JP2001335220A - Paper ejection device and image forming device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent a paper jam by maintaining a curved state for increasing the bending rigidity of recording paper,
Provided is a paper discharge device having a configuration capable of preventing a new adverse effect such as permanent distortion due to bending remaining on recording paper. SOLUTION: The paper discharging device 1 is provided at the center of parallel rotating shafts 5, 6 and sandwiches and discharges a recording sheet S by rollers 7 and 8 which cooperate while abutting each other. A configuration 10 is provided in which the recording paper S is curved by a flange portion 7A having a large diameter provided on one side 7 of the contacting roller, and a curved surface is formed at both ends in the width direction of the recording paper S. It is characterized by.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a paper ejection device and an image forming apparatus using the same, and more particularly, to a jam prevention structure for recording paper ejected after image formation.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile, a printer, and a printing machine, an unfixed image transferred and carried on a recording sheet may be fixed to produce a copy or print output.

The recording paper after fixing is discharged to a paper discharge tray or the like provided in the image forming apparatus. As a configuration for discharging the paper, a pair of rollers rotatable in a direction in which the recording paper can be nipped and conveyed in a state where the recording paper is confronted with another harm is often used.

[0004] The recording paper discharged by the roller pair, especially when the recording paper having a small thickness is discharged at a low discharge speed, has a small bending stiffness of the recording paper. Due to frictional resistance at the time of movement, the way to the rear end in the discharge direction is bent, and the rear end in the discharge direction tends to stop at the position of the roller pair. For this reason, the leading end of the subsequently discharged recording paper in the discharge direction may interfere with the trailing end of the discharged recording paper, causing a paper jam at that position, causing a so-called jam.

Conventionally, there is a configuration shown in FIG. 7 as a configuration for strengthening a recording paper.

FIG. 7 is a front view of a pair of rollers used in the paper discharge device. In FIG. 7, the paper discharge device is provided with a pair of parallel rotating shafts 30 and 31 and a rotating shaft 3.
Paper discharge rollers 32 and 33 are integrated with each of 0 and 31 so as to be rotatable.

On one rotating shaft 30, a discharge roller 32 is juxtaposed at the center in the width direction corresponding to a direction perpendicular to the discharge direction of the recording paper S, and on the other rotating shaft 31, the discharge roller 32 is disposed. A pinch roller 33 that is in contact with and abuts on the roller 32 is arranged side by side.
4 are juxtaposed.

The discharge roller 32 is provided with large-diameter flanges 32A at both ends in the axial direction, and the recording paper S is pressed and curved by the flanges 32A.

FIG. 6B shows a state in which the recording paper S is nipped and conveyed by the discharge rollers 32 and the pinch rollers 33.
As shown in (2), the area near the center in the width direction is curved and discharged.

[0010]

In the width direction of the recording paper S, as shown in FIG. 6B, the recording paper S is locally pressed to bend to increase the sectional rigidity in the discharge direction. Later, the amount of bending may be reduced and the strength of the waist may not be maintained.

In FIG. 7, the recording paper S sandwiched between the paper ejection roller 32 and the pinch roller 33 applies a clamping pressure (see FIG. 7).
In the position corresponding to the guide rollers 34 located at both ends in the width direction, the shape is curved by its own shape restoring force (the force indicated by the symbol F2 in FIG. 4). Warp to the other side. For this reason, when the effect of the clamping pressure is removed, the recording paper S returns to the flat state by the shape restoring force of the portion of the recording paper S, as shown in FIG. Together, it is leveled in the width direction,
It becomes a flat state over the entire area in the width direction and reaches the discharge tray. As a result, despite the fact that the stiffness has been increased during the nipping conveyance, the state becomes the same as a state where the paper is not curved with time, and when moving on the paper output tray, the paper is easily bent due to frictional resistance. The problem that the rear end in the direction tends to stop at the position of the roller pair still remains. When a paper jam occurs in the paper discharge unit, even when the subsequent recording paper advances, it causes a paper jam, and the image forming process in the image forming apparatus is interrupted.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a paper jam by maintaining a curved state for increasing the bending rigidity of a recording sheet in view of the problems in the conventional sheet discharging apparatus and the image forming apparatus. Another object of the present invention is to provide a sheet discharging device and an image forming apparatus having a configuration capable of preventing a new adverse effect such as permanent deformation due to bending remaining on recording paper.

