JPS6380287A - Developing and cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To prevent ground fogging, ground contamination, a ghost, etc., and to obtain an image having a high quality by providing a guidance device for moving a transfer residual powder to a non-latent image area for holding the high potential of a photosensitive body, before a develop- and cleaning process. CONSTITUTION:At the time of cleaning, a transfer residual powder is guided to the high potential part of a photosensitive body, and due to a potential difference between the surface potential of the photosensitive body and a developing bias, the transfer residual powder can be collected easily to a developing roller. That is to say, the transfer residual powder 45 on the photosensitive body 32 is guided to a non-latent image area 32b having a high potential before reaching the developing roller 42, therefore, simultaneously with the developing process of a latent image by the developing roller 42, the transfer residual powder 45 is collected easily and exactly to the developing roller 42 and cleaned due to the potential difference of the developing bias and the non-latent image area 32b, and ground fogging and a ghost, or contamination, etc., caused by the transfer residual powder 45 can be prevented.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Field of Application) The present invention relates to a process for developing an electrostatic latent image formed on a photoreceptor by the same developing row in a laser printer, a copying machine, etc. The present invention also relates to an improvement in a developing cleaning device in an image forming apparatus that simultaneously performs a cleaning process for powder remaining after transfer on a photoreceptor.

(Prior Art) Generally, in copiers, laser printers, etc. that use an electrophotographic recording process, the photoreceptor is used repeatedly. a transfer step in which the image is transferred to a transfer member;
A photoconductor cleaning step is provided to remove powder remaining after transfer on the photoconductor during an electrostatic marking forming step in which an electrostatic latent image is formed on the photoconductor by charging and exposing the photoconductor.

For example, FIG. 8 is a schematic explanatory diagram of a first conventional laser printer. In this laser printer, the photoreceptor 2 is uniformly negatively charged by the charging charger 6, while being scanned by the polygon mirror 4. Laser beam 1'B
is focused and exposed onto the photoreceptor 2 by the Fθ lens 3, and the power supply is turned on and off as in the case of semiconductor laser light.
The charge on the photoreceptor 2 is attenuated by exposure, and an electrostatic latent image is formed.

This electrostatic latent image on the photoreceptor 2 can be formed by applying a predetermined developing bias to the developing sleeve 19 of the developing device 5.
The developed powder image developed by the developing device 5 is transferred onto the transfer member P by the transfer charger 11 and fixed onto the transfer member P by the fixing device 13.

On the other hand, the transfer residual powder remaining on the photoreceptor 2 without being transferred to the transfer member P by the transfer charger 11 is removed from the photoreceptor 2 by the cleaning blade 17 of the cleaning device 16 .

The thus cleaned photoreceptor 2 is de-charged by the static elimination lamp 7 and charged again by the charger 6, so that the above-described image forming process can be continued.

FIG. 9, FIG. 10, and FIG. 11 show each conventional process when viewed from the top of the process of repeatedly using a photoreceptor.

In Figure 9, the flow of ■ → ■ → ■ → (to) → ■ → 0 → ω is a type that develops by adsorbing powder with the opposite polarity to the charged part of the electrostatic latent image on the photoreceptor. , that is, it shows the process of repeated use of the photoreceptor in the regular development process.

In Figure 10, ■→■→(3)→)→■→0→■
This flow indicates a type in which powder having the same polarity as the high potential area is adsorbed to the exposed part of the electrostatic latent image on the photoreceptor for development, that is, a two-component reversal process in which the photoreceptor is used repeatedly.

In Fig. 11, the flow of ω→■→■→)→■→0→0) induces or injects charges from the developing roller into the one-component powder in the electrostatic latent image discharge area of the photoreceptor, and this This shows a type in which a charged one-component powder is adsorbed and developed, that is, a one-component reversal development process using a photoreceptor.

As is clear from these three examples, in order to use the photoreceptor repeatedly, it is necessary and essential to remove the transfer residual powder on the photoreceptor from the photoreceptor after the transfer process.

In fact, in the regular development process shown in Fig. 9, if the cleaning step ■ is omitted and the static electricity removal step is directly performed, the result is α)′→■
In the process of repeatedly using the photoconductor from ′→■→0)→(6)′→■′→, the powder remaining after transfer is charged in the charging process.
After that, when exposed to light, the charged powder remaining in the exposed area will be cleaned during development even if it goes to the development step (3) because the afterglow potential of the photoreceptor after exposure and the development bias are almost the same. It remains as it is and is transferred to the transfer member in the next transfer step (a), causing development deterioration such as ghost images, ground blur, and background smudges.

