JPH04217276A - Corona discharge device - Google Patents

Abstract

PURPOSE:To provide a corona discharge device, which can reduce a degree of a supporting member coming into contact with a saw tooth-shaped electrode and improve assembly workability, by decreasing a number of parts of the supporting member coming into contact with an electrode member. CONSTITUTION:An electrode member 10 is formed in a thin flat plate shape, and a plurality of electrodes 11, having directivity in a discharge direction, are formed in a sawtooth-shape by a fixed pitch P1 in the lengthwise direction. In order to arrange the sawtooth-shaped electrode 11 of this electrode member 10 on a straight line, the electrode member 10 is supported into contact from both respective sides, with a non-discharge surface in the lengthwise direction of the electrode member 10 by the first/second supporting members 12, 13. In either one of the first or second supporting member 12, 13, for instance, in the second supporting member 13, a plurality of contact locations 52 are formed to make contact with the non-discharge surface of the above-mentioned electrode member 10 by a predetermined pitch P2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corona discharge device used for charging, transferring, neutralizing, etc. in an electrophotographic image forming apparatus, and particularly to a corona discharge device that is easy to assemble.

0002

[Prior Art] Conventionally, as non-contact type corona discharge devices, wire discharge devices (for example, corotron, scorotron, dicorotron, etc.) or needle-like electrode discharge devices (pin electrode type, sawtooth electrode type, etc.) have been generally used. It is used. Here, since the needle-shaped electrode discharge device generates less ozone (about 1/3 compared to the wire discharge device), it has come to be used in PPC and the like in recent years.

Conventional corona discharge devices of this type include:
For example, there is a method described in Japanese Patent Application Laid-Open No. 63-15272 or U.S. Patent No. 3,691,373, etc., and FIG.
It is shown as follows. What is shown in the figure is a sawtooth electrode type corona discharge device, and the electrode member 10 is formed into a thin flat plate shape of about 0.1 mm or less.
A plurality of electrodes 11 having directivity in the discharge direction shown in the upper part of the figure are formed in a sawtooth shape at a constant pitch in the longitudinal direction. As shown in FIG. 7, this electrode member 10 has first and second support members 1 that are in contact with and sandwich the non-discharge surface from both sides.
The sawtooth electrodes 11 are supported by 2 and 13 so as to be aligned in a straight line. The supported electrode member 10 is fitted into the groove 15 of the holder 14 which becomes the main body of the discharge device, and is fastened with the holding pin 16 as shown in FIG. Note that the electrode member 10 is energized via the energizing terminal 18 connected to the extension portion 17 of the second support member 13 .

As another conventional example, as shown in FIG. 9, leaf springs 20 that support the electrode member 10 and conduct electricity are provided on both sides of the electrode member 10 in the longitudinal direction. Some have achieved straightness.

[0005]

[Problems to be Solved by the Invention] However, in the former type of conventional corona discharge device, the electrode member 10
In the step of sandwiching the serrated electrode 11 between the supporting members 12 and 13, care must be taken to prevent the sawtooth electrode 11 from coming into contact with the supporting members 12 and 13 and being deformed, resulting in problems such as difficulty in handling and poor assembly. Furthermore, even in the latter type of corona discharge device, since the leaf spring material 20 is attached to the thin electrode member 10, care must be taken to prevent deformation or breakage of the electrode member 10.
Again, there was a problem of poor assembly. For this reason, there has been a problem that it is difficult to facilitate or automate mass production assembly.

[0006]

OBJECT OF THE INVENTION Therefore, the invention as claimed in claim 1 provides the following advantages:
It is an object of the present invention to provide a corona discharge device that can reduce the degree of contact between a support member and a sawtooth electrode and can improve assemblability. Furthermore, an object of the invention as set forth in claim 2 is to provide a corona discharge device in which the sawtooth electrode can be easily protected during assembly by bringing the electrode member into contact with the support member while avoiding the extension line of the sawtooth electrode. .

