JPH03171181A - Paper powder removing device - Google Patents

Abstract

PURPOSE:To prevent an imperfect image and the deterioration of a photosensitive body, to simplify the structure and to facilitate the replacement of a paper powder removing member by attaching the root part of an elastic thin sheet with the upper surface of the tip part on which the paper powder removing member is fixed to the shielding case of a transfer charger so that it can be attachably/detachably replaced. CONSTITUTION:An image forming part is constituted of the photosensitive body 1, a main charger 2, an exposure part 3, a developing device 4, a pre-transfer guiding device 5, the transfer charger 6, a transfer sheet separating charger 7, a cleaning device 8, resist rollers 9 constituted of an upper roller 9a and a lower roller 9b and the paper powder removing member 10 for removing the paper powder sticking to the upper roller 9a. And the paper powder removing member 13 abutting on the lower roller 9b is successively arranged to the shielding case 6a of the transfer charger 6 through the elastic thin sheet 14. Then, the paper powder on the back surface of the transfer sheet is made to stick to the lower roller 9b, and then, wiped up by the paper powder removing member 13. And when the paper powder removing member is replaced, the paper powder removing member 13 is integrally inserted and pulled by inserting and pulling the transfer charger 6. Thus, the imperfect image and the deterioration of the photosensitive body can be prevented, and the structure can be simplified and also the replacement of the paper powder removing member can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dust removal device for an image forming apparatus such as an electrostatographic copying machine or a facsimile machine. [Prior Art] In the conventional image forming apparatus, as shown in Fig. 4,
In order to prevent paper dust from getting caught between the cleaning blade l9 and the photoreceptor l, a dust removing member such as a sponge is provided which comes into contact with the upper roller 9a of the registration roller 9 provided on the upstream side of the transfer charger 6. 10 were installed to form a paper dust removal device. Although this conventional example is effective in removing paper dust from the upper surface of the transfer paper, it has the following drawbacks.

■The paper powder on the lower surface of the transfer paper temporarily adheres to the lower roller 9b of the registration roller 9, but most of it adheres to the lower surface of the transfer paper again and is transported to the transfer area of the photoreceptor 1. Become.

For this reason, the dust adheres to the transfer charger 6 and the transfer paper separation charger 7, causing uneven discharge, and as a result,
White or black streaks may appear on the image on the transfer paper, and extreme unevenness in discharge can also cause deterioration of the photoreceptor.

■Some of the paper dust attached to the lower roller 9b of the registration roller 9 passes through the nip of the registration roller 9 and passes through the upper roller 9a.
It adheres to and transfers to the powder removing member lO of the upper roller 9a.
Therefore, the replacement cycle of the powder removing member 10 is short.

[Problem to be solved by the invention]

As a solution to such conventional drawbacks, it has first been considered to provide a paper dust removing member on the lower roller 9b side as well, but if this is done, the following problems are likely to occur. That is, the vicinity of the lower roller 9b of the registration roller 9 corresponds to the lower part of the conveyance path of the transfer paper, and generally, maintenance and inspection are not possible without removing the conveyance guide 20 etc. on the lower surface of the conveyance path. If a dust removal member and its support member are provided in the machine, an attachment/detachment mechanism such as the conveyance guide 20 will be provided in addition to the attachment/detachment mechanism for the dust removal member or support member, which will complicate the structure. Replacing parts is also quite difficult.

The present invention provides a paper dust removing device that can eliminate the above-described conventional drawbacks without causing such inconveniences.

[Means to solve the problem]

The technical means taken by the present invention to achieve the above object are as follows. That is, the feature of the present invention is that the shield case of the transfer charger, which is provided so as to be freely insertable and removable, is provided with a retaining member that comes into contact with the lower roller of the registration roller provided on the upstream side of the transfer charger. .

