JPH0223148A - Paper discharge device - Google Patents

Abstract

PURPOSE:To precisely discharge a transfer medium onto the surface of a discharge sheet without curling and damage, by specifying the ratio between a height difference in a flange part of a drive roller and the distance from a clamping roller associated with the former roller to the flange part. CONSTITUTION:A drive roller 1 in a paper discharge device, is a flanged roller having a height difference 1A. A ratio H/L is set to a value between 6 and 8, where H is the height difference of a flange part 1A, and L is the distance between the end face of a clamping roller 3 associated with the drive roller 1 and the flange part 1A. As a result, the conveyance of a transfer medium which has been softened due to fixing by heat in, for example, an electrophotographing copy machine, is enhanced without giving damage and deformation after discharge, thereby it is possible to discharge the transfer medium in a normal condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper ejecting device for a fixed transfer material, etc., provided in a copying device of an electrophotographic copying machine.

[Background of the invention]

The transfer material on which the image has been transferred is pressed by a heat roller in the fixing device to melt and fix the developer, and then is held and conveyed by a pair of rollers in the paper discharge device and discharged to a paper discharge tray outside the device. Even when the transfer material is ejected, it is still in a high temperature state and the paper quality is soft, so it is prone to curling. Therefore, it cannot be stacked neatly on the paper ejection tray and ejected, resulting in "wrinkles" on the transfer material. In some cases, the paper may crease, or fall from the discharged paper onto the floor and become soiled.

As a means of compensating for such weakening of the transfer material, the driving side roller of the roller pair of the paper ejecting device is a flange roller, and the transfer material is deformed into a corrugated plate shape by the pressure of the flange to increase its rigidity. An improved paper ejecting device has been proposed so that paper can be ejected without causing curling.

[Problem that the invention seeks to solve]

However, the amount of deformation of the transfer material is very subtle, and if it is too small, it will not be effective, and if it is too large, it will leave vertical streak-like marks on the transfer material due to the deformation, significantly reducing the quality of the copy. .

The present invention solves this problem and improves it, and as a result of numerous experimental results, it provides a paper ejection device for a copying machine that can accurately eject the transfer material onto a paper ejection tray without causing curling or damage. The purpose is to

[Means for solving problems]

The above purpose is to satisfy the following condition: 6≦L/H≦8, where the roller on the drive side of the paper ejecting device is a flanged roller with a step, and the distance between the flange and the mating roller that clamps the step at H1 is L. This is achieved by a paper ejecting device which is characterized in that it clasps and ejects the paper sheet material.

〔Example〕

A paper discharge device of the present invention is shown in FIGS. 1 and 2.

FIG. 2 shows a cross-sectional structure of the sheet discharging device, and FIG. 1 shows the shape and arrangement of each roller that constitutes the roller attachment of the device, as viewed from arrow A.

1 and 2 are a plurality of drive rollers forming drive-side rollers and their rotating shafts; 3 and 4 are a plurality of driven rollers and their support shafts that are mating rollers of the drive rollers; is fixed to the rotating shaft 2 at a predetermined interval, while the driven roller 3 is positionally regulated by a retaining ring 3A so that it can freely rotate at a position corresponding to the driving roller 1 with respect to the supporting shaft 4. ing.

The drive roller 1 is a so-called flange roller having a flange portion IA with a slightly larger diameter integrally formed at each outer end when viewed from the center line XX of the copying device, and the flange portion IA corresponding to the drive roller 1 is The driven rollers 3 each have the flange l.
It is attached at a predetermined distance from A.

The rotating shaft 2, that is, the driving roller I is connected to the driving device of the main body of the copying apparatus, and is rotated counterclockwise at the start of the copying operation, while the supporting shaft 4 is pushed downward by the action of a pressing member 5 containing an elastic member. , the driven rollers 3 are brought into pressure contact with the driving rollers II, respectively, and driven to rotate clockwise.

The driving roller 1 is made of ABS resin material, for example, and the driven roller 3 is made of polyacetal resin material, both of which are hard rollers, and the diameter of the driving roller 1 is in the range of 20 to 30 um. Correspondingly, the diameter of the driven roller 3 is set to be slightly smaller.

Reference numeral 6 denotes a guide plate that guides the transfer material to the pressure contact portion between the driving roller I and the driven roller 2, and 7 is a wire-shaped static electricity removing member that comes into contact with the transfer material.

Furthermore, 8 is a heat roller that heats and fixes the toner on the transfer material;
Reference numeral 9 indicates a pressure roller that presses the heat roller 8, IO indicates a separating claw that separates the transfer material that is in close contact with the heat roller 8, 11 indicates a guide member that receives and guides the transfer material, and 12 indicates each of these for heat fixing. The housing contains the above-mentioned paper ejecting device, and is also integrated into a unit as a fixing device and incorporated into a copying machine.

The operations of fixing the transfer material and discharging the paper by the fixing device and the paper discharging device are performed as follows.

When the transfer material with the image transferred to its upper surface is carried into the housing 12 under the guidance of the guide member 11, the nip formed by the heat roller 8 and the pressure roller 9 in pressure contact grips the transfer material. In parallel with the conveyance, the heat roller 8 melts the toner forming the image, and as it passes through the nip, the toner is melted and fixed under pressure, thereby fixing the image.

The transfer material that has been heat-fixed is carried along the guide plate 6 to the pressure contact area between the driving roller 1 and the driven roller 3, is conveyed and discharged by the frictional force of the pressure contact area, and is removed by the static electricity removing member 7. The paper is removed and discharged onto a paper discharge tray 13 provided on the outer wall of the copying machine.

When conveying and discharging by the pressure contact portion between the drive roller I and the driven roller 3, the flange I provided on each drive roller I is
Since A temporarily deforms the transfer material into a corrugated plate shape, the transfer material increases its rigidity in the conveying direction, and as a result, it is normally conveyed without curling, etc., and the flatness is restored to the sheet discharge tray 13. Paper is ejected in a straight line without curling.

The amount of corrugated deformation applied to the transfer material is mainly determined by the step H of the flange IA relative to the circumferential surface of the drive roller l in FIG.
This relates to the spacing between the end faces of the flange portion IA and the driven roller 3, and the present invention sets the step H to several steps, and also prevents the transfer material from leaving traces due to deformation at each step. When we investigated the conditions under which conveyability could be ensured without leaving any residue by changing the above-mentioned spacing, we obtained the results shown in Table 1.

Table 1 shows that by satisfying the relationship 6≦--8, it is possible to transport the transfer material normally without leaving any traces of deformation, and this result has been confirmed through numerous experimental examples conducted since then. . The transfer material for the experiment weighs 80g/
m', size A3 size transfer paper was used.

〔Effect of the invention〕

According to the present invention, for example, it is possible to improve the transportability of a transfer material that has been softened by heat fixing in an electrophotographic copying machine without causing any damage or deformation that remains after ejection, and to eject the paper in a normal state. It is now possible to provide a paper ejecting device such as a copying apparatus that prevents the transfer material from falling or becoming dirty due to ejecting the paper, thereby producing high-quality copies.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a pair of rollers of a paper discharge device of the present invention, and FIG. 2 is a sectional view of the paper discharge device.

Claims (1)

[Scope of Claims] When the roller on the driving side of the paper ejecting device is a flanged roller with a step, the step of the flange is H, and the distance between the mating roller and the nipping portion is L, then 6≦L/ A paper discharge device characterized in that it pinches and discharges paper sheets under the relationship H≦8.