JPH04165366A - Process unit and picture recording device having the same - Google Patents

Abstract

PURPOSE:To recover the residual toner after cleaning to make reuse possible in a developing apparatus by arranging a cleaning means to a developing utensil side than a latent image forming position of an image holding body. CONSTITUTION:Residual toner recovered by a cleaning blade 118 is gathered in a toner gathering part 164 together with paper dust and refuse. Among these, the toner is magnetic toner involving magnetic dust, therefore stuck to the surface of a non-magnetic toner carrying roller 161 having magnetic poles in the inside, and carried in the direction designated in an arrow mark. Meanwhile, because paper dust, refuse and the like are non-magnetic, gathered to the toner gathering part 164 without sticking to the toner carrying roller 161. The toner carried on the toner carrying roller 161 is stripped off by a scraper blade 163, fallen down into the toner in a developing apparatus 104 with gravity, and mixed. It is possible thereby to recover the transferring residual toner to the developing apparatus side to reuse this.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a process unit using an electrophotographic process and an image recording apparatus using this process unit.

[Prior Art] In recent years, in various image recording apparatuses using electrophotographic processes, the configuration of a photoreceptor drum as an image bearing member and some of the process means for charging, developing, cleaning, etc. around the photoreceptor drum have been changed. It has become common to use a so-called process unit in which the means is integrally configured and can be attached to and detached from the main device.

3 and 4 show an example of an image recording apparatus using a conventional process unit. Exposure aperture 1 for forming a latent image on the photoreceptor drum 101 by a charger 102 that performs primary charging and an optical scanner 150 that blinks based on an image signal.
03. Developing device 104 that develops the latent image with toner, after transferring the toner on the photosensitive drum to the transfer material (paper),
It consists of cleaning means 115 for collecting residual toner that has not been completely transferred.
0, it is configured to be detachable at will.

The developing device 104 includes a toner container 106 that stores enough toner to last the set life of the process unit 120, a developing sleeve 107 that applies toner to the photoreceptor drum 101, and the like. On the other hand, the cleaning means 115 includes a cleaning blade 118 that scrapes off residual toner on the photoreceptor drum, and a cleaning blade 118 that scrapes off residual toner on the photoreceptor drum, and a cleaning blade 118 that scrapes off residual toner on the photoreceptor drum;
The process unit includes a waste toner container 119 for storing waste toner (waste toner) for a set life of the process unit.

This process unit has the following advantages over conventional technology, for example.

(1) Replacement of consumable parts such as photoreceptors and toner can be easily performed by general users rather than by dedicated service personnel, thereby reducing costs related to maintenance of image recording apparatuses.

(2) Provide means for correcting variations in characteristics of the photoreceptor, developer, etc. for each process unit, or notify the main unit of the variations in signals for each process unit, for example, Adjust the output voltage, etc.
Reduces variations in image quality that occur every time consumables such as photoreceptors and toner are replaced.

(3) Since the process unit is integrally constructed and is detachable from the main unit, there is no possibility of damaging the photosensitive drum or spilling toner when replacing the process unit.

[Problems to be Solved by the Invention] However, although the process unit described above has many advantages, it also has the following problems.

That is, the photosensitive drum 1 constituting the process unit
01, the capacity of the developing toner container 106, and the capacity of the waste toner container 119 are preferably balanced with each other. However, as the lifespan of the photoreceptor drum 101 has become longer due to advances in technology in recent years, the toner container 106 has a large capacity to match the lifespan of the photoreceptor drum.
, and a waste toner container 119 have become necessary. especially,
The transfer efficiency of the transfer charger to paper is generally about 70 to 80%, and 20 to 30% of the toner capacity stored in the toner container 106 on the developer side is stored in the waste toner container 119 as waste toner. was to be done.

As a result, when trying to configure a process unit with a long life, the volume of the process unit increases, and the ease of replacing the process unit increases. Also, there was a problem that miniaturization of the main body device was hindered.

Furthermore, when disposing of a process unit that has reached the end of its lifespan, the volume to be disposed of is large, making it difficult to dispose of it as bulky industrial waste.

In order to solve these problems, as shown in FIGS. 5 and 6, the process unit 120 is provided with a conveying means for collecting the waste toner in the cleaning means 115 to the developing device 104. A patent application has been filed for a method of reusing (recycling) waste toner by providing a 141.

However, in order to convey the toner, the toner conveying means 14 is composed of a cylindrical conveying pipe and a spiral rotating shaft.
2.143.144 must be combined, making the entire device complex, which not only increases cost, but also poses reliability problems such as toner clogging in the conveying means. .