[0013]

According to the first aspect of the present invention,
A paper discharge device provided at the center of a parallel rotating shaft to pinch and discharge a recording sheet by rollers interlocking while abutting against each other, and a large diameter provided on one side of the roller abutting against the above. The recording paper is curved by a flange portion, and a curved surface is formed at both ends in the width direction of the recording paper.

According to a second aspect of the present invention, in the paper discharging device of the first aspect, guide rollers for guiding the recording paper are disposed at both ends in the width direction of the recording paper, and the guide roller is provided with the guide rollers. It is characterized in that a pressing member is provided to bend when the recording paper passes and to bend the recording paper.

According to a third aspect of the present invention, in the paper discharging device according to the second aspect, the pressing member abuts on a peripheral surface of the guide roller below a recording paper nipping position of the roller that abuts and opposes. It is characterized in that the position of the recording paper guide surface by the guide roller is positioned below the nipping position of the roller that is in contact with the opposing roller.

According to a fourth aspect of the present invention, in the paper discharge device of the second aspect, the pressing member is lower than the nipping position from the roller side in contact with the opposite side toward both ends in the width direction of the recording sheet. The present invention is characterized in that a guide member is used.

The invention described in claim 5 is the invention according to claim 2 or 4
In the paper discharge device described above, the pressing member is provided at a position where both ends in the width direction of the recording paper are prevented from floating from the peripheral surface of the guide roller.

According to a sixth aspect of the present invention, in the paper discharge device according to the second aspect, the pressing member is capable of abutting on the entire area of the guide roller in the width direction.

The invention according to claim 7 is the invention according to claim 3 or 4.
In the paper discharge device described above, the pressing member is provided so that a base end thereof is connected to a solenoid having an actuator capable of moving forward and backward so as to be able to contact and separate from the guide roller. It is characterized in that it is matched with the pinching position of the roller in the moving direction of the paper in the moving direction of the paper.

According to an eighth aspect of the present invention, in the paper discharge device according to the seventh aspect, the solenoid is connected to a detecting means capable of detecting that the recording sheet moves toward the holding position. The operation of the control unit is controlled by the control unit, and the control unit causes the elastic member to contact the guide roller before the leading end of the recording paper reaches the holding position.

According to a ninth aspect of the present invention, there is provided a paper discharge device according to one of the first to eighth aspects.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of an image forming apparatus to which a paper discharge device according to an embodiment of the present invention is applied. In FIG. 1, the image forming apparatus 1 corresponds to a copying machine, a printer, a facsimile machine, or the like. .

The image forming apparatus 1 includes an image forming section 1A and a sheet discharging device 2 for discharging a recording sheet S conveyed from the image forming section 1A. Paper discharge device 2 in the present embodiment
Has a configuration capable of sorting the recording paper after image formation, and thus includes a plurality of paper discharge trays 2A. The details will be described later.

Although the image forming section 1A is not shown in detail,
A photosensitive member 1A1 serving as a latent image carrier is provided therein.
A charging device, a writing device, a developing device, a transfer device (for convenience, indicated by reference numeral 1A2), a cleaning device, and a paper feeding device 1B that perform image forming processing on A1 are provided.

The recording paper fed from the paper feeder 1B (for convenience, the conveyance path indicated by a dashed line is indicated as recording paper S)
The image transfer from the photoreceptor 1A is performed at a transfer position where the photoreceptor 1A1 and the transfer device 1A2 face each other, and the image carried on the surface is fixed. Transported.

