JPH01271334A - Transfer material transfer device for picture image forming device - Google Patents

Abstract

PURPOSE:To securely prevent the flutter and speed change of a transfer material being transferred for obtaining a good quality picture image by providing a roller which is followingly rotated by a drivingly rotating roller and by which the transfer material is transferred while being held. CONSTITUTION:On the downstream side of a transfer passage 3, a guide roller 4 consisting of a conductive rubber is arranged. On the upper side of a guide upper plate 3, elastic supporting members 8 are fitted at prescribed intervals, and to each elastic supporting member 8 a roller 9 is rotatably supported, and it is so constituted that the roller 9 is brought into pressedly contact with the guide roller 4. When a transfer material P is fed to the transfer passage 3, the end thereof proceeds along the undersurface of the elastic supporting member 8, and passes through between the guide roller 4 and the rollers 9. And, even after the rear end of the transfer material P has passed through a resist- roller pair 5, the transfer material is always held by the guide roller 4 and rollers 9, and it is transferred to a transfer section. Thus, the transfer material P is prevented from fluttering, and the instantaneous speed change is not transmitted to the transfer section, so that picture image is not disturbed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transfer material conveying device for an image forming apparatus using an electrostatic recording process, such as an electrostatic copying machine or a printer.

(Prior Art) Conventionally, in this type of image forming apparatus, a copying machine equipped with a cylindrical photoreceptor is used as a means for supplying a sheet-like transfer material such as paper to a toner image area on the surface of an image carrier. For example, as shown in FIG. 6, the transfer material P is transferred in the direction of arrow B through a pair of registration rollers 105 and through a conveyance path 103 to a transfer site where a transfer charger 107 is placed close to a photosensitive drum 100 rotating and running in the direction of arrow B. Such things as feeding are known.

(Problem to be Solved by the Invention) However, in the configuration of the prior art, the upper guide plate 103a and the lower guide plate 1 forming the conveyance path 103 are
Bent portion 103a' on guide upper plate 103a at 03b
As a result, there is a locking problem in which the transfer material P fluttering and causing image disturbance.

Furthermore, as shown in FIG. 7, it has been proposed that at least one guide roller 104 is disposed on the downstream side of the conveyance path 103 to facilitate conveyance of the transfer material P. Even in the above example, it was not possible to prevent the flapping of the rear end portion of the transfer material and the change in speed of the transfer material P particularly when it escaped from the registration roller 105, which caused image quality deterioration.

Furthermore, as shown in FIGS. 6 and 7, in order to reliably convey the transfer material P to the transfer site, the tip of the bent portion X03a' of the upper guide plate 103a extends to the vicinity of the photosensitive drum 100. When the photosensitive drum 100 is attached or detached, the bent portion 103
There is a problem in that the surface of the photosensitive drum 100 is damaged at the edge portion of a'.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to reliably prevent fluttering and speed changes of the transferred transfer material with a simple structure, and to improve quality. It is an object of the present invention to provide a transfer material conveying device for an image forming apparatus, which allows an image to be obtained and does not damage the surface of an image carrier when it is attached or detached.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a pair of registration rollers that temporarily regulate the leading edge of the transferred transfer material and transport it to a transfer section where an image is transferred. a roller that is disposed between the registration roller and the image carrier and near the image carrier and is driven to rotate; and a roller that rotates as a result of the roller to hold the transfer material. It is constructed by being equipped with rollers for transporting the machine while transporting the machine.

(Function) In the present invention having the above configuration, the portion of the transfer material that has reached a position away from the registration rollers is held and conveyed by the rollers, so that the transfer material entering the transfer site does not flap. In addition, speed changes are reliably prevented so that transfer is not adversely affected.

(Example) The present invention will be explained below based on the illustrated example. 1st
Figures (a) and (b) show a first embodiment in which the present invention is applied to a copying machine equipped with a rotating cylindrical photosensitive drum. The photosensitive drum 1 is rotating in the direction of the arrow, and a transfer charger 7 is disposed close to the photosensitive drum 1. Then, the transfer material P is conveyed to the transfer site as shown in the direction of arrow B through the conveyance path 3 formed by the upper guide plate 3a and the lower guide plate 3b.

As is well known, there are, of course, disposed around the photosensitive drum l the members required for image formation, such as a charger, a developing device, and a cleaning device, but these are not directly related to the present invention. Since it is not relevant, I will omit it all.

Further, reference numeral 5 denotes a pair of distrollers 1/2 that temporarily regulates the leading edge of the conveyed transfer material P and conveys it to the transfer site.

In the above-mentioned conveyance means, FIG. 1(a).

As shown in (b), a guide roller 4 made of conductive rubber is arranged on the downstream side of the conveyance path 3, and a guide upper plate 3a
An elastic support member 8 such as a leaf spring is attached to the upper part of the guide roller 4 with a plurality of screws at predetermined intervals, and a roller 9 is rotatably supported on the elastic support member 8. It is configured to be pressed into contact. And the guide roller 4
is operatively connected to the photosensitive drum 1 via a drive transmission means such as a gear provided on its shaft, and is driven in synchronization with the circumferential speed of the photosensitive drum 1. Moreover, since the roller 9 is in pressure contact with the guide roller 4, it rotates as the guide roller 4 rotates.

