JP2001341917A - Paper delivering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper delivering device capable of decelerating transfer materials, discharged at a high speed, and loading the transfer materials in a good order state on a paper delivery tray in a simple constitution. SOLUTION: This paper delivery device comprises a paper delivery tray 7 to load transfer materials, a delivering means 8 to deliver the transfer materials on the paper delivery tray 7, a conveyance passage 9 to guide the transfer materials to the delivering means 8, a drive means 10 to drive the delivering means 8, and a detecting means 12 positioned upstream from the delivering means 8 and detecting the presence of the transfer materials on the conveyance passage 9. When the rear end of the transfer material is detected by the detecting means 12 or after a lapse of a second given time from the detection, the drive of the drive means 10 is stopped and a delivery speed is reduced by the inertia of the delivering means 8 to deliver the transfer materials to the paper delivery tray 7.

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 provided in an image forming apparatus such as a copying machine and a printer, and more particularly, to a method of collecting transfer materials discharged from an apparatus body on a paper discharge tray in an orderly manner. The present invention relates to a paper discharge device capable of performing the following.

[0002]

2. Description of the Related Art A transfer material as a sheet on which an image has been formed is discharged from a discharge port of an image forming apparatus by discharge means such as a discharge roller and a driven roller driven by the discharge roller. 2. Description of the Related Art There is known a paper discharge device in which paper is sequentially accumulated on a paper discharge tray having a surface inclined upward in a discharge direction of a transfer material. The transfer material discharged from the discharge port moves along the top surface of the transfer material or the top surface of the transfer material that has been accumulated at the top of the transfer material. When the transfer material is completely discharged from the discharge port, the transfer material The ends are aligned with the vertical wall located below the outlet, and the ends are aligned so that the ends are aligned.

Generally, the copying speed for image formation and the discharging speed of the discharging means are set to be the same. However, when the copying speed is increased and the discharging speed of the transfer material is increased in accordance with this, the transfer material in the above-described paper discharging device of the image forming apparatus is discharged so that it vigorously jumps out of the discharge port, and is arranged on the discharge tray in an orderly manner. It becomes impossible to accumulate. Particularly, in an image forming apparatus having a copying speed of 500 mm or more per second, it is necessary to accumulate almost two sheets per second to accumulate A4 size transfer material.
It is necessary to discharge the sheets, and there are many problems in orderly stacking the transfer materials.

Conventionally, for solving the above-mentioned problem, for example, Japanese Patent Application Laid-Open No. H11-255390 is known.
According to the invention described in the publication, a detecting means provided on the upstream side of the discharge roller detects a rear end of a conveyed sheet, and after a lapse of a predetermined time from the detection, detects a discharge speed of the discharge roller by a first drive. The transfer material is stacked on the discharge tray at a reduced speed after switching from the row to the second drive row.

[0005]

SUMMARY OF THE INVENTION The above-described paper discharging device is
In order to reduce the speed of the discharging means, a new reduction gear must be provided, which causes a problem that the apparatus becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simpler structure so that a transfer material discharged at a high speed can be decelerated and stacked on a discharge tray in an orderly state. It is an object to provide a paper device.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a discharge tray for stacking a transfer material discharged from an apparatus main body, and discharge means for discharging the transfer material to the discharge tray. A conveyance path for guiding the transfer material to the discharge unit, a drive unit for driving the discharge unit, a drive transmission unit for transmitting the drive from the drive unit to the discharge unit, and an upstream side of the discharge unit. Detecting means for detecting the presence or absence of a transfer material to be positioned and conveyed, wherein the driving means is constantly driven at least during an image forming process, and when the detecting means detects the leading end of the transfer material or After a lapse of a first predetermined time, the drive transmission means transmits the drive of the drive means to the discharge means, and the detection means detects the rear end of the transfer material or the second after the detection. At a prescribed time After the lapse of time, the drive transmission unit cuts off transmission of the drive to the discharge unit, and reduces the discharge speed of the transfer material by the inertia of the discharge unit to discharge the transfer material to the discharge tray. I do.

[0008] Further, the discharge means is further provided with a load means for reducing the driving force of the discharge means, and the load means is a torque limiter.

Further, the drive transmission means includes an electromagnetic clutch, and connects or disconnects the electromagnetic clutch based on a detection signal from the case detection means to transmit drive to the discharge means. A transport unit is provided on the transport path for transporting the transfer material toward the discharge unit, and the transport unit is provided so as to be constantly driven at least during image formation by receiving the drive of the drive unit. It is characterized by having been done.