Furthermore, even in the reversal development process using two-component and one-component developers shown in FIGS.
→■'→■→Ω)→0'→■' In the process of repeatedly using the photoreceptor, the transferred charged powder remaining on the charged part of the electrostatic latent image after passing through exposure ■' is removed in the developing step ■. Since the developing bias VB is set to be approximately equal to the surface potential Vo of the charged portion of the photoreceptor, the toner remains without being cleaned and is transferred to the transfer member in the transfer step 0) in the same manner as in the case of FIG. It is clear that this is also a factor in image deterioration.

Therefore, in the process of repeatedly using the photoconductor as shown in FIGS. 9, 10, and 11, the transfer process (to) and the charging process α
) It becomes essential to provide a cleaning process for the photoreceptor between the two steps.

However, providing such a cleaning device causes the problem that the cleaning device must be installed, which requires a large volume of space, and therefore the recording device becomes large.

In order to overcome such drawbacks, a second conventional example omitted the cleaning device, - During the image forming process, the photoreceptor is rotated twice, the developing bias is changed every two rotations, and the developing process is completed every rotation. A device has been created that uses the developing device that was responsible for this as a cleaning means. FIG. 12 shows this process of repeatedly using the photoreceptor.

In Figure 12, the photoreceptor rotates approximately - at the stage of (g)→■→■→)→0, and in the next approximately one rotation, the cleaning process of (g)→0→■ is performed. .

In FIG. 12, the photoreceptor is uniformly negatively charged in the charging step (g) and has a surface potential Vo. It is exposed in the exposure step (2) to form an electrostatic latent image. In the developing step (2), a developing roller biased to a potential that is approximately the same as or slightly higher than the residual germ potential of the exposed discharge area of the photoreceptor adsorbs powder of opposite polarity to the charged area of the electrostatic latent image. develop. In the transfer step 6), the developed powder image is transferred to a transfer member by a transfer charger. Thereafter, in a static elimination process 0, the photoreceptor is electrically neutralized by a static elimination light and a static elimination charger.

Here, the photoreceptor rotates approximately once. After that, the bias VB of the developing roller is set between O<Va<Vo. Here, the developing roller transforms into a cleaning means and removes the transfer residual powder on the photoreceptor from the photoreceptor.

In this way, two rotations of the photoreceptor form one recorded image. However, in the process of repeatedly using such a photoreceptor, the circumference of the photoreceptor must be at least the length of one recorded image. In other words, if the circumference of the photoreceptor is shorter than the length of one recorded image, when the leading edge of one recorded image on the photoreceptor reaches the developing roller position, the rear end of the photoreceptor of one recorded image is still in the developing process. Since the developing roller cannot function as a cleaning means, the transfer residual powder at the leading end of the photoreceptor of one recorded image is not cleaned by the photoreceptor.

Therefore, it has the disadvantage that the circumference of the photoreceptor, that is, the outer diameter, has to be increased, and at the same time, one of the two rotations
Since the rotation must be used as a Hf1S process, the photoreceptor usage efficiency is only 50%, which is extremely poor. For this reason, there are problems such as having to slow down the speed and changing the bias of the developing roller.
There are problems such as the need to prepare two bias power supplies. Further, in an electrophotographic apparatus using a reversal development process using a two-component developer, a cleaning process is provided between the transfer process and the charging process as shown in FIG. 8, following the example described in the explanation of the conventional example above. The photoconductor has been cleaned.

In addition to the above-mentioned drawbacks, the structure of the conventional electrophotographic recording apparatus also has the following problems.

First, since the cleaning device occupies a certain volume, there is a restriction on the conveyance path of the transfer member. For example, as shown in FIG. 8, the transfer path of the transfer member is a straight bus for the reasons mentioned above.

Therefore, when a transfer member is jammed in the apparatus, there is a problem in that in order to remove the jammed transfer member, the transfer member must be separated vertically with the conveyance path as a boundary.