FIGS. 2(a) and 2(b) show the arrangement of the rollers 9 with respect to the guide rollers 4, and in FIGS. is provided at a position shifted by a minute distance d on the upstream side in the conveyance direction of the transfer material P with respect to the other rollers 9b. Also, Fig. 3(a), (
B) shows that the roller 9a is provided at a position shifted by a minute distance d on the downstream side in the conveyance direction of the transfer material P with respect to the other rollers 9b, and the roller 9 is provided at a position shifted by a minute distance d from the other rollers 9b in the conveyance direction of the transfer material P. It can be placed anywhere, such as.

In the configuration of L, as shown in FIG. 1(a), arrow B
The leading edge of the transfer material P fed to the conveyance path 3 in the direction of the direction travels along the lower surface 8a of the elastic support member 8, passes between the guide roller 4 and the roller 9, and the rear end of the transfer material P advances along the lower surface 8a of the elastic support member 8. Even if it leaves the pair 5, it is always held by the guide rollers 4 and rollers 9 and is conveyed to the transfer site. As a result, the transfer material P
It does not flap, instantaneous speed fluctuations are not transmitted to the transfer site, and the image is not disturbed.

Further, since the roller 9a is provided at a position shifted by a minute distance d to the upstream side or downstream side in the conveyance direction of the transfer material P with respect to the other rollers 9b, the rear end of the transfer material P is at least When the transfer material P leaves the nip between the long guide roller 4 and the roller 9, the transfer material P does not leave the nip instantly over the entire width of the transfer material P, which reduces the shock caused by the transfer material P.
By suppressing speed fluctuations of the transfer material P, image disturbance can be further prevented.

4(a) and 4(b) show a second embodiment of the present invention, and the same members as in the first embodiment are given the same reference numerals.In this embodiment, the guide roller A roller 9a is disposed approximately at the center in the axial direction of the guide roller 4, and rollers 9c and 9b are disposed near both ends of the guide roller 4 in the axial direction at a predetermined angle θ with respect to the axis of the guide roller 4. As a result, as in the first embodiment, it is possible to suppress the shock release when the guide roller 4 and the roller 9 come out of the nip, and also because the transfer material P is pulled to both sides with respect to the center in the width direction. , it is possible to prevent wrinkles from forming on the transfer material P.

FIG. 5 shows a third embodiment of the present invention, in which the same members as in the first embodiment are given the same reference numerals.In this embodiment, a guide roller 4 and a roller 9 are shown. The vertical arrangement is opposite to that of the first embodiment shown in FIG. 1(a).

Even with this configuration, the same functions as in the first embodiment can be obtained.

In each of the above embodiments, in the transfer material conveyance device of the image forming apparatus, the transfer material P is held by the guide roller 4 and the rollers 9 at a position before the transfer material P reaches the transfer site so as not to interfere with the conveyance. Transfer material P enters the transfer site from
Prevents flapping and speed changes. Furthermore, since the distance between the guide roller 4 and the roller 9 with respect to the transfer site is short, the transfer material P can enter the transfer site at a constant angle, and the same transfer conditions can always be obtained for all types of paper. Further, since the rollers 9 are disposed near the photosensitive drum 3, the surface of the photosensitive drum 3 is not damaged when the photosensitive drum 3 is attached or detached.

(Effect of the invention) The present invention consists of the above configuration and operation.

With a simple configuration, it is possible to reliably prevent fluttering and speed changes of the transferred transfer material, obtain high-quality images, and prevent damage to the image carrier even when it is attached and detached.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are main part configuration diagrams and main part perspective views showing the first embodiment of the present invention, and FIGS. 2(a) and (b) are diagrams showing the rollers relative to the guide rollers in the same embodiment. A plan view, a side view, and FIGS. 3(a) and 3(b) showing the arrangement state are a plan view, a side view, and FIGS. b) is a plan view and side view showing the arrangement of the rollers with respect to the guide rollers showing the second embodiment of the present invention, FIG. 5 is a main part configuration diagram showing the third embodiment of the present invention, and FIG. 6 is the conventional FIG. 7 is a diagram illustrating a main part of a transfer material conveying device according to another conventional example. Explanation of symbols 1... Photosensitive drum (image carrier) 3... Conveyance path 4... Guide roller 5...
Registration roller pair 7... Transfer charger 9... Roller/bee d Fig. 2 (a) (b) Fig. 3 Fig. 4 (a) Cb") Fig. 5

Claims (3)

[Claims] (1) A pair of registration rollers that temporarily regulate the leading edge of the transferred transfer material and transport it to the transfer section where the image is transferred, and a pair of registration rollers that temporarily regulate the leading edge of the transferred transfer material and transport it to the transfer section where the image is transferred, and a position that is located between the registration rollers and the image carrier and near the image carrier. A transfer material conveying device for an image forming apparatus, comprising: a roller that is arranged and driven to rotate; and a roller that rotates following the roller and conveys the transfer material while holding the transfer material with the roller. (2) The roller driven near the image carrier has a width of the transfer material to be conveyed and is arranged parallel to the image carrier, and the roller that rotates following the roller is divided into a plurality of parts. 2. A transfer material conveying device for an image forming apparatus according to claim 1, wherein the rotational axis of at least one of the rollers is disposed offset from the rotational axis of the other rollers. (3) The transfer material conveyance device for an image forming apparatus according to claim 2, wherein at least one of the plurality of rollers is positioned non-parallel to the roller.