JPH0820458A - Paper feeding device - Google Patents

Abstract

PURPOSE:To simplify the structure (of a paper feeding device) and to facilitate and ensure the switching between cancelling the separating function of a sheet material separating mechanism in order to carry the sheet material through manual insertion and continuous sheet material feeding through the sheet material separating mechanism. CONSTITUTION:A paper feeding device is provided with a sheet material separating function cancelling device, which is installed in between a paper feeding roller (c) and a sheet material separating mechanism (d) in a freely attachable manner and, owing to its installation, its tip end separates the sheet material separating mechanism (d) from the paper feeding roller (c) in order to cancel the separating function of a sheet material (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer or a facsimile, which is capable of releasing a sheet material separating function in a sheet feeding apparatus having a sheet material separating function. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine, a printer or a facsimile, a paper feeding / conveying device is equipped with a sheet material separating mechanism, and a tray or a tray on which a large number of sheet materials are stacked. It is configured so that only one sheet can be separated from the orchest and continuously conveyed to the downstream side.

As shown in FIG. 5, in the sheet feeding section e, a large number of sheet materials b are stacked on a tray a and are pressed against a sheet feeding roller c by a spring s1. Paper feed roller c is in the direction of the arrow
By rotating to x, several sheets of the sheet material b are conveyed to the downstream side, only the uppermost one sheet is separated by the sheet material separating mechanism d, and further conveyed to the downstream side via the guide plates ia, ib. . Further, the sheet material b is conveyed to the transfer portion f,
The transfer portion f transfers the toner to form an image. Note that s2 is a spring that presses the sheet material separating mechanism d against the sheet feeding roller c.

As shown in FIG. 6, after image formation, the image is further conveyed to the downstream side, and then conveyed to the fixing section g via the conveyor belt f1 and the guide plate ic. The fixing unit g fixes the transferred toner on the sheet material b and discharges it onto the discharge guide plate id.

[0005]

However, the sheet feeding section e having the above-mentioned structure is not suitable for the sheet material b of the fixing section g in the sheet material of 50 g / m ² or less or the environment of the humidity of 70% or more. There is a problem that wrinkles, image defects due to defective transfer of toner at the transfer portion f, paper jam of the sheet material b at the paper feeding portion e, and the like may occur, and continuous feeding cannot be performed.

Therefore, for continuous sheet feeding, the type and environment of the sheet material b used in the image forming apparatus are limited. In order to remove such a limitation, the separating mechanism d as shown in FIG. 7 is removed and only the sheet feeding roller pair h is provided. There has been a method of solving the above problem by transporting the sheet to the sheet feeding roller pair h via the guide plate if.

However, in such a structure, when a large number of sheet materials b are stacked, the sheet materials b cannot be separated and all the sheet materials b are conveyed, so that not only continuous feeding is not possible, There was a risk of paper jams and equipment damage. Therefore, in such a case, it is necessary to manually feed the sheets one by one instead of continuously feeding the sheets. For this reason, it is necessary to release the sheet material separating mechanism d and switch to manual paper feeding.

In order to solve the above-mentioned problems, an object of the present invention is to have a simple structure and to release the separating function of the sheet material separating mechanism so as to convey the sheet material by hand or to continue the sheet material by the sheet separating mechanism. An object of the present invention is to provide a paper feeding device that is easy and reliable to feed paper.

[0009]

In order to achieve the above object, the present invention provides a sheet feed roller, a tray for loading a plurality of sheet materials which is pressed against the sheet feed roller, and the sheet feed roller. In a sheet feeding device having a sheet material separating mechanism that presses against a roller and separates the sheet material conveyed from the tray to prevent double feeding, the sheet material is detachably attached between the sheet feeding roller and the sheet material separating mechanism. A sheet feeding device provided with a sheet material separating function canceling device which is provided and has a front end portion which separates the sheet material separating mechanism from the sheet feeding roller to release the function of separating the sheet material.

[0010]

By employing the sheet feeding device of the present invention, the sheet material separating mechanism is detachably provided between the sheet feeding roller and the separating mechanism, and the leading end portion pulls the sheet material separating mechanism away from the sheet feeding roller. By providing a sheet material separation function release device that releases the separation function of the sheet material, the configuration is simple and the separation function of the sheet material separation mechanism is released to convey the sheet material manually or continuously pass the sheet material by the sheet separation mechanism. Easy and reliable switching to paper.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an explanatory view of a state in which a sheet material separating function is released according to an embodiment of the present invention, and FIG. In FIGS. 1 and 2, the sheet feeding section e is configured by a sheet feeding roller c, a sheet material separating mechanism d, an intermediate plate j, a tray a, and a sheet material separating / releasing device p. The paper feed roller c is rotationally driven in the direction of arrow x, and conveys a large number of sheet materials b mounted on the tray a to the downstream side.

