JPH0825666B2 - Sheet body alignment device - Google Patents

Description

The present invention relates to a sheet aligning device, and more particularly to a sheet aligning device effective for use in a copying machine that performs multiplex copying or double-sided copying.

(Prior Art) In recent years, there has been an increasing need for multifunctional copying machines.
There is a demand for a copying machine capable of performing multiple copying of about two colors and automatic double-sided copying with one copying machine.

Many copiers developed to meet these requirements feed the paper set in a paper cassette to a transfer device such as a photosensitive drum that transfers a toner image onto the paper by a paper feed mechanism, and then use a fixing device such as a pressure roller. Fix it. When multiplex or double-sided copying is selected, the sheets are once stacked on the re-feeding tray and fed to the transfer device by the re-feeding mechanism to perform the second copying.

In such a copying machine, when performing the second and subsequent copying, it is necessary to take measures to prevent the front-rear, left-right deviation and skew from occurring with respect to the previous copying position.

On the other hand, conventionally, when the image is transferred and fixed on the first surface of the copy paper (hereinafter abbreviated as paper) and then once accumulated on the re-feed tray, the misalignment of the left and right of the paper is adjusted. .
(For example, Japanese Patent Laid-Open No. 59-143853) In this invention, the refeed tray is provided with a side plate that reciprocates left and right to adjust the misalignment of the left and right sheets. However, with such a positioning mechanism, it is difficult to set the contact force of the side plate with respect to the sheet, and if the contact force is too large, the sheet is bent and the sheet is not reliably positioned.

In particular, when multiple copies are made on the same side with different colors over two or more times, subtle misalignment of the paper also poses a problem.

(Problems to be Solved by the Invention) As described above, in the copying machine, there is a problem in that a position shift occurs when performing multiplex copying or double-sided copying.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sheet body aligning device capable of accurately positioning a sheet body.

[Structure of Invention]

(Means for Solving Problems) In order to solve the above problems, the sheet body aligning device of the present invention includes a deforming unit that bends the sheet member in the conveying direction, and a bending unit that bends the sheet member. The holding means holds the sheet body in a direction orthogonal to the conveying direction and the thickness direction of the sheet body while maintaining the above state.

(Operation) An extremely thin sheet body such as a copy sheet easily buckles and bends when subjected to a compressive force in a direction orthogonal to its thickness direction. However, if the sheet body is deformed by applying a force in a direction orthogonal to the compression direction in advance, the apparent rigidity of the paper in the compression direction is increased, and buckling is less likely to occur than in a flat state. The present invention utilizes such an effect to apply a clamping force to the sheet body in a direction orthogonal to the transport direction and the thickness direction, and when moving and aligning the sheet body with a predetermined position, the apparent force in the direction orthogonal to the transport direction and the thickness direction is applied. The rigidity is increased so that the position is surely corrected.

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

i) First Embodiment FIG. 1 is a perspective view showing a first embodiment. For convenience of explanation, the guide plate 25 and the paper 30 are shown to be transparent.

The sheet 30 is sent between the side plates (sandwiching means) 33a and 33b by a conveyance roller (deformation means) 41 that sends the sheet into the positioning mechanism. At this time, the transport roller 11 for feeding the paper to the photosensitive drum 7 is stopped, the leading edge of the paper 30 is applied to the transport roller 11 by the transport roller 41, and when only the transport roller 41 rotates, the paper 30 becomes as shown in the figure. It bends in a U shape. The paper 30 is sandwiched by the side plates 33a and 33b to position the paper. However, since the paper 30 is bent in the paper feeding direction D as shown in the figure, the paper 30 is apparently moved in the direction E perpendicular to the paper feeding direction. The rigidity is increased, and even when sandwiched by the side plates 33a and 33b, it does not easily bend in the sandwiched direction E. Therefore, the sheet is reliably positioned by the main positioning mechanism.

Support guides 39 are provided on the side plates 33a and 33b, respectively, and by supporting the support guides 39 with the support rods 38,
The side plates 33a and 33b can reciprocate in a direction E perpendicular to the paper feeding direction D. In addition, the racks 35a, 3 are attached to the side plates 33a, 33b.
5b is attached, and the gear 36 that meshes with these racks 35a, 35b
By driving the step motor 34 to the side plates 33a, 33
By moving b in conjunction with the E direction, the sheet 30 is sandwiched and the center position of the photosensitive drum 7 and the center position of the sheet 30 are made to coincide with each other. The distance between the side plates 33a and 33b varies depending on the size of the paper 30 selected by the user of the copying machine, but for any size, set the width slightly wider than the paper width until the paper 30 is conveyed. Control the step motor.

