JPH0922161A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of leakage between a shield and a grid by providing a connecting means for making the shield of an electrifier electrically conductive with the grid, so as to obtain the same potential. SOLUTION: A corotron wire 48 is extended between a block 46 on one side and a block 47 on the other side provided on both side parts in the longitudinal direction of the metallic shield 45 of a primary electrifier 3 and a spring shield 53 is attached to the other side. The spring shield 53 is constituted of a U-shaped fitting piece 54 and a hook-like attaching piece 55 and the fitting piece 54 is snap-fitted to the shield 45, to be attached. The attaching piece 43 of the grid 33 and the attaching piece 55 of the spring shield 53 are brought into press-contact with each other and the fitting piece 54 of the spring shield 53 comes into press-contact with the shield 45, so that the shield 45 of the primary electrifier 3 is electrically conductive with the grid 33. Accordingly, the shield 45 and the grid 33 have the same potential, the leakage never occurs therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a printer.

[0002]

2. Description of the Related Art As an image forming apparatus, an image forming apparatus such as a primary charger, an image exposure unit, a developing device, a transfer charger, and a cleaner is provided around an image carrier, and the image is carried by the primary charger. After uniformly charging the surface of the body, it is imagewise exposed to form an electrostatic latent image, and the electrostatic latent image is developed into a visible image by a developing machine, and the visible image is transferred onto a sheet by a charger. It is known that after the transfer, the sheet is sent to a fixing device to be fixed, and the residual toner on the image carrier is cleaned with a cleaner.

[0003]

When the charging device in the above-mentioned image forming apparatus, for example, a so-called scorotron type charging device in which the primary charger has a grid, the electric field strength E between the grid and the shield is increased. (KV / cm) was high and a leak had occurred.

Therefore, an object of the present invention is to provide an image forming apparatus capable of solving the above-mentioned problems.

[0005]

In an image forming apparatus having an image carrier and a charging device for charging the surface of the image carrier, the charging device includes a corotron wire and a shield covering the periphery of the corotron wire. A connection which is provided between the corotron wire and the image carrier and electrically connects the shield and the grid such that a biased grid and the shield and the grid have the same potential. And an image forming apparatus including a means.

[0006]

[Operation] According to the image forming apparatus of the present invention, since the shield of the charging device and the grid are electrically connected and have the same potential, no leak occurs between the shield and the grid.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 5 is a schematic explanatory view of an image forming apparatus. An image carrier 2 is provided in a main body 1 of the apparatus, and a primary charger 3, a developing device 4, and a developing device 4 are provided around the image carrier 2. A pre-transfer charger 5, a transfer charger 6, a separation charger 7, a cleaner 8 and the like are sequentially arranged, and the surface of the image carrier 2 is uniformly charged by the primary charger 3 and then the image is exposed by the image exposure mechanism 9. An electrostatic latent image is formed by exposure, the electrostatic latent image is developed into a visible image by the developing device 4, and the paper in the paper tray 10 is fed by the paper feeding mechanism 11
Then, the visible image is conveyed toward the image carrier 2 and transferred onto a sheet by the transfer charger 6, and the sheet is sent to the fixing device 12 to be fixed to form a copy.

The image exposure mechanism 9 is a laser system including a laser oscillator, a rotating mirror, and a plurality of mirrors, and receives image information from an office automation device such as an external computer or a word processor to perform image exposure on an image carrier. Configured.

The image carrier 2, the primary charger 3, and the cleaner 8 are attached to a housing 13 to form a print cartridge A, and the housing 13 can be inserted and pulled out along a guide rail 14 provided in the apparatus main body 1. The print cartridge A can be pulled out from the apparatus main body 1 and inserted.

As shown in FIGS. 6 to 9, the housing 13 includes one side plate 20, another side plate 21, and a peripheral wall 22. The peripheral wall 22 has a cleaner housing 23, and the cleaner housing 23 has the cleaning blade 2 attached thereto.
4. Disturber brush 25 in which a cleaning brush is planted in an annular shape, and an auger 26 are provided.
A cover body 28 is attached to the upper surface of the one side plate 20 and the other side plate 21. The cover body 28 is attached to the upper surface of the one side plate 20 and the other side plate 21, and an opening window 29 is formed in the cover body 28 in the longitudinal direction. This is the other side slide rail 30, the side plate 31 for positioning is provided on the one side plate 20, the side plate 32 is attached to the other side plate 21, and the primary charger 3 is attached on the cover 28. A grid 33 of the primary charger 3 is attached between the unit 28 and the upper surfaces of the one side plate 20 and the other side plate 21.

