JPS62203182A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the size, weight, and cost of an image forming device by providing an electrostatic charging device and a developing bias device and developing the exposed part of a photosensitive body with a single-component developer at a developing part while cleaning a single-component developer which remains on the photosensitive body. CONSTITUTION:The surface of the photosensitive body 18 is charged uniformly and electrostatically by the electrostatic charging device 20 to +900V as the photosensitive body 18 rotates. Then, the photosensitive body is exposed to laser light based on image information when reaching an exposure part 21a and the surface potential of the exposed part of the photosensitive body 18 is reduced to about +70V. Then, the photosensitive body reaches the developing device 22 and at this time, the photosensitive body is rotated as shown by an arrow (t) and slides on a coating blade 27 to coat the surface with toner 25. The potential difference in DC component between a developing roller 26 and the exposed part of the photosensitive body 18 is about 330V and large enough to scatter the toner 25 from the developing roller 26 to the exposed part of the photosensitive body 18, so the toner 25 is scattered from the developing roller 26 to the exposed part of the photosensitive body 18, so that the development of the photosensitive body 18 is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an image forming apparatus having a developing section that causes a one-component developer to fly onto a latent image in a non-contact manner.

[Conventional technology]

For image forming devices such as printers and electrophotographic devices,
Conventionally, a device as shown in FIG. 11 has been generally used.

That is, this device is a charging device i! provided around the photoreceptor drum (10). I (11), fla optical device (12),
Developing device (13).

While a copy image is formed on a transfer paper (16) by a transfer device (14), etc., a contact type cleaning device (17) consisting of a cleaning blade (17a) removes toner remaining on the photoreceptor drum (10) after transfer. The purpose of this is to remove the following.

However, in such a device, the developing section! (13
), it is necessary to install a cleaning device (17) at a position almost opposite to the cleaning device (17). Therefore, in the image forming process, the installation position of other devices such as the exposure bag RFI (12) and the transfer device (14) is limited. However, when cleaning, the cleaning blade (
Furthermore, the charging device (11) has the disadvantage that the surface of the photoreceptor drum (10) is worn due to sliding contact with the photoreceptor drum (17a), resulting in deterioration of characteristics and shortening of its lifespan. Ozone products are generated when charging is applied, but organic photoconductors of negative polarity (hereinafter referred to as OPC)
Because ozone products cause deterioration, it is necessary to immediately exhaust the ozone products generated in excess of necessary, but the problem is that the exhaust route is blocked by the cleaning device (17). There are also
Further, the toner collected in the cleaning device (17) must be disposed of, which makes maintenance complicated and causes staining of the surrounding area. For this reason, a device has been developed that uses a developing device to perform development in the first rotation of the photoreceptor drum, and then performs cleaning using the same developing device in the second rotation of the photoreceptor drum. Although such devices do not require a dedicated cleaning device, since the development process and cleaning process are performed separately, the circumference of the photoconductor drum is longer than the length of the image to be formed. This has the disadvantage that it prevents miniaturization of the body drum and thus of the entire apparatus. Furthermore, in recent years, as in Japanese Patent Application No. 58-32429 and Japanese Patent Application No. 58-7726, a single developing device has been developed that performs the developing process and the cleaning process at the same time. Since development and cleaning are carried out using a two-component developer containing toner and carrier, there are problems in that the developing device itself is large and heavy, and furthermore, it requires automatic toner, resulting in high costs. Yes. Furthermore, if the potential difference between the unexposed area of the photoconductor and the developing roller is increased too much in an attempt to ensure the recovery of residual toner, the carrier will have a polarity opposite to that of the toner, and will flow from the top of the developing roller toward the photoconductor. , and because the resistance of the carrier is lower than that of the toner, charges of opposite polarity to the toner are easily injected into the carrier due to a high electric field, which causes the carrier to adhere to the photoreceptor side, causing damage to the photoreceptor. There are also problems such as deterioration and deterioration of image quality.

[Problem that the invention seeks to solve]

Conventionally, the cleaning device for the neck of one image forming bag had to be installed at a position almost opposite the developing device, which created constraints in the design of the device, reduced the degree of freedom in design, and ultimately reduced the size and cost of the device. It's getting in the way. Furthermore, if a cleaner that generates recovered toner is provided, it is necessary not only to replenish toner but also to dispose of the recovered toner once, which is the biggest cause of complicating maintenance.

For this reason, recycling methods have been carried out in which the collected toner is returned to the actual genitals, but this method is complicated and increases costs. There is also a method of storing the collected toner in a cleaner, but this method has drawbacks such as high cost, increased device size, and increased toner consumption.