The image forming section 1A is provided with a paper discharge tray 1D separately from the paper discharge device 2 so as to discharge the recording paper S that is not subjected to post-processing such as sorting after image formation. .

The paper discharge device 2 has a plurality of paper discharge trays 2A which are arranged in a plurality of stages in the vertical direction in the figure, and the configuration for extracting and discharging S toward each paper discharge tray 2A is the same. The following description is directed to the sheet discharge tray 2A located below the uppermost stage.

A transport path 2B is provided inside the paper discharge device 2 toward the paper discharge tray 2A, and branches to the respective paper discharge trays 2A in the transport path 2B except for the uppermost paper discharge tray 2A. The transport direction switching claws 3 are respectively arranged at the positions.

The transport path switching claw 3 is constituted by a swinging member capable of switching the transport path by a control unit, which will be described later. The transport path switching claw 3 is configured to control the transport path toward the corresponding discharge tray 2A or another discharge tray 2A. It is to be set. In this embodiment, a solenoid whose operation is controlled by a control unit (to be described later, which is referred to as SO in FIG.
L (indicated by L).

A discharge roller group 3 is provided upstream of the discharge direction (in the direction of the arrow in the drawing) of the recording paper S with respect to the discharge tray 2A.

As shown in FIGS. 2 and 3, the paper discharge roller group 3 includes rollers 7 and 8 which are arranged at the axial center of the parallel rotating shafts 5 and 6 and are in contact with each other. In this embodiment, one of the opposing and contacting rollers 7 functions as a paper discharge drive roller, and the other of the opposing and contacting rollers 8 functions as a driven roller. It can be transported.

The rollers that are in contact with each other, that is, the paper discharge drive roller 7 and the driven roller 8 are juxtaposed along the axial direction of the rotating shafts 5 and 6, and the paper discharge drive roller 7 has the configuration shown in FIG. Similarly, a flange 7A having a large diameter portion at both ends in the axial direction.
Is formed, and the recording paper S is pressed and curved.

A guide roller 9 is juxtaposed on one of the rotating shafts 5 separately from the driven roller 8 on both ends in the axial direction. The guide roller 9 is formed of an elastically deformable roller having an outer diameter larger than the other roller 8 that is in contact with the guide roller 9.

The recording paper S nipped and conveyed by the discharge drive roller 7 and the driven roller 8 is nipped and conveyed while being pressed by the flange 7A of the discharge drive roller 7, so that the direction perpendicular to the moving direction corresponds. The center in the width direction is curved, and both ends in the width direction can be curved.

FIGS. 2 and 3 show a configuration for forming curved surfaces at both ends in the width direction of the recording sheet S. In FIG. Is provided so as to be able to approach and separate.

As shown in FIG. 3, the pressing member 10 is constituted by a rocking member made of an elastic material whose base end is integrated with a support shaft 12 rotatable by an actuator 11A of a solenoid 11, and has a distal end. The position is selected between a position where the portion contacts the guide roller 9 and a position where the portion is separated therefrom.

As shown in FIG. 2, the distal end of the pressing member 10 has a width capable of opposing the entire width of the guide roller 9. When the distal end of the pressing member 10 comes into contact with the guide roller 9, the discharge driving roller 7 and the driven roller 8, the recording paper S is positioned below (the position lowered by the distance indicated by the symbol h in FIG. 3) below the nipping and conveying position of the recording paper S (the position indicated by the symbol NP in FIG. 3). . As a result, the guide roller 9 is partially elastically pressed and elastically deformed to contract. At this time, the pressing member 10 prevents both ends in the width direction of the recording sheet S from rising in the axial direction of the rotating shaft 6 as shown in FIG. By locating the guide surface of the recording sheet S below the transport position, both ends in the width direction of the recording sheet S can be pressed down from the clamping position to be curved.

The operation of the solenoid 11 is controlled by a control unit 13.

