JPH10319647A - Paper sheets carrying device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the advancing direction of a paper sheet gently variable by making the intrusion angle with a switching gate, of the paper variable, at the time of operating the switching gate. SOLUTION: In this carrying device, a pair of first carrying rollers 36 carries the paper in a first direction. The switching gate 42 selectively changes over the paper carried in the first direction by a pair of the first rollers 36 into a second direction different from the first direction. A variable means K makes the intrusion angle with the gate 42, of the paper variable, when the changeover operation of the switching gate 42 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus and an image forming apparatus applied to, for example, an electrophotographic copying machine capable of performing double-sided copying.

[0002]

2. Description of the Related Art Some image forming apparatuses such as electrophotographic copying machines can perform double-sided copying. The image forming apparatus capable of performing double-sided copying includes a switching gate for switching the sheet conveyance direction between single-sided copying and double-sided copying between a fixing device and a discharge roller.

The switching gate guides the single-sided image-formed sheet sent from the fixing unit in the horizontal direction and feeds the sheet to the discharge roller during one-sided copying. And send it to the automatic double-sided conveyance path.

The paper fed to the automatic double-sided conveyance path is again fed to the image transfer section between the photoreceptor and the transfer charger in a state where the paper is inverted, and an image is formed and both sides are copied.

[0005]

However, in the prior art, the body of the copying machine has been reduced in size, and it has become impossible to secure a sufficient space for installing the switching gate. For this reason, at the time of double-sided copying, the paper sent out from the fixing device cannot be fed into the automatic double-sided conveyance path at a gentle switching angle, and the switching angle is sharp.

For this reason, the paper is jammed at the switching gate, and the paper is greatly curled because the toner image is fixed and the temperature is high due to the toner image being fixed, and is sent again to the image transfer section to transfer the image. In such a case, the transfer may be omitted, or the paper may be jammed on the carry-in side of the fixing device.

[0007] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a paper sheet transport apparatus and an image forming apparatus that can change the paper sheet transport direction at a gentle switching angle even when the installation space of the switching means is narrow.

[0008]

In order to solve the above-mentioned problems, the present invention is directed to a conveying means for conveying paper sheets in a first direction, and a conveying means for conveying the paper sheets in a first direction. Papers conveyed to the second direction different from the first direction
And switching means for changing the angle at which the paper sheet enters the switching means during the switching operation of the switching means.

According to a second aspect of the present invention, a conveying means for conveying a sheet in a first direction and a sheet conveyed in a first direction by the conveying means are different from the first direction. Switching means for selectively switching in the second direction; and variable means for changing the position of the transport means and changing the angle of the paper sheet entering the switching means during the switching operation of the switching means. .

According to a third aspect of the present invention, there is provided a conveying means for conveying a sheet in a first direction, and a sheet conveyed in a first direction by the conveying means different from the first direction. Switching means for selectively switching in the second direction, and interlocking with the switching operation of the switching means, changing the position of the transport means,
Variable means for varying the angle of entry of the paper sheet with respect to the switching means.

According to a fourth aspect of the present invention, the conveying means for conveying the paper sheets in the first direction and the paper sheets conveyed in the first direction by the conveying means are different from the first direction. Switching means for selectively switching in the second direction; and an interlocking member for changing the position of the transport means in conjunction with the switching operation of the switching means, wherein the angle at which the paper sheet enters the switching means is variable. And variable means for performing the operation.

According to a fifth aspect of the present invention, there is provided a transport roller pair for transporting a paper sheet in a first direction, and a paper sheet transported in a first direction by the transport roller pair in the first direction. A switching gate for selectively switching to a different second direction;
A driving means comprising an operating lever and a solenoid for operating the switching gate; and an interlocking member for changing the position of the transport roller pair in conjunction with the switching operation of the switching gate by the driving means, and Variable means for varying the angle at which paper sheets enter.