An embodiment of a method for bending the paper 30 into a U-shape will be described with reference to FIG. However, the side plates 33a and 33b and the drive mechanism thereof are omitted from the drawing.

FIG. 2A shows a state in which the sheet 30 is fed by the transport roller 41. At this time, the transport roller 11 remains stopped. When the transport roller 41 is further driven, the paper
The sheet 30 is applied to the interval between the conveying rollers 11 (b), and gradually the sheet 30 buckles and bends upward as shown in (c). At this time, the side plate sandwiches the sheet of paper 30 as described above, but the side plate of the sheet of paper 30 does not pinch the sheet of paper 30 as shown in FIG.
Most preferably, the rear end of the sheet 30 is pulled out from the transport roller 41. This is because if the paper 30 is held by the transport rollers 41, it becomes difficult for the side plate to move the paper 30, and the positioning accuracy of the paper 30 will be reduced. Then, while the sheet 30 is sandwiched by the side plates, the transport roller 11 is driven to transport the sheet (d), whereby the positioning of the sheet 30 in the direction perpendicular to the feeding direction is completed.

FIG. 5 is a schematic diagram of an embodiment in which the paper positioning mechanism according to the present invention is used in a copying machine having double-sided copying and multiplex copying functions, and a series of copying operations will be described with reference to this drawing.

The original 2 placed on the upper part of the copying machine is illuminated by the lamp 3, and the reflected light 6 is scanned by the mirrors 4a, 4b, 4c. By moving the mirror 4a and the mirrors 4b and 4c at a speed ratio of 1: 1/2, the document 2 is scanned while the optical path length in front of the lens 5 is always kept constant. Reflected light 6 is lens 5, mirror
An image is formed on the photosensitive drum 7 by the optical projection means composed of 4d, 4e and 4f.

The photosensitive drum 7 is uniformly charged by the charging charger 8, but an electrostatic latent image is formed when the reflected light 6 forms an image on the photosensitive drum 7. This photosensitive drum 7
The upper electrostatic latent image is developed by one of the two developing devices 1a and 1b provided to enable two-color copying, and a toner image is formed.

On the other hand, a desired non-copied paper in any of the paper cassettes 9a, 9b, 9c in which papers of various sizes are set is fed into the copying machine through the paper feed path 31 by the paper feed rollers 10a, 10b, 10c. The paper 30 (not shown) fed into the copying machine by the paper feed rollers 10a, 10b, 10c is further conveyed by the conveyance rollers.
After being sent by 41, the side plates 33a and 33b (33b is not shown) are positioned so that the center of the photosensitive drum 7 and the center of the sheet 30 are aligned with each other, and then are conveyed to the photosensitive drum 7 by the conveying roller 11.

The conveyance roller 11 conveys the paper 30 based on the signal from the front end detection sensor 12 of the paper 30 so that the contact position of the paper 30 and the photosensitive drum 7 in the paper feed direction always coincides with each other, and thus the deviation of the paper feed direction does not occur. I am trying.

The toner image formed on the photosensitive drum 7 is transferred onto a sheet by the transfer charger 13, and the toner image is fixed by the fixing roller 14, and the first copying is completed.

When copying is performed only once on one side, the sheets are sent to the sheet discharge roller 45 by the sorting gate 15 and stacked on the sheet discharge tray 16, but when performing double-sided copying or multiple copying, the sorting gate 15 is used. Re-feed tray 17
The sheet is conveyed to the sheet re-feed path 22 to be stacked on the sheet. The sheets conveyed to the sheet re-feeding path 22 are once stacked on the sheet re-feeding tray 17 and are sent to the sorting gate 21 by the take-out roller 18 that descends and comes into contact with the sheet surface only when the sheet is taken out for the next copy. Be done. The sorting gate 21 selectively reverses the sheet for double-sided copying and multiple copying. The sheet that has passed through the sorting gate 21 passes through the re-feeding path 22 and is fed from the sheet feeding cassettes 9a, 9b, 9c. After passing through the confluence point 40 of the sheet feeding path 31 and the sheet re-feeding path 22, the sheet is again fed to the conveying roller 41. After that, the process is the same as the above-mentioned first copying.

