JPH0452206Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an elastic synthetic resin sheet for use in image forming apparatuses, and in particular, the invention relates to an elastic synthetic resin sheet for use in image forming apparatuses, and in particular for guiding an image forming paper to a photoreceptor drum for transfer. The present invention relates to an elastic synthetic resin sheet for an image forming apparatus that is attached to a guide plate for an image forming apparatus to prevent defective transfer of image forming paper.

[Conventional technology]

Generally, in an image forming apparatus, for example, a copying machine, as shown in FIG. It is configured to be transferred onto paper P. In order to perform this transfer process, registration rollers 4 and 5 for supplying copy paper P to the transfer section 7 and a guide plate are provided. This guide plate is composed of an upper guide plate 3 and a lower guide plate 2 for guiding the copy paper P onto the photosensitive drum 6.

In such guide plates 2 and 3, the image forming paper P fed from the registration rollers 4 and 5 is guided by the guide plates 2 and 3.

By the way, since the guide plates 2 and 3 are relatively hard, they inherently have a unique rigidity. .
There was a problem in that the vibrations at this time were transmitted from the guide plate 3 to the transfer section 7, resulting in defective transfer of the image forming paper P.

As a measure to eliminate such inconvenience, an elastic synthetic resin sheet 1 having a uniform thickness is pasted on the lower guide plate 2.

This elastic synthetic resin sheet 1 is thin and has elasticity, and has a stiffness smaller than that of the guide plates 2 and 3, so that it absorbs the stiffness and softens.

Therefore, when the rear end of the copy paper P guided by the guide plates 2 and 3 comes off the registration rollers 4 and 5, the image forming paper P is moved by the elastic synthetic resin sheet 1 stuck to the guide plate 2. , the rigidity of the lower guide plate 2 is prevented from being directly transmitted to the image forming paper P, and the image forming paper P is no longer pushed by the lower guide plate 2, and as a result, the image forming paper P
This prevents the rear end from jumping up and prevents vibration from transferring to the transfer section 7.
Since the transfer is not transmitted to the image forming paper P, defective transfer of the image forming paper P does not occur.

In this way, between the registration rollers 4, 5 and the guide plates 2, 3, the elastic synthetic resin sheet 1 as described above is stuck to the lower guide plate 2, and the image forming paper P is attached to the elastic synthetic resin sheet 1. By guiding the image forming paper P over the sheet 1, it is possible to prevent the rear end of the image forming paper P from bouncing.

However, when the image forming paper P is guided over the elastic synthetic resin sheet 1 and comes off the tip of the elastic synthetic resin sheet 1 facing the photoreceptor drum 6, the elastic synthetic resin sheet 1 and the transfer corona discharger 8 Since there is a gap between the image forming paper P and the image forming paper P, the rear end of the image forming paper P suddenly falls downward.

By the way, since the image forming paper P is in contact with the photosensitive drum 6 at the transfer section 7, the sudden downward drop of the rear end of the image forming paper P is transmitted to the transfer section 7 as vibration, causing a transfer failure.

Therefore, the present applicant has developed a device that reduces the elasticity of the elastic synthetic resin sheet from the upstream side to the downstream side by forming the tip of the elastic synthetic resin sheet into a triangular protrusion.

As the elasticity of the elastic synthetic resin sheet is reduced, the supporting force of the elastic synthetic resin sheet 1 supporting the image forming paper P is gradually reduced. Then, when the image forming paper P is conveyed to the protruding part of the elastic synthetic resin sheet 1, the elastic synthetic resin sheet 1 is gradually displaced downward due to the weight of the image forming paper P. 1 to image forming paper P
Since the distance that the image forming paper P falls downward becomes smaller, the image forming paper P falls gently from the elastic synthetic resin sheet 1, and as a result, vibration to the transfer section 7 can be prevented and image defects will not occur.

