JPH0659559A - Device for electrostatically charging photosensitive body - Google Patents

Abstract

PURPOSE:To facilitate the grounding of the electrostatic charger and the grid plate of a device for electrostatically charging a photosensitive body. CONSTITUTION:The grid plate 31 is spanned between the right and left side plates 32a and 32b of a photosensitive body case 32 where a photosensitive body 12 is housed. The electrostatic charger 30 is fitted in the recessed part 32f of the case 32 and opposed to the surface of the photosensitive body 12 through the grid plate 31. A projection 39b is integrally formed in the device case 39 of the electrostatic charger 30 and pressed to the grid plate 31 when the electrostatic charger 30 is fitted, so that the case 39 is brought into contact with the grid plate 31 to electrically conduct between both of them and attain the attaching position of the grid plate 31 by aligning. Then, the case 39 is connected to the main frame of an electrophotographic recorder, for example, so as to be grounded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention can be applied to an electrophotographic recording apparatus for recording on a sheet by an electrophotographic system, such as a printer, a copying machine and a facsimile, which uses a laser. More specifically, the present invention relates to a photoconductor charging device in which a charging device is provided so as to face the surface of a photoconductor, which is an image bearing member, with a grid plate serving as a grid electrode facing the surface of the photoconductor.

[0002]

2. Description of the Related Art Conventionally, in this type of photoconductor charging device, a grid plate is supported by a photoconductor case for accommodating the photoconductor,
Alternatively, the end block that supports the corona discharge wire of the charger is configured to support the grid plate and position the mounting position of the grid plate, and the grid electrode is applied to the grid plate to charge the surface of the photoconductor. The potential was controlled.

[0003]

However, in the conventional photoconductor charging device, since the grid plate and the charger are not electrically connected to each other, the grid plate and the charger must be individually grounded. It was troublesome.

Therefore, an object of the present invention is to facilitate grounding of a charger and a grid plate of a photoconductor charging device.

[0005]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
A charger 30 is provided on the surface of the photoconductor 12 via a grid plate 31.
In the photoconductor charging device 13 that is provided to face each other, the container case 39 of the charger 30 and the grid plate 31 are brought into contact with each other to electrically conduct them.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiments, in the photoconductor charging device 13 according to the first aspect, the projection 39b.3 is provided on the container case 39.
9b is provided, and the projections 39b and 39b are pressed against the grid plate 31, the container case 39 and the grid plate 31 are brought into contact with each other, and the mounting position of the grid plate 31 is positioned.

[0007]

According to the first aspect of the present invention, when grounded, the container case 39 of the charger 30 or the grid plate 31.
Either one is grounded.

According to the second aspect, when assembled, the grid plate 3 is formed by the projections 39b, 39b of the container case 39.
Locate the mounting position of 1.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a laser printer including a photoconductor charging device according to an embodiment of the present invention, and shows an overall schematic structure of an internal mechanism thereof.

Reference numeral 10 in the drawing is a main body of the apparatus. A belt-shaped photoreceptor 12 is provided in the main body 10 of the apparatus at substantially the center thereof. Around the photoconductor 12, the photoconductor charging device 13, the developing device 14, the transfer device 15, and the cleaning device 16 of the present invention are arranged in order in the driving direction indicated by the arrow in the figure. An optical writing device 17 is arranged above the photoconductor charging device 13 and the cleaning device 16.

Further, a paper feeding device 20 is provided below the device body 10. A paper feed cassette 21 accommodating sheets S is detachably attached to the paper feed device 20. Then, on the upper right side of the sheet feeding cassette 21 in the figure, the rubber feeding roller 2
2 is provided.

However, when recording is performed using the illustrated laser printer, the sheet S in the paper feed cassette 21 is
The sheet feeding roller 21 of the sheet feeding device 20 is rotated and fed in the direction of arrow A in the figure, and abutted against the pair of registration rollers 23 to be stopped. Then, the registration roller pair 23 conveys the sheet S to the lower side of the photoconductor 12 at a timing. The photoconductor 12 is driven in the clockwise direction indicated by the arrow, and at that time, the surface of the photoconductor 12 is uniformly charged by the photoconductor charging device 13, and the laser light L from the optical writing device 17 is irradiated to the photoconductor 12 so that the photoconductor 12 is statically charged. Form a latent image. This latent image is visualized by toner as it passes through the position of the developing device 14. Then, this visible image is transferred by the transfer device 15 onto the upper surface of the sheet S conveyed to the lower side of the photoconductor 12. After the image transfer, the sheet S is guided by the conveyance guide 24 and conveyed to the fixing device 25,
The transfer device is fixed by the fixing device 25. Then, the sheet S exiting the fixing device 25 is further conveyed by the sheet ejection roller 26 and ejected in the direction of arrow B or C in the figure.

On the other hand, after the image transfer, the photosensitive member 12 is cleaned by a cleaning device 16 to remove residual toner, and then discharged by a discharging device 27.

The photoconductor 12 is housed in a photoconductor case 32, as shown in FIG. The photoconductor case 32 is formed in a box shape using an insulating material. The left and right side plates 32a and 32b are respectively provided with small window holes 32c at the upper part of the photoconductor case 32, and the tip end is bent outward at a right angle from the lower side edge of the right small window hole 32c in the figure. And the protrusion 32d is integrally provided. Further, the right side plate 3 is slightly attached to the upper surface 32e of the photoconductor case 32.
It is recessed toward the 2b side to provide a horizontally long concave hole 32f in the figure.

Below the recess 32f, the grid plate 31 of the photoconductor charging device 13 is installed. The grid plate 31 is formed of a conductive thin plate member such as stainless steel in a laterally long shape, and one end thereof is hooked on the protrusion 32d through a small window hole 32c on the right side in the figure, while the other end is small on the left side in the figure. It is provided through the window hole 32c, and one end of the tension spring 35 is hooked on the other end side. The tension spring 35 is
A gap 36 between the left side plate 32a and the side wall portion 32g of the recessed hole 32f
And the grid plate 31 is tensioned.

The charger 30 of the photoconductor charging device 13 is provided in the recess 32f of the photoconductor case 32. The charging device 30 has a container case 39 formed in a horizontally long box shape in the figure, and includes end blocks (not shown) inside both ends in the longitudinal direction, and the end blocks are provided between the end blocks in FIGS.
The corona discharge wire 40 shown in FIG. In the container case 39 of the charger 30, as shown in FIG. 1, the protrusions 39b are projected downward to the lower surface from both ends.
・ Form 39b integrally. Those protrusions 39b and 39
As shown in FIG. 2, b is formed in a substantially U-shape in an upward cross section, and connects the long side plate portions 39a, 39a of the container case 39. Then, as shown in FIG.
The charger 30 is fitted into the recessed hole 32f of the second portion, and the projection 39b.
39b is pressed against the grid plate 31, and the container case 39
And the grid plate 31 are brought into electrical contact with each other and the mounting position of the grid plate 31 is positioned.

Further, as shown in FIG. 2, one end of a leaf spring 42 attached at an appropriate position is brought into contact with the container case 39 of the charger 30. The container case 39 is grounded via the leaf spring 42. Reference numeral 39c in FIG. 3 is a bent portion in which the lower edge of the container case 39 is bent slightly inward.

[0018]

Therefore, according to the first aspect of the present invention, when grounding, either the container case of the charger or the grid plate is grounded, so that the charger and the grid plate are grounded separately. The trouble can be saved.

According to the second aspect, since the mounting position of the grid plate is positioned by the projection of the container case when assembled, it is possible to omit a separate member for positioning the grid plate.

[Brief description of drawings]

FIG. 1 is a partial configuration diagram of a laser printer showing a photoconductor charging device according to an embodiment of the present invention.

FIG. 2 is an end view of a section taken along the line EE.

FIG. 3 is an end view of a section taken along the line FF.

FIG. 4 is an overall schematic configuration diagram of an internal mechanism of a laser printer including the photoconductor charging device.

[Explanation of symbols]

 12 Photoreceptor 13 Photoreceptor Charging Device 30 Charger 31 Grid Plate 39 Device Case 39b Protrusion

Claims (2)

[Claims] 1. A photoconductor charging device comprising a charging device facing the surface of a photoconductor via a grid plate, wherein a container case of the charging device and the grid plate are brought into contact with each other to electrically conduct the two. A photoconductor charging device. 2. The projection is provided on the container case, the projection is pressed against the grid plate, the container case and the grid plate are brought into contact with each other, and the mounting position of the grid plate is positioned. The photoconductor charging device according to.