The sheet material separating mechanism d is pressed against the feeding roller c by a spring s2 via a sheet material separating member k which is a friction pad in this embodiment. The friction pad k is made of a material having a friction coefficient larger than that of the sheet material b. The intermediate plate j is provided on the upstream side of the sheet material separating mechanism d and presses the sheet material b carried out from the tray a against the sheet feeding roller c by the spring s1.

The sheet material separation releasing device p is provided with a sheet feeding roller c.
And the sheet material separating mechanism d are detachably provided, and the sheet material separating mechanism d is detached from the sheet feeding roller c at the leading end by mounting, and the pressing plate 1 for releasing the sheet material separating function, and the sheet feeding roller c. And a rotatable roller m for assisting the conveyance of the sheet material b together with the sheet feeding roller c.

Therefore, as shown in FIG. 1, in the sheet material separating mechanism d, the pressing relationship between the sheet material separating mechanism d and the sheet feeding roller c is released by the pressing plate l, and the roller m is connected to the sheet feeding roller c by the intermediate plate j. The sheet feeding unit e holds the pressing relationship of No. 2 and does not have a sheet material separating function.

For this reason, the sheet material b can be manually inserted and fed regardless of the sheet feeding from the tray a, and the sheet material b is piled up two thick sheets of paper b1 on the lower side, and the sheet material b is placed downstream. By transporting the sheet material to the sheet material b of 50 g / m ² or less or the environment of humidity of 70% or more, wrinkles of the sheet material b in the fixing portion g, image defects due to defective transfer of toner in the transfer portion f, and paper feeding. The occurrence of a paper jam of the sheet material b in the portion e is prevented.

FIG. 3 is an explanatory view of the state of releasing the sheet material separating function according to another embodiment of the present invention, and FIG. 4 is an explanatory view of the state of recovering the sheet material separating function in FIG. 3 and 4, the sheet material separating mechanism, which is the load control member n in this embodiment, retains the function of rotating and separating the sheet material b when a certain load is applied. The paper feeding section e includes a feeding roller c, a load control member n provided in pressure contact with the feeding roller c, a paper transporting roller o disposed on the upstream side thereof,
It is composed of an intermediate plate j and a sheet material separation releasing device p.

Therefore, the sheet material separation releasing device p is detachably provided between the sheet feeding roller c and the load control member n, and the load control is performed by mounting the sheet material separation releasing device p as shown in FIG. The member n is separated from the paper supply roller c to release the sheet material separating function, and the sheet material to be manually inserted can be fed.

As shown in FIG. 4, in the feeding section e, the sheet material separating / releasing device p is taken out, and a large number of sheet materials b on the intermediate plate j are pressed against the paper conveying roller o by the spring s1.
The sheet is conveyed by the rotation of the sheet conveying roller o, and is sent between the sheet feeding roller c and the load control member n via the guide plate i.
The load control member n separates only the uppermost sheet from the fed sheet material b and conveys it to the fixing unit g.

The present invention is not limited to the above-described embodiment, but can be similarly implemented in other modes by making appropriate design changes.

[0021]

As is apparent from the above description, the sheet feeding apparatus of the present invention is detachably provided between the sheet feeding roller and the separating mechanism, and the leading end portion of the sheet feeding mechanism feeds the sheet material separating mechanism. By providing a sheet material separating function releasing device that separates from the paper roller and releases the separating function of the sheet material,
The problems of the conventional technology are easily solved, its configuration is simple, and the separation function of the sheet material separating mechanism is released to facilitate the manual feeding of the sheet material or the switching of the sheet separating mechanism to continuous sheet feeding. Is certain.

[Brief description of drawings]

FIG. 1 is an explanatory view of a state in which a sheet material separating function is released according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a sheet material separation function recovery state in FIG.

FIG. 3 is an explanatory diagram of a sheet material separating function canceled state according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a sheet material separating function recovery state in FIG.

FIG. 5 is a schematic configuration diagram of a sheet feeding unit and a transfer unit of a conventional image forming apparatus.

FIG. 6 is a schematic configuration diagram of a fixing unit.

FIG. 7 is a schematic configuration diagram of a conventional manual paper feeding unit.

[Explanation of symbols]

 a tray b sheet material c paper feed roller e paper feed section i, ia, to if if guide plate j middle plate l holding plate m roller n load control member o paper feed transfer roller p sheet material separation release device

Claims (1)

[Claims] 1. A paper feed roller, a tray for loading a plurality of sheet materials that is pressed toward the paper feed roller, and a sheet material that is pressed against the paper feed roller and conveyed from the tray. In a sheet feeding device having a sheet material separating mechanism for preventing double feeding, the sheet material separating mechanism is detachably provided between the sheet feeding roller and the sheet material separating mechanism so that the leading end portion feeds the sheet material separating mechanism. A sheet feeding device comprising: a sheet material separating function releasing device that separates the sheet material from a roller to release the sheet material separating function.