According to a sixth aspect of the present invention, there is provided a transfer means for transferring a toner image to a transfer material, and a fixing means for fixing the toner image by passing the transfer material onto which the toner image has been transferred by the transfer means. And a mode setting for setting a single-sided image forming mode for forming an image on one side or a double-sided image forming mode for forming an image on both sides of the transferred material. Means, when the single-sided image forming mode is set by the mode setting means, the transfer direction of the transfer medium carried out from the transfer means is set to the first direction, and when the double-sided image forming mode is set, A switching unit for switching to a second direction different from the first direction, and when the transport direction of the paper sheet is switched to the second direction by the switching unit, the switching unit switches to the front of the switching unit. The entry angle of the sheet; and a varying means for varying.

According to a seventh aspect of the present invention, there is provided a transfer means for transferring a toner image to a transfer material, and a fixing means for fixing the toner image by passing the transfer material onto which the toner image has been transferred by the transfer means. A first transport unit for transporting the transfer material sent from the fixing unit, and a single-side image formation mode for forming an image on one side or a double-side image formation mode for forming an image on both surfaces for the transfer material. When the one-sided image forming mode is set by the mode setting means, the first direction is set as the conveying direction of the transfer material carried out from the conveying means, and the two-sided image forming mode is set. A switching means for switching to a second direction different from the first direction, and the transfer medium switched to the second direction by the switching means is conveyed toward the transfer means. And second transport means, when the conveying direction of the paper sheet is switched to the second direction by said switching means comprises a variable means for varying the approach angle of the paper sheet to said switching means.

According to the present invention, the advancing direction of the paper sheet (transferred material) is gently changed by changing the angle at which the paper sheet (transferred material) enters the switching means during the switching operation of the switching means. Make sure that the paper does not curl significantly.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 shows the internal configuration of the electrophotographic copying machine. In FIG. 1, reference numeral 1 denotes an apparatus main body, and a document table 2 on which an original is placed is provided on the upper surface of the apparatus main body 1. An illumination lamp 3 for illuminating the original placed on the original table 2 is provided below the original table 2.
A reflection plate 4 for condensing the illumination light generated from the original on the original, and a first carriage 5 for reflecting the reflected light from the original toward the second carriage 7 are arranged.

The first carriage 5 incorporates a first mirror 6 for bending light reflected from a document. The first carriage 5 is arranged so as to be movable in parallel with the document table 2 and is moved in parallel along the document table 2 by a pulse motor (not shown) via a toothed belt (not shown) or the like.

The second carriage 7 has a first carriage 5
A second mirror 9 and a third mirror 10 are arranged at right angles to each other to sequentially fold the reflected light from the document bent via the first mirror 6. The second carriage 7 is driven by the first carriage 5 by a toothed belt or the like (not shown) that drives the first carriage 5, and is moved to the document table 2 at half speed with respect to the first carriage 5. Are moved in parallel.

Below the first carriage 5, a plane including the optical axis of the light turned back through the second carriage 7 is formed so as to be movable via a drive mechanism (not shown).
An imaging lens 11 that gives convergence to the reflected light from the second carriage 7 and forms an image of the reflected light at a desired magnification by moving itself, and a reflected light transmitted through the imaging lens 11 will be described later. Fourth to sixth guides leading to the photosensitive drum 16
Mirrors 12 to 14 are provided.

A photosensitive drum 16 is rotatably provided obliquely below the sixth mirror 14. Photosensitive drum 1
6, a charging device 17 for charging the photoconductor 16 with a predetermined charge along its rotation direction, an erasing LED (light emitting element) 18 used for trimming, masking, frame erasing, and the like, a photoconductor 16 Developing device 18 that supplies toner to an electrostatic latent image formed on a photosensitive member 16, a transfer material as paper sheets fed from a paper cassette or the like described later, that is, a toner image on photoreceptor 16 Transfer device 19 for transferring the paper, a peeling device 20 for peeling the paper from the photoconductor 16,
A cleaning device 22 is disposed in order to remove the distribution of the charge on the photoconductor 16 while returning the charging characteristics of the photoconductor 16 to the initial state and scraping off the residual toner.

