JPH0413263B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention provides an electrostatic recording method that eliminates the shift in image position on recording paper caused by a detachable paper feed roller for jam processing. The present invention relates to a paper feeding device of an apparatus.

(b) Prior art In electrostatic recording devices such as electrophotographic copying machines and facsimile machines, a photoconductor or dielectric material is recorded using reflected light obtained by exposing and scanning a document or electrical information signals transmitted from the outside. An electrostatic latent image of a document or electrical information is formed, this electrostatic latent image is developed into a visible image, and this visible image is transferred to recording paper fed from a predetermined position and then fixed and recorded. forming an image.

In this type of recording apparatus, recording paper is fed and conveyed through a predetermined path, but paper jams (so-called jams) may occur along the way.
In such a case, the jammed paper is removed by performing appropriate jamming treatment depending on the location where the jam has occurred.

Here, in order to explain jam processing on the paper feed side in a conventional electrostatic recording device, first the schematic structure of an electrophotographic copying machine as an example of an electrostatic recording device is shown in Fig. 1. A platen glass P on which a document M is placed is provided on the top surface of 1.
A scanning optical system 2 is provided below the platen glass P within the main body 1. The scanning optical system 2 includes a reciprocating document irradiation lamp 2a, mirrors 2b and 2c, and a fixed lens 2d and mirror 2e. A photoreceptor drum 3 is provided in the center of the main body 1 so as to be rotatable in the direction of the arrow.A charging electrode 4 for uniformly charging the photoreceptor 3a along the rotation direction and a toner replenishing device are arranged around the photoreceptor drum 3. 5, a developing device 6 is supplied with toner and has a built-in developing sleeve 6a.
, a transfer electrode 7 , a separation electrode 8 , and a static elimination electrode 9
and the cleaning device 10 are arranged in this order. Paper feed cassettes 11 and 11' each contain two types of recording paper of different sizes and are set in the main body 1. Reference numeral 12 denotes a first paper feed roller that feeds the recording paper stored in the paper feed cassette 11 to a standby position before a second paper feed roller 13, which will be described later. It is composed of rollers 12a, 12a rotated via the rollers 12a, and a stop roller (also referred to as a sorting roller) 12b. 13 is an appropriate timing so that the recording paper fed by the first paper feed roller 12 is temporarily stopped at the standby position, and then the leading edge of the visible image on the photoreceptor 3a and the leading edge of the recording paper are aligned at the transfer position. a second paper feed roller that feeds the paper again toward the transfer position at
Reference numeral 14 denotes a guide plate for guiding the recording paper fed by the first paper feed roller 12 to the position of the second paper feed roller 13, and is opened and closed by operating a lever (not shown). You can put your hand in and take out the jam paper. 15 is a conveying device that conveys the recording paper after transfer to a fixing position, and the fixing device 16 includes a heating roller 16a and a pressure roller 16.
It consists of b. Reference numeral 17 denotes a paper discharge roller that discharges the recording paper after fixing to the outside of the main body.

In the above device, when the copy button is operated, the original M on the platen glass P is transferred to the scanning optical system 2.
The photoreceptor 3 of the photoreceptor drum 3 is exposed and scanned by
An electrostatic latent image of the document M is formed on a. This electrostatic latent image is made into a visible image by the developing device 6, and this visible image is transferred by the transfer electrode 7 onto the recording paper fed from either of the paper feed cassettes 11, 11' of the main body 1. Ru. After the transfer, the recording paper is separated from the photoreceptor 3a by the separation electrode 8, transported by the transport device 15 to the fixing device 16, where it is fixed, and then the paper is transferred to the paper ejection roller 1.
7, the paper is ejected.

If a jam occurs near the second paper feed roller 13 while recording with the above device, the lever is operated to open the guide plate 14 and remove the jam paper. If a jam occurs with the trailing edge of the recording paper remaining on the cassette 11 or 11' side or with the leading edge of the recording paper protruding from the second paper feed roller 13, the jam can be easily disposed of.

However, as there is a recent trend toward downsizing of recording apparatuses, it is not possible to obtain the space necessary for jam handling even if the guide plate 14 is opened.
The other end is sandwiched between a and 12b, and the second paper feed roller 13,
13 If a jam occurs when the paper is sandwiched between paper sheets, the jam paper may not be processed smoothly and the paper may be torn, or the torn paper may remain in the paper feed path and cause problems during the next recording. There is a problem that jam occurs again.