Moreover, the position of the cleaning means as shown in FIG. 8 is an ideal position for the cleaning means, and therefore the conveyance path of the transfer member must also be a straight path. Further, since the insertion direction of the transfer member and the direction of ejection of the transfer member are below the machine body and in completely opposite directions, this is extremely inconvenient for use as a component device of a system device such as a laser printer, for example. This is because a worker sitting facing a CRT display can discern the printed content from his/her sitting position, and furthermore, all equipment can be placed with their back to the wall, so systems such as word processors are This is because it is one of the characteristics required as a matter of course for a vessel. Therefore, in order to compensate for the above drawbacks, a third conventional example of a device as shown in FIG. 13 has been developed.

That is, this device includes a photoreceptor 211 rotating charger 22
, an exposure section 23, a development and cleaning device 24 that performs the development process and cleaning (Φ process) at the same time, and a transfer charger 26, etc., are provided, and an electrostatic latent image is formed through the charging process and exposure process during continuous image formation. When the photoreceptor 21, on which transfer residual powder from the previous image formation has been deposited, reaches the developing and cleaning device 24, the electrostatic latent image is developed on the photoreceptor 21 by the developing roller 27. Removal of transfer residual powder will be performed at the same time.

That is, after the first image forming process is completed, the photoreceptor 21 to which the remaining transfer powder is attached is charged with -V by the charging charger 22.
O is uniformly charged, and then an electrostatic latent image is formed in the exposure section 23, but at this time, even if transfer residual powder is attached,
If the transfer efficiency at the time of transfer is about 80%, the coverage of the photoreceptor 21 by the powder remaining after transfer is very small.Moreover, since the powder particles are about 10[JJIn], for example,
Even if the laser beam is aimed at the zero spot, a sufficient electrostatic latent image can be formed on the photoreceptor 21. At this time, the developing roller 27 to which a bias voltage of approximately V o / 2 is applied is in fixed contact with the magnetic brush, and powder is applied to the electrostatic latent image to perform development. is collected by a magnetic brush and cleaned.

However, in such a device, when charging by the transfer charge p22, a large amount of charge 22a is generated on the powder layer 2 at the part where the transfer residual powder is attached, as shown in FIG.
8 cannot pass through, and the charge at that part is the normal 1
/2. In this case, if a scorotron charger that has the ability to control the surface potential of the photoreceptor 21 is used, the remaining transfer powder layer and the surface of the photoreceptor are held at almost the same surface potential, but if a scorotron charger that has the ability to control the surface potential of the photoreceptor 21 is used, If a tron charger is used, the untransferred powder layer 28 will have a very high potential compared to the surface of the photoreceptor. However, no matter which type of transfer charger is used, the photoreceptor 21 is difficult to be charged at the part where the transfer residual powder is attached, and its surface potential is only about the same level as the developing bias. Cleaning is performed on the surface of the photoreceptor to which the transfer residual powder is attached, and on the developing bias -Vo/2.
The untransferred powder is collected toward the magnetic brush side not by a direct potential difference between the magnetic brush and the magnetic brush, but by the electrical charge around the transferred untransferred powder when the magnetic brush comes into sliding contact with the magnetic brush and the potential difference between the magnetic brush and the untransferred powder. For this reason, the collection of transfer residual powder by the magnetic brush is not perfect, and if image formation is performed continuously, some powder may remain even after cleaning, causing fog, ghosts, or background smudges on the image. , there is a problem that the image quality is degraded.

(Problems to be Solved by the Invention) Conventionally, the surface of the photoreceptor is difficult to be charged in the area where the transfer residual powder is attached, and when the developing process and cleaning process are performed simultaneously, the developing bias is The potential difference between the surface potential of the photoreceptor to which the transfer residual powder is attached is small, and the transfer residual powder is difficult to be collected by the developing roller. For this reason, image quality is reduced by 3E due to ghosting, fogging, etc., and in order to obtain clear images, it is necessary to use other special techniques (hanging means), and measures such as downsizing the device or simplifying maintenance must be taken. This poses an obstacle in terms of ease of use.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and uses a developing cleaning device that simultaneously performs the developing process and cleaning (hanging process) using the same developing roller without using any other cleaning means, making it possible to sufficiently remove the untransferred powder. An object of the present invention is to provide a developing and cleaning device for an image forming apparatus, which can improve image quality while maintaining compactness and ease of handling.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention moves the untransferred powder to a non-latent image area of the photoreceptor that maintains a high potential before the development and cleaning process that is performed at the same time. It is equipped with a guidance device for folding.