A built-in paper cassette 24 for supplying paper, for example, copy paper, OHP sheet, etc., toward the photoreceptor 16 is inserted into the inner bottom of the apparatus main body 1.
A feed tray 25 for feeding sheets having various sizes one by one is arranged at a position corresponding to the rotation direction upstream of the photoconductor 16 and to the right of the photoconductor 16.

Between the photoreceptor 16 and the paper cassette 24, a paper feed roller 26 for pulling out the paper one by one from the cassette 24, a paper feed roller 27 for feeding the paper supplied from the feed tray 25, The upper and lower transport roller pairs 28 and 29 for feeding the paper pulled out via the roller 26 toward the photoconductor 16, and the paper is fed from the transport roller pair 29 or the paper feed roller 27 to the photoconductor 16. The feeding path 30 for feeding and correcting the inclination of the sheet, aligning the leading end of the toner image on the photoreceptor 16 with the leading end of the sheet, and the same speed as the moving speed of the outer peripheral surface of the photoreceptor 16 And a pair of registration rollers 31 for feeding the sheet.

The toner image formed on the photosensitive member 16 is transferred to a position corresponding to the downstream side of the photosensitive member 16 in the rotation direction, and is transported to transport the sheet on which the toner is electrostatically attached. A fixing device 3 for heating the toner transferred to the sheet to melt the toner and fixing the toner to the sheet;
4, and a first and a second pair of discharge rollers 36 and 37 for discharging the sheet on which the toner image is fixed to the outside of the apparatus. Further to the left of the second discharge roller pair 37,
A discharge tray 38 for storing a sheet on which the toner image discharged from the second discharge roller pair 37 is fixed is arranged.

On the upper side of the paper feed cassette 24, an automatic double-sided mechanism 41 is provided. In the automatic double-sided mechanism 41, a guide plate 44 constituting a double-sided conveyance path 68 is disposed below a switching gate 42 as a switching means described later, and the guide plate 44 has a pair of conveyance rollers 45 for conveying a sheet. … Is arranged. A stack section 46 for stacking sheets is provided below the guide plate 44. On the sheet discharge side of the guide plate 44, a U-turn guide 47 for making a U-turn of the discharged sheet and stack / feed rollers 48 and 49 for feeding the sheet to the stack section 46 and feeding the sheet from the stack section 46 are provided. I have.

FIG. 2 shows a switching mechanism 51 for switching the conveying direction of the sheet sent from the fixing device 34. The switching mechanism 51 includes a switching gate 42 provided between the first and second transport roller pairs 36 and 37 for switching the paper transport direction between a first direction and a second direction orthogonal to the first direction. Have. The switching gate 42 is rotatably attached to the lower roller shaft 53 of the second discharge roller pair 37. A first projection 54 projects from one end of the switching gate 42, and a second projection 55 projects from the other end. A gate switching operation lever 56 is provided below the first protrusion 54 of the switching gate 42 so as to be vertically movable along the vertical direction. A drive mechanism 5 for vertically moving the operation lever 15 is provided below the operation lever 56.
7 are provided.

A driving mechanism 57 is abutting against the lower end of the operating lever 56 to rotate the operating lever 56 up and down.
And a solenoid 60 for rotating the rotation lever 58 about a support shaft 59. The rotation lever 58 is biased by a coil spring 58a so as to rotate counterclockwise.

The energization of the solenoid 60 is turned on and off in accordance with the one-sided or two-sided image forming mode set by the mode setting means 67. That is, in the single-sided image forming mode, the power to the solenoid 60 is turned off and demagnetized. In the double-sided image forming mode, the power to the solenoid 60 is turned on and magnetized, and the switching gate 42 is rotated. .

