JPH02158548A - Manual paper insertion device for picture forming device - Google Patents

Abstract

PURPOSE:To facilitate a sure hand paper feed with no misfeed of paper slipped off and so on by providing in the vicinity of a manual paper feed port a friction roll having no driving source so as to be unable to reversely rotate. CONSTITUTION:When paper 26 is manually inserted between a single friction roll 21 not driven and a guide plate 20, the friction roll 21 is freely rotated in a direction of insertion. Thus, the paper 26 can be easily inserted. Next the paper 26, when its point end is once held between the friction roll 21 and the guide plate 20, is prevented from retracting by the own weight because the friction roll 21 is prevented from rotating in a reverse direction to the insertion direction by a reverse rotation impeding means (consisting of ratchet wheel and stopper pawl). Accordingly, the paper 26 of even a large length, when its point end is once inserted, can be surely fed by hand with no misfeed of the paper such as slipping down.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a manual paper feeding device for an image forming apparatus such as a printer or a copying machine.

[Prior art]

2. Description of the Related Art Conventionally, it has been known to provide an image forming apparatus with a manual paper feeding device to manually feed one sheet of paper to another address.

Conventional manual paper feed devices are equipped with a detection sensor that detects whether paper is set manually by paper inserted from the paper insertion slot, and when it detects that paper has been set, it drives a pair of manual feed rollers to feed the paper. It is configured to feed the roller until it comes into contact with a pair of registration rollers.

Conventional devices are provided with a detection sensor and a pair of rollers in order to manually feed only one sheet of paper, which increases the cost of the image recording device.

Furthermore, when manually feeding a long sheet of paper whose trailing edge protrudes from the temporary guide in the paper insertion slot and hangs down, if the leading edge of the sheet comes into contact with the pair of manual feed rollers and you immediately release your hand, the paper will It will slide down to the rear, causing a feeding error.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a paper manual feeding device that is inexpensive and has a simple configuration and is capable of reliable manual paper feeding.

[Means to solve the problem]

The present invention solves the above problem by supporting a friction roller in a non-driven state near the manual paper feed port of an image forming apparatus so as to be able to press the paper against a guide plate, and in which the friction roller is moved in the opposite direction to the paper insertion direction. The problem was solved by a paper manual feeding device of an image forming apparatus, which is characterized by being prevented from rotating in one direction.

[Effect]

According to the present invention, when paper is manually inserted between one non-driven friction roller and the guide plate, 11! Since the rubbing roller is rotatable in the insertion direction, paper can be easily inserted. - When the leading edge of the paper is caught between the friction rollers and the guide plate, the friction rollers are prevented from rotating in the opposite direction to the insertion direction, so the paper will not retreat under its own weight.

Therefore, even if the paper is long, once the leading end is inserted, it will not retreat and fall out of the insertion slot unless manual intervention is performed.

〔Example] The details of the present invention will be explained based on embodiments shown in the drawings.

The first example shows a laser printer as an example of an image forming device.
In the figure, a charger 2, a developing unit 3, a transfer charger 4, and a cleaning unit 5 are arranged on the circumferential surface of the photoreceptor drum l in the order of the rotational direction indicated by an arrow. A writing optical unit 7 is provided so that a writing beam enters and exposes the photosensitive drum l at a position 6 between the two.

The charger 2 and the optical writing position 6 are arranged below the photoreceptor drum 1, and the writing optical unit 7 is provided below the photoreceptor drum L developing unit 3 and cleaning unit 5. The transfer charger 4 is arranged above the photosensitive drum l. A paper feed cassette 8 is provided further below the writing optical unit 7, and the transfer paper in the paper feed cassette 8 is separated and sent out one by one by a feed roller 9 and a corner claw 10, and further by a pair of intermediate rollers 11 and a guide plate. The image is fed to the upper part of the developing unit 3 by the resist roller pair 12, and fed to the transfer section at a timing such that the image formed on the photoreceptor drum 1 is aligned with the image formed on the photoreceptor drum 1 by the pair of registration rollers 12.

A static elimination brush 13 and a suction fan 1 are installed in the transfer paper path after transfer.
4. A fixing unit 15 and a paper discharge tray 16 are provided.

The electrostatic latent image formed on the photoreceptor drum l by the charger 2 and the writing optical unit 7 is developed by the developing unit 3 to form a toner image, which is then transferred onto a transfer paper fed by a pair of registration rollers 12. The image is transferred by the transfer charger 4. After the transfer, the transfer paper is separated from the photoreceptor drum l by the static elimination brush 13 and is sent to the fixing unit 15 while being sucked and held by the suction fan 14, where it is fixed and discharged to the paper discharge tray 16.

On the other hand, after the transfer, the toner remaining on the photosensitive drum 1 is cleaned by a cleaning unit 5, and the charge on the photosensitive drum 1 is removed by a static eliminator 17, in preparation for the next image forming process.

In addition to automatic paper feeding using the paper feed cassette 8, the image forming apparatus includes a paper manual feeding device 18 so that paper can be manually fed one by one.
is provided.

Paper manual feeder [18 has a manual paper feeder 19 for inserting paper.0 The manual paper feeder 19 is provided with a guide plate 20 that guides and supports the paper.In the example shown in FIG. Although it is also used as a part of the guide section that guides the paper when it is printed, it is not limited to this.

The manual paper feed port 1 is inserted so that the paper is pressed against the guide plate 20.
A friction roller 21 is rotatably supported near 9 without being driven.

A registration detection sensor 22 is provided in front of the pair of registration rollers 12, and paper is inserted from the manual paper feed port 19.
When the leading edge of the paper passes between the friction rollers 21 and the guide plate 20 and abuts against the pair of registration rollers 12, the registration detection sensor 22 detects the paper and becomes ready to start image formation by manual feeding.

As shown in FIG. 2, the shaft of the friction roller 21 is rotatably supported by a support portion formed on the upper guide plate 23, for example. The friction roller 21 is provided with a reverse rotation prevention member. In the example shown in FIG. 0, the rotation prevention member is fixed to the shaft of the friction roller 21 and
1, and a stop pawl 25.

As shown in FIGS. 2 and 3, the stop pawl 25 is rotatably supported by a pin 26 on a lug 27 formed on the upper guide plate 23, and its tip portion engages with the teeth of the ratchet wheel 24. The ratchet wheel 24 can freely rotate in the paper insertion direction as shown by arrow A in FIG. 3 without engaging the stop pawl 25, and can rotate in the opposite direction to the insertion direction as shown by arrow B. For reverse rotation, the stop pawl 25 is formed to engage and prevent the mold wheel 24 from rotating.

When manually feeding the paper 26, as shown in FIG.
0, and is inserted so that the tip comes into contact with the pair of registration rollers 12. At that time, resist detection sensor 2
2 is pushed up by the paper 26 and a registration detection signal is issued.Even if the paper 26 contacts the registration roller pair 12 and is further inserted, it is regulated by the upper guide plate 23 and is prevented from being inserted more than necessary. Friction roller 24 is paper 26
Rotates freely when inserted. Even if the paper 26 is long and the trailing end as shown in FIG. 4 is hanging down, the friction rollers 21 are prevented from reversing, so the paper 26 will not retreat and fall out.

In order to ensure that the paper 26 is prevented from retreating, the friction rollers 21 reduce the pressing force that presses the paper 26 against the guide plate 20 and the friction coefficient of the rollers, so that the paper slides against the surface of the friction rollers 21 due to its own weight. It is set to the extent that there is no problem. Also paper 26
If the paper is made of thin paper, it is best to use rubber such as sponge for the friction rollers, as it will not curl up.

〔effect〕

According to the present invention, a friction roller that does not have a driving part is installed in the manual paper feed slot so that it cannot rotate in the opposite direction by means of a reverse rotation prevention means. Enables reliable manual paper feeding without paper errors.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram of a laser printer which is an example of an image forming apparatus using the present invention, FIG. 2 is a perspective view of a manual paper feeder, FIG. 3 is a front view of a reverse rotation prevention means, and FIG. FIG. 2 is a cross-sectional view showing a state of the manual paper feeder when paper is manually inserted. 18...Manual paper feeder 19...Manual paper feed port 20...Guide plate 21...Friction roller 24...Type wheel (reverse rotation prevention means) 25...Stop claw (reverse rotation prevention means) means) (1 other person)

Claims (1)

[Claims] A friction roller is supported in a non-driven state near a manual paper feed port of the image forming apparatus so as to be able to press paper against a guide plate, and the friction roller is prevented from rotating in a direction opposite to the paper insertion direction. A paper manual feeding device for an image forming apparatus characterized by: