JPS60209769A - Developing device for electrostatic latent image - Google Patents

Abstract

PURPOSE:To make grounding complete and hold a developing roll and recording paper at a constant interval, and improve picture quality by providing a nonmagnetic conductive paper feed roller which is grounded near a development point and at the opposite side in the advancing direction of a recording body. CONSTITUTION:The developing device consists of a toner hopper 1 which contains toner 2, developing roller 3 which rotates having the toner 2 stuck, recording paper 4, grounded original guide plates 5 and 6, and conductive grounded paper feed roller 6 which is made of a nonmagnetic body. The tangent to the contacting point between both rollers is coincident with the top surface of the original guide plate 5. Development is carried out successively according to the advance of the recording paper 4 and unnecessary charges generated near the development area are all discharged from the grounded original guide plate 5 or paper feed roller 6 which is grounded through the recording paper 4. The paper feed roller 6 is made of the nonmagnetic body, so it is not magnetized when provided closely to the developing roller 3 and no toner 2 sticks thereupon, thereby improving the picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic latent image developing device used in facsimile machines and the like.

In this type of device, electrostatic recording paper, on which an electrostatic latent image has been formed in advance in a recording section, is moved over a document guide plate by a paper feed roller, and a one-component system is carried on the upper surface of the electrostatic recording paper on the outer periphery of a developing roller. Development is performed by bringing the toner into contact with and adsorbing it. In this gap, unnecessary materials near the developing area
Is one original kite board near the development area grounded to remove the TTF load? It has a structure.

However, the recording paper itself is moving, and sometimes the recording paper is curved, resulting in situations where the recording paper cannot make sufficient contact with the QI document guide plate, or the recording paper and the document guide plate Due to the inflow of magnetic toner between the original plate and the document board, a certain distance β41 (grounding or incomplete contact occurs), which causes toner fog during development and deteriorates the image quality. In order to solve this drawback,
It has been considered to install a grounded conductive blank near the developing area so that its tip touches the recording paper surface, but since it contacts only the recording medium surface, it is difficult to ground it. Since the recording paper is imperfect and the conductive brush is constantly pushing the recording paper upwards, the recording paper is extremely unstable and the distance between the developing roller and the recording paper changes gradually, so the image quality is not the same. Extremely low.

The present invention has been made in view of the above-mentioned drawbacks, and provides an inexpensive electrostatic latent image developing device that improves image quality by completely grounding the developing roller and keeping the distance between the developing roller and recording paper constant. The purpose is to

The present invention aims to achieve the above-mentioned object by providing a grounded non-magnetic conductive paper feed roller near the development point and on the opposite side of the recording medium traveling direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The F1 present invention will be described below along with one embodiment thereof using the drawings. FIG. 1 schematically shows an electrostatic latent image developing device according to an embodiment of the present invention, in which 1 is a toner hopper that stores toner 2, 3 is a developing roller that rotates with toner 2 attached thereto, and 4 is a toner hopper that stores toner 2; 6 is a recording paper, 6 is a grounded document guide plate, 6 is a grounded conductive and non-magnetic paper feed roller, and the tangent at the contact point of both rollers coincides with the top surface of the document guide plate 6. It is set up like this.

Four sheets of recording paper on which an electrostatic latent image has been formed by the recording means are advanced in the direction of the arrow on the document guide plate 6 by the paper feed roller 6, and toner 2 is deposited on the electrostatic latent image by the rotation of the developing roller 3.
is supplied and development is performed. The paper feed roller 6 is provided close to the developing area, and the tangent line at the contact point of both paper feeding rollers is substantially aligned with the upper surface of the document guide plate 6, so that when the recording paper 4 reaches the developing area, Recording paper 4
The leading edge of the document advances while being in close contact with the document guide plate 6. Therefore, the toner 3 flows between the recording paper 4 and the original kite plate 5. So-called back-side development can be almost prevented.

Development is performed sequentially as the recording paper 4 advances (or unnecessary charges generated in the vicinity of the developing area at this time are removed from the grounded document guide plate 5 or through the recording paper 4 and grounded). All of the toner will escape from the paper feed roller 6. Since the paper feed rollers 6 are made of non-magnetic material, they will not become magnetized even if they are placed close to the developing roller 3, and the toner 2 will land on the first side. Never.

It goes without saying that the present invention can also be used in a developing device that does not use a document guide plate and uses a grounded non-magnetic electrostatic roller.

As is clear from the above description, the present invention provides a grounded conductive non-magnetic roller in the vicinity of the developing area and on the opposite side of the recording medium traveling direction, and a grounded paper feed roller 7. In addition, since the advance position of the recording paper is determined by both paper feed rollers, toner back-up does not occur and the grounding is ensured, which prevents the occurrence of so-called fogging. The resulting deterioration in image quality can be completely prevented, and since the distance between the recording paper and the developer is kept constant, extremely good image quality can be obtained, even though recording unevenness may occur.

[Brief explanation of the drawing]

The figure is a schematic configuration diagram of an electrostatic latent image developing device according to an embodiment of the present invention. 1... Toner hopper, 3... Developing roller, 6...
・Document guide plate, 6 ・Paper feed roller.

Claims (1)

[Claims] a toner supplying means, a developing port which rotates while holding the supplied toner, a recording medium supporting means provided opposite to the developing roller so as to sandwich the recording medium, a region near the developing area and a recording medium; Two electrocardiographic non-magnetic rollers are provided facing each other so as to sandwich the recording medium on the opposite side in the direction of movement of the body, and at least one of them is grounded! '40! ii
An electrostatic latent image developing device.