On the other hand, the shaft 62 of the lower roller 36b of the first conveying roller pair 36 has an L
An arm 61 as an interlocking member having a letter shape is rotatably attached. An upper roller 36a of the first conveying roller pair 36 is attached to one end of the arm 61, and the upper roller 36a is
Is pressed.

The other end of the arm 61 is connected to the coil spring 6
4, the second projection 55 of the switching gate 42 is in contact with the other end of the arm 61. Next, the switching operation of the switching gate 42 will be described.

In the case of one-sided copying, as shown in FIG. 1, the power supply to the solenoid 60 is turned off, the excitation is released, and the rotating lever 58 is actuated by the urging force of the spring 58a.
Is turned downward. As a result, the operation lever 56 is lowered, the switching gate 42 is urged by the spring 64 so as to rotate clockwise about the roller shaft 53, and is retracted downward from the paper discharge path 66.

Therefore, the sheet on which the transfer toner image is fixed is sent out from the first conveying roller pair 36 to the discharge path 66, and the sheet P is transferred to the first guide surface 42 of the switching gate 42.
The sheet is conveyed in the direction of arrow A along the line a, and is discharged to an external discharge tray 38 via the second conveying roller pair 37.

In the case of double-sided copying, as shown in FIG. 3, the power to the solenoid 60 is turned on, and the rotating lever 5 is turned on.
8 is turned upward against the urging force of the spring 58a. By this rotation, the operation lever 56 moves upward as shown by the arrow C, and the first protrusion 54 of the switching gate 42 is moved.
Push up. This push-up causes the switching gate 42 to rotate counterclockwise about the shaft 53 to project the second guide surface 42 b into the paper discharge path 66.

At this time, the second end of the switching gate 42
The arm 55 is rotated counterclockwise around the roller shaft 62 against the urging force of the spring 42 by the projection 55 of FIG.
Is displaced by the angle θ1 from the state shown in FIG.

Due to this displacement, the entering angle θ2 of the sheet P with respect to the second guide surface 42b of the switching gate 42 is, for example, 42.5 degrees as compared with the case where the upper roller 36a of the first discharge roller pair 36 is not displaced. From 37 to 37 degrees.

The paper discharged from the first discharge roller pair 36 is sent in the direction of arrow B along the second guide surface 42b of the switching gate 42, and is sent to the double-sided conveyance path 68. The sheet is conveyed along the conveyance path 68 and discharged, and is sent to the stack roller 48 via the U-turn guide 47.
Will be stacked.

The sheets stacked on the stacking section 46 are sent out by the rotation of the paper feed roller 49, and sent to the pair of registration rollers 31 in an inverted state through the pair of transport rollers 29 and the feed path 30. After the paper is aligned here, the paper is sent to an image transfer section between the photosensitive drum 16 and the transfer charger 19. Then, after the image is transferred again by the image transfer unit, the image is separated by the separation charger 20 and is conveyed to the fixing device 34 by the movement of the conveyance belt 33, where the image is fixed. After the fixing, the sheet is discharged from the first discharge roller pair 36.

At this time, the excitation of the solenoid 60 is released, and as shown in FIG.
Evacuated from 6. Thereby, the first discharge roller pair 3
The paper discharged from 6 is sent to the second discharge roller pair 37 along the first guide surface 42a of the switching gate 42 and discharged to the external discharge tray 38.

As described above, at the time of the switching operation of the switching gate 42, the angle at which the sheet enters the switching gate 42 can be varied and reduced, so that even if the installation space of the switching gate 42 is narrow, the traveling direction of the sheet Can be gently changed and sent to the conveyance path 68 for both sides.

Accordingly, the curl amount of the paper can be reduced, and the paper jam at the switching gate 42, the transfer omission at the image transfer unit, or the paper jam at the paper carry-in side of the fixing device 34 can be prevented. it can.

[0040]

As described above, according to the present invention, at the time of the switching operation of the switching means, the entering angle of the paper sheet (transfer material) with respect to the switching means is changed. It can be changed to 37 °.