The present invention has been made to solve the above-mentioned problems, and its purpose is to collect residual toner on the photosensitive drum after cleaning and reuse it in a developing device. 5. [Means for Solving the Problems] In order to achieve the above object, the process unit and image recording device of the present invention have an image bearing member. a charging means for charging the image bearing member; a developing means for developing a latent image formed by exposing the image bearing member with an optical signal; and a collecting means for recovering residual waste toner on the image bearing member. Of the cleaning means, the cleaning means has long been located closer to the developing device than the latent image forming position of the image bearing member, and waste toner collected from the photoreceptor and used again in the developing device. It is configured to do so.

Furthermore, the cleaning means is configured integrally with the developing device, and a filter member for removing impurities in waste toner may be provided between the developing device and the developing device.

Further, in the process unit having the above structure, the cleaning means and the developing means may be integrated.

Further, the process unit may include a removing means for removing impurities other than toner from the waste toner collected from the image carrier in the cleaning means.

Furthermore, in the image recording apparatus, the cleaning means may include a removing means for removing impurities other than toner from the waste toner collected from the image carrier.

[Function] According to the process unit, throat, and image recording apparatus of the present invention having the above configuration, the photoreceptor drum is primarily charged by the charger via the toner layer remaining on the photoreceptor drum, and then A latent image is formed on the photoreceptor drum by exposing it to a light beam modulated by an image recording signal, and thereafter, residual toner on the photoreceptor drum is removed by a cleaning means. Thereafter, the electrostatic latent image on the photosensitive drum is developed by a developing device 1 and transferred onto a transfer material, thereby forming a visible image on the transfer material.

The cleaning means described above is located just before the developing device, so the cleaning blade collects (and removes residual toner from) the developing device.
Instead of waste toner, it is guided into the developing device and reused. Further, impurities such as paper powder of the transfer material in the residual toner collected by the cleaning means are removed from the toner by a removing means between the cleaning means and the developing device, and then the toner is used for development. .

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of the present invention,
In FIG. 1, an image recording apparatus 200 includes a process unit 120 including a photoreceptor drum 101 as an image carrier, an optical scanner 150 for forming a latent image on the photoreceptor drum 101, and a sheet of paper as a transfer material. a paper cassette 211 that stores the paper, a paper feed roller 212 that feeds the paper, a registration roller 213 that takes the timing of the paper, a transfer charger 214 that electrostatically transfers the toner on the photosensitive drum 101 onto the paper, and a paper cassette 211 that stores the paper. It consists of a fixing device 215 for fixing the upper toner, a paper discharge roller 216 for discharging the paper to a paper discharge tray 220, and the like.

The photosensitive drum 101 is made by dispersing a conventionally known photoconductive substance such as phthalocyanine in a binder resin on a conductive cylindrical base material such as aluminum. It consists of a negatively charged organic photoreceptor (OPC) that has the property of transporting holes.

In addition, the toner contains magnetic powder made of triiron tetroxide (magnetite), etc. in a styrene-acrylic binder polymer, and if necessary, azo metal-containing dye, charge control agent such as chlorinated paraffin, carbon black, etc. A negatively charged powder containing a coloring agent, etc., and pulverized to an average particle size of 8 to 15 micrometers is used.

FIG. 2 shows the process unit 120 in more detail, in which a process unit 120f;t, a primary charger for charging the photoreceptor drum is provided around the photoreceptor drum 101 rotating in the direction of the arrow in the figure. 102 , an exposure aperture 103 for exposing the photoreceptor drum with the light beam from the optical scanner 150 , a cleaning blade 118 for cleaning residual toner on the photoreceptor drum, and toner collected by the cleaning blade 118 . a removing means 160 for removing impurities in the toner, a toner container 106 for storing the developing toner, a developing device 104 for developing the toner onto the photosensitive drum, and a container for holding these components together. It consists of 130 national polities.

The removing means 160 is for removing impurities such as paper powder in the paper mixed in the toner collected by the cleaning blade 118 from the photosensitive drum 101 and dust adhering to the paper. It has a toner reservoir section 164 that temporarily stores the residual toner collected by the cleaning blade 118, and a fixed magnet roller 162 inside which is magnetized alternately in a point-symmetrical manner.
A non-magnetic toner conveying roller 161 rotated in the direction of the arrow by a drive source (not shown), and a toner conveying roller 161
Scraper blade 163 for scraping off the toner on the top
It consists of.

Further, the developing device 104 has a toner container 106, an agitator 112 for agitating and conveying the toner in the toner container 106, and a fixed magnet roller 108, which is internally divided and magnetized alternately and point-symmetrically, and is driven by a drive (not shown). A non-magnetic developing sleeve 107 rotated in the direction of the arrow by a source, and a blade 10 that equalizes the layer thickness of toner on the developing sleeve.
9, a partition 113 having a plurality of openings in the longitudinal direction that partitions the toner container 106 and the sleeve 107, and the like.

Next, the operation of the process unit according to this embodiment will be explained using FIG. 2.