[0010] Further, the discharge angle of the transfer material discharged from the discharge means is set to 20 upward in the discharge direction.
The paper is discharged at an inclination angle of up to 30 degrees, and the inclined surface of the discharge tray is provided at a loading angle larger than the inclination angle.

A discharge tray on which a transfer material discharged from the apparatus main body is stacked; discharge means for discharging the transfer material to the discharge tray; a conveyance path for guiding the transfer material to the discharge means; A driving unit for driving the discharging unit, and a detecting unit positioned upstream of the discharging unit and detecting the presence or absence of a transfer material in the transport path, and when the detecting unit detects the leading end of the transfer material or After a lapse of a first predetermined time from the detection, the drive unit is driven to operate the discharge unit, and when the detection unit detects the rear end of the transfer material or after a lapse of a second predetermined time from the detection. Later, the driving of the driving unit is stopped, the discharge speed is reduced by the inertia of the discharging unit, and the transfer material is discharged to the discharge tray.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an image forming apparatus provided with a paper discharge device of the present invention, and FIG. 2 is a schematic sectional view of the paper discharge device. FIG. 3 is a schematic front view of a main part of the sheet discharging apparatus viewed from the direction of arrow A in FIG. As shown in FIG. 1, the image forming apparatus 1 is roughly divided into a sheet feeding section 2, an image forming section 3, and a stacking section 4. A sheet discharging apparatus 5 is provided above the stacking section 4, and a well-known image forming apparatus. The transfer material subjected to the above is discharged outside the apparatus and collected. In the embodiment, an electrophotographic system in which an image is formed by repeating the steps of charging, exposing, developing, and removing electricity around the photosensitive drum 6 is shown.

As shown in FIG. 2, the sheet discharging device 5 according to the present invention
Is a discharge tray 7 on which the transfer material is stacked, discharge means 8 for discharging the transfer material to the discharge tray 7, a transport path 9 for guiding the transfer material to the discharge means 8, and a driving means for driving the discharge means 8. A drive transmission unit 11 for transmitting the drive from the driving unit 10 to the discharge unit 8; a detection unit 12 positioned upstream of the discharge unit 8 and detecting the presence or absence of the transfer material conveyed on the conveyance path 9. Having.

The paper discharge tray 7 is located below the discharge port 13 and has an inclined surface 14 inclined upward in the traveling direction of the transfer material discharged from the discharge port 13, and the inclined surface 14 will be described later. It has an inclination angle larger than the inclination angle for discharging the transfer material. At one end of the inclined surface 14 where the rear end of the transfer material is located, an abutment wall 15 extending in a substantially vertical direction is provided to align the rear end of the stacked transfer materials. In the embodiment, the abutment wall 15 is provided with a plurality of ribs extending in the vertical direction. In order to align one side surface of the transfer material to be stacked, the inclined surface 14 is inclined in a direction transverse to the discharge direction of the transfer material. The angle is set to be lower.

The discharge means 8 is located near the discharge port 13 and has a discharge roller 16 to which the drive of the drive means 10 described later is transmitted, and a driven roller 17 which is driven to face the discharge roller 16. Then, the transfer material is nipped and discharged outside the apparatus. In the embodiment, two discharge rollers 16 are provided on a shaft 18 supported on a side plate 37 via a bearing 39 as shown in FIG. Large diameter roller 19
The driven roller 17 provided on the shaft 23 opposed to the discharge roller 16 and supported on the side plate 37 via a bearing 38 has a contact portion 20 whose central portion is in contact with the discharge roller.
And a large-diameter portion 21 having both ends of the contact portion 20 having a diameter larger than the diameter of the contact portion 20 so that the transfer material is stiffened when the transfer material is sandwiched. As a result, the transfer material discharged from the discharge port 13 is discharged at a predetermined inclination angle in an obliquely upward direction without hanging down.

The transfer path 9 guides the transfer material through the transfer means 22 to the discharge means 8 and comprises a substantially parallel plate-like upper guide member 24 and lower guide member 25.
The conveying unit 22 includes a driving roller 26 that is constantly driven during the image forming process in response to the driving of the driving unit 10, and a driven roller 27 that faces the driving roller 26. Transport inside. The transfer path 9 in the vicinity of the discharge unit 8 may be provided such that the transfer material discharged from the discharge unit 8 is discharged at an inclination angle of 20 to 30 degrees upward in the discharge direction. Preferably, the stacking angle of the discharge tray 7 is provided at an inclination angle larger than the discharge angle.