Therefore, in order to solve this problem, as shown in FIG.
2, the second paper feed roller 13, the guide plate 14, and the guide plate 141 are combined to form a paper feed unit 19, and the entire paper feed unit 19 is pulled out from the main body in the direction of the arrow to perform jam removal. There is. However, if the second paper feed roller 13 is removed from the main body, the distance from the second paper feed roller 13 to the transfer position may change. It becomes difficult to match the positions, resulting in so-called leading edge timing deviation, and there is a problem that the image position on the recording paper is no longer at a predetermined position.

(C) Object and Structure of the Invention The present invention has been made in view of the above points, and consists of feeding the recording paper in the paper feed cassette once to a predetermined position by a first paper feed roller, and then feeding the recording paper in the paper feed cassette to the predetermined position. In a paper feeding device that feeds recording paper fed to a position to a transfer position by a second paper feeding roller, the second paper feeding roller is made detachable for jam processing. The purpose is to eliminate misalignment of the image position, and for this purpose, the paper feed cassette and the first paper feed roller are detachable as a unit, and the second paper feed roller remains fixed to the main body. It is something.

(d) Examples The present invention will be explained below based on the drawings.

FIG. 3 shows a schematic configuration of an electrophotographic copying machine as an example of an electrostatic recording device using a paper feeding device according to the present invention, and in the figure, the same reference numerals as in FIG. 1 indicate the same components. . In this example,
Paper feed cassettes 11, 11' and first paper feed roller 12,
12' can be attached and detached integrally, the cassette holder 18, the first paper feed roller 12, and the guide plate 141 on the cassette side of the paper feed guide plates constitute a paper feed unit. A parallel rail 21 (for example, AkyuRide Rail made by Nippon AkyuRide Rail) is provided at the lower part of the paper feed side of the paper feed unit 20 so that the paper feed unit 20 can slide along this rail 21. The rest of the structure is exactly the same as the conventional example shown in FIG.

With this configuration, when a jam occurs near the second paper feed roller 13, the paper feed unit 20 is slid to the position shown by the chain line and pulled out from the main body 1, thereby opening the paper feed path and Since sufficient space can be secured near the paper feed roller 13, jam processing can be easily performed. In this way, the second paper feed roller 13 remains fixed to the main body 1, and therefore the distance from the second paper feed roller 13 to the transfer position does not change, so that the leading edge of the toner image and the leading edge of the recording paper do not change. There will be no discrepancy. Furthermore, since a sufficient space can be secured near the second paper feed roller 13 in this way, there is no need to open and close the guide plate 14 using a special lever or the like. Therefore, there is no need to provide, for example, a joint (hinge) on the guide plate 14 for opening and closing as in the conventional case.
Jams do not occur at seams, and the frequency of jams can be reduced.

Further, in this embodiment, a recording apparatus in which paper feed cassettes are set in two stages is exemplified, but it goes without saying that the present invention can also be applied to a recording apparatus in which paper feed cassettes are set in one stage or three or more stages.

(E) Effects of the Invention As explained above, the present invention allows recording paper in a paper feed cassette to be once fed to a predetermined position by a first paper feed roller, and then fed from the predetermined position to a second paper feed roller. In this feeding device, the paper feed cassette and the first paper feed roller are made integrally attachable and detachable, and the first paper feed roller is fixed. Since the distance from the two paper feed rollers to the transfer position is always constant, even if the paper feed roller is attached and detached for jam processing, there will be no leading edge timing shift.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional electrophotographic copying machine.
FIG. 2 is a schematic diagram of a conventional paper feeding unit, and FIG. 3 is a schematic diagram of an electrophotographic copying machine using a paper feeding device according to the present invention. 11, 11'...paper feed cassette, 12...first
Paper feed roller, 13...Second paper feed roller, 14...
Guide plate, 18...Cassette holding part, 19, 20
...Paper feed unit, 21...Parallel rail.

Claims (1)

[Claims] 1. A feeding system in which recording paper in a paper cassette is once fed to a predetermined position by a first paper feeding means, and then fed from the predetermined position to a transfer position by a second paper feeding means. In the paper device, the paper feeding cassette, the first paper feeding means, and a pair of guide plates provided across a feeding path for recording paper fed by the first paper feeding means. A paper feeding device characterized in that one side of the paper feeding side is integrally attachable and detachable.