JPH01197768A - Copying machine - Google Patents

Abstract

PURPOSE:To convey copying sheets of any sizes other than a prescribed one without coming into contact with a conveying member and to prevent a part from being omitted by arranging a conveying member, which gives forced conveying power in the conveying direction to conveyed sheets, in the direction orthogonal to the conveying direction of copying sheets of the copying machine and on the halfway of the conveying route of conveyed sheets so as to correspond to the conveying position of prescribed sized copying sheets. CONSTITUTION:A conveying device 2 is arranged between a photosensitive drum 3 and a fixing part 4 of the title machine and copying sheets are conveyed from a kick roller 23 to the fixing part 4. Conveying rollers 25 and 26 are arranged on halfway of a guide plate 20 fixed between the exposed roller 23 and the fixing part 4 and in a direction orthogonal to the conveying direction. They are arranged near the connecting side of the projecting part of a feeding tray 5, and turn into short columnar conveying rollers 25 and 26 whose upper and lower contact parts project slightly from the surface of the guide plate 20. They can convey copying sheets of any sizes other than a prescribed one are fed without bringing said sheets into contact with the conveying part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying machine, and more specifically to the structure of a paper conveying device inside a copying machine.

[Prior art]

FIG. 4 is a partially cutaway schematic front view of a conventional copying machine. In the figure, l is provided with a paper feed tray 5 and a paper ejection tray 6, respectively, on both sides of which hold copy paper and copied ejected paper on top, and the copy paper on the paper feed tray 5 is , a photosensitive drum 3 that rotates around a horizontal axis perpendicular to the direction of conveyance, and a pair of upper and lower photosensitive drums that rotate around axes parallel to this, respectively. The main body of the copying machine has a fixing unit 4 consisting of an upper fixing roller 4o and a lower fixing roller 41 arranged in this order in the direction of conveyance, and a document table 8 is provided on the upper side of the main body 1 of the copying machine. In addition, an optical scanning unit 7 is configured, which includes a linear light source (not shown) and an optical scanning mechanism that scans the light emitted by the linear light source onto the surface of a document placed on a document table 8.

The transport device 2 includes a plurality of transport members arranged along the transport route, and guide plates 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, .
Consisting of In the copying machine shown in FIG. 4, each of the conveyance members rotates around a horizontal axis perpendicular to the conveyance direction, and a feeder is provided facing the end of a paper feed tray 5 inside the copying machine main body 1. a paper feed roller 21; a pair of upper and lower timing rollers 2 disposed between the paper feed roller 21 and the photosensitive drum 3;
2.22, a kicking roller 23 disposed below the photosensitive drum 3, and a conveyor 24 disposed between the photosensitive drum 3 and the fixing section 4 with its upper surface substantially horizontal. It is equipped with 2.

The copying operation of the copying machine is a series of steps in which a copy sheet is transported by the transport device 2, a copy image of the image on the original surface is formed on the surface of the copy paper being transported, and the ejected paper on which the copy image has been formed is discharged. Next, this copying operation in the conventional copying machine shown in FIG. 4 will be briefly explained.

First, by the operation of the optical scanning unit 7, the light emitted by the linear light source is scanned at a predetermined speed on the document surface on the document table 8, and the reflected light from this document surface is guided to the copying machine main body 1. The previously charged outer surface of the photosensitive drum 3, which is rotating at a predetermined speed, is exposed to light, and an electrostatic latent image corresponding to the image on the document surface is formed on this outer surface. As the photosensitive drum 3 further rotates, this electrostatic latent image is visualized by adhesion of the toner fed to the outer surface of the photosensitive drum 3, and a toner image is formed on the outer surface of the photosensitive drum 3. On the other hand, the copy paper on the paper feed tray 5 is taken into the copying machine main body l by the rotation of the paper feed roller 21, is conveyed to the position where the timing rollers 22 and 22 are disposed, and the leading end is inserted between these. The timing rollers 22 and 22, which start rotating when the photosensitive drum 3 passes a predetermined rotational position, feed the timing rollers 22 and 22 to the lower part of the photosensitive drum 3. After the toner image on the outer surface of the photosensitive drum 3 is transferred onto the upper surface of the photosensitive drum 3, the toner image is transferred onto the conveyor 24 by the rotation of the kicking roller 23. It is conveyed while being placed on the top and fed to the fixing section 4. The fixing section 4
In this, the copy paper is held between an upper fixing roller 40 and a lower fixing roller 41, and while being conveyed by the rotation of these rollers, the upper fixing roller 40 and the lower fixing roller 40 are heated to a predetermined temperature by a built-in heater. Due to the close contact, the toner image is fixed, and the sheet with the copied image formed thereon is discharged onto the sheet discharge tray 6.

