JPH03223773A - Corona discharger - Google Patents

Abstract

PURPOSE:To give tension to a corona wire and a grid electrode by freely rotatively attaching an end block to a casing centering around its intermediate position and balancing moment centering around a fulcrum by means of one spring. CONSTITUTION:When the corona wire 17 and the grid electrode 19 are attached to the end block 15 freely rotatively attached to the casing 14, one end of the corona wire 17 whose other end is fixed on the other end block is engaged with a hook 18 via a spring 23. The end block 15 is rotated clockwise centering around a pin 21 with respect to the tension of the spring 23, and one end of the grid electrode 19 whose other end is fixed on the other end block is engaged with a hook 20. When the grid electrode 19 is attached in such a manner, the end block is rotated counterclockwise centering around the pin 21 by the tension of the spring 23, and the spring 23 balances with the moment centering around the pin 21. Thus, the tension is given to the corona wire 17 and the grid electrode 19 by the tension of one spring 23.

Description

[Detailed description of the invention] Production 1”! ■11 starvation The present invention includes a corona wire stretched inside a casing,
The present invention relates to a scorotron type corona discharger having a grid electrode stretched over an opening of a casing.

The above-mentioned type of corona discharger is well known, and a laser printer using an electrostatic electrophotographic process.

Used in copy machines, facsimiles, etc. This corona discharger charges and neutralizes the surface of a chargeable body, applies corona ions to form an electrostatic latent image on a photoreceptor, and uses an electric field to transfer a developed toner image to a recording paper. It is used to form etc.

Among this type of corona discharger, the scorotron type with a grit electrode has lower charging efficiency than the corotron type, but it has been widely adopted because it has excellent uniformity of charging potential. It has become. The grit electrode of this corotron type corona discharger uses several wires or a mesh plate etched with stainless steel of about 0°11.

In such a discharge device, it is common to apply tension to the corona wire and the grid electrode. This is because the corona discharge that occurs at the corona wire becomes unstable when the corona wire or the like is sagging, causing unevenness in the potential and charge on the light body. Such unevenness has a negative effect on the quality of the image.

Therefore, conventionally, as shown in FIG. 9, the corona wire 5
1 and grit electrode 52 were applied tension to the end block 50 using separate springs 53 and 54, respectively.

However, applying tension to the corona wire S1 and the grid electrode 52 using separate springs 53 and 54 has the problem of requiring a large number of parts and requiring a large number of assembly steps.

The present invention aims to provide a corona discharger in which the corona wire and the grid electrode can be tensioned by a common spring.

means to The structure of the present invention that achieves the above object is as follows.

In a scorotron type corona discharger having a corona wire stretched inside a casing and a grit electrode stretched over an opening of the casing, an end block supporting the corona wire and the grit electrode is connected to the corona wire and the grit electrode. It is rotatably mounted on the casing with a midpoint between the electrode and the electrode as a fulcrum, and a spring is provided between either one of the corona wire or the grit electrode and the end block, and the spring balances the moment about the fulcrum. A corona discharger characterized by applying tension to a corona wire and a grid electrode.

Effects According to the above configuration, the end block supporting the corona wire and the grit electrode is rotatable in the casing using the intermediate position as the fulcrum, so that the corona wire and the grit electrode are supported by one spring by balancing the moment about the fulcrum. tension is applied to the

Nu】11 Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a laser printer equipped with a corona discharger according to the present invention.

In FIG. 1, recording paper 2 fed in the direction of arrow A from paper feeder ff is timed by a pair of registration rollers 3 and transported to a latent image carrier consisting of a drum-shaped photoreceptor 4. The photoreceptor 4 is rotationally driven in a clockwise direction, and its surface is charged by the charging charger 5 at this time. Then, it is irradiated with laser light from the laser optical system 6 to form an electrostatic latent image on the photoreceptor. This latent image is processed by the developing device 7.
When passing through the photoreceptor 4, the toner forms a visible image, and this visible image is transferred to the recording paper 2, which is conveyed to the photoreceptor 4 by the transfer/separation charger 8, and the recording paper 2 that is in close contact with the photoreceptor 4 is electrostatically be separated. after that.

