JPS60143376A - Image forming device - Google Patents

Abstract

PURPOSE:To remove the accumulation of toner at a toner stirring member and perform stable image formation for a long period by providing a process of cleaning the toner stirring means in the cleaning process of an image carrier. CONSTITUTION:The cleaning process 21 of the toner stirring member is provided in the cleaning process 20 of the photosensitive drum. A transfer electrode 12 is turned on 22 in the cleaning process 21 to charge electrostatically the drum, and the 1st light eraser 13 which is held on after the time t2 up to when a drum electrostatically charge position reaches the position of the 1st light eraser 13 is turned off 23 and held on a desired time t3 later. Consequently, the toner sticking on the stirring member is attracted to the side of the photosensitive drum and cleaned with a developing and cleaning means. Thus, toner accumulation on the stirring member is prevented and a stable image is formed for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus that effectively removes toner adhering to a toner disturbance member used in an image forming apparatus that serves as both a developing and a cleaning means. The present invention relates to an image forming apparatus having a cleaning means.

[Prior art and its problems]

Various types of image forming apparatuses have been proposed, but one in particular is Special Application No. 58-21333 filed by the present applicant.
An image forming apparatus using a toner-disturbing member that also serves as a developing and cleaning means as shown in 2 is designed to reduce the size and cost of the apparatus body, but as the number of copies increases, toner disturbs the toner-disturbing member Object of the Invention In view of the above-mentioned drawbacks, the present invention has been devised to prevent toner from being deposited on a toner disturbing member. It is an object of the present invention to provide an image forming apparatus that can eliminate the accumulation of images and provide stable images over a long period of time.

[Key points of the invention]

In order to achieve the above object, the present invention is provided with at least a transfer means, a static eliminating means, a toner agitating means, a charging means, and a developing/cleaning means in the vicinity of the image bearing means, and after forming an image by each of the above means. The present invention is characterized in that the 1-ner disturbance means is cleaned during cleaning of the image bearing means.

[Embodiments of the invention]

FIG. 1 is a schematic side view of the image forming apparatus of the present invention, and FIG. 2 is a time chart showing a toner-disturbing member cleaning process for explaining the present invention.

Reference numeral 1 denotes an image forming apparatus as a whole, and the upper surface of the image forming apparatus has a document scanning section 2 for exposing and scanning a document, and the left and right side walls have a paper insertion slot 4 for inserting transfer paper 3 and paper to be copied. It has a paper discharge port 5 for discharging paper. Reference numeral 6 denotes an exposure means consisting of a plurality of reflection mirrors and an exposure lamp 7, and the reflected light image of the document passing through the document scanning section 2 is projected onto the photoreceptor drum 8 via the plurality of reflection mirrors to form an electrostatic latent image. do. The photoreceptor drum has a photoconductive material such as Se, Z-n○, or Cds organic photoconductive phase deposited on its surface.
−i is selected. In this case, the maximum document size is A4, the circumference of the photoreceptor tram has a circumference shorter than the length in the longitudinal direction of A4, and the length in the axial direction of photoreceptor tram 8 is the width of A4 vertical feed. That is, it is selected to be approximately 210 degrees. Around the photoreceptor tram 8 is a charged electrode 9. Developing/cleaning means 10° resist roll 11. Transfer surface 12. First optical eraser 1a, toner disturbance member 14. A second optical eraser 15 is arranged. 16 is a paper feed row, 17 is a separation means, 18 is a fixing means, and 19 is a paper discharge row.

To explain the operation of the above structure, the photosensitive drum 8 rotates in the direction of arrow A at the same time as copying starts, and the photosensitive drum 8 is uniformly charged to a predetermined polarity by the charging electrode 9. Further, the document passing through the document scanning section 2 is irradiated by an exposure lamp 7, and a reflected light image of the document is projected onto the photoreceptor drum 8 by the exposure means 6 having a reflection mirror, and is electrostatically charged i11.
! form an image. The photoreceptor drum 8 on which the latent image has been formed is developed at the position of the developing/cleaning means 10 . A one-component magnetic toner with relatively low resistance is used as the developer, and toner having a polarity opposite to the charge on the photoreceptor drum surface is formed as a magnetic brush by electrostatic induction, and the electrostatic charge on the photoreceptor drum is The latent image is visualized and developed by passing through the magnetic brush.

On the other hand, the transfer paper 3 inserted from the paper insertion slot 4 is transferred to the paper feed roller 16.
The transfer paper 3 is fed to the position of the registration roller 11 by the operation of , and the timing is aligned with the developed image formed on the photoreceptor drum 8 , and the rotation of the registration roller 11 causes the transfer paper 3 to move along the outer periphery of the photoreceptor drum 8 to the transfer pole. Sent on 12.

A voltage of opposite polarity to the developed toner on the photosensitive drum 8 is applied to the transfer pole 12 from the back side of the transfer paper 3, and the toner is transferred onto the transfer paper.

In this image forming apparatus, the diameter of the photosensitive drum is 5011I11, so when copying an A4 size original, a copying process is performed continuously after the above-mentioned copying process is completed. That is, after the transfer process of the first half of the transfer paper, the photoreceptor tram 8
enters the static elimination process. For this purpose, the charge corresponding to the electrostatic latent image on the surface of the photoreceptor drum 8 is erased by the first optical eraser 13.

Furthermore, since the transfer efficiency performed on the first half of the transfer paper in the transfer process described above is not 100%, residual toner remains on the surface of the photosensitive drum 8. The remaining toner is then disturbed by the bristle brush of the toner disturbance member 14 disposed, and the residual toner is uniformly disturbed on the photoreceptor drum 8. The first (7p optical eraser 13) on the photosensitive drum 8 removes the charge that could not be completely defrosted by the -second optical eraser 15.
The electric potential on the outer periphery of the photoreceptor drum 8 is attenuated to near 0.