On the other hand, in a device that is different from the above-mentioned device and performs the developing process and the cleaning process simultaneously using the same developing roller, conventionally it is intended for two-component developers, and the developing device itself is They tend to be heavier and larger, and there are also restrictions on the settings of the voltage applied to the charging device and developing roller, and if the potential difference is too large, carriers with the opposite polarity to the toner will fly, resulting in image staining. There is also.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and it eliminates the need for a dedicated cleaning device in a device using a one-component developer, improves the degree of freedom in designing the device,
In turn, making the equipment smaller and lighter; improving efficiency and reducing costs;
A further object of the present invention is to provide an image forming apparatus that can prevent deterioration of the photoreceptor, extend its life, and obtain clear images.

[Means for solving problems]

In order to solve the above problems, the present invention applies a developing bias that causes the latent image toner on the photoreceptor to fly from the developing roller and at the same time causes the residual toner to fly from the charged photoreceptor surface to the developing roller side. A developing device equipped with a developing roller that performs a developing process and a cleaning process simultaneously without contact is provided.

[For production]

Toner remaining on the photoconductor can be reliably removed without the need for a dedicated cleaning device, allowing clear images to be obtained and design constraints being removed, making the device smaller and lighter, which in turn reduces cost. I can do it. Further, since only toner needs to be replenished and there is no need to dispose of collected toner, maintenance efficiency is greatly improved.

〔Example〕

6 Image forming apparatus main body A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Positive polarity O for laser with diameter 30 (on) inside (not shown)
Around the photoreceptor (18), which is an image carrier made of PC,
A charging device (20) that charges the surface of the photoconductor (18) to about +900 (Vl), an exposure section (21a) that is irradiated with laser light according to image information by an exposure device (21), and development of the photoconductor (18). A developing device (22), a negative transfer charger (23), and a static elimination lamp (24) are provided in this order.A charging device (20), an exposure portion (21a),
The developing device (22) is housed in the unit (19), and the developing device (22) has a housing (22a).
Toner (25), which is a non-magnetic one-component developer, is supplied from a toner hopper (22b) in ) to a developing roller (26).

The developing roller (26) has a diameter of 16 [mm] and is made of an aluminum sleeve that has been sandblasted and electroless plated with nickel to increase its surface strength and has a surface roughness of 0.1 to 5 [μs]. The photoreceptor (18) and about 2
They are provided with a gap of 50 [μm] interposed therebetween. The developing roller (26) also includes a coating blade (27) for coating the toner (25), and a collection blade (2) for collecting the toner (25) after development.
8) Furthermore, there is a stirring roller (
30) are in sliding contact. Furthermore, to the developing roller (26).

The power supply (31) provides a DC voltage of +400 (V), a frequency of 2 (KHz), and a peak-to-peak of 1.6.
(KV) AC voltage is applied. Furthermore, (32) is
This is a window formed in the unit (19) to pass the laser light from the exposure device (21), and (33) is a transfer paper.

Next, we will discuss the effect. When copying is started as shown in the timing chart of FIG.

In order to make a first copy, the photoreceptor (18) is rotated in the direction of arrow S, the static elimination lamp (24) is turned on, and then each image forming apparatus is operated. That is, as shown in FIG. 3, as the photoreceptor (18) rotates, the surface of the photoreceptor (18) is uniformly charged to +900 (V) by the charging device (20). Next, when it reaches the exposed part (21a), it is exposed to laser light according to the image information, and the surface potential of the exposed part of the photoreceptor (18) is reduced to about +70 (V). Thereafter, it reaches the developing device (22), at which time it is rotated in the direction of the arrow and the toner (25) is coated on its surface by sliding contact with the coating blade (27). At that time, the toner has the same polarity as the photoreceptor (18), and in this case, the developing roller (26), which is positively charged, is charged with a bias voltage of +
A direct current voltage of 400 (V) is applied, and the toner (25) is vibrated and easily blown away by the application of an alternating current voltage. Moreover, the developing roller (2G) and photoreceptor (18)
The DC potential difference of the exposed part is about 330 (V),
Toner (25) is transferred from the developing roller (26) to the photoreceptor (18).
) As shown in FIG. 4, the toner (25) is flown from the developing roller (26) to the exposed area of the photoreceptor (18), and the gl of the photoreceptor (18) is ,
Then, the toner image on the photoreceptor (18) is transferred to a transfer paper (33) by a negative transfer charger (23). After this, the transfer paper (33) is discharged to the outside of the main body via a fixing device (not shown), while
The entire surface of the photoreceptor (18) is irradiated by the static elimination lamp (24), the image forming process for the first copy is completed, and the second copy is started. However, at this time, there is still toner remaining on the photoreceptor (18), but this residual toner (2
5a) is only about 10% of the toner amount during development, and even when the second copy is being made, it does not have any adverse effect on the charging process and exposure process. Therefore, the third
As shown in the figure, as the photoreceptor (18) rotates, the charging device (20)
8) is all + including the part with residual toner (25a)
The exposed area (21a) is uniformly charged to 900 (V) and
The surface potential of the unexposed area is +900 (V) regardless of the presence or absence of residual toner (25a).
while the surface potential of the exposed area is approximately +70 (V).
will be reduced to The reason for this is that during exposure, the laser beam removes residual toner (
When fully irradiated to the bottom of 25a) and charged.

This is because the excessive charge on the residual toner (25a) leaks due to a decrease in the resistance of the photoreceptor (18) under the residual toner (25a). When the photoreceptor (18) reaches the developing device (22) in this state, the developing roller (2G) and the photoreceptor (18)
) The potential difference in the fa light area becomes approximately 330 (Vl), and the toner (25) on the developing roller (26) is flown to the exposed area of the photoreceptor (18), and the photoreceptor (18) is developed.

Even if there is residual toner (25a) in the exposed area, this residual toner (25a) is buried by new developed toner (25). On the other hand, at this time, the DC potential difference between the unexposed area of the photoreceptor (18) and the developing roller (26) is about 500.
(V), as shown in FIG. The remaining toner (25a) on the second copy image is cleaned, and no fogging occurs on the second copy image.

Then, the photoreceptor (18) on which the development for the second copy and the cleaning for the first copy were simultaneously performed by the developing device (22) is transferred to the negative transfer charger ( After the transfer is performed by step 23), the charge is removed by a charge removal lamp (24) and the next copy is started. Thereafter, the above steps are repeated to make the required number of copies, and when the final copy is completed, the exposure device (21) and negative transfer charger (23) are stopped as shown in FIG. However, the charging device (20)
and the static elimination lamp (24) continue to operate, while in the developing device (22), the DC component of the power supply (31) is set to zero and only AC voltage is applied to clean the photoreceptor (18). It will be done. That is, as shown in FIG. 3, as the photoreceptor (18) rotates, the surface of the photoreceptor (18) is uniformly charged to +900 (V) by the charging device (20). Next, the photoreceptor (18) reaches the developing device (22) without being exposed, and since no DC bias voltage is applied to the developing roller (26), the photoreceptor (18) reaches the developing device (22) without being exposed.
) and the developing roller (26), the DC potential difference is approximately 90
0 (Vl), and the residual toner (25
a) are all flown toward the developing roller (26) and cleaned. Then, the photoconductor (18) is connected to the static elimination lamp (2).
4), A (F main device (20), @ image device (
22) The static elimination lamp (24) and photoreceptor (18) are stopped, and all steps are completed.

With this configuration, the developing device (22) can remove the residual toner (25) at the same time as the development, without having to provide a dedicated cleaning device in the lit that is almost opposite to the developing device (22).
Since a) can be reliably removed, the degree of freedom in design is improved, the device can be made smaller and lighter, and the charging device i! (20) The exhaust path of the ozone products generated by the ozone product is not obstructed, and there is no fear that the ozone products will degrade the ozone product even when a negative polarity OPC or the like is used, for example. Furthermore, there is no need to dispose of the removed toner in the developing device as in the conventional case, and its maintainability is improved.

On the other hand, compared to an apparatus that uses a two-component developer and performs a developing process and a cleaning process at the same time, it is possible to reduce the size and weight of the developing apparatus and the main body of the image forming apparatus, and to prevent the carrier from flying toward the photoreceptor. No photoreceptor (18
) A clear copy image can be obtained without the risk of deterioration or staining of the image.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 7. Note that the same parts as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

This device has a DC power supply (3
6) to which +500 (V) of the same polarity as the toner is applied, and the non-patterning device 1 consists of a non-patterning roller (37) made of a roller-shaped acrylic brush with a length of 4 [m].
(3g), and its static eliminator (4g).
0) is used together with a static elimination lamp (24) to ensure that the surface potential of the photoreceptor (18) and the charge of the residual toner are zero.
An AC voltage is applied by an AC power supply (42) connected to a 0.2 [μF] capacitor (41), and it is composed of a static elimination charger (43) that discharges the positive and negative coronas evenly. Note that (44) is a mirror that irradiates the photoreceptor (18) with light from the static elimination lamp (24).

