JPH0467077A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate need for applying a high bias voltage to a developing sleeve by providing an electret having polarity reverse to toner at a developing position in a photosensitive drum. CONSTITUTION:The electret E having the inverse polarity to the toner for developing T is provided in the developing area inside the photosensitive drum 1. Besides, the electret E having the polarity same as the developing toner T is provided inside the developing area of the developing sleeve 3 so as to be fixed to a developing device 2. Since the electret having the inverse polarity to the toner is provided in the developing area inside the drum 1 and the electret having the polarity same as the toner is provided in the developing area inside the sleeve 3 in such a way, attraction force by the inverse polarity and repulsion by the same polarity effectively act in a direction that a developing action is promoted. As the result, the density of the developing is improved and the toner is prevented from being uselessly splashed. Besides, the developing bias need not be applied by a high-voltage transformer or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and more specifically, by supplying toner to a photoreceptor tram through a developing sleeve of a developing device, a latent image on the surface of the drum is formed. This relates to an image type l1i32 device for visualizing images.

[Prior Art] Conventionally, when an image forming apparatus uses a non-magnetic component development method, since the toner is a non-magnetic material, a developing sleeve of a developing device that supplies toner to a photoreceptor drum magnetically transfers the toner onto the sleeve surface. cannot be adsorbed.

Therefore, a method has been used in which a high bias voltage is applied to the developing sleeve and the toner is attracted by the electrostatic action.

[Problems to be Solved by the Invention] However, in the conventional image forming apparatus that uses a high-voltage transformer to apply a bias voltage to the developing sleeve, the mechanism is complicated and expensive, and it is difficult to balance image density. There was an 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 the following image forming apparatus. That is, the present invention provides (1) an image forming apparatus that supplies developing toner to a photoreceptor tram via a developing sleeve, wherein an electret having a polarity opposite to that of the toner is provided at a development position in the photoreceptor tram. An image forming device featuring:

(2) An image forming apparatus that supplies developing toner to a photoreceptor tram via a developing sleeve, wherein an electret having a polarity opposite to that of the toner is provided at a developing position in the photoreceptor drum, and characterized in that the development area is provided with an electret having the same polarity as the toner;
It is an image forming apparatus.

[Function] In the above configuration, the electret inside the photoreceptor drum in the development area has a polarity opposite to that of the toner on the development sleeve, so that an attractive force acts on the toner.

Further, since the electret in the development area inside the development sleeve has the same polarity as the toner, the toner on the development sleeve receives a repulsive force and becomes easily separated from the sleeve.

Therefore, the two electrets act in the same direction as the direction of development action in which the latent image on the photosensitive drum or the toner on the development sleeve is attracted, so that they have the effect of promoting development.

[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 diagram of an embodiment of the present invention. In the figure, 1 is a photoconductor drum, and a developing sleeve 3 of a developing device 2 is rotatably disposed adjacent to the photoconductor tram 1. .

Further, an electret E having a polarity opposite to that of the developing toner T is provided in the developing area inside the photoreceptor tram 1.

Further, inside the developing area of the developing sleeve 3, an electret E having the same polarity as the developing toner T is fixedly provided to the developing device 2.

The electret here refers to a polymeric material that can semi-permanently maintain an electrically polarized state at a high voltage.For example, the material itself can maintain its polarity even without connecting a power supply circuit that applies a bias voltage. Therefore, it is said that electret was added to magnets because it is similar to how permanent magnets can maintain their magnetic poles for a long period of time.

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

The toner T on the developing sleeve 3 is moved by the rotation of the sleeve 3, and when it reaches the developing area, the toner T on the developing sleeve 3 is moved.
Since the electret E inside has the same polarity as the toner T, a repulsive force acts, and the toner T becomes easily detached from the developing sleeve 3.

On the other hand, on the surface of the photoreceptor drum 1, a latent image is formed due to static electricity, and since this latent image is charged with the opposite polarity to the toner T, an attractive force is exerted between it and the toner T, so that the developing Toner T in the development area on sleeve 3
flies toward the latent image on the photosensitive drum 1 and is attracted to it.

The toner T is electrostatically attracted to the latent image on the photosensitive drum 1, whereby the latent image is visualized and developed.

The developing area inside the photoreceptor tram 1 is provided with an electret E having a polarity opposite to that of the toner T, as described above.

Therefore, the force of attracting the toner T to the latent image is enhanced by the electret E provided in the photoreceptor tram 1.

Furthermore, this toner development easily separates from the sleeve 3 and efficiently flies to the photoreceptor tram 1 due to the repulsive action of the electrolyte having the same polarity as the toner at the development position in the development sleeve. Toner development density can be increased.

As described above, the present invention includes an electret with the opposite polarity to the toner in the developing area inside the photoreceptor drum, and an electret with the same polarity as the toner in the developing area inside the developing sleeve. The adsorption force of the opposite polarity and the repulsion force of the same polarity act effectively to promote the development action, thereby improving the development density and preventing unnecessary toner scattering.

Furthermore, by using an electret, there is no need to apply a developing bias using a high-voltage transformer or the like, which makes it possible to simplify the structure, downsize equipment, and reduce costs.

Since the inside of the developing sleeve is equipped with an electret with the same polarity as the toner, the attraction force of the opposite polarity and the repulsive force of the same polarity are generated by the electrostatic latent image on the photoreceptor tram or the electrostatic latent image on the developing sleeve. It promotes the development action of adsorbing toner, improving the development density and suppressing toner scattering.

In addition, since the developing sleeve is equipped with an electret,
There is no need for a developing bias using a high-voltage transformer, which has the effect of simplifying the structure, reducing space, and reducing costs.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a first embodiment or an embodiment of the present invention. 1...photosensitive drum, 3...Developing sleeve, E. electret, T-...toner [Effects of the invention 1

Claims (2)

[Claims] (1) An image forming apparatus that supplies developing toner to a photoreceptor drum via a developing sleeve, characterized in that a development position within the photoreceptor drum is provided with an electret having a polarity opposite to that of the toner. , image forming device. (2) An image forming apparatus that supplies developing toner to a photoreceptor drum through a developing sleeve, wherein an electret having a polarity opposite to that of the toner is provided at a developing position in the photoreceptor drum, and characterized in that the development area is provided with an electret having the same polarity as the toner;
Image forming device.