In this embodiment, since the paper 30 is positioned immediately before being fed to the photosensitive drum 7, the paper by the conveyance roller is used.
Even if the sheet 30 meanders or the sheets 30 are not aligned on the stack tray 17, the sheet 30 is always in the same contact position with the photosensitive drum 7. Therefore, especially when superimposing images in multiplex copying, the image shift due to the positional shift of the paper 30 is reduced.

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

Supporting guides 39 are provided on the side plates 33a, 33b, which are the sandwiching means, and by supporting the supporting guides 39 with the support rods 38, the side plates 33a, 33b are step motors 34, racks 35,
By the moving means composed of the gear 36, it is possible to reciprocate in the arrow E direction which is perpendicular to the feeding direction (arrow D) of the paper 30.
Attach the racks 35a and 35b to the side plates 33a and 33b, and
By driving the gear 36 meshing with 35a, 35b by the step motor 34, the side plates 33a, 33b are interlocked and moved in the arrow E direction. The paper 30 is indicated by the arrow D from the paper cassettes 9a, 9b, 9c.
, It has a proper friction coefficient such as sponge,
The sheet 30 is fed into the space of the deforming means 23 by the roller 32 which is movable in the direction perpendicular to the feeding direction D. The deforming means 23 is composed of a pair of steel belts or the like having appropriate intervals, and the paper 30 meanders in a U-shape so as to bend in the U-shape in the feeding direction D. While passing through the deforming means 25, the sheet 30 is sandwiched by the side plates 33a and 33b, and its position is corrected so that its center coincides with the center of the photosensitive drum 7.
At this time, since the paper 30 is bent in a U shape, both side plates 33a, 33
The sheet 30 has high rigidity against pinching by b, and the sheet 30 is reliably positioned by the side plates 33a, 33b without being bent in the pinching direction even if the pressing force is slightly large.

The distance between the side plates 33a and 33b varies depending on the size of the paper 30 selected by the user of the copying machine, but for any size, it should be set slightly wider than the paper width until the paper 30 is conveyed. Then, the step motor 24 may be controlled so as to sandwich the sheet 30 when the sheet 30 has completely entered the deforming means 23.

As described above, the paper 30 is flexed in the feeding direction D, and the rigidity of the paper 30 is apparently increased with respect to the pinching by the side plates 33a and 33b, so that the paper 30 is reliably positioned and the first copy and the second copy are performed. Image shift due to the second copy is reduced.

The shape of the deforming means 23 is not limited to the U shape, but may be an S shape, a wave shape, or the like.

The deforming means 23 may be provided as shown in FIG. It can also be used to align a plurality of sheet bodies.

〔The invention's effect〕

As described above in detail, according to the present invention, it is possible to provide the paper aligning device capable of accurately correcting the position of the sheet body.

[Brief description of drawings]

1, 3 and 4 are perspective views showing an embodiment of the present invention, FIG. 2 is a schematic view for explaining a method of bending a sheet body into a U shape, and FIG. 5 is a book. It is a schematic diagram of a copying machine using the paper aligning device according to the invention. 7 ... Photosensitive drum, 9a, 9b, 9c ... Paper cassette 11 ... Roller, 21 ... Sorting gate 22 ... Re-feeding path 23 ... Deformation means, 30 ... Paper 31 ... Paper feeding path 33 ... … Side plate (sandwiching means) 34 …… Step motor (driving means) 35 …… Rack (driving means) 36 …… Gear (driving means) 41 …… Conveying roller (deforming means)

Claims (2)

[Claims] 1. A deforming means for bending a sheet body in a conveying direction, and a sheet body in a conveying direction and a thickness direction of the sheet body while maintaining a state of being bent by the deforming means. A sheet body aligning device for holding the sheet body in a direction orthogonal to each other. 2. The sandwiching means is capable of interlocking a plurality of side plates for sandwiching the sheet body and the side plates in a direction orthogonal to the transport direction and the thickness direction of the sheet body. The sheet body aligning device according to claim 1, wherein the sheet body aligning device comprises drive means.