Due to the relationship between the transfer material discharge angle and the angle of the discharge tray, the leading end of the transfer material is first inclined 14
Alternatively, it contacts the previously accumulated transfer material and slides on the inclined surface 14 or the previously loaded transfer material while containing air between the transfer material and the inclined surface 14 or the previously accumulated transfer material. The rear end is aligned by abutting against the abutting wall 15, so that a large amount of transfer materials can be stably accumulated.

The driving means 10 includes a driving motor 28 as a driving source, a pulley 30 provided on a motor shaft 29, a gear 31 provided on one end side of the shaft 18 of the discharging roller 16 of the discharging means 8, and an intermediate gear 32a. , 32b, a pulley 33a provided coaxially with the intermediate gear 32b, a toothed timing belt 34, a pulley 33b, and a pulley 33c provided coaxially with the drive roller 26. The timing belt 34 includes a pulley 330 and pulleys 33a, 33b,
33c and is driven by a motor. The pulley 33b is provided movably in the direction of arrow B so that the timing belt 34 has an appropriate tension, and is adjusted by a biasing means 35 such as a spring. With this configuration, if the driving unit 10 is driven, the transport unit 22 is always driven.

The detecting means 12 has a reflection type photosensor provided on the upper guide member 24 in the embodiment, and detects the presence or absence of the transfer material passing through the detecting means 12 to detect the front end or the rear end of the transfer material. are doing. The position of the detecting means 12 is located at a predetermined distance upstream from the position where the discharging means 8 is provided. The drive transmission unit 11 controls the discharge unit based on the detection signal from the detection unit 12. The detection means 12 may be a transmission type photo sensor, or may be provided on the lower guide member 25.

The drive transmission means 11 appropriately transmits the drive of the drive motor 28 to the discharge roller 16, and an electromagnetic clutch having a fast response speed is preferably used. The drive transmission means 11 is provided at one end of the shaft 18 of the discharge roller 16 of the discharge means 8 and at least drives the gear 31 which is constantly rotating during image formation by driving from the drive means 10 when the electromagnetic clutch is turned on and the discharge roller To communicate. Further, when the electromagnetic clutch is off, the drive transmission to the discharge roller 16 is cut off,
The driven discharge roller 16 is rotated by inertia, and is decelerated by a load due to the attachment of the discharge roller 16 and the driven roller 17 to the apparatus and a load due to a passing transfer material. Preferably, by providing a torque limiter on at least one of the paper discharge roller 16 and the driven roller 17, a desired rapid deceleration of the discharge means 8 can be obtained. For example, if a load of 200 gf · cm is applied to a driven roller, the speed can be reduced in a short time.

Next, the operation will be described. When the operator starts image formation, the drive unit 10 starts driving, and in conjunction with this, the drive roller 26 of the transport unit 22 starts rotating at the image forming speed. Next, the transfer material on which an image has been formed by a known image forming method is conveyed by the conveying means 22 to the detecting means 12 through the conveying path 9. When the leading end of the transfer material is detected at the detection position of the detection means 12 or after a lapse of a first predetermined time from the detection, the electromagnetic clutch as the drive transmission means 11 is turned on, and the driving of the gear 31 of the drive means 10 is performed by the discharge means. 8 to the discharge roller 16. The discharge roller 18 to which the drive has been transmitted reaches the image forming speed instantaneously, clamps the transferred transfer material, and
Is conveyed at the set angle toward.

Next, when the rear end of the transfer material passes through the detecting means 12, the detecting means 12 detects the rear end. Detecting means 12
The electromagnetic clutch as the drive transmission means 11 cuts off the transmission of the drive to the discharge roller 16 when the rear end of the transfer material is detected or when a second predetermined time has passed after the detection. The discharge roller 16 whose driving has been cut is rotated by inertia, the discharge speed is reduced, and the transfer material is discharged from the discharge port 13. At this time, the transfer material is discharged before the discharge roller 16 completely stops, and the momentum of the discharged transfer material is changed to the discharge tray 7.
It is desirable to set so that the transfer material is stacked with the rear ends thereof aligned. Further, the speed is rapidly reduced by the action of the torque limiter 36 provided in the discharging means.

When the transfer material is discharged without force, the leading end of the transfer material first contacts the sheet discharge tray 7 or the transfer material already loaded, and the rear end of the transfer material abuts while sliding on the inclined surface of the sheet discharge tray. It is tied to the wall 15 and is collected in an orderly manner.

The discharge roller which has finished discharging the transfer material is stopped or slightly rotated, and when the leading end of the next conveyed transfer material is detected by the detecting means, the electromagnetic clutch is connected again and the discharge roller is moved. Rotate. By repeating these steps, the plurality of transfer materials are orderly stacked on the paper discharge tray.

