JPH0230504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording paper guide member for guiding recording paper conveyed from a recording paper supply device to a joining portion with the surface of an image carrier in a copying machine or the like, and more specifically to a recording paper guide member for guiding recording paper conveyed from a recording paper supply device to a joint portion with the surface of an image carrier. The present invention relates to a device for obtaining clear copied images using a means attached to a member that brings recording paper into good contact with the surface of an image carrier.

When copying is performed using a copying device, in order to transfer the toner image formed on the surface of the image carrier onto transfer paper, for example, a transfer paper supply device feeds the transfer paper one by one and transfers it to a paper feed roller. Transport the paper in a pinch,
The transfer paper guide member guides the transfer paper to the joint portion with the surface of the image carrier, and transfers the toner image onto the transfer paper. Subsequently, the transfer paper on which the toner image has been transferred is peeled off from the image carrier and sent to a fixing section where the toner image is fixed and a copy is obtained.

Figure 1 shows only the main parts related to a transfer device used in conventional copying machines, etc.
In the figure, reference numeral 11 denotes an image carrier which is made of a photoconductive photoreceptor or a dielectric material, forms an electrostatic latent image on its surface, and carries a toner image by toner development. Reference numeral 12 denotes a transfer paper fed out sheet by sheet from a transfer paper cartridge (not shown) by a feeding roller (not shown), and 12 a No. 2 paper feed rollers. Reference numerals 13 and 13a designate upper and lower transfer paper guide members that guide the transfer paper P, which is gripped and conveyed by the paper feed roller 12, to the joint between the surface of the image carrier 11 and the transfer paper P.

In addition, a deviation prevention member may be placed in parallel with the upper and lower transfer paper guide members 13 in order to prevent the transfer paper P from deviating from the conveyance path (not shown). Next, the toner image is transferred from the surface of the image carrier 11 to the transfer paper P using the electrode 14.
transfer paper P to which the toner image was transferred.
A transfer paper peeling electrode 14a for peeling the paper from the surface is provided in parallel.

In particular, the transfer means is extremely important in maintaining a good transferred image. In particular, the image carrier 11 on which the electrostatic latent image has been formed is formed in the shape of a dome or a belt, and it is necessary to receive the recording paper P to be transferred in close contact with the visible image surface while moving sequentially. The entrance angle of the recording paper P at the receiving point may determine the quality of image formation. Therefore, the conveyance angle of the recording paper P is configured to finely adjust the gap between its discharge portions and to obtain a contact angle that provides the best transferred image. This is done by setting the angle at which the drum approaches the surface of the image carrier and the gap between the ejecting parts to the best position, taking into consideration all conditions such as the drum's curvature, rotational speed, paper feed speed, paper quality, average room temperature, etc. However, it is necessary to make final adjustments to some dimensional variations in the parts due to parts accuracy, processing accuracy, etc., making it extremely difficult to assemble the product.

Due to poor adhesion of the transfer paper P to the surface of the image carrier 11, toner transfer may be insufficient, resulting in white spots, blurred characters, blurring, or duplication of multiple images due to displacement of the transfer paper during toner transfer. This results in a decrease in image quality.

In order to eliminate the above-mentioned disadvantages and improve adhesion, the transfer peeling electrode 14 is installed independently of the guide member 13.
It has been proposed to provide a pre-transfer guide member near the image carrier side. Due to the adhesive force of the guide member surface, the transfer paper may peel off before the toner is sufficiently transferred, causing jamming.

The first object of the present invention is to provide a copy of good image quality by improving the adhesion between the surface of an image carrier and a transfer paper during toner image transfer.

The second purpose is to provide a transfer paper guide member that has been installed to achieve the first purpose and has improved adhesion.

The object of the present invention as described above is to provide a recording paper guide for guiding the recording paper to the joint portion with the surface of the image carrier in a copying apparatus, in which the recording paper is placed on the surface of the image carrier at the end of the recording paper guide member. This can be achieved by a recording paper guide device characterized in that it is provided with an abutting member that comes into contact with it.

Next, the present invention will be specifically explained using examples. FIGS. 2 and 4 are explanatory diagrams of essential parts of one embodiment of the present invention. In the figure, 21 is an image carrier, P
2 is a transfer paper, 22 is a paper feed roller, and 23 is a guide device of the present invention. 24 is a transfer electrode; 24a
is the transfer paper peeling electrode.