The main part of the control section 13 is constituted by a microcomputer, and an optical detection for detecting a moving position before the recording paper S reaches the holding position is provided on an input side via an I / O interface (not shown). The sensor 14 is connected, and the output side is connected to a conveyance path switching claw (indicated by a symbol T for convenience) and the solenoid 11.

In the control section 13, when the optical detection sensor 14 detects that the recording paper S has reached the nipping position,
The solenoid 11 is excited to set the pressing member 10 in a position where the tip thereof presses the guide roller 9, and this position is continued until the passage of the recording paper S is no longer detected. As a result, the pressing member 10 is driven by the discharge drive roller 7 and the driven roller 8.
The guide surface of the recording sheet S is positioned lower than the holding position of the recording sheet S, and the recording sheet S passing through the holding position is formed at both ends in the width direction in addition to the formation of the curved surface at the holding position. Is discharged while a curved surface is formed.

Since the present embodiment has the above configuration,
The operation and operation of the control unit 13 will be described below with reference to the flowchart shown in FIG.

When the recording paper S is transported from the image forming processing section 1A, the transport motor for driving the transport roller 1CO and the preliminary roller group 3 is driven, and the paper discharge device 2 is driven.
When the recording paper is conveyed to the side, the discharge tray 2A to be sorted
Among them, the conveyance path switching claw 3 toward the corresponding discharge tray 2A is driven by the solenoid T to set the receiving state of the recording paper S (ST1).

When the recording paper S is conveyed toward the roller group 3 mounted on the paper receiving tray 2A in the receiving state, the optical detection sensor 14 detects the recording paper S before the nipping position. Is (ST2), the optical detection sensor 1
4 is output to the control unit 13. The control unit 13 excites the solenoid 11 to swing the pressing member 10 that has been separated from the guide roller 9 to make it contact the guide roller 9 (ST3).

Since the pressing member 10 abuts against the entire area of the guide roller 9 in the width direction, the pressing member 10 contacts the entire area of the guide surface of the recording paper S unlike the case where the pressing member 10 abuts locally on the peripheral surface of the guide roller 9. Therefore, the load is not concentrated on the recording paper S, and thus, it is possible to prevent the recording paper S from being permanently distorted and leaving a pressing mark.

When the pressing member 10 comes into contact with the guide roller 9, the recording paper S is curved by being pressed by the flange 9A of the discharge driving roller 7 at the center in the width direction, and is further discharged by the pressing members 10 at both ends in the width direction. Collar 9 of paper drive roller 9
It is curved by being pressed downward from A.
As a result, as shown in FIG. 6 (A), the recording paper S discharged in the pressed state while the lifting at the both ends in the width direction is prevented is maintained in a state where the curved surfaces at both ends in the width direction remain. Since the state in which the bending rigidity is increased is maintained, it is possible to move in a state where bending due to frictional resistance when contacting the surface of the paper discharge tray 2A is unlikely to occur. Since the recording paper S is unlikely to bend, the rear end of the recording paper S in the discharge direction does not stop at the position of the roller group 3, so that the discharge driving roller 7 and the driven roller 8 as shown by arrows in FIG. The trailing end of the recording paper S that has deviated from the nipping position falls as it is and is placed on the paper discharge tray 2A.

The excitation state of the solenoid 11 is maintained until the recording paper S passes through one of the optical detection sensors 14 (ST4), and when the detection by the optical detection sensor 14 is completed, the excitation is released (ST4). ST5), the transport motor and the transport path switching claw 3 are returned to the initial state (ST6).

According to the present embodiment, the pressing member 10 comes into contact with the guide roller 9 only when the recording paper S passes, so that the peripheral surface deformation of the guide roller 9 that tends to occur when the pressing member 10 always comes into contact with the guide sheet 9 is prevented. Can be prevented. This prevents the curvature of the curved surface from becoming extremely large without lowering the positioning accuracy of the distal end position of the pressing member 10 and prevents a situation in which bent portions are generated at both ends of the recording paper S. Can be

Next, another embodiment of the present invention will be described.