[Effect]

According to the above structure, the paper dust on the lower surface of the transfer paper adheres to the lower roller, and the paper dust adhered to the lower roller is wiped off by the dust removal member. When replacing the paper dust removing member, by inserting and removing the transfer charger, the paper dust removing member is also inserted and removed at the same time. [Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows an image forming section in an electrostatographic copying machine which is an example of an image forming apparatus. The image section consists of a main charger 2, an exposure section 3, a developing device 4, a pre-transfer guide device 5, a transfer charger 6, a transfer paper separation charger 7, and a cleaner. The devices 8 are arranged in this order in the rotational direction of the photoreceptor 1. Reference numeral 9 denotes a registration roller consisting of an upper roller 9a and a lower roller 9b provided on the upstream side of the transfer charger 6. The registration roller 9 is arranged at a predetermined position so that the leading edge of the transfer paper a enters the photoreceptor 1 at a predetermined tie-edge. It is driven at the timing of 10
is a dust removal member such as a sponge that removes dust adhering to the upper roller 9a. The pre-transfer guide device 5 includes an upper guide plate 11 and a lower guide plate 12, and the downstream end of the lower guide plate 12 protrudes beyond the downstream end of the upper guide plate l1. The transfer charger 6 and the transfer paper separation charger 7 are respectively installed in a shield case 6a. 7a and the discharge wire 6b stretched across the shield cases 6a and 7a.
7b, and is configured to be freely inserted and removed in the axial direction of the photoreceptor l.

Incidentally, in the illustrated embodiment, the transfer charger G and the shield cases 6a, 7a of the transfer paper separation charger 7 are integrated, but they may be made separately, and instead of the transfer paper separation charger 7, Other separation means may also be employed.

A is a paper dust removing device provided for the lower roller 9b of the registration roller 9. As shown in FIG. 2, the paper dust removing device A is constructed by connecting a dust removing member 13 such as a sponge to the shield case 6a of the transfer charger 6 and contacting the lower roller 9b. It is. To explain in more detail, the base end of the elastic thin plate 14 such as a resin plate or stainless steel plate, to which the powder removing member 13 is fixed by adhesive or other means to the upper surface of the tip, is attached and detached to the shield case 6a of the transfer charger 6. The structure is such that the paper dust removing member 13 comes into elastic contact with the lower roller 9b when the transfer charger 6 is placed in a predetermined position with respect to the photoreceptor 1. It has been done. Various attachment means can be used to attach the base end of the elastic thin plate l4 to the shield case 6a, but in this embodiment, double-sided adhesive tape 5 is used to attach the powder removing member 13 from the shield case 6a. A surplus double-sided adhesive tape 15 located between the two protects a toner receiving portion B that can catch toner that has fallen from the photoreceptor 1 or the developing sleeve.

That is, a gap S is formed between the solder case 6a of the transfer charger 6 and the lower guide plate 12 of the pre-transfer guide device 5 to allow the toner that has fallen from the photoreceptor l or the developing sleeve to pass through. Transfer paper a at upper position p
The top surface of the elastic thin plate l4, which is a member for connecting and supporting the paper dust removing member l3 to the shield case 6a, is provided with an elastic thin plate. Place the base end of l4 in the shield case 6a.
A double-sided adhesive tape 15 that is longer than the length necessary for attachment to the bottom of the double-sided adhesive tape 15 is pasted, and
The portion located between the shield case 6a and the powder removing member 13 constitutes the toner receiving portion B located below the gap S and spanning the entire width of the gap S. The powder removing member l3 shown in the figure is fixed to the top surface of the tip of the elastic thin plate l4 by adhesive or other means, but the double-sided adhesive tape 15 is extended to the tip of the elastic thin plate l4, and the double-sided adhesive tape l5 is The rice grain removing member l3 may be fixed to the upper surface of the tip of the elastic thin plate 14 by the extended portion.

According to the above embodiment, the paper dust on the lower surface of the transfer paper a adheres to the lower roller 9b, and the paper dust adhered to the lower roller 9b is wiped off by the paper dust removing member l3.

