6 Negative pressure means (fan) 5 Printed paper 9 Blower means (blower fan) 10,20 Retaining member (pin) 12 Retaining member (block)

Claims (7)

[Claims] 1. A paper discharge device, which is connected to an image forming apparatus and stacks printed paper sheets, is arranged downstream of a printed paper sheet conveyance direction, and has an abutting portion on which an end of the printed paper sheet comes into contact. A paper ejection table including a front panel having a plate, a rear panel arranged on the upstream side in the printed sheet conveying direction, left and right side panels, and a bottom panel, and connecting the image forming apparatus and the paper ejection table. In a paper discharge device, which is provided in a paper discharge path and includes a jump base for stiffening the printed paper, the paper discharge base includes a lower portion of the left and right side plates on the upstream side in the printed paper conveyance direction and And / or the rear plate has a negative pressure means for applying a negative pressure to the inside of the discharge tray. 2. The paper discharge device according to claim 1, wherein the negative pressure means is provided so as to be movable in the vertical direction. 3. The air blower for blowing air toward the inside of the paper discharge tray is provided at an upper portion of the left and right side plates on the downstream side in the printed sheet conveying direction or the front plate. The paper discharge device according to claim 2. 4. The abutting plate, wherein a contact surface of the abutting plate with the front end of the printed paper is formed in an arc shape in which the front end is directed upward. The paper discharge device according to claim 2 or claim 3. 5. An ejecting device, which is connected to an image forming apparatus and stacks printed sheets, is provided at a downstream side in the printed sheet conveying direction and has an abutting plate on the upper side thereof, with which the leading ends of the printed sheets come into contact. A sheet discharge tray including a front plate, a rear plate arranged on the upstream side in the printed sheet conveying direction, left and right side plates, and a bottom plate, and a sheet discharge connecting the image forming apparatus and the sheet discharge tray. A transport table and a jump table that is disposed on the paper discharge transport table and supports the printed paper, and the paper discharge tray is located downstream of the left and right side plates in the printed paper transport direction. Of the printed sheet, and a blowing means for blowing air toward the inside of the discharge tray and an upper portion of the left and right side plates near the downstream side of the printed sheet conveying direction, and the printed sheet. Stop for temporarily stopping the vehicle on its upper surface The abutting plate is characterized in that the abutting plate is bent at its front end toward the rear face plate side so that the front end of the printed sheet does not get over the abutting plate. Paper equipment. 6. The discharged sheet according to claim 5, wherein the retaining member has a contact surface with the printed sheet formed in an arc shape in which the printed sheet is directed upward. apparatus. 7. The retaining member is movably provided between the left and right side plates near the downstream end and the upstream end in the printed sheet conveying direction in synchronization with the conveying speed of the printed sheet. The sheet discharge device according to claim 5, wherein the sheet discharge device is provided.