The photoreceptor drum 101 that has completed the transfer process is charged by the next charger 102 with a small amount of residual toner on the surface. Residual charges based on the previous image recording remain on the photosensitive drum 101, but since the next generation device uses a conventionally known scorotron, it is uniformly charged to a potential approximately equal to the grid voltage.

Next, the photoreceptor drum 101 is transferred to the process unit 120
Image information is written by a light beam through the exposure aperture 103, and an electrostatic latent image is formed.

Here, the light beam is exposed to a portion of the photoreceptor drum where toner is to be developed. (Reversal development method).

Next, a cleaning blade 118 scrapes off a small amount of residual toner on the photoreceptor tram and conveys the toner to an impurity removal means 160 for removing impurities in the toner.

Thereafter, the electrostatic latent image on the photosensitive drum 101 is developed with negatively charged toner by the developing device 104, and the toner is developed on the portion exposed to the light beam.

Thereafter, as shown in FIG. 1, toner is transferred to the paper by the transfer charger 214, fixed by the fixing device 215, and the paper is discharged to the paper discharge tray 220.

The operation of the impurity removing means 160 in the toner will be explained.

The residual toner collected by the cleaning blade 118 accumulates in the toner reservoir 164 together with paper powder, dust, and the like. Among these toners, since the toner is a magnetic toner containing magnetic powder as described above, it adheres to the surface of the non-magnetic toner conveying roller 161 having an internal magnetic pole and is conveyed in the direction of the arrow. On the other hand, paper powder, dust, and the like in the residual toner are non-magnetic, so they do not adhere to the toner transport roller 161 and remain in the toner reservoir 164 . The toner conveyed on the toner conveying roller 161 is scraped off by a scraper blade 163, falls into the toner in the developing device 104 by gravity, and is mixed.

In the developing device 104, the toner in the toner container 106 is sent to the developing sleeve 107 side through the opening of the partition 113 by the agitator 112, but since the residual toner is mixed in to be reused, the developing sleeve The toner is sent out as appropriate depending on the amount of toner around it.

After the residual toner that has not been transferred is collected by a cleaning blade, any impurities contained therein are removed, and the remaining toner is mixed with the unused toner in the toner container in the developing device 104 and reused, i.e., collected. Both the toner and the unused toner are magnetically attracted to the surface of the developing sleeve 107 by the magnetic force of the magnet roller 108, and are conveyed counterclockwise as shown by the arrow as the developing sleeve rotates.
After the toner layer thickness is made uniform by step 9, an electrostatic latent image is developed in a portion facing the photoreceptor drum 101.

Note that the present invention can be modified in various ways without departing from the spirit of the invention.

For example, if there are few impurities such as paper dust in the transfer residual toner, it is not necessary to provide the impurity removing means 160. The residual toner scraped off by the cleaning blade 118 is mixed directly into the developing device 104.

Further, the impurity removing means 160 may include a mesh screen having an opening through which only toner passes between the cleaning blade 118 and the developing device 104, for example, in addition to the one shown in this embodiment. The toner may fall into the developing device 104 by vibrating the screen.

[Effects of the Invention] As is clear from the above detailed description, according to the present invention, residual toner after transfer is collected on the developing device side using a simple structure and is reused, so that the amount of toner per unit weight of toner is reduced. The number of pages that can be printed is increased by 20 to 30% compared to conventional methods, reducing running costs and being advantageous in terms of resource conservation.

Furthermore, the volume of the process unit itself is reduced, making handling easier and contributing to the miniaturization of the main device.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a sectional view showing the structure of a process unit according to the above embodiment and an image recording apparatus incorporating this process unit, and FIG. FIG. 2 is a cross-sectional view showing details of the process unit. 3 to 6 show a conventional process unit and an image recording device using the same, and FIG. 3 is a sectional view showing the configuration of a conventional image recording device and a process unit used therein. Fig. 4 is an explanatory diagram showing the state in which a conventional process unit is attached and removed from the main body of the apparatus, Fig. 5 is a perspective view showing the structure of a conventional process unit for recycling waste toner, seen through inside, and Fig. 6. is a plan view of FIG. 5;

Claims (1)

[Claims] 1. An image bearing member, a charging means for charging the image bearing member, a developing means for developing a latent image formed by exposing the image bearing member with an optical signal, and an image carrier. In a process unit in which at least two of the cleaning means for collecting residual waste toner on the image carrier are integrally configured, the arrangement of the cleaning means is located closer to the developing position than the latent image forming position of the image carrier. A process unit characterized by being located on the vessel side. 2. An image carrier, a charging means for charging the image carrier, a developing means for developing a latent image formed by exposing the image carrier with an optical signal, and a residual waste on the image carrier. In an image recording apparatus that has a cleaning means for collecting toner and records a visible image by transferring the toner image on the image carrier to a transfer material, the cleaning means is located at a position closer to the latent image forming position on the image carrier. , an image recording device characterized in that it is located on the side of a developing device.