(Function) The present invention uses the above-mentioned means to guide the transfer residual powder to the high potential part of the photoreceptor during cleaning, and remove the transfer residual powder by the potential difference between the surface potential of the photoreceptor and the developing bias. It is designed so that it can be easily collected on the developing roller, and cleaning can be reliably performed at the same time as development using only the developing cleaning device without using any other cleaning means, and as a result, image quality can be improved and the device can be made more compact. .

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. In the figure, 31 is a housing, 32 is a photoreceptor which is an image carrier having a latent image area 32a where an electrostatic latent image is formed and a non-latent image area 32b which does not contribute to image formation.
A charging charger 33 for uniformly charging the photoreceptor 32 to -Vo, an exposure section 34, a developing cleaning device 436, a transfer charger 37, a paper charger 38, and a charger lamp 39 are arranged around the photoreceptor 32. It is set up. The developing cleaning device 36 has a built-in magnet roller (not shown), and has a developing bias Vn (similar to Vt5=
A developer 4 consisting of a sleeve to which Vo/2) is applied and consisting of negatively charged colored powder and xeria.
This is a guide device that is pressed against the photoreceptor 32 in front of the developing roller 42, which forms a magnetic brush 41 by adhering 0 to the periphery of the developing roller 42.
5 to the non-latent image area 32b.
3 is provided. However, this urethane blade 43
has a hardness of 60 [degrees], and as shown in FIG.
The angle φ1 with the photoconductor 32 is about 20[degrees], while the angle φ2 with respect to the longitudinal direction of the photoconductor 32 is about 25[degrees], and its width is about jO[%]. The biting depth at the end of the urethane blade 43 for pressure welding is approximately 1.8[
#] is said to be. Further, 44 is an FQ lens, 46 is a polygon mirror, 47 is a storage container for the transfer member P, 48 is a paper feed roller, 49 is an aligning roller, 51 is a fixing device, 5
2 is a laser beam, and 53 is a paper discharge tray. In this device, the circumferential speed of the photoreceptor: 6B, 0 [m/sea
], photoreceptor diameter: 60.0 [#], and laser power on the photoreceptor: 3.5 [mW].

Next, we will discuss the operation. When printing is started, the photoreceptor 32, developing roller 42, each roller, etc. are operated by the drive motor as shown in FIG. Charger 3 at the same time
3 and the static elimination lamp 39 are turned on.

The photoreceptor 32 is then rotated at a rotational speed of W radian/sec, and is uniformly charged to -Vo over the entire surface of the latent image area 32a and non-latent image area by the charging charger 33, and then scanned by the polygon mirror 46 in the exposure section 34. A negative electrostatic latent image is formed in the latent image area 32a by the laser beam 52. After this, the photoconductor 32 reaches the developing and cleaning device 36, and its surface is first firmly attached by the urethane blade 43, but at this time, the transfer residual powder 45 is not attached to the latent image area 32a, and the photoconductor 32 is It reaches the developing roller 42 as it is. Since the urethane blade 43 is insulative, the electrostatic latent image formed on the photoreceptor 32 is not disturbed at all. Also, after the charger 33 is turned on, θ1/W [seconds] (θ1 is the charger 33
and the developing roller 42), then the developing roller 4
2, a developing bias Va is applied. Therefore, as the photoreceptor rotates, the magnetic brush 41 around the developing roller 42
Coloring powder is applied to the electrostatic latent image and developed. - The transfer member P is sent out from the storage container 47 toward the aligning roller 49 by the paper feed roller 48 in synchronization with the image on the photoconductor 32. Further, the transfer member P moves to the double transfer position registered to the aligning roller 49. Then, when the transfer member P reaches the image transfer position, that is, after the development bias Va is applied, θ3/W [seconds] (
(θ3 is the phase difference between the developing roller 42 and the transfer charger 37) After the elapse of time, the transfer charger 37 and the paper charger 38 are turned on at the same time. As a result, a positive charge is applied from the surface of the transfer member P, and the potential of the transfer member P decreases.
%] moves onto the transfer member P. After this, the transfer member P is A
The charge is removed by a paper charger 38 consisting of a C charger, peeled off from the photoreceptor 32, and further held between the heating rollers of the fixing device 51. Here, the powder image on the transfer member P is melted and fixed on the transfer member P, and is discharged from the apparatus and stacked on the paper discharge tray 53. In the above, each step of drilling the photoreceptor 32 has been completed up to α)→■→■→Ω) in FIG.

Therefore, when one more sheet is printed after the transfer shown in FIG. .

