JPH0467075A - Image forming device having belt photosensitive body - Google Patents

Abstract

PURPOSE:To facilitate developing by providing an electret having inverse polarity to toner on a supporting roller faced to a developing position in the inside of a belt photosensitive body. CONSTITUTION:The electret E having the inverse polarity to the toner is provided on the supporting roller 5a faced to a developing device 9 in the inside of the belt photosensitive body 6. The electret is the base stock of high polymer which can semipermanently maintain an electric polarization state by a high voltage. For example, even when a power source circuit which applies a bias voltage is not connected, the polarity can be maintained by the base stock itself. By providing the electret E in such a way, the toner T supplied to the latent image of the photosensitive body on a belt 4 from the developing device 9 is attracted to the latent image by attraction force by the inverse polarity. As the result the efficiency of the developing is improved and the density of the developing is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field] The present invention relates to an image forming apparatus having a belt-type photoreceptor.

[Prior Art] Conventionally, a belt-type photoreceptor is manufactured by depositing conductive aluminum on an insulating cloth or film 1, as shown in FIG.
Furthermore, a belt 4 provided with an organic photosensitive layer 3 that becomes conductive when exposed to light is formed into a loop shape, and is supported by a plurality of support rollers 5 and rotated.

The belt-type photoreceptor 6, which is composed of the belt 4 and the support rollers 5, 5, and 5, is flexible, so it resembles a photoreceptor tram and can be arranged flexibly to fit the spatial shape of the image forming apparatus. He had the characteristic of being able to do things.

[Problem to be solved by the invention]

However, in an image forming apparatus having such a belt-type photoreceptor 6, the conventional developing device that uses a high-voltage transformer to apply a bias voltage to the developing sleeve has a complicated and expensive mechanism, and is not capable of achieving sufficient image density. There was a problem in that the conditions for obtaining this were very strict, and it was difficult to obtain a high density due to the balance with background fog.

Further, in the transfer device of the image forming apparatus having the belt-type photoreceptor 6, a charger voltage is conventionally required to be applied by a high-voltage transformer, so the mechanism becomes complicated and the cost increases as described above.

Another problem was that the resistance of the transfer paper decreased due to the influence of moisture, resulting in poor transfer efficiency.

Furthermore, in order to improve the cleaning efficiency of the cleaning device for the image forming apparatus 55 having the belt-type photoreceptor 6, the tip of the cleaning blade is pressed against the rotating belt-type photoreceptor, so mutual wear due to friction is large. This was considered a maintenance issue.

The present invention aims to solve such problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image forming apparatus having the following belt-type photoreceptor.

That is, the present invention provides: (1) an image forming apparatus having a loop-shaped belt-type photoreceptor that is supported by a support roller and rotates; An image forming apparatus having a belt-type photoreceptor, characterized in that an electret having a polarity opposite to that of toner is provided.

(2) An image forming apparatus having a loop-shaped belt-type photoreceptor that is supported by a support roller and rotates, the support roller facing a transfer position inside the belt-type photoreceptor has a toner of the same polarity as the toner. An image forming apparatus having a belt-type photoreceptor, characterized in that an electret is provided.

(3) An image forming apparatus having a loop-shaped belt-type photoreceptor that is supported by a support roller and rotates, the support roller facing a cleaning position inside the belt-type photoreceptor has a toner of the same polarity as the toner. This is an image forming apparatus having a belt-type photoreceptor and characterized in that an electret is provided.

[Effect]

In the above configuration, the electret, which is provided on the support roller facing the developing position inside the belt-type photoreceptor and has a polarity opposite to that of the toner, uses suction force to make it easier for the developing toner to adhere to the latent image on the belt-type photoreceptor, thereby developing the image. Facilitates development by equipment.

An electret with the same polarity as the toner provided on the support roller facing the transfer position inside the belt-type photoreceptor uses repulsive force to easily release the developed toner from the photoreceptor surface, making it easier for the transfer device to transfer it to paper. do.

The electret, which has the same polarity as the toner, is installed on the support roller facing the cleaning position inside the belt-type photoreceptor.
The repulsive force causes residual toner to be released, making cleaning by a cleaning device easier.

[Example] Regarding an example of the present invention, how the configuration of the present invention is actually embodied will be described below with reference to the drawings, along with its operation.

FIG. 1 is an explanatory view of one embodiment of the present invention, and in the figure, 4 is a loop-shaped belt, and this loop-shaped belt 4 is rotatably supported on the inside by three support rollers 5a, 5b, and 5c. has been done.

The belt 4 has a flexible insulating cloth or film 1 as a base, on which conductive aluminum 2 is vapor-deposited, and an organic photosensitive layer 3 is further provided thereon.

The belt 4 and support rollers 5a, 5b, and 5c form a belt-type photoreceptor 6.

Around the belt-type photoreceptor 6, there is a main charging device 7 that uniformly charges the surface of the photosensitive layer 3 of the belt 4 from above, and a main charging device 7 that uniformly charges the surface of the photosensitive layer 3 of the belt 4, and exposes the charged surface on the belt 4 according to the image to form a latent image. An exposure device 8, a developing device 9 which supplies the developing toner T to the latent image via the developing sleeve 9a and electrostatically attracts it to develop it into a visible image, and the developing toner T on the belt 4 is transferred to a separately supplied paper P. A cleaning device that presses a cleaning blade lla to remove the toner T remaining on the surface of the photosensitive layer 3 of the belt 4 after the transfer, by applying pressure to the transfer device 1fIO1 to the transfer charger 10a.
IL etc. are arranged clockwise.

Further, downstream of the transfer device 10, the transfer device! 10
A fixing device 12 is provided to stably fix the toner T transferred by the toner T onto the paper P.