[Problem to be solved by the invention]

In the conventional copying machine configured as described above, the fixing unit 4, which includes the upper fixing roller 40 and the lower fixing roller 41, and the timing rollers 22 and 22 are arranged so that the copy paper is placed between a pair of upper and lower rollers. The conveyor 2 between the photosensitive drum 3 and the fixing portion 4
In the arrangement position No. 4, the copy sheet placed on top of the paper is only given a conveying force corresponding to the frictional force generated between it and the conveyor 24, and reliable conveyance is not possible. The problem is that it is not done. When using large-sized copy paper, the leading edge of the paper reaches the fixing section 4 before it is sent out from between the timing rollers 22 and 22, and the upper fixing roller 40 and lower fixing roller 41 are connected to each other. However, when using small-sized copy paper, the conveying force is insufficient while conveying it, and paper jams occur frequently inside the copier main body 1. , a problem arises in that the copying operation has to be interrupted each time.

In order to solve this problem, a pair of upper and lower rollers is provided between the photosensitive drum 3 and the fixing section 4, instead of the conveyor 24, for holding the widthwise edges of the copy paper. There is a copying machine that is configured to apply a conveyance force to the copy paper, but the copy paper that is conveyed between the photosensitive drum 3 and the fixing section 4 has a toner image formed on its upper surface before being fixed. Contact with the upper roller erases this toner image, creating an additional drawback in that the copy image is missing across the width of all sizes of copy sheets.

In addition, some large-sized copying machines are equipped with a vacuum source inside the copying machine body 1 to vacuum-adsorb the copy paper onto the transport conveyor 24 to ensure reliable transport by the transport conveyor 24. If such a vacuum source is installed in a copying machine, the installation area will increase due to the increase in size, the copying cost will increase due to the increase in power consumption, and the equipment cost will increase due to the increase in the number of parts. There are some difficulties.

The present invention has been made in view of the above circumstances, and provides a copying machine that is capable of transporting copy paper reliably regardless of its size, and that can minimize the occurrence of missing portions of copied images. The purpose is to provide this with a simple configuration.

[Means to solve the problem]

A copying machine according to the present invention is a copying machine that transports copy paper fed to one side along a transport path formed inside the copy machine and forms a copy image on the surface of the copy paper, in the direction of the transport. A forced conveyance force in the direction of conveyance is provided in the middle of the conveyance path, corresponding to the conveyance position of a copy sheet of a predetermined size that is fed to a different position in a direction perpendicular to the others. It is characterized by comprising a conveying member that imparts.

[Effect]

In the present invention, when copy paper of a predetermined size is fed to a position different from that of copy paper of other sizes in a direction perpendicular to the transport direction, when it is transported on an extension line of this supply position, the copy paper is transported to this transport position. While a forced conveying force is applied by the correspondingly arranged conveying member, copy sheets of other sizes are conveyed through a position different from the conveying position in a direction perpendicular to the conveying direction. It is transported without contacting the parts.

〔Example〕

The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is an external perspective view of a copying machine according to the present invention, and FIG. 2 is a schematic diagram showing the configuration of a conveying device inside the copying machine.

In the figure, l is equipped with a paper feed tray 5 on one side that holds copy paper with copy paper placed on top, and
A paper ejection tray 6 that also holds the copied ejected paper is mounted on the other side, and the copy paper on the paper feed tray 5 is conveyed in the direction toward the paper ejection tray 6, as shown in FIG. It has a built-in conveyance device 2, a photosensitive drum 3 that rotates around a horizontal axis perpendicular to the conveyance direction, and a pair of upper and lower fixing rollers 40 and lower fixing rollers 41 that rotate around axes parallel to the photosensitive drum 3, respectively. The fixing unit 4 consisting of
The main body of the copying machine is arranged in this order in the direction of transport along the transport path, and the upper part of the main body 1 of the copying machine includes a document table 8 on the upper side, and a linear light source (not shown). An optical scanning unit 7 that includes a built-in optical scanning mechanism (not shown) that scans the light emitted by this onto the surface of a document placed on a document table 8
is configured.

As shown in FIG. 2, the conveyance device 2 is disposed facing the end of the paper feed tray 5 inside the copying machine main body l, and includes a paper feed roller 21S that rotates around a horizontal axis perpendicular to the conveyance direction. A pair of upper and lower timing rollers 22 and 22 are disposed between the paper roller 21 and the photosensitive drum 3 and rotate around a horizontal axis perpendicular to the conveyance direction; A kicking roller 23 that rotates around a horizontal axis, and an upper and lower roller that are spaced apart from each other in the conveyance direction between the photosensitive drum 3 and the fixing unit 4 and that rotate around horizontal axes perpendicular to the conveyance direction. Each pair of conveyor rollers 2
5.25, transport rollers 26, 26, and guide plates 20, 20, etc., which are fixedly installed between the positions of the respective rollers and support and guide the paper being transported from the lower surface side.