FIG. 5 is a view showing a case where the structure of the pressing member is different from the structure shown in FIG. 2. In FIG. 5, the pressing member 20 is not a swinging member, but a vertically arranged plate. The guide member is composed of members 20A and 20B. Therefore, in this embodiment, the solenoid 11 shown in FIG. 3 is not used.

The plate members 20A and 20B are spaced apart from each other with a gap through which the recording paper S can pass. The plate members 20A and 20B are separated from the nipping position where the discharge driving roller 7 and the driven roller 8 are located in the width direction of the recording paper S. Also, both ends are shaped to be downward.

Since the present embodiment has the above configuration,
The recording sheet S, which is to be pushed up by the guide roller 9, is prevented from being lifted up by the pressure member 20 covering both ends in the width direction, and is further pressed downward from the clamping position. Are discharged while being formed.

According to the present embodiment, since a driving system for the pressing member 20 is not required, it is possible to improve the transportability of the recording paper S with a simple configuration.

According to the above embodiments, the recording paper S
Is discharged in a state where the curved surfaces at both ends in the width direction are maintained, the recording sheet S fed from the roller group 3 is bent in the middle of the discharge direction due to frictional resistance generated when the recording sheet S comes into contact with the discharge tray 2A. Since the rear end in the discharge direction can drop onto the discharge tray 2A without stopping at the position of the aura group 3, the occurrence of a jam in the discharge portion is reduced, and the image forming process is interrupted. Opportunities can be reduced. Moreover, even when the waist is strengthened over the entire area in the width direction, the curved surface habits, in other words, since there is no pressing mark or the like for forming the Ko Yasui construction surface,
The appearance of the recording paper S is not spoiled.

[0055]

According to the first aspect of the present invention, in addition to the curved surface formed on the recording paper by the flange provided on one side of the roller that is in contact with the opposing roller, the recording paper is also curved at both ends in the width direction of the recording paper. Since the surface is formed, the curved surface at both ends in the width direction does not disappear. As a result, the curved surface can be maintained over the entire area of the recording paper in the width direction, so that the rigidity of the recording paper is strengthened, so that the recording paper is prevented from being carelessly bent on the paper discharge tray and the discharge performance is improved. Becomes possible.

According to the present invention, the pressing member capable of contacting the guide roller is located below the clamping position of the roller which is in contact with the guide roller, or from the clamping position to both ends in the width direction of the recording paper. Since the shape of the recording paper that is lowered downward is used, both ends in the width direction of the recording paper abutting on the guide roller can be pressed downward and curved. As a result, a curved surface is formed at both ends in the width direction in addition to the nipping position of the roller in abutting contact, so that the bending rigidity is increased over the entire width direction of the recording paper and the recording paper is bent when discharged onto the paper discharge tray. It is possible to improve the discharge performance by preventing the occurrence of the discharge.

According to the fifth aspect of the present invention, since both ends in the width direction of the recording paper can be prevented from rising from the guide roller by using the pressing member, the curved surface due to the shape restoring force of the recording paper is eliminated. Can be reliably prevented.

According to the sixth aspect of the present invention, since the pressing member can be brought into contact with the entire area of the guide roller in the width direction, there is no load concentration unlike local contact. As a result, a pressing mark is not generated on a part of the recording paper by the pressing member, and it is possible to prevent the quality of the recording paper as a copy or a printed matter from deteriorating.

According to the seventh and eighth aspects of the present invention, the state in which the pressing member abuts on the guide roller is set via a signal from the detecting means for detecting the movement of the recording paper.
When the recording sheet is conveyed while being nipped by rollers that are in opposition to contact, the recording sheet is ejected after forming both ends in the width direction of the recording sheet with curved surfaces. As a result, the recording paper is nipped by the rollers that are in opposition to each other, and at the same time, curved surfaces are also formed at both ends in the width direction of the recording paper, so that the recording paper can be discharged while maintaining the bending rigidity. Bending due to the above frictional resistance is prevented beforehand, and dischargeability is improved.