In the guide device 23 of the present invention, 231 is a lower guide plate of the transfer paper, and 232 is an upper guide plate of the transfer paper. 25 and 25a are lower guide plates 231
is in close contact with both ends of the non-image forming surface on the outer surface of the image carrier 21, and is attached to the tip of the lower guide plate 231,
This is a contact roller for improving the adhesion of the transfer paper P to the surface of the image carrier 21, and is driven by the rotation of the image carrier 21. By selecting appropriate diameters of the contact rollers 25 and 25a, a gap is set between the leading edge of the lower guide plate 231 and the surface of the image carrier 21 such that the transfer paper P enters at the best angle. Reference numeral 231 is a pressure spring for urging the lower guide plate 231 toward the image carrier, and is placed at a convenient location for the operation of the contact rollers 25 and 25a attached on both sides of the lower guide plate 231, for example, the contact rollers. One end of the pressing spring 251 is fixed to a bearing provided on a lower guide plate 231 on which the members 25 and 25a are rotatably provided, and the other end is fixed to an immovable location inside the copying apparatus. Reference numeral 252 denotes a support shaft provided at the base of the lower guide plate 231 on the side of the paper feed roller 22, which allows the rocking of the contact rollers 25 and 25a due to the unevenness of the surface of the image carrier 21 to be transmitted through the lower guide plate 231. to obey freely. Also 2
Reference numeral 53 is a tongue plate provided extending the lower guide plate 231 beyond the contact rollers 25 and 25a, and is used to prevent the transfer paper P from leaving the surface of the image carrier 21 after passing the contact rollers 25 and 25a. and effectively prevent jamming. The shape is determined by the circumferential speed of the image carrier 21, the driven speed of the contact rollers 25 and 25a, the moving speed of the transfer paper P, and the image carrier 21.
It is configured in the most preferable shape depending on the radius of curvature of the paper and the average physical properties of the paper.

In addition, the structure of the lower guide plate 231 is such that the contact rollers 25 and 25
In order to avoid impairing the adhesion of a to the surface of the image carrier 21, and to prevent the finishing accuracy or mounting accuracy from being forced, the bearing parts of the contact rollers 25 and 25a and other parts are placed in the moving direction of the transfer paper P. It is also effective to divide the section into multiple sections and make them into independent thin plates or bars.

The contact rollers 25 and 25a are biased toward the image carrier 21 by the aforementioned pressing spring 251 and the support shaft 2.
In the set of 52 combinations, the lower guide plate 231 itself may be made of an elastic body made of a controlled material such as phosphor bronze, or an appropriate portion of the lower guide plate 231 may be provided with contact rollers 25 and 25a, for example, at the end or base thereof. Instead of using an elastic body, the force may be applied by fixing the base, and the pressing spring 251 and the support shaft 252 may be omitted.

Next, FIG. 3 shows another embodiment. In this embodiment, in place of the above-mentioned contact rollers, contact members are provided which contact the non-image forming surface of the image support 21 at both ends of the lower guide plate. The biasing of the abutting member toward the image carrier and the configurations of the lower guide plate and the tongue plate are the same as in the previous embodiment.

In the figure, 33 is a guide device, 331 is a lower guide plate, and 332 is an upper guide plate. Further, 35 is an abutting member.

The lower guide plate 331 is an elastic body made of phosphor bronze, and its base 333 is curved and fixed to an immovable part within the copying apparatus, and is in contact with the image carrier 31 while being gently biased as a whole. .

The material of the contact member 35 is preferably a slippery material such as Teflon, or a flexible rubber or synthetic resin kneaded with a matting agent or whose surface is matted can be used. The abutting member 35 may be attached to the end of the lower guide plate 331 by baking and pasting, or the abutting member 35 may be attached to the end of the lower guide plate 331 by pasting.
The end portion may be shaped into the shape, and the above-mentioned Teflon or the like may be applied or pasted to the processed portion.

Toner stains caused by the contact roller and contact member directly contacting the image carrier can be removed by removing static charges outside the original image circle on the surface of the image carrier using conventional techniques. Toner does not adhere to areas other than the document image area on the front surface, and therefore the abutting member is not soiled with toner. If an abutment roller is used, if a cleaner for the abutment roller is additionally provided, there is no need to use the above-mentioned conventional technique. In particular, in the present invention, as shown in FIG. 5 of the embodiment, slippery contact members such as Teflon may be provided on the non-image forming portions at both ends of the recording paper guide plate, and the contact members may be brought into contact with the image carrier. With this configuration, there is no need to use rotating members such as rollers, so there is no toner contamination, no damage to the image carrier, and no abrasion of the contact members, so the guide plate is always in place. This has the effect of feeding the recording paper toward the image carrier in an accurate direction.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a portion of an electrostatic copying apparatus according to the present invention, that is, a portion centered on a transfer paper guide member. FIGS. 2 and 3 are explanatory views of different embodiments of the transfer paper guide device of the present invention. FIG. 4 is a side view of the embodiment shown in FIG. 2 above. 13, 23 and 33...transfer paper guide device, 1
31, 231 and 331...lower guide plate, 13
2, 232 and 332...Upper guide plate, 25 and 35...Abutting member.

Claims (1)

[Claims] 1. A recording paper guide device having a guide member for forming a toner image on the surface of the image carrier and guiding the recording paper to a joining portion with the surface of the image carrier in order to transfer the toner image to the recording paper. , a contact portion provided between the image carrier and the recording paper feed roller, pivotally supported on the recording paper feed roller side, and provided on the free end side of the guide member is biased by a spring means; A recording paper guide device configured to be brought into contact with the surface of the image carrier.