However, in this lever device, the steps from charging to transfer are carried out in exactly the same way as in the first embodiment, and the charge removal device (40) is reached, but at this time, the surface potential of the photoreceptor (18) is As shown in FIG. 6(a), the surface potential of the photoreceptor (18) varies depending on the atmosphere, the thickness and material of the transfer paper (33), etc.6. remains the same as when charged, but the exposed area is increased by about 100 (V) from the exposed area due to the adhesion of toner (25). During transfer, if the amount of negative charge that flows into the photoreceptor (18) through the transfer paper (33) is small, then depending on the type of transfer paper (33), as shown in Fig. 6 (
As shown in b), the entire surface potential of the photoreceptor (I8) only decreases, whereas the photoreceptor (I8) through the transfer paper (33)
8), the surface potential of the photoreceptor (18) is reversed to negative polarity as shown in FIG. 6(c) depending on the type of transfer paper (33). Therefore, the photoreceptor (18)
The static eliminator (40
), but the static eliminator (48) uses the static eliminator lamp (24) and #charger (43) together, and the AC power source (42) of the static eliminator (43) is connected to the capacitor (41). The photoreceptor (18
) so that it is always 0 [V], so regardless of whether the surface potential of the photoreceptor (18) is in the state shown in FIG. 6(b) or (c), the photoreceptor (18) and the residual Toner (25
a) will definitely reduce the charge to zero. As a result, the residual toner (25a) is not bound by the photoreceptor and reaches the non-patterning device (38) in a highly mobile state. Then, the residual toner on the photoreceptor (18) is brought into sliding contact with a non-patterned roller (37) rotating in the direction of arrow U, and the remaining toner on the photoreceptor (18) changes from the state of 7th [1l(a) to the state of FIG. In this state, the next new image forming process is started.

Moreover, at this time, the non-patterned roller (37) has +50
Since a voltage of 0 [V] is applied, there is no possibility that the residual toner (25a) will adhere to the non-patterned roller (37) due to the electric charge generated by frictional charging.

With this configuration, after the residual toner (25a) is collected by the developing device (22), even if some residual toner (25a) remains on the photoreceptor (18), it will become a temporary afterimage on the next copy and will affect the resolution of the image. There is no influence,
It is possible to keep the amount of fogging to a certain extent as a whole. Furthermore, by applying a positive voltage, the non-patterned roller (
37) is free from residual toner (25a) and the non-patterned roller (37) is replaced.

There is no need to dispose of collected toner, and maintainability is not compromised.

It should be noted that this invention is not limited to the above-mentioned embodiments, and can be modified in various ways. For example, the photoreceptor (18) and the developing roller (26)
The gap between the two is arbitrary as long as the development process and the cleaning process are possible, but it is preferably 150 to 5.
The developing device is not limited to that of the present invention, but any non-contact developing device that performs development and cleaning at the same time can be used for experiments for the same purpose. For example, even if magnetic toner is used, the same condition can be achieved only by changing the conditions due to magnetic force.

In addition, the electrification level of the photoconductor, the potential of the exposed part, the magnitude of the developing bias, etc. are arbitrary, but in order to satisfy the image density of development, the conditions for recovering residual toner, or the prevention of fogging due to toner of opposite polarity, etc. For example, in the above embodiments, the following ranges are preferable.

In other words, in order to obtain sufficient image density, the following [inequality 1] is used.
It is preferable that the DC voltage of the developing bias and the photoreceptor potential of the exposed portion satisfy the following conditions.

(DC voltage of developing bias) - □□□ Photoconductor voltage in the light section ≧ Electric power to obtain continuous image density D = 250 (V
] (Inequalities 1) This [Inequalities 1] is determined from the developing characteristics of the developing device, but as in the example, the exchange of developing bias is frequency 2 (Kllz), voltage 1.6 [KV],
When the toner charge is 10 [μq/g], the development characteristics are as shown in FIG. 8, and if the sufficient image density is 1.3, [Inequality 1] is obtained. Incidentally, when the voltage or frequency of the alternating current of the developing bias is further increased, the rise of the developing characteristics shown in FIG. 8 is further accelerated, so that the potential difference for obtaining an image density of 1.3 is further reduced.