When a predetermined amount of paper dust has accumulated in the paper dust removal member 13, the paper dust removal member 13 can be taken out of the machine along with the transfer charger 6, and the paper dust removal member 13 can be replaced with a new one. This exchange is
When replacing the transfer charger 6, the entire transfer charger 6 may be replaced. In addition, the upper roller 9a and the lower roller 9
Since a paper dust removing member is provided for each of the paper dust removal members b, it is possible to lengthen the replacement cycle.

Even if toner may fall from the photoconductor L or the developing sleeve due to air currents generated as the developing roller rotates, this toner will pass through the gap S and reach the toner receiving portion B.
Since there is no risk that the transfer paper a will fall and accumulate on the protruding portion of the lower guide plate 12 of the pre-transfer guide device 5, stains on the lower surface of the transfer paper a can be prevented. The toner that has fallen into the toner receiving part B is captured by the double-sided adhesive table 15 of the toner receiving part B, so that the fallen toner is prevented from scattering into the machine or falling out of the machine.

In addition, when the leading edge of the transfer paper a comes into contact with the photoconductor 1 due to poor timing of the leading edge of the transfer paper a entering the photoconductor l,
Even if the toner on the surface of the photoconductor l is dropped by the tip of the transfer paper a, in this embodiment, the transfer paper a is configured to enter the photoconductor l at a position p above the gap S. Therefore, there is no risk that the fallen toner will fall into the gap S and into the shield case 6a of the transfer charger 6. Therefore, there is an adverse effect on the discharge state caused by the toner falling due to the rush of the transfer charger 6 falling into the shield case 6a of the transfer charger 6, uneven discharge, image defects such as white streaks and black streaks caused by the uneven discharge, and exposure to light. It is possible to avoid deterioration of the body. Figure 3 shows another embodiment of the present invention. In this embodiment, a large number of ventilation holes 16 are formed in the elastic thin plate l4, and a filter 17 such as a sponge (this may be integrated with the powder removing member l3) is attached to the upper surface of the elastic thin plate l4. In addition to forming the toner receiving portion B, the elastic thin plate 14
The present invention is characterized in that a suction fan 18 is provided below the toner receiving portion B so that the toner is captured by the filter 17 of the toner receiving portion B. Since other structures and functions are the same as those in the previous embodiment, the same constituent members are given the same reference numerals and their explanations will be omitted.

〔Effect of the invention〕

In order to avoid the above-mentioned precautions, the present invention can remove dust from the lower surface of the transfer paper with a paper dust removing member provided for the lower roller, and the replacement cycle of the paper dust removing member on the upper roller side is improved. In addition to making it possible to lengthen the transfer time, it also eliminates conventional drawbacks such as image defects and photoreceptor deterioration caused by uneven discharge caused by paper dust on the bottom surface of the transfer paper adhering to the transfer charger separation charger. Since the paper dust removal member for the lower roller is connected to the shield case of the transfer charger that can be inserted and removed, the transfer charger is used as a structure for supporting and attaching/detaching the paper dust removal member. The structure of the removing device can be simplified, and the paper dust removing member can be easily replaced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic longitudinal side view of an image forming section of an image forming apparatus, and FIG. 2 is a longitudinal side view of the main part. FIG. 3 is a longitudinal sectional side view of the main parts showing another embodiment of the present invention. Figure 4 is an explanatory diagram of a conventional example. I...Photoreceptor, 6...Transfer charger, 6a...
Shield case, 9... Registration roller, 9b...
Lower roller, 13... powder removing member.

Claims (1)

[Claims] A paper dust removing device comprising a paper dust removing member that comes into contact with a lower roller of a registration roller provided upstream of the transfer charger and is connected to a shield case of a transfer charger that is provided in a manner that the transfer charger can be freely inserted and removed.