Image forming apparatus

Abstract

An image forming apparatus includes: a developing container; a concave-convex member which has a plurality of grooves formed in a rotation direction; a collecting portion; and a receiving member, wherein each groove has side surfaces including a first side surface formed in one direction and a second side surface formed in the other direction in a circumferential direction of the concave-convex member, wherein the first side surface has a smaller inclination angle than the second side surface, and when a direction which moves down the first side surface in the circumferential direction of the concave-convex member is set to be positive, a relative velocity of a surface velocity of the concave-convex member to a surface velocity of the receiving member is set to be positive, at a position in which the concave-convex member and the receiving member come into contact with each other.

Description

technical field [0001] The present invention relates to an image forming apparatus using an electrophotographic system, such as a copier, a printer, a facsimile, and the like. Background technique [0002] As prior art related to a hybrid development method (hereinafter referred to as an HV development method), an image forming apparatus described in Japanese Patent Laid-Open No. H9-211970 is known. Japanese Patent Laid-Open No. H9-211970 discloses an image forming apparatus including a developing roller facing a photosensitive drum carrying toner, and facing the developing roller carrying a double roller including toner and a magnetic carrier. Conveying roller for component developer. In the image forming apparatus, an electric field is caused to act between a developing roller and a conveying roller to form a toner layer on the surface of the developing roller, and develop an electrostatic image on a photosensitive drum. [0003] In the HV developing method, since the ch...

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Problems solved by technology

Therefore, it can be seen that, in the method of coating the toner covered on the magnetic carrier by using the potential difference between two rollers as in the HV developing apparatus, the density of the toner is easy mainly due to the following two reasons. was lowered

[0018] (1) When passed such as figure 1 When the shown potential difference between the developer carrier 31 and the toner carrying member 27 coats the toner on the surface of the toner carrying member 27, due to the force acting on the The toner causes the toner to have multiple forces acting on it, so it is difficult to place the toner evenly on the surface of the toner carrying member 27

In addition, the toner is multilayered on the surface of the toner bearing member 27, so that as Figure 2A As shown, it is easy to reduce the density of the toner occupying the surface of the toner carrying member 27

[0019] (2) Furthermore, when the toner carried on the toner bearing member 27 is projected onto the photosensitive drum 1, as in Figure 2A and Figure 2C In the case where the shown toner is formed as a multi-layered and non-uniform toner layer, since the amount of toner adhered differs from one another, developing residue is likely to be generated, which further reduces the amount of ink developed on the photosensitive drum 1 . Density of the toner image

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