Next, in order to obtain the conditions for recovering the residual toner, it is preferable that the charging position of the portion having the residual toner which satisfies (inequality 2) shown below is in the 4th position and the DC voltage of the developing bias.

(5) Charging of the part with residual toner ω - (DC voltage of developing bias) ≧ Potential difference to obtain a reasonable toner recovery rate) =
250 (V) (Inequalities 2) This [Inequalities 2] is the 9th
This is determined from the toner recovery characteristics shown in the figure, and is when the sufficient toner recovery rate is set at the limit of 50%, which is almost a practical level.Ideally, the larger the potential difference, the better. The conditions generally depend on the amount of residual toner, and as the amount of residual toner increases.

The potential difference in [inequality 2] must be increased. For this reason as well, it is advantageous to disperse the residual toner by non-patterning. In [Inequality 2], residual toner can be recovered if the voltage is approximately 250 (V) or higher, but if the potential difference on the left side becomes too large, the oppositely charged toner (in this case, negatively charged) can be collected on the photoreceptor. Fogging occurs when the toner flies to the photoreceptor, or when the potential difference becomes even larger, charges are injected into the positive donor due to a strong electric field and the toner becomes negative toner, causing the toner to fly toward the photoreceptor. The former occurs at a relatively low potential difference, but this does not pose a problem since there is usually a small amount of toner of opposite polarity. or,
According to experiments, the latter does not cause any problems even at 800 [V].
If it was less than that, there would be no problem at all. Therefore, the developing bias etc. may be set so as to simultaneously satisfy each of the above conditions.

Furthermore, the timing of the operation of each device is arbitrary. For example, if the cleaning process after the final copy is not performed as shown in the example, all the devices may be stopped after the final copy is completed, but the timing of the operation of each device is arbitrary. By providing a process that only performs cleaning, it is possible to improve the recovery rate of residual toner on the photoconductor, improve image quality without causing fogging, and reduce exposure to light caused by toner adhesion for a long time. It is possible to prevent deterioration of the body and extend its lifespan. During this cleaning process, in order to improve the cleaning effect, in the embodiment, the DC component of the developing bias was lowered compared to the normal copying time, but compared to the normal copying time, the a? )
A similar effect can be obtained by increasing the FIA level or increasing the voltage or frequency of the b-developing bias alternating current. Also, this process is not only used when cleaning, but also when a single paper gets jammed.

By performing this before starting the next copy in the event of an emergency stop, it is also effective for collecting untransferred toner remaining due to the emergency stop. Furthermore, the structure of the device for non-patterning the residual toner is arbitrary.

Any type of charger (43) may be used as long as it does not allow residual toner to adhere to the device.
) Instead, if a static elimination charger to which a larger AC voltage is applied is used to not only eliminate static electricity but also move the residual toner (25a) by vibration, it is not necessary to use a non-patterned roller (37). It is possible to perform non-patterning without contacting the photoreceptor at all, prolonging the life of the photoreceptor, and completely preventing toner staining in the non-patterning device. Furthermore, as in the other modification shown in Fig. 10, approximately 100 (V) is generated by the DC power supply (47a).
If a non-patterned device (47) is used that slides into contact with the photoreceptor (18) a conductive brush (47b) made of rayon with carbon (C) dispersed in rayon with a resistor of 101o (Ω) or less to which a voltage of Photoreceptor (18) by sex brush (47b)
Since the residual toner (25a) is de-patterned at the same time as the residual toner (25a) is destaticized, there is no need to provide a separate destaticizing device. The conductive brush (47b) may be a roller brush, and its resistance value may be sufficient as long as excess charge from the photoreceptor (18) and residual toner (25a) flows. Also, in this modification, the conductive brush (47b) is connected to the DC power source (47a).
, a low voltage of the same polarity as the residual toner (25a) is applied, and the residual toner (25a) is transferred to the conductive brush (4).
7b) and remains on the photoreceptor (18). These non-patterning means may be provided anywhere from after transfer to before development, and may be provided anywhere as long as it does not disturb the electrostatic latent image. However, if there is a large amount of toner remaining after transfer or if there is a problem due to paper jams, etc., charging may result in too much toner being collected during development. Therefore, it is advantageous from this point of view to perform non-patterning before charging, and it is desirable to provide this means after the transfer is completed and before reaching the charging device.