As a result, the housing 13 is slidable in the axial direction of the image carrier 2 along the guide rails 14 provided on the apparatus main body 1 with the one side slide rail 27 and the other side slide rail 30.

Next, the mounting of the primary charger 3 and the grid 33 will be described.

As shown in FIG. 4, the grid 33 is provided with a large number of slit grooves 41 in the longitudinal middle portion of the thin plate 40, and
Openings 42, 42 are respectively formed at both ends in the longitudinal direction of the thin plate 40, and one end is bent to form a mounting piece 43. As shown in FIG. 1, both ends in the longitudinal direction of the thin plate 40 are sharp end portions of the one side plate 20. 20a and the tip 21a of the other side plate 21 are pressed by the cover body 28, the leaf spring 44 provided on the one side plate 20 is engaged with the one opening 42, and the mounting piece 43 is described later on the outer surface of the other side plate 21. Connected with screws, grid 3
3, the other opening 42 is pressed against the projecting piece 21b of the other side plate 21 by a plate spring 44 and positioned in the housing 13.

As shown in FIG. 1, the primary charger 3 is provided with one side block 46 and the other side block 47 on both sides in the longitudinal direction of a metallic shield 45, and the one side block 46 and the other side block 47 are provided in the one side block 46 and the other side block 47. A corotron wire 48 is stretched, and a positioning pin 49 is provided on the one side block 46.
A mounting piece 50 and a connector 51 are provided on the other side block 47, a pair of positioning holes 52, 52 are formed in the mounting piece 50, and a spring shield 53 is mounted on the other side in the longitudinal direction of the shield 45. The spring shield 53 includes a U-shaped fitting piece 54 and a hook-shaped mounting piece 5.
5, the fitting piece 54 is snap-fitted and attached to the shield 45.

The positioning side plate 31 of the housing 13 is formed with a positioning hole 56, and the other side plate 21 is provided with a pair of positioning pins 57, 57.
By moving the primary charger 3 along the cover body 28 as described above, the pair of positioning pins 49, 49 provided on the one side block 46 are fitted to the positioning side plate 31, and the other side block 47 is supported. The primary charging device 3 is positioned in the housing 13 by fitting the positioning holes 52 formed in the piece 50 into the positioning pins 57 provided in the other side plate 21, and as shown in FIGS. The primary charger 3 is attached to the housing 13 by screwing the screw 58 from the hole 50a to the other side plate 21 of the housing 13 from the hole 55a of the attachment piece 55 of the spring shield 53 and the hole 43a of the attachment piece 43 of the grid 33.

As a result, the mounting piece 33 of the grid 33 and the mounting piece 55 of the spring shield 53 come into pressure contact with each other, and the fitting piece 54 of the spring shield 53 comes into pressure contact with the shield 45, so that the shield 45 of the primary charger 3 and the grid 33. Is electrically conductive.

As shown in FIG. 1, an apparatus body side connector 60 is attached to the apparatus body 1 so as to face the connector 51, and the apparatus body side connector 60 comprises a terminal 61 for energizing a corotron wire and a spring. A bias applying terminal 62 is provided, and when the housing 13 is moved in the arrow direction, the connector 51 of the primary charger 3 is fitted to the terminal 61 of the apparatus body side connector 60 as shown in FIG. A high voltage is applied from the main body 1 side, and the shield 45 contacts the bias applying terminal 62 so that the shield 45 and the grid 33 have the same potential.

[0018]

According to the image forming apparatus of the present invention, since the shield and the grid of the charging device are electrically connected to each other and have the same potential, no leak occurs between the shield and the grid. .

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a mounted state of a primary charger and a grid.

FIG. 2 is a side view.

FIG. 3 is a plan view.

FIG. 4 is an exploded perspective view.

FIG. 5 is a schematic explanatory diagram of an image forming apparatus.

FIG. 6 is a plan view of the print cartridge.

FIG. 7 is a left side view.

FIG. 8 is a right side view.

FIG. 9 is a central longitudinal sectional view.

[Explanation of symbols]

2 ... Image carrier, 3 ... Primary charger, 33 ... Grid, 45
… Shield, 53… Spring shield.

Claims (1)

[Claims] 1. An image forming apparatus having an image carrier and a charging device for charging the surface of the image carrier, wherein the charging device includes a corotron wire, a shield covering the periphery of the corotron wire, and the corotron. It has a grid that is provided between the wire and the image carrier and that is biased, and connection means that electrically connects the shield and the grid so that the shield and the grid have the same potential. An image forming apparatus characterized by being a thing.