32, about 20 [%] of the powder during development is transfer residual powder 45
It reaches the static eliminating lamp 39 while being attached to the latent image area 1ti32a of the photoreceptor 32, and the absorbed charge is almost attenuated as shown in FIG. is charged again.

However, the surface potential of the photoconductor 32 in the area where the transfer residual powder 45 is attached is only about -Vo/2, which is half of the area where the transfer residual powder 45 is not attached, and the latent image on the photoconductor 32 is The region 32a includes a high potential part of -Vo and a V o /2
This results in a mixture of low potential parts.

Thereafter, as the photoreceptor 32 rotates, a negative latent image is formed in the latent image area 32a by the laser beam 52, as shown in FIG. 5, and reaches the urethane blade 43. When the urethane blade 43 slides on the surface of the photoreceptor 32, the untransferred powder 45 on the latent image area 32a is removed from the second
The light is guided along the urethane blade 43 to the non-latent image areas 32b at both ends of the photoreceptor 32, which are high potential parts, as shown in the direction of the arrow and the direction of the arrow in the figure. (FIG. 50) As mentioned above, the sliding contact with the urethane blade 43 does not disturb the 8° latent image formed on the photoreceptor 32.

In this state, when the photoreceptor 32 having a surface potential as shown in FIG. An electrostatic latent image having a potential of -VER and colored powder are applied by the brush 41 and developed. However, V o /
The portion to which the transfer residual powder 45 having a potential of about 2 was attached has no significant potential difference Iυ with the developing bias VB, and there is no risk of colored powder adhering due to sliding contact with the magnetic brush 41. On the other hand, a non-latent image area 32 with a surface potential of -Vo
In b, due to the potential difference with the developing bias Va, the magnetic brush 41 slides into contact with the magnetic brush 41, and the accumulated transfer residual powder 45 is collected by the developing roller 42 and cleaned. Thereafter, the photoreceptor 32 undergoes a transfer process, as shown in FIG. 50, as in the case of printing on the first sheet, and is neutralized as shown in FIG. 50, making it ready for the next printing. The transfer member P to which the image has been transferred passes through a peeling process and a fixing process, and is then discharged from paper sheets 1 to 1.
The paper is stacked on the tray 53 and printing of the second sheet is completed. After this, the above steps are repeated as many times as necessary.

That is, for the photoreceptor 32, ω′→■′→0→ in FIG.
■' → 0) → 0 → ■' will be repeated. Next, referring to FIG. 4, a case will be described in which the printing of the final sheet is completed and the operation of each device is stopped. When (θ1+θ3)/W [seconds] (θ3 is the phase difference between the developing roller 42 and the transfer charger 37) elapses after the image forming process for printing on the final sheet is completed, that is, after the laser beam for printing on the final sheet has stopped. Since the transfer of the developed image printed on the final sheet is completed, the transfer charger is turned off, and after a while, the paper electricity removal charger 38 is turned off.

When the photoreceptor 32 rotates once after the laser beam stops, the charger 33 is turned off, and then θ1/W [seconds]
After the elapse of time, the developing bias Va is turned off. In other words, during this period, the photoreceptor 32 is not exposed to light after being charged, and reaches the developing roller 42 to which the developing bias VB is applied with the entire surface held at a high potential, so that the photoreceptor 32 is guided to a non-latent image area by the urethane blade 43. Along with the transfer residual powder, the powder remaining in the latent image area is also collected to the developing roller 42 side and completely cleaned. Then, when θ3/W [seconds] (θ is the phase difference between the developing roller 42 and the static elimination lamp 39) have elapsed after the developing bias Va is turned off, the drive motor and the static elimination lamp 39 are turned off. In this final charge removal step, the photoreceptor 32 is completely removed from charge, and image deterioration factors such as image blur caused by residual charges are removed. Although each device is stopped in this way, the drive motor, charging charger 33, and static elimination lamp 39 are turned on almost simultaneously by the next printing command, but the charging portion of the developing bias Va photoreceptor 32 is transferred to the developing roller 42. It will not turn on until it reaches. Therefore, the uncharged area will not be developed. That is, since image formation is not performed in areas other than the image forming area both at the start of printing and at the end of printing, excessive powder does not adhere to the photoreceptor 32 and does not adversely affect the printed image.

With this configuration, the transfer remaining powder 4 on the photoreceptor 32
5 is guided to the non-latent image area 32b having a high potential of +'+ff which reaches the developing roller 42. Therefore, at the same time as the developing process of the latent image by the developing roller 42, due to the potential difference between the developing bias and the non-latent image area 32b, The untransferred powder 45 is easily and reliably collected by the developing roller 42 and cleaned, and it is possible to prevent ground blur, ghost, stain, etc. due to the untransferred powder 45, and the image quality is improved.

In addition, since a special cleaning device (W) for removing the transfer residual powder 45 is not required, the device can be made smaller and maintenance efficiency is also prevented. As shown in FIG. 1, the conveyance path of the transfer member P is in an L-shape surrounding the photoreceptor 32 with respect to the traveling direction, so that the discharge direction of the transfer member P is located diagonally above the photoreceptor 32. Furthermore, the processing direction and content discrimination/reading direction of the ejected transfer member P are matched, and the shape is ideal as a component of a system device such as a word processor.

Note that this invention is not limited to the above-mentioned embodiments, and can be modified in various ways. For example, light emitted light may be used as the exposure means.
A light emitting element such as a diode array or an optical switching element may also be used.

In addition, the material of the guiding device that moves the transfer residual powder is also electrostatic.
g! The material is not limited to urethane as long as it is an elastic insulator that does not disturb the i-image or damage the surface of the photoreceptor. Furthermore, the shape of the guiding device and the angle at which it presses against the photoreceptor are completely arbitrary.As shown in another modification shown in FIG. It may also be a urethane blade 56 that guides. In this case, since it is only necessary to provide the non-latent image area 54b at one end of the photoreceptor 54, the latent image area which is the effective part of the photoreceptor 54 can be enlarged.

〔Effect of the invention〕

As explained above, according to the present invention, the transfer residual powder is accumulated in the non-latent image area of the image bearing member before the development and cleaning process by the guiding device, so that the same developing roller is used for both the development process and the cleaning process. When the steps are performed at the same time, the powder remaining after transfer is easily and reliably cleaned by the developing roller, thereby preventing background blurring, scumming, ghosting, etc. that conventionally occur, and making it possible to obtain high-quality images. Furthermore, since the special cleaning and suppressing device that has been used in the past is no longer necessary, the device can be made more compact, and the shape is more preferable as a component device of a system device such as a laser printer.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram thereof, FIG. 2 is a perspective view showing a photoreceptor to which the urethane blade is slidably contacted, and FIG. 3 is a perspective view thereof. An explanatory diagram showing the arrangement position of the urethane blade with respect to the photoconductor, FIG. 4 is a timing chart that does not show the printing process, FIG. 5 is an explanatory diagram showing each printing process, and FIG. 6 is the photoconductor during development and cleaning. FIG. 7 is a top view showing the installation position of the urethane blade with respect to the photoreceptor of another modification of the present invention, and FIGS. 8 to 11 show the first conventional device. FIG. 8 is a schematic diagram of the configuration, FIG. 9 is an explanatory diagram showing each printing process of regular development using the two-component developer, and FIG. 10 is an explanatory diagram showing each printing process of reversal development using the two-component developer. 11 is an explanatory diagram showing each printing step of reversal development using the one-component developer, FIG. 12 is an explanatory diagram showing each printing step of the second conventional example, and FIGS. 13 and 14 are The third conventional example is shown in Fig. 13, its schematic configuration diagram, and Fig. 14.
The figure is an explanatory diagram showing the state in which the photoreceptor having the transfer residual powder is charged. 32... Photoreceptor 33... Charger 34... Exposure section 36... Development and cleaning process 40... Developer 41... Magnetic brush 42... Developing roller 43... Urethane blade 45 ... transfer residual powder

Claims (1)

[Scope of Claims] 1. The development process of the latent image and the cleaning process of the residual transfer powder of the image bearing member, on which the latent image is formed and the transfer residual powder is attached, are performed using the same developing roller. A development and cleaning device for an image forming apparatus, characterized in that the development and cleaning device is equipped with a guide device for guiding the transfer residual powder to a non-latent image area of the image carrier before the development and cleaning step. 2. Claim 1, characterized in that the guiding device is comprised of an insulating blade that has approximately the same width as the image carrier and is pressed against the image carrier so as to have a slope with respect to the moving direction.
A developing and cleaning device in the image forming apparatus described in 1. 3. The image according to claim 1 or 2, wherein the absolute value of the surface potential of the non-latent image area of the image carrier is larger than the absolute value of the bias potential of the developing roller. A developing cleaning device in a forming device.