JP2001312120A - Electrostatic charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charging device capable of preventing the occurrence of conduction failure between a changer case and a grid as well as the occurrence of an image defect. SOLUTION: This electrostatic charging device is provided with projecting parts 1a being integrally formed with the charger case 1 so as to provide elastic force in a lengthwise outward direction, erected from a bottom surface of an approximately u-shape toward an opening part in both ends in the lengthwise direction of the charger case 1, hooking parts 1b each being a tip end of the projecting part 1a, and hole parts 3a each engaged with the hooking part 1b on both end parts in the lengthwise direction of a grid 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device in an electrophotographic apparatus such as a printer, a copying machine, or a facsimile, and more particularly, to a charging device having a substantially U-shaped charging case made of a conductive material. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device in which a charging wire is applied and a grid is stretched to generate a corona discharge by applying a charging voltage when a body is charged.

[0002]

2. Description of the Related Art As shown in FIG.
A metal charger case 11 having a substantially U-shape is provided, and a substantially U-shaped opening is provided in the direction of the photoconductor. The corona wire (not shown) is disposed substantially at the center of the charger case 11, and a charging voltage is applied from a high-voltage power supply to discharge a constant current. The grids 13 are arranged at regular intervals in parallel with the photoreceptor axis, and are connected to a grid potential control circuit 15 through a leaf spring 14 for extending the grid 13 and a charger case 11 so that the photoreceptor surface has a constant potential. I have. This allows
Leakage generated between the charger case 11 and the grid 13 can be prevented. The grid 13 is generally like A, but is omitted in FIG.

A hole 13a is formed at both ends in the longitudinal direction of the grid 13, and a hook 14b is formed at the tip of the leaf spring 14, and the hole 13a and the hook 14b are engaged with each other to form the grid 13a. Can be installed.

[0004]

However, in the conventional charging device, it is necessary that the leaf spring 14, which is a single component, always contact the charger case 11 connected to the grid potential control circuit 15. There has been a problem in that conduction irregularities may be caused by variations in contact pressure. In addition, the leaf spring 14 is often press-fitted into the charger frame 11 and may fall off, which may affect image formation.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a substantially U-shaped charger case made of a conductive material and a substantially central portion of the charger case. A charging wire, and a grid extending in the vicinity of the substantially U-shaped opening of the charger case. And a projection formed integrally with the charger case so as to have an elastic force in a longitudinally outward direction from the bottom surface of the grid, and to the projection at both longitudinal ends of the grid. And a mating engaging portion.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a charging device of the present invention, which comprises a charger case 1, a corona wire 2, and a grid 3. Although FIG. 1 is a view of only the vicinity of the right end in the longitudinal direction, the center is the same as the left side in the drawing, and the left end has the same shape as the right end. The functions of the corona wire 2 and the grid 3 are the same as those of the related art.

The charger case 1 may be made of a conductive material, for example, metal, and may have a substantially U-shape. According to the present invention, the charger case 1 is erected at both ends in the longitudinal direction of the charger case 1 from the U-shaped bottom surface toward the opening, and has an elastic force (return force) at B which is a longitudinal outer direction. 1 is provided with a projection 1a integrally formed therewith, and a hook 1b is provided at the tip thereof.

The projecting portion 1a may have any shape as long as it has an elastic force in which B, which is the longitudinal outer direction, returns in the returning direction, and may have any shape other than the leaf spring shape as in this embodiment. There may be. The length between the projections 1a at both ends when no force is applied (not pressed) to the projections 1a is longer than the length between the holes 3a provided at both ends of the grid 3, and the projections 1a By pressing, the length between the holes 3a can be made substantially the same.

The Rona wire 2 is arranged to be stretched substantially at the center of the charger case 1.

The grid 3 has holes 3a at both ends in the longitudinal direction.
Is provided, and the hook 1
By engaging the b with the hole 3a, the grid 3 is stretched and the charger case 1 and the grid 3 are connected. Note that the grid 3 is entirely A
However, they are omitted in FIG.

With such a configuration, it is possible to prevent poor conduction between the charger case 1 and the grid 3, and since the projection 1 a is formed integrally with the charger case 1, it is possible to prevent image defects from occurring, and The man-hour can be reduced by reducing the number of parts.

In this embodiment, the hook portion 1b and the hole portion 3a are configured to engage with each other. However, instead of the hole portion 3a, a substantially L-shaped bent portion is formed, and the bent portion is engaged with the hook portion 1b. A configuration that engages with each other, or a configuration in which a concave portion (or a convex portion) is used instead of the hook portion 1b, and a convex portion (or a concave portion) replaces the hole portion 3a may be used.

[0013]

As described above, according to the electrophotographic apparatus of the present invention, the projection integrally formed on both ends in the longitudinal direction of the charger case and the projections on both ends in the longitudinal direction of the grid. By providing an engaging portion that engages with the charging device, a charging device that can prevent the occurrence of malfunctions and poor image conduction between the charger case and the grid can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a part of a charging device of the present invention.

FIG. 2 is a diagram showing a part of a conventional charging device.

[Explanation of symbols]

 1, 11: Charger case 1a: Projecting portion 1b, 14b: Hook portion 2: Corona wire 3, 13: Grid 3a, 13a: Hole portion 14: Leaf spring 15: Grid potential control circuit

Claims (2)

[Claims] 1. A substantially U-shaped charger case made of a conductive material, a charge wire extending substantially in the center of the charger case, and a vicinity of a substantially U-shaped opening of the charger case. And a grid extending from the substantially U-shaped bottom surface toward the opening at both ends in the longitudinal direction of the charger case, and having an elastic force in the longitudinal outer direction. A charging device, comprising: a projection integrally formed with the charger case; and engagement portions that engage with the projection at both ends in the longitudinal direction of the grid. 2. The charging device according to claim 1, wherein holes are provided at both ends in the longitudinal direction of the grid, and the projections engage with the holes.