According to the ninth aspect of the present invention, a curved surface for increasing the bending rigidity is formed over the entire width of the recording paper so that the recording paper can be ejected, and the curved surface is locally formed. Since there is no such thing as a trace, the appearance of the recording paper as a copy or printed matter is not spoiled.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining an example of an image forming apparatus to which a paper discharge device according to an embodiment of the present invention has been applied.

FIG. 2 is a schematic front view of the paper discharge device according to one embodiment of the present invention.

FIG. 3 is a schematic side view for explaining a main part of the paper discharge device according to one embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of a control unit used for a main part of the sheet discharging device illustrated in FIG. 3;

FIG. 5 is a schematic front view of a paper ejection device according to another embodiment of the present invention.

FIGS. 6A and 6B are diagrams for explaining a state of recording paper discharged from a paper discharge device, wherein FIG. 6A shows a case according to an embodiment of the present invention, and FIG. ing.

FIG. 7 is a schematic front view for explaining the configuration of a conventional paper ejection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Image forming part 2 Paper discharge device 2A Paper discharge tray 4 Roller group 5, 6 Rotating shaft 7 Paper discharge drive roller which is one of the rollers forming a roller group 8 Other rollers forming a roller group One driven roller 9 Guide roller 10, 20 Pressing member 11 Solenoid 11A Actuator 13 Control unit 14 Optical detection sensor 20A, 20B Plate member constituting pressing member

Claims (9)

[Claims] 1. A paper discharge device provided at a center side of parallel rotating shafts for nipping and discharging a recording sheet by rollers interlocking and abutting against each other, provided on one side of the roller which abuts against the rotation. A sheet discharging device having a configuration in which the recording sheet is curved by a flange portion having a large diameter portion and a curved surface is formed at both ends in the width direction of the recording sheet. 2. The paper discharging device according to claim 1, wherein guide rollers for guiding the recording paper are arranged at both ends in the width direction of the recording paper, and the guide rollers pass through the guide rollers when the recording paper passes therethrough. And a pressing member for bending the recording paper in contact with the recording paper. 3. The paper discharging device according to claim 2, wherein the pressing member abuts on a peripheral surface of the guide roller below a recording paper nipping position of the roller which is in opposition and abuts with the recording paper by the guide roller. A sheet discharging device, wherein the position of the guide surface is positioned below the holding position of the roller that is in contact with the opposing surface. 4. The paper discharging device according to claim 2, wherein the pressing member has a guide member having a shape lower than the nipping position toward the both ends in the width direction of the recording sheet from the roller contacting the opposing member. A paper ejection device characterized by being used. 5. The sheet discharging device according to claim 2, wherein the pressing member is provided at a position where both ends in the width direction of the recording sheet are prevented from floating from the peripheral surface of the guide roller. Discharge device characterized by the following. 6. A paper discharging apparatus according to claim 2, wherein said pressing member is capable of abutting on and facing the entire area of said guide roller in the width direction. 7. The paper discharge device according to claim 3, wherein the pressing member is provided with a base end connected to a solenoid having an actuator that can move forward and backward so as to be able to contact and separate from the guide roller. A sheet discharging device, wherein a contact position with the guide roller coincides with a nipping position of the opposing roller in the moving direction of the recording sheet. 8. The sheet discharging device according to claim 7, wherein the operation of the solenoid is controlled by a control unit to which a detection unit that can detect that the recording sheet moves toward the holding position is connected, The paper discharge device, wherein the control unit causes the elastic member to contact the guide roller before the leading end of the recording paper reaches the holding position. 9. An image forming apparatus using the sheet discharging device according to claim 1. Description: