JP2564721Y2 - Paper guide plate - Google Patents

Description

[Detailed description of the invention] [Summary] In an electrophotographic recording apparatus, with regard to a paper guide plate for guiding a paper on which an image is formed on a photosensitive drum to a fixing device, improvement in reliability of paper transport and reduction in price have been achieved. A sheet guide plate for guiding the sheet by contacting the back surface of the sheet on which an image is formed, wherein a plurality of ventilation holes are provided on a contact surface of the sheet, and a contact surface that contacts the sheet around the ventilation hole; Is formed so that a corner formed between the airflow direction and the airflow direction is a curved surface.

[Industrial applications]

The present invention relates to a paper guide plate for guiding a paper image formed on a photosensitive drum to a fixing device in an electrophotographic recording apparatus.

[Conventional technology]

As shown in the side view of FIG. 3, the paper transport path 3 between the photosensitive drum 1 and the fixing unit 2 of the paper transport device in the electrophotographic recording apparatus has two upper and lower plates facing each other at a predetermined interval. The upper paper guide plate 3a has a heat roller
In order to dissipate the heat of the fixing section 2 which is provided with 2a and perform the heat fixing, and not to affect the photosensitive drum 1, about 20 oblong ventilation holes 4 are formed in parallel by press working. .

The paper 5 is inserted into the space between the photosensitive drum 1 and the transfer device 6 from the right side of the drawing, and the toner image on the photosensitive drum 1 is transferred while moving to the left.

The sheet 5 onto which the toner image has been transferred is guided to the sheet transport path 3 and sent to the fixing unit 2.

At this time, the paper 5 is charged by the transfer unit 6, and a strong electric field is generated between the paper 5 and the sharp edge of the side edge of the ventilation hole 4 when passing through the paper guide plate 3a.

Then, this electric field affects the unfixed toner on the sheet 5 to cause image disturbance, that is, a polka dot pattern.

In order to prevent this, a neutralizing brush 7 for neutralizing the paper 5 is provided beside the transfer unit 6.

The lower paper guide plate 8 is a plurality of ribs 8a protruding above the plate-like member, and heated air is discharged from the ventilation holes 4 to the upper part through the gaps between the ribs 8a.

[Problems to be solved by the invention]

The static elimination brush is used to eliminate static electricity from the paper. However, the static elimination brush causes problems such as contamination of the apparatus due to separation of hair, obstruction of paper transport, and an increase in cost.

An object of the present invention is to improve the reliability of paper conveyance and reduce the cost.

[Means for solving the problem]

In order to achieve the above object, in the present invention, as shown in the side view of FIG. 1, the photosensitive drum 1 of the electrophotographic recording apparatus for forming an image on the surface of the sheet 5 and the photosensitive drum 1 are used. A sheet guide plate 9a disposed between the fixing device 2 for fixing the image and guiding the sheet 5 in contact with the back surface of the sheet 5 on which the image is formed;
Contact surface with the paper 5 around the ventilation hole 10 and the ventilation hole
This is a paper guide plate 9a in which a corner 11 formed between the air flow direction of FIG.

[Action]

Even if the charged paper comes into contact with the corners of the ventilation holes, since the corners in the transport direction are curved, a strong electric field is not generated between the paper and the papers, so that a neutralizing brush is not required.

〔Example〕

 1 and 2 show an embodiment of the present invention.

 The same parts are denoted by the same reference numerals throughout the drawings.

In the present invention, as shown in the side view of FIG. 1, a ventilation hole 10 is formed in a paper guide plate 9a above a paper conveyance path 9 provided between the photosensitive drum 1 and the fixing unit 2. The corner 11 in the paper transport direction is raised, for example, by about 1.5 mm by drawing or the like, and has an R surface (curved surface).

As shown in the plan view of FIG.
Approximately 20 oblong ones are arranged in parallel in 9a, and the same curved surface processing is performed for all of them.

In this way, even if the charged paper 5 comes into contact with the corner 11 of the ventilation hole 10, a strong electric field is not generated between the corner 5 and the paper because the corner 11 is curved.

For this reason, a neutralizing brush is not required, and even without the neutralizing brush, the toner image on the sheet 5 can be prevented from being disturbed, that is, polka dots can be prevented from being generated.

The lower paper guide plate is the same as that of the prior art, and is freely ventilated.

[Effect of the invention]

According to the present invention, the toner image on the paper can be prevented from being disturbed without using the charge elimination brush, and the paper conveyance problem and the cost increase due to the charge elimination brush can be prevented. .

[Brief description of the drawings]

FIG. 1 is a side view of the paper guide plate of the present invention, FIG. 2 is a plan view of the paper guide plate of the present invention, and FIG. 3 is a side view of the conventional paper guide plate. In the figure, 1 is a photosensitive drum, 2 is a fixing unit, 2a is a heat roller, 3,
9 is a paper transport path; 3a and 9a are upper paper guide plates;
Is a ventilation hole, 5 is a paper, 6 is a transfer device, 7 is a discharging brush, 8
Is a lower paper guide plate, 8a is a rib, and 11 is a corner.

Claims (1)

(57) [Scope of request for utility model registration] 1. A photosensitive drum (1) of an electrophotographic recording apparatus for forming an image on a sheet (5) and a fixing device (2) for fixing an image formed by the photosensitive drum (1). A paper guide plate (9a) which is disposed on the paper and guides the paper (5) in contact with the back surface of the paper (5) on which the image is formed, wherein a plurality of ventilation holes (10) are formed in the contact surface of the paper (5). Corner (11) formed between a contact surface around the ventilation hole (10), which is in contact with the paper (5), and the air ventilation direction of the ventilation hole (10).
Paper guide plate characterized by having a curved surface.