Said developing device! Support roller 5 located opposite f9
A is provided with an electret E having a polarity opposite to that of the toner T on its peripheral surface.

Here, electric left is a polymer material that can semi-permanently maintain an electrically polarized state at a high voltage. It is said that the name electret was given to magnets because it is similar to the ability of permanent magnets to maintain their magnetic poles over long periods of time.

Electret has an extremely simple structure and can be made lightweight and compact, so as technology advances in the polymer field, it has recently become a material commonly used in ultra-small microphones, speakers, and other audio equipment.

By providing this electret E, the developing device ff
Toner T supplied from 19 to the latent image on the photoreceptor of the belt 4
is adsorbed to the latent image by the attraction force due to the opposite polarity, improving the developing efficiency and increasing the developed density.

Next is the transcription! Support roller 5 located opposite to 10
In b, an electret E having the same polarity as the toner T is provided on the surface.

By providing the electret E having the same polarity, the developing toner T on the photosensitive layer 3 of the belt 4 is subjected to a repulsive force due to the same polarity.

On the other hand, on the transfer device 10 side, a high voltage having a polarity opposite to that of the toner T is applied to the transfer charger 10a, and the toner T is electrostatically absorbed from the back surface of the paper P, so that the repulsive force of the electret E is Due to the synergistic effect of toner T
is efficiently transferred onto the paper P.

The transferred paper P is pressurized and
The toner T is fixed and stabilized on the paper by heating.

The toner T that was not completely transferred during this transfer and remained on the photosensitive layer 3 of the belt 4 is removed by pressure contact with the cleaning blade lla of the cleaning device 11.

At this time, an electret E having the same polarity as the toner T is provided on the support roller 5c at a position facing the cleaning device 11.

Due to the electret E, the residual toner T on the belt 4 receives a repulsive force and becomes easily separated from the photosensitive layer 3, and the cleaning blade lla comes into pressure contact with the photosensitive layer 3 of the belt 4, and the residual toner T Scrape off the cleaning position to help.

Therefore, the pressing force of the cleaning plate lla can be set to a small value, thereby suppressing the wear and tear of the cleaning plate lla and the photosensitive layer 3 of the belt 4 due to friction, extending the life of the parts, and improving maintainability. .

As described above with respect to the embodiments, the present invention is an image forming apparatus having a belt-type photoreceptor, and the support roller facing the development position is provided with an electric left having a polarity opposite to that of the toner, and the support roller facing the development position is provided with an electric left having the opposite polarity to the toner. The support roller is provided with an electret of the same polarity as the toner, and the support roller facing the cleaning position is provided with an electret of the same polarity as the toner, and the toner attraction force due to the opposite polarity and the toner repulsion force due to the same polarity are utilized. Accordingly, the development g1
This improves the performance, transfer function, and cleaning function.

〔Effect of the invention〕

As described above, according to the present invention, since the electret having the opposite polarity to the toner is provided on the support roller facing the developing position inside the belt-type photoreceptor, the toner is removed by the suction force of the electret. It becomes easier to fly and transfer from the developing device to the belt-type photoreceptor, increasing the developed density.

In addition, the suction force of the electret suppresses toner scattering due to toner flying transfer, thereby making it possible to prevent surrounding contamination.

According to the second aspect of the invention, since an electret having the same polarity as the toner is provided on the support roller facing the transfer position inside the belt-type photoreceptor, the repulsive force of the electret facilitates the separation of the toner from the belt-type photoreceptor. This improves the transfer efficiency of the transfer device.

Further, since the transfer efficiency is high, the voltage applied to the transfer charger of the transfer device can be low, and the cost of the transfer device can be reduced.

Furthermore, since the transfer efficiency is high, residual toner on the belt-type photoreceptor is reduced, and therefore cleaning performed after transfer is facilitated.

In the third aspect of the invention, since an electret having the same polarity as the toner is provided on the support roller facing the cleaning position inside the belt-type photoreceptor, residual toner is easily separated from the belt-type photoreceptor, and the cleaning efficiency of the cleaning device is improved. Improves cleaning performance and eliminates poor cleaning.

In addition, since the cleaning efficiency is high, the force required to press the cleaning blade of the cleaning device against the belt-type photoreceptor is small, which reduces the amount of wear and tear caused by friction between both the cleaning blade and the photoreceptor, extending the lifespan of the parts for maintenance. It has the effect of improving sex.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional example. 5, 5a, 5b, 5C...Support roller, 6...Belt type photoreceptor, 9...Developing device, 10...Transfer device, 11...Cleaning device, E...Electret, P. ...Paper, T...Toner Figure 1 0a

Claims (3)

[Claims] (1) An image forming apparatus having a loop-shaped belt-type photoreceptor that is supported by a support roller and rotates, the support roller facing a developing position inside the belt-type photoreceptor has a toner with a polarity opposite to that of the toner. An image forming apparatus having a belt-type photoreceptor, characterized in that an electret is provided. (2) An image forming apparatus having a loop-shaped belt-type photoreceptor that is supported and rotated by a support roller, and an electret having the same polarity as the toner is attached to the support roller facing a transfer position inside the belt-type photoreceptor. An image forming apparatus having a belt-type photoreceptor, characterized in that it is provided with a belt-type photoreceptor. (3) An image forming apparatus having a loop-shaped belt-type photoreceptor that is supported and rotated by a support roller, and the support roller facing a cleaning position inside the belt-type photoreceptor has an electret of the same polarity as the toner. An image forming apparatus having a belt-type photoreceptor, characterized in that it is provided with a belt-type photoreceptor.