The copying operation of the copying machine according to the present invention configured as described above is similar to that of a conventional copying machine, and detailed explanation will be omitted.

Now, as shown in FIG. 1, the document table 8 has a document cover 81 on one side of a transparent glass document placing plate 80, which is large enough to cover the entire surface of the document plate 80, and can be opened and closed around a horizontal axis. The document to be copied is placed on the document placement plate 80 with its image forming surface facing downward, and after the document cover 81 is closed to block light from the outside.
Due to the operation of the optical scanning section 7, the light emitted from the linear light source is
Scanning is performed from the back side of the document placement plate 80.

In the copying machine according to the present invention, the original i1W plate 80
has a planar shape as shown in FIG. 1, in which a protrusion of a predetermined length is formed on one side in the width direction of a rectangle whose longitudinal direction is the conveying direction of the copy paper from the side where the four paper feed trays 5 are installed. A small-sized document such as a business card or postcard is placed in the placement position A with its long side aligned with the long side of the protrusion, as shown by the two-dot chain line in the figure. In addition, a large-sized document is placed in the placement position A with its long side aligned with the long side of the rectangle on the protrusion side, as shown by the dashed line in the figure.
An index defining the document placement position is formed around the document placement plate 80 so that the document 2 is placed on the document placement plate 80 .

Therefore, if the manuscript is placed according to these indicators,
The small-sized original is placed at a position that projects from the large-sized original by a predetermined width in the width direction of the original placing plate 80, that is, in a direction perpendicular to the conveying direction of the copy paper.

The paper feed tray 5 is in the shape of a rectangular flat plate whose longitudinal direction is the conveyance direction, and is located on the same side as the protrusion on the document placement plate 80 in the width direction and has approximately the same width as the protrusion. It is a member as shown in FIG. 1, which is made up of a series of protrusions having a predetermined length from the side to be attached to the machine main body 1, and is a member shown in FIG. 3! Position A, the original placed on top, that is, the business card.

Copy paper of a size corresponding to a small-sized original such as a postcard is placed in paper feed position B with its long side aligned with the long side of the protrusion, as shown by the two-dot chain line in the figure. The copy paper that is placed and has a size that corresponds to a large-sized original is fed with its long side aligned with the long side of the rectangle on the protrusion side, as shown by the dashed line in the figure. The paper is placed at position B2. Therefore, the copy paper on the paper feed tray 5 is taken into the copying machine main body 1 by the rotation of the paper feed roller 21 at a position corresponding to the paper feed position B+ or B2, depending on the size of the copy paper, respectively. During the subsequent transport by the transport device 2, the paper is transported over transport positions corresponding to the sheet feeding position B or B2, respectively, in a direction perpendicular to the transport direction.

As described above, the document placement positions A, , A on the document placement plate 80 and the copy paper feeding positions B, , B on the paper feed tray 5 are defined in the width direction of the copying machine main body 1. In other words, since they correspond to each other in the direction orthogonal to the conveyance direction of the copy paper, the toner image formed by the exposure of the reflected light from the document surface on the document placement plate 80 is in the axial length direction of the photosensitive drum 3. The forming position and the conveyance position of the copy paper inside the copying machine main body 1 correspond to each other in the direction perpendicular to the conveyance direction, and as mentioned above, the copy paper being conveyed has a The toner image is reliably transferred.

FIG. 3 is a perspective view of the conveying device 2 between the photosensitive drum 3 and the fixing section 4. FIG.

In this figure, the copy paper is conveyed in the direction from the kicking roller 23 toward the fixing unit 4, that is, in the direction from the right side to the left side of the figure.
The conveyance rollers 26 and 26 are arranged in the middle of the guide plate 20 fixedly installed between the kick-out roller 23 and the fixing unit 4, so that the protruding portion of the paper feed tray 5 is fixed in the direction perpendicular to the conveyance direction. It is a short cylindrical roller arranged in such a manner that the contact part of the upper and lower rollers is slightly protruded upward from the upper surface of the guide 120, and is coaxially fixed to each roller. A belt 28 is wound between the belt pulleys 27 and 27, and the belts are rotated in conjunction with each other via the belt 28. As mentioned above, the conveyance position of the copy paper by the conveyance device 2 is as follows.
With respect to the direction perpendicular to the conveying direction, this corresponds to the paper feeding positions B+ and Bz on the paper feeding tray 5, so it is indicated by a two-dot chain line in FIG. between transport position C6 corresponding to small-sized copy paper, which is indicated by a dashed line in FIG. In the paper feed position B,

A deviation of a width equal to the deviation width between B2 exists on the paper feed tray 5 on the side where the protrusions are connected in a direction perpendicular to the conveying direction. The conveyance rollers 25.25 and 26.2
The arrangement position in the direction perpendicular to the conveyance direction of No. 6 is conveyance position 1c.
As shown in FIG.
．． 26 at its widthwise end, and the transport position if
The large-sized conveyed paper conveyed on the Cl does not come into contact with the conveying rollers 25.25 and 26.26.