Therefore, even when the installation space for the switching gate is small, the curl amount of the paper sheet (transfer material) can be reduced, and for example, the transfer loss of the image is reduced by 5%.
/ 1000 can be reduced to 0/1000, and the paper jam at the switching gate and the jam at the entrance side of the fixing unit after re-feeding can be reduced from 3/1000 to 1/1000.

[Brief description of the drawings]

FIG. 1 is an internal configuration diagram showing an electrophotographic copying machine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a sheet conveyance path switching device.

FIG. 3 is a diagram illustrating a switching operation state of the transport path switching device.

[Explanation of symbols]

 P: paper (transfer material) 19: transfer charger (transfer unit) 34: fixing device (fixing unit) 36: first transport roller pair (first transport unit) 37: second transport roller pair (second) K: Variable means 42: Switching gate (switching means) 61: Arm (interlocking member) 67: Mode setting means

Claims (7)

[Claims] 1. A conveying means for conveying a paper sheet in a first direction, and a paper sheet conveyed in a first direction by the conveying means is selected in a second direction different from the first direction. And a variable means for changing an angle of the paper sheet entering the switching means during a switching operation of the switching means. 2. A transport means for transporting paper sheets in a first direction, and a paper sheet transported in a first direction by the transport means is selected in a second direction different from the first direction. Switching means for changing the position of the transport means at the time of the switching operation of the switching means, and changing means for changing the angle at which the paper sheet enters the switching means. Paper transport device. 3. A transport means for transporting paper sheets in a first direction, and selecting paper sheets transported in a first direction by the transport means in a second direction different from the first direction. Switching means for changing the position of the conveying means in conjunction with the switching operation of the switching means, and changing means for changing the angle of entry of the paper sheet with respect to the switching means. Paper sheet transport device. 4. A transport means for transporting paper sheets in a first direction, and selecting paper sheets transported in a first direction by the transport means in a second direction different from the first direction. Switching means for changing the position of the conveying means in conjunction with the switching operation of the switching means, and changing means for changing the angle at which the sheet enters the switching means. A paper sheet transport device, comprising: 5. A transport roller pair for transporting paper sheets in a first direction, and a paper sheet transported in a first direction by the transport roller pair in a second direction different from the first direction. A driving means comprising an operating lever and a solenoid for operating the switching gate; and an interlocking member for changing the position of the transport roller pair in conjunction with the switching operation of the switching gate by the driving means. Has,
A variable means for varying an angle at which the paper sheet enters the switching gate; 6. A transfer means for transferring a toner image to a transfer material, a fixing means for fixing the toner image by passing the transfer material onto which the toner image has been transferred by the transfer means, Transport means for transporting the material to be transferred; mode setting means for setting a single-sided image forming mode for forming an image on one side or a double-sided image forming mode for forming an image on both sides of the material to be transferred; By means, when the one-sided image forming mode is set, the transfer direction of the transfer medium carried out from the transfer means is set to the first direction, and when the two-sided image forming mode is set, the transfer direction is set to the first direction. Is a switching means for switching to a different second direction, and when the transport direction of the paper sheet is switched to the second direction by this switching means, the approach angle of the paper sheet with respect to the switching means An image forming apparatus characterized by comprising a variable means for varying the. 7. A transfer device for transferring a toner image to a transfer material, a fixing device for fixing the toner image by passing the transfer material onto which the toner image has been transferred by the transfer device, Transporting the transfer material to be transferred
Conveying means; and a mode setting means for setting a single-sided image forming mode for forming an image on one side or a double-sided image forming mode for forming an image on both sides of the transfer material; When the mode is set, the transfer direction of the transfer medium carried out from the transfer means is set to the first direction, and when the double-sided image forming mode is set, the second direction is different from the first direction. Switching means for switching the medium to be transferred, which has been switched in the second direction by the switching means, to the transfer means; and An image forming apparatus, comprising: a variable unit that changes an angle at which the paper sheet enters the switching unit when the direction is switched to the direction of (b).