〔Effect of the invention〕

As explained above, according to the present invention, the developing process and the cleaning process can be performed simultaneously without contact using a single roller. Since there is no need to install the device in the charging device, space is saved, design constraints are removed, and the degree of freedom during design is improved, making it easier to reduce the size and weight of the device. The product exhaust path is not blocked by the cleaning device, and deterioration of the photoreceptor can be prevented, and the life of the photoreceptor can be extended. Furthermore, it is no longer necessary to dispose of the toner collected in the cleaning device, which greatly improves maintainability and prevents staining of the surrounding area. Further, the cleaning process can be performed in a non-contact manner, and in that case, wear on the photoreceptor is prevented compared to a contact type cleaning device.

Moreover, since the developer used is a one-component developer, compared to one using a two-component developer, the developing device can be made smaller, lighter, and cheaper, and furthermore, the carrier can fly away. Development and cleaning can be performed reliably and high-quality images can be obtained without causing deterioration of the photoreceptor or staining of the image caused by such problems.

[Brief explanation of drawings]

1 to 4 show a first embodiment of this invention,
FIG. 1 is a schematic configuration diagram, FIG. 2 is a timing chart, FIG. 3 is an explanatory diagram showing the image forming process, FIG. 4 is an explanatory diagram showing the principle of toner flight, and FIGS. The figures show a second embodiment of the present invention, FIG. 5 is a schematic diagram thereof, FIG. 6(a) is a graph showing the surface potential of the photoreceptor before transfer, FIG. 6(b), c) is a graph showing the surface potential of the photoreceptor after the transfer, FIG. 7(a) is a plan view showing the residual toner immediately after the transfer, and FIG. 7(b) is a graph showing the residual toner after non-patterning. 8 and 9 show the characteristics of the embodiment of the present invention, FIG. 8 is a graph showing the developing characteristics of the developing device, and FIG. 9 is a graph showing the toner recovery characteristics of the developing device. FIG. 10 is a partial sectional view showing a non-patterning device according to another modification of the present invention;
FIG. 11 is a schematic configuration diagram showing a conventional device. 18... Photoreceptor (image carrier), 20... Charging device. 21... Exposure device, 22... Developing device, 23... Negative polarity transfer charger, 24... Static elimination lamp, 25... Toner, 26
...Developing roller, 31...Power source, 33...Transfer paper, 38...Non-patterning device. Agent Patent Attorney Inoue - Male Figure 1 Rin 4 Zugo Figure 6 <ct) tb) Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (11)

[Claims] (1) In an image forming apparatus having a developing section that performs non-contact development on a photoreceptor using a developing roller using a one-component developer, the photoreceptor that holds the residual developer after transfer is the same as the one-component developer. A charging device that charges the polarity, and the one-component developer is ejected from the developing roller to the exposed portion of the photoreceptor, and the residual developer on the unexposed portion of the photoreceptor is ejected to the developing roller. The developing roller is equipped with a developing bias device that applies a voltage of the same polarity as that of the one-component developer, and the developing section cleans the one-component developer remaining on the photoreceptor and at the same time cleans the exposed portion of the photoreceptor. An image forming apparatus characterized by developing with a one-component developer. (2) The image forming apparatus according to claim 1, wherein the developing bias is a voltage obtained by superimposing an alternating current voltage and a direct current voltage. (3) A non-patterning device is provided that moves the one-component developer remaining on the photoreceptor while it reaches the developing roller after the transfer is completed and does not substantially collect the remaining developer. The image forming apparatus according to any one of the ranges 1 and 2. (4) The image forming apparatus according to claim 3, wherein the non-patterning device is provided after the transfer ends and before reaching the charging device. (5) According to either claim 3 or 4, the non-patterning device includes a brush that is applied with a voltage of the same polarity as that of the one-component developer and slides into contact with the photoreceptor. image forming device. (6) The non-patterning device is A. C. Claim 3 or 4, characterized in that it consists of a corona charger.
The image forming apparatus according to any one of the items. (7) The image according to any one of claims 1 to 6, wherein the charging device and the developing section operate even after image formation is completed, and the developing section only performs cleaning of the photoreceptor. Forming device. (8) In an image forming apparatus having a step of simultaneously performing a developing step of attaching a developer to a latent image formed on the image carrier and a cleaning step of removing the developer from the image carrier, the image carrier An image forming apparatus comprising a non-patterning step for moving residual developer. (9) Image forming according to claim 8, wherein the image forming apparatus has a charging process, a latent image forming process, and a developing cleaning process, and the non-patterning process is performed before charging. Device. (10) The image forming apparatus according to claim 8 or 9, wherein the non-patterning step does not substantially collect the developer. (11) The image forming apparatus according to any one of claims 8 to 10, wherein the developer is a one-component developer.