By the way, copy paper to be copied is not only relatively thin and soft plain paper, but also thick and hard small paper such as postcards, which pass through the same elastic synthetic resin sheet 1 and are fed into the transfer section 7. be done. Here, it is desirable that the guide plate 2 be placed as close to the photosensitive drum 6 as possible in order to guide the copy paper to the photosensitive drum 6.
However, when the distance between the elastic synthetic resin sheet 1 and the photoreceptor drum 6 is reduced, thin and soft plain paper has good flexibility and is smoothly fed to the photoreceptor drum 6, but thick and hard paper such as a postcard Since small-sized paper has poor flexibility, it is inconvenient that it cannot be fed smoothly to the photoreceptor drum 6 and may become jammed.

Therefore, as shown in FIG. 4, the tip 1 of the elastic synthetic resin sheet 1 facing the photosensitive drum 6
An elastic synthetic resin sheet 1 with a notch S ₁ cut out in the center of a is attached to a guide plate 2. That is, S ₁ is an area through which thick, hard small paper such as a postcard passes, and S ₂ is an area of thin, soft plain paper. A device has been devised in which a small-sized paper photoreceptor can be fed by notching the center portion by l and making the distance from the photoreceptor drum 6 by l larger than that of plain paper.

[The problem that the idea attempts to solve]

However, with the elastic synthetic resin sheet 1 cut out in the center, the purpose is not to simply feed thick, hard, small-sized paper to the photoreceptor drum 6, but rather to feed thin, soft, plain paper into the photoreceptor drum 6. The purpose is to send it to the photosensitive drum 6.

Therefore, the elasticity of the elastic synthetic resin sheet 1 is suitable for thin and soft plain paper, and the elasticity of the thick and hard small paper area _S1 is the same as that of the thin and soft plain paper areas _S2 and _S2 . It's like that.

Therefore, when a thick, hard, small piece of paper is conveyed on the elastic synthetic resin sheet 1, the elasticity of the elastic synthetic resin sheet 1 is suitable for conveying thin, soft, plain paper, so that the photoreceptor drum is smoothly transported. There is a problem that the paper is not sent to the photoreceptor drum 6 and bounces or shifts.
The development of an elastic synthetic resin sheet 1 that can be guided to the surface has been expected.

[Means to solve the problem]

Therefore, this idea is based on an image forming device that is attached to a guide plate that is provided between a registration roller and a photoreceptor drum to guide the copy paper to the photoreceptor drum in order to transfer the copy paper so as to protrude toward the photoreceptor drum. An elastic synthetic resin sheet for use in image forming apparatuses, the elastic synthetic resin sheet for image forming apparatuses has an area at the leading end facing the photoconductor through which relatively thin and soft plain paper passes and a region through which thick and hard small paper passes. The object of the present invention is to provide a means for solving the above problems by providing an elastic synthetic resin sheet in which each region has a different elastic modulus.

[Effect]

In the above configuration, a thick, hard copy paper such as a postcard is sent to an elastic synthetic resin sheet by the registration rollers, guided on the elastic synthetic resin sheet toward the photoreceptor drum, and when it reaches the leading end of the photoreceptor drum,
The copy paper is guided by a soft small paper guide portion having a large elastic modulus at the center of the leading end, and the copy paper is smoothly fed to the photoreceptor drum without the rear end bouncing or shifting and without clogging.

When thin, soft plain paper is fed to an elastic synthetic resin sheet by the registration rollers, the elastic synthetic resin sheet is guided toward the photoreceptor drum, and when it reaches the leading edge of the photosensitive drum, the leading edge of the sheet is The copy paper is guided by the plain paper guide section and the small paper guide section, which have a small elastic modulus around the copy paper, and is smoothly fed to the photosensitive drum without the trailing edge of the copy paper bouncing up or shifting.

〔Example〕

Hereinafter, how the configuration of the present invention is actually implemented will be explained along with its operation. Figure 1 is a perspective view of an elastic synthetic resin sheet that is an embodiment of the present invention being affixed to a guide plate. In the figure, 1 is an elastic synthetic resin sheet, and two elastic synthetic resin sheets 1' and 1'' are superimposed and adhered to the guide plate 2 with adhesive.