A visible image is fixed on the recording paper 2 by a fixing device 9, and the recording paper 2 is sent in the direction of arrow B and discharged to a discharge section 10.

On the other hand, residual toner is removed from the photoreceptor 4 after the visible image has been transferred by a cleaning device 11 having a cleaning blade 12. The toner removed from the photoreceptor is collected in a toner collection tank 13 and stored there.

In this embodiment, a scorotron type corona discharger is used as the charging charger 5, as shown in FIGS. 2 and 3. Note that a scorotron type corona discharger may be used as the transfer/separation charger 8. This corona discharger includes a casing 14, and an end block 15 is attached to the end of the casing 14. A support plate 16 is formed approximately in the center of one of the end blocks 15, and this support plate 16 is set at approximately half the height of the casing 14, and a corona wire 17 is attached to the upper end of the support plate 16. A hook 18 for locking is provided.

Hooks 2o are provided on both sides of the upper end of the end block 15 for locking a grid electrode 19 formed in the shape of a mesh plate. In addition, a pin 21 is integrally provided on the end block 15 at the same position on both sides thereof and at a position intermediate between the hook 18 and the hook 20, and the pin 21 is fitted into the hole 22 of the casing 14. . With this configuration, the end block 15 is rotatable relative to the casing 14 about the pin 21 as shown in FIGS. 4 and 5.

Note that the other end block, not shown, is fixed to the casing 14.

Here, a corona wire 17 and a grit electrode 19 are attached to an end block 15 rotatably attached to the casing 14.
When installing the corona wire 17, one end of the corona wire 17, the other end of which is fixed to the other end block, is locked to the hook 18 via the spring 23. At this time, the end block 15
rotates counterclockwise around pin 21, and is held at the position shown in FIG. 6 by an appropriate stopper (not shown).

Next, as shown in FIG. 7, the end block 15 is rotated clockwise about the pin 21 against the tensile force of the spring 23, and one end of the grit electrode 19, whose other end is fixed to the other end block, is rotated clockwise. It is secured to the hook 20. When the grit electrode 19 is attached in this way, it rotates counterclockwise about the pin 21 due to the tension of the spring 23, and the spring 23 balances the moment about the pin 21. Therefore, the length of the grit electrode 19 Accordingly, the position of the end block 15 is determined as shown in FIG.

Thus, due to the tensile force of one spring 23,
Tension is applied to the corona wire 17 and the grid electrode 19.

According to the above-mentioned configuration, the present invention can apply tension to the corona wire and the grid electrode with only the tensile force of one spring, so the number of parts is reduced and the ease of assembly is improved.

[Brief explanation of drawings]

FIG. 1 is an overall view of a printer to which a corona discharger according to the present invention is applied, FIG. 2 is an explanatory diagram showing one end side of the corona discharger, and FIG. 3 is a longitudinal sectional view of FIG. Figures 4 and 5
The figure is an explanatory diagram showing the movement of the end block, Fig. 6 is an explanatory diagram with the corona wire attached, Fig. 7 is an explanatory diagram of the grit electrode installation, and Fig. 8 is an explanatory diagram with the corona wire and grit electrode installed. FIG. 9 is an explanatory diagram showing one end side of a conventional corona discharger. 14...Casing 15...End block 17...Corona wire 20...Grit Electrode 21... Pin 23... Spring Figure 6 Figure 7

Claims (1)

[Scope of Claims] A scorotron type corona discharger having a corona wire stretched inside a casing and a grit electrode stretched over an opening of the casing, comprising: an end supporting the corona wire and the grit electrode; A block is rotatably mounted on the casing with a midpoint between the corona wire and the grid electrode as a fulcrum, and a spring is provided between either one of the corona wire or the grit electrode and the end block, and the spring supports the fulcrum. A corona discharger characterized in that tension is applied to a corona wire and a grid electrode by moment balance at the center.