In the next step, the process proceeds to an exposure step for exposing the second half of the document, and the photosensitive drum 8 is charged again.

An electrostatic latent image is formed. At this time, the amount of toner remaining on the photoreceptor drum 8 is extremely small, so it does not affect latent image formation. Further, while the residual toner is removed by a developing/cleaning means 10 disposed next, the electrostatic latent image formed on the photosensitive drum 8 is visualized and transferred again at the transfer pole 12. Of the residual toner described above, the toner that has not been cleaned by the developing/cleaning means 10 is also charged with the same polarity as the outer circumference of the photoreceptor drum 8 by the charging electrode 9, so that it is transferred to the transfer paper 3 in the transfer process. It will not be done.

In this way, the photosensitive drum 8 rotates one or more revolutions, and copying of one sheet of transfer paper is completed. Transferred transfer paper 3
The paper is separated from the photoreceptor tram 8 via the separating means 17, and further sent to the fixing means where it is thermally fixed and ejected from the paper ejection port 5 via the paper ejection roller 19. Further, the photosensitive drum 8 enters a dedicated cleaning process in which it rotates one or more revolutions to completely remove residual toner.

In the dedicated cleaning process, the charge on the photosensitive drum 8 is removed by the first optical eraser 13.

The residual toner is disturbed by the toner disturbance member 14, and the charge is completely eliminated by the second optical eraser 15.

Further, the photoreceptor drum 8 is
Any residual toner on top is cleaned.

As explained above, when the cleaning process starts after the copying process is completed, the charging electrode 9 is in the OFF state, as shown in the time chart of FIG. Since no voltage is applied to 12, the first and second optical erasers 13 and 15 are "on".
is in the first region.

The next step is a cleaning step 2 of the toner disturbance member 14 of the present invention.
1 is arranged around the outer periphery of the photoreceptor drum 8.
Turn on the transfer pole 12 22. Photosensitive state
2) When the body drum 8 is charged for a given time (tl) and the charging position of the light drum 8 reaches the position of the first light eraser 13, the first
The optical eraser 13 is turned off 23 for a desired time (
After t3), it is sufficient to turn it into an "on" state.

In the cleaning process of the toner disturbing member 14, the operation shown in area 2 in FIG. 2 is performed, and then the process moves to the process shown in area 2, which is similar to the first area. In the toner-disturbing member cleaning process shown in area (2), the lamp of the first optical eraser 13 is not turned on, and the surface of the photoreceptor drum-8 is charged by the transfer pole 12, and the charged photoreceptor drum 8 is transferred to the toner-disturbing member 14. The toner adhering to the bristle brush of the disturbance member 14 when it passes in front is attracted to the photoreceptor drum 8 side and cleaned. The photoreceptor drum 8 that has absorbed the toner is neutralized by the second optical eraser 15, and the developing/cleaning means 10
cleaned by.

In the cleaning process in the area (2), the photosensitive drum 8 is completely cleaned by the first optical eraser l3, the toner disturbing member 14, the second optical eraser 15, and the developing/cleaning means 10. In the above embodiment, the cleaning process is performed in the first region and the second region.

Although it was separated from the area ■, the part ■ of the toner disturbance member cleaning process 21
It is also possible to omit the process dedicated to cleaning the first region before the region or the second region after the region.

Further, in FIG. 1, the photoreceptor that has absorbed toner from the toner disturbing member 14 is charged with electricity by the second optical eraser 15, but the electricity may be removed by the exposure means 6 without providing the second optical eraser.

〔Effect of the invention〕

Since the present invention is constructed and operated as described above, the toner-disturbing member cleaning step is simply inserted into the cleaning-only step of an image forming apparatus having a cleaning means that also serves as a developing device, and the copying time is not affected. By simply changing the application and the state of the optical eraser, the disturbance effect of the toner disturbance member can be improved, and the cleaning effect of the developing and cleaning means can also be improved, so that the transferred copy image can be extremely stabilized.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a conventional image forming apparatus. FIG. 2 is a time chart diagram of the image forming apparatus of the present invention. ■... Image forming apparatus Kokutai 2... Original scanning section 3... Transfer paper 4... Paper insertion slot 5... Paper ejection port 6... Exposure means 7... Exposure lamp 8... Photosensitive Body drum 9...Charging electrode 10...Developing/cleaning means 11...Register roll 12...Transfer pole 13...First light eraser 14...Toner disturbance member 15...Second Optical eraser 16...Paper feed roller 17...Separating means 18...Fixing means 20...Dedicated cleaning process 21...Toner disturbance process Cleaning process Patent applicant Casio Computer Co., Ltd. Same as above I.D. Co., Ltd. Agent Yoshiyuki Osuga, Patent Attorney

Claims (3)

[Claims] (1) At least transfer means 1 static elimination means around the image bearing means;
An image forming apparatus comprising a toner agitating means, a charging means, and a developing/cleaning means, wherein the toner agitating means is cleaned during cleaning of the image bearing means after image formation is performed by each of the above means. (2) The image forming apparatus according to claim 1, wherein the cleaning of the toner disturbance means is performed by adsorbing toner adhering to the toner disturbance means to the image bearing means. (3) The cleaning of the toner disturbance means is characterized in that the transfer means is operated, the static eliminating means is inoperative, and the toner adhering to the toner disturbance means is adsorbed by the charge charged on the image bearing means. An image forming apparatus according to claim 1.