[0025]

The detecting means detects the leading and trailing ends of the transfer material, connects or disconnects the discharging means by the drive transmitting means, and discharges the transfer material in a state where the force of the transferring material is weakened by the inertia of the discharging means. The device can be made extremely inexpensive and simple, and it is only necessary to adjust how long the drive transmission means is cut off from the time of detection by the detection means. Further, since the torque limiter is provided in the discharging means, the distance between the transfer materials which are decelerated from the detecting means in a short time and conveyed continuously can be shortened, which is suitable for high-speed copying. Further, since the driving unit is always driven at least at the time of image formation, and this driving is transmitted to the conveying unit, the discharge roller can be decelerated by only one driving source.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image forming apparatus provided with a paper discharge device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a main part of a paper discharge device according to the present invention.

FIG. 3 is a schematic front view illustrating a main part of the sheet discharging device viewed from a direction of an arrow A in FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming apparatus 2 paper feed unit 3 image forming unit 4 stacking unit 5 paper discharge device 6 photosensitive drum 7 paper discharge tray 8 discharge unit 9 transport path 10 drive unit 11 drive transmission unit 12 detection unit 13 discharge port 14 inclined surface 15 thrust Abutment wall 16 discharge roller 17 driven roller 18 shaft 19 roller 20 contact portion 21 large diameter portion 22 conveying means 23 shaft 24 upper guide member 25 lower guide member 26 drive roller 27 driven roller 28 motor 29 motor shaft 30 pulley 31 gear 32a b Intermediate gear 33a, b, c Pulley 34 Timing belt 35 Biasing means 36 Torque limiter 37 Side plate 38 Bearing 39 Bearing

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F049 AA02 DA12 EA10 EA14 EA28 LA02 LA07 LB03 3F053 GA03 GB02 LA02 LA07 LB03

Claims (7)

[Claims] A discharge tray for loading the transfer material discharged from the apparatus main body; discharge means for discharging the transfer material to the discharge tray; a transport path for guiding the transfer material to the discharge means; A drive unit for driving the discharge unit, a drive transmission unit for transmitting the drive from the drive unit to the discharge unit, and a detection unit for detecting the presence or absence of a transfer material conveyed positioned upstream of the discharge unit. The drive unit is always driven at least during the image forming process, and when the detection unit detects the leading end of the transfer material or after the first predetermined time elapses after the detection, the drive transmission unit The drive of the drive unit is transmitted to the discharge unit, and when the detection unit detects the rear end of the transfer material or after a lapse of a second predetermined time from the detection, the drive transmission unit drives the discharge unit to the discharge unit. of A sheet discharging device, wherein the transfer is cut, and the discharging speed of the transfer material is reduced by the inertia of the discharging unit to discharge the transfer material to the discharge tray. 2. The paper discharging apparatus according to claim 1, wherein said discharging means further includes a load means for reducing a driving force of said discharging means. 3. The sheet discharging device according to claim 2, wherein said load means is a torque limiter. 4. The drive transmission means includes an electromagnetic clutch, and connects or disconnects the electromagnetic clutch based on a detection signal from the case detection means to transmit drive to the discharge means. Claim 1 or 2
The paper ejection device described in the above. 5. A transporting means for transporting the transfer material toward the discharge means on the transporting path, the transporting means being driven by the driving means and being constantly driven at least during image formation. 5. The sheet discharging device according to claim 1, wherein the sheet discharging device is provided as follows. 6. The transfer material discharged from the discharge means is discharged at an inclination angle of 20 to 30 degrees upward in the discharge direction, and the stacking surface of the discharge tray is inclined. 6. The sheet discharging device according to claim 1, wherein the stacking angle is larger than the stacking angle. 7. A discharge tray for loading a transfer material discharged from the apparatus main body, discharge means for discharging the transfer material to the discharge tray, a transport path for guiding the transfer material to the discharge means, A driving unit that drives the discharging unit, and a detecting unit that is located upstream of the discharging unit and that detects the presence or absence of a transfer material in the transport path, and when the detecting unit detects the leading end of the transfer material. Alternatively, after the first predetermined time has passed since the detection, the driving means is driven to operate the discharge means, and when the detection means detects the rear end of the transfer material or for a second predetermined time after the detection. A paper discharge device, wherein after the lapse of time, the driving of the driving means is stopped, the discharge speed is reduced by the inertia of the discharge means, and the transfer material is discharged to the paper discharge tray.