Developing unit

Abstract

A developing unit including: a first agitating and conveying rotor and second agitating and conveying rotor for agitating and conveying toner inside a casing; and a developing roller for supplying the toner to a photoreceptor drum is constructed such that the first agitating and conveying rotor has a rotary shaft arranged approximately parallel to the developing roller and a multiple number of agitating vanes arranged on the rotary shaft with an inclination to the axial direction of the rotary shaft; each agitating element is formed asymmetrically about a normal that passes through the rotational center and adjacent agitating elements are asymmetrical to each other; and an odd number of asymmetrical agitating elements are arranged alternately.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view showing an overall configuration of an image forming apparatus adopting a toner supply device according to the present invention;

FIG. 2 is a schematic side sectional view showing a configuration of a developing unit and a toner supply device that constitute the image forming apparatus;

FIG. 3 is an overall front view showing the developing unit and toner supply device;

FIG. 4 is a perspective view showing the configuration of the developing unit;

FIG. 5A is a sectional side view showing a configuration of an agitating and conveying means for the developing unit according to the present embodiment; FIG. 5B is a view from a plane b1-b1 in FIG. 5A; FIG. 5C is a view from a plane b2-b2 in FIG. 5A; FIG. 5D is a view from a plane b3-b3 in FIG. 5A; FIG. 5E is a view from a plane b4-b4 in FIG. 5A; and FIG. 5D is a view from a plane b5-b5 in FIG. 5A;

FIG. 6 is a perspective view showing a mounting example when toner supply assemblies are set in toner supply assembly mounting mechanisms that constitute the toner supply devices;

FIG. 7 is a perspective view showing the configuration of the toner supply assembly mounting mechanisms;

FIG. 8A is a side view showing a configuration of a toner supply assembly as a part of the toner supply device and FIG. 8B is its front view, viewed from the end face side of the toner supply assembly from which toner is supplied;

FIG. 9A is an illustrative view showing a bottle holder with its toner discharge port open, FIG. 9B is an illustrative view showing the bottle holder with the toner discharge port closed by a shutter mechanism;

FIG. 10 is an illustrative view showing the schematic structure of the rear side of the bottle holder;

FIG. 11 is an illustrative view showing the structure of the toner supply assembly mounting mechanism;

FIG. 12 is an illustrative view showing the structure of a supply passage part for coupling the toner supply assembly mounting mechanism with a developing unit;

FIG. 13A is an illustrative view showing the positional relationship between a regulating member and a projection piece before the toner supply device is mounted to a mount base; FIG. 13B is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device has been mounted to the mount base; and FIG. 13C is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device is dismounted from the mount base; and,

FIG. 14 is an illustrative view showing an overall configuration of a copier according to another embodiment of the present invention.

Claims

1. A developing unit comprising: an agitating and conveying portion for conveying a developer stored in a developing hopper while agitating the developer; anda developing roller for supplying the developer conveyed from the agitating and conveying portion to an electrostatic latent image bearer,

2. The developing unit according to claim 1, wherein the odd number of agitating elements arranged in series are formed as a first set on the first side and a second set on the second side, on both sides, bounded at the approximate center of the agitated area of the agitating and conveying portion; the order of arrangement of the agitating elements in the second set with respect to the direction toward the approximate center is asymmetrical to that of the agitating elements of the first set; andthe first and second sets are adapted to convey the developer toward the approximate center.

3. The developing unit according to claim 1, further comprising a toner concentration sensor disposed close to the agitating and conveying portion, wherein the agitating element disposed close to the toner concentration sensor is formed with a cutout at a position opposing the toner concentration sensor.

4. The developing unit according to claim 1, wherein the agitating elements arranged at both ends of the agitating and conveying portion are each formed in a hemi-elliptic shape with symmetry about the normal line.

5. The developing unit according to claim 1, wherein the agitating element at the approximate center of the rotary shaft among the multiple agitating elements is formed as an approximate circular plate.

6. The developing unit according to claim 1, wherein the agitating elements are arranged with an inclination of 45 degrees with respect to the axial direction of the rotary shaft.