As shown in FIG. 1A, the lower elastic synthetic resin sheet 1'' has a central portion _S1 of the tip portion 1a facing the photoreceptor drum 6 (FIG. 3) shaped into a triangular shape 1b, and the entire portion is shaped like a triangle. This central part _S1 is a region through which only thick and hard copy paper such as postcards passes, and the leading end part 1a of the elastic synthetic resin sheet 1 is soft, that is, has a large elastic modulus. Elastic synthetic resin sheet 1 with large coefficient
A small guide portion 1c is formed.

As shown in FIG _. 1B, the upper elastic synthetic resin sheet 1' has a triangular peripheral portion _S2 , _S2 excluding the central portion S1 of the tip portion 1a facing the photosensitive drum 6. At the same time, the entire structure is made hard, that is, the elastic modulus is made small. And these peripheral parts S ₂ and S ₂ are
In the region through which only the thin and soft normal-sized copy paper passes, the leading end portion 1a of the elastic synthetic resin sheet 1 is a plain paper guide portion 1d, which is a hard elastic synthetic resin sheet 1 with a small elastic modulus. 1d is formed.

When a hard elastic synthetic resin sheet 1'' is superimposed on the soft elastic synthetic resin sheet 1'' having such a structure and is adhered to the guide plate 2 with an adhesive, the structure shown in FIG. 1 is obtained.

As explained in the conventional technology example, the state in which the central part of the sheet 1 made of elastic synthetic resin is cut out can be considered to be an infinitely soft state, and therefore, it is possible to make small paper made of relatively soft elastic synthetic resin. When the small paper is passed over the sheet, it is guided by the small paper guide portion 1c of the soft elastic synthetic resin sheet 1, so that the bouncing and shifting of the trailing edge of the copy paper, which frequently occurred in the past, can be suppressed. be.

Further, thin and soft plain paper is guided by the hard plain paper guide portions 1d, 1d made of elastic synthetic resin sheets and the small paper guide portion 1c, and is smoothly fed to the photoreceptor drum 6.

The soft elastic synthetic resin sheet 1'' is located below the hard elastic synthetic resin sheet 1',
It may also be located above, as shown in FIG. In addition, the soft elastic synthetic resin sheet 1 is
As shown in FIG. 2A, only the area of the small paper guide area _S1 may be attached to the guide plate 2.

Further, in this embodiment, the center reference of the copy paper, that is, the small paper, is guided at the center of the elastic synthetic resin sheet 1, but the one-sided reference, that is, the small paper is guided by bringing it closer to one end of the elastic synthetic resin sheet. It is okay to do so.

[Effect of idea]

As described above, according to the present invention, the area through which comparatively thin and soft plain paper passes and the area through which thick and hard small paper passes, at the leading end of the elastic synthetic resin sheet facing the photoreceptor drum, are determined by the respective elastic modulus. Because they are configured differently, both small paper and plain paper are guided by the elastic synthetic resin sheets in each region, and the copy paper is smoothly fed to the photoreceptor drum without shifting or the trailing edge bouncing, and the image is It has the effect of eliminating the disturbance of

[Brief explanation of drawings]

Figures 1, 1A, and 1B are perspective views of elastic synthetic resin sheets of the present invention, Figures 2 and 2A are views of other embodiments of the present invention, and Figure 3 is a conventional elastic synthetic resin sheet. FIG. 4 is a perspective view of a conventional elastic synthetic resin sheet. 1...Elastic synthetic resin sheet, 1a...Top end of elastic synthetic resin sheet, 1c...Small paper guide section, 1d...Plain paper guide section, _S1 ...Small paper passage area, _S2 ... ... Plain paper passage area, 2, 3... Guide plate, 4, 5... Registration roller, 6... Photosensitive drum.

Claims (1)

[Scope of utility model registration request] An elastic composite for image forming apparatuses that is attached to a guide plate provided between a registration roller and the photoreceptor drum for guiding the image forming paper to the photoreceptor drum in order to protrude toward the photoreceptor drum. In the resin sheet, an area where comparatively thin and soft plain paper passes through and an area where thick and hard small paper passes through at the leading end facing the photoreceptor of this elastic synthetic resin sheet for image forming apparatuses are respectively defined. An elastic synthetic resin sheet for an image forming apparatus, characterized in that the sheet has different elastic modulus.