The above-mentioned small-sized copy paper is one whose dimension in the conveyance direction is smaller than the separation distance between the timing roller 22, 22 in front of the photosensitive drum 3 and the fixing section 4, and is used in the copying machine according to the present invention. Since such a small-sized copy sheet is conveyed above the conveyance position C1, while it is held between the timing rollers 22 and 22, the conveyance force is applied by the rotation of the timing rollers 22 and 22. After the end portion is sent out from the timing roller 22.22 and until the leading end reaches the fixing unit 4, the conveyance rollers 25, 25, and then the conveyance roller 2
The ends in the width direction are held between 6° and 26, and conveying force is applied by the rotation of these.Furthermore, after the end portions are sent out from the conveying rollers 26 and 26, prior to this sending out, Conveying force is applied by the rotation of the upper fixing roller 40 and lower fixing roller 41 of the fixing unit 4 that clamp the leading edge, and sufficient conveying force is applied over the entire area in the conveying direction, so that small-sized copy paper can be Reliable transportation is possible.

Also, large size copy paper can be handled by the timing roller 22.
The leading end reaches the fixing unit 4 before it is sent out from the timing roller 22, 22, and the upper fixing roller 40 is rotated by the timing roller 22. Reliable conveyance is possible by the rotation of the lower fixing roller 41. Therefore, in the copying machine according to the present invention, the large size paper is transported above the transport position C2, and the transport roller 25.
and by avoiding contact with 26.26,
This prevents the toner image from being erased at the contact portion with these, and prevents the occurrence of missing portions in the copied image. Note that it is inevitable that copy paper transported above transport position C+ will have missing parts of the copy image in the portions sandwiched between transport rollers 25 and 25 and 26 and 26; What is held between the conveyor rollers 25.25 and 26.26 is only a small-sized copy sheet that can be given sufficient conveyance force by the rollers with a small width. By using a roller with a width as small as possible, it is possible to keep the area where the defect occurs within a range where there is no practical support.

In this embodiment, the conveyance rollers 25.25 and 26.26 are used as conveyance members that apply conveyance force to a copy sheet of a predetermined size. Other conveyance members such as a pair of upper and lower belts are connected to the conveyance rollers 25, 25 and 26.
．． It may be used instead of 26.

Furthermore, the upper rollers 25, 25 and 26, 26 have a large number of teeth on their circumferential surfaces, and these teeth mesh with the copy paper to apply a conveyance force, thereby making it possible to eject the paper. Although it is unavoidable that marks from the engagement with the teeth will occur on the paper, it should not affect the application of conveying force (
It is possible to further narrow the area in which the defect occurs.

In addition, in a copying machine configured to perform optical scanning by moving the document table 8, the protrusion direction of the protrusion that defines the placement position A of the small-sized document on the document placement plate 80 is the first direction.
It goes without saying that, contrary to what is shown in the figure, this is the opposite side of the paper feed tray 5 to the side on which the protrusions are connected.

〔effect〕

As described in detail above, in the copying machine according to the present invention, copy paper of a predetermined size is fed to a position different from that of copy paper of other sizes in a direction perpendicular to the conveying direction, and the copy paper is arranged in a manner corresponding to the supply position. Since a forced conveying force is applied by the provided conveying member, the copy paper inside the copying machine is reliably conveyed regardless of its size. (Because it is conveyed, if copy paper of this size is used, there will be no defective parts in the copied image, and the occurrence of such defective parts is limited to the case where copy paper of the predetermined size is used.) The present invention has excellent effects such as: □

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a copying machine according to the present invention, FIG. 2 is a schematic diagram showing the configuration of an internal conveyance device, FIG. 3 is a perspective view of a part of the conveyance device, and FIG. 4 is a conventional copying machine. FIG. 2 is a partially cutaway front view of the copying machine.

Claims (1)

[Claims] 1. In a copying machine that transports copy paper fed to one side along a transport path formed inside the copy machine and forms a copy image on the surface of the copy paper, the direction of the transport A forced conveyance force in the direction of conveyance is provided in the middle of the conveyance path, corresponding to the conveyance position of a copy sheet of a predetermined size that is fed to a different position in a direction perpendicular to the others. A copying machine characterized by comprising a conveying member that imparts.