[0007] The invention as set forth in claim 3 also provides a corona discharge device in which ease of assembly can be improved by integrally forming one support member with the discharge device main body and snap-fitting the other support member. The purpose is

[0008]

[Means for solving the problem] The invention according to claim 1 includes:
In order to achieve the above object, an electrode member is provided which is formed into a thin flat plate shape and has a plurality of electrodes having directivity in the discharge direction formed in a sawtooth shape at a constant pitch in the longitudinal direction, and a sawtooth electrode of this electrode member. A corona discharge device comprising two support members that support the electrode member by contacting the non-discharging surface in the longitudinal direction of the electrode member from both sides so as to be arranged in a straight line, wherein either of the two support members The present invention is characterized in that a plurality of contact portions are formed on one side of the electrode member to contact the non-discharge surface of the electrode member at a predetermined pitch.

Further, in order to achieve the above object, the invention as claimed in claim 2 sets the pitch of the contact portions formed on the support member to an integral multiple of the pitch of the sawtooth electrodes formed on the electrode member. , the contact portion is arranged so as to avoid the extension line of the sawtooth electrode. Also,
In order to achieve the above object, the invention according to claim 3 engages one support member on which a contact portion is formed with the discharge device main body by snapping, and the other support member is formed integrally with the discharge device main body. It is characterized by the fact that

0010

[Operation] In the invention according to claim 1 having the above configuration, a plurality of contact parts are formed at a predetermined pitch on one of the two supporting members, and the contact parts are brought into contact with the non-discharge surface of the electrode member. . Further, in the invention according to claim 2 having the above configuration, the formation pitch of the contact portions is set to an integral multiple of the formation pitch of the sawtooth electrodes, and the contact portions are arranged avoiding the extension line of the sawtooth electrodes. .

Further, in the invention as set forth in claim 3 having the above-mentioned configuration, one support member on which the contact portion is formed is engaged with the discharge device main body by a snap fastening, and the other support member is engaged with the discharge device main body. Formed integrally.

0012

EXAMPLES The present invention will be explained below based on examples. 1 to 5 are diagrams showing an embodiment of the invention according to any one of claims 1 to 3. In this embodiment, the same components as those in the above-mentioned example are designated by the same reference numerals, and detailed explanation thereof will be omitted.

First, referring to FIG. 5, a laser printer to which this embodiment is applied will be explained as an example. Printer body 3
0 from the paper feed device 32 by the paper feed roller 31
The recording paper 33 fed in the direction
The image is conveyed to a latent image carrier made of a drum-shaped photoreceptor 35 at a certain timing. The photoreceptor 35 is rotationally driven in a counterclockwise direction, and at this time, its surface is charged by the charging device 36 of this embodiment. Then, an electrostatic latent image is formed on the photoreceptor 35 by being irradiated with laser light L from the laser optical system 37 . This latent image is made visible by toner as it passes through development device 38. This visualized toner image is transferred onto the recording paper 33 that is conveyed to the photoreceptor 35 by the transfer device 39. The transferred toner image on the recording paper is fixed by a fixing device 40. Then, the recording paper 33 that has passed through the fixing device 40 is discharged by a paper discharge roller 41 to a discharge section 42 in the direction of arrow B.

On the other hand, the photoreceptor 35 after the toner image transfer is removed by a cleaning device 44 having a cleaning blade 43.
The residual toner is removed by the static elimination LED 45.
Static electricity is removed by The toner removed from the photoreceptor 35 is collected by a collection auger 46 and stored in a toner collection chamber (not shown). Here, the charging device 36 of the first embodiment is shown as shown in FIG. In the figure, an electrode member 10 is formed into a thin plate shape of about 0.1 mm or less by etching or precision pressing of copper, stainless steel, or the like. Note that the extension portion 50 is used as a current-carrying terminal. Further, plating treatment can be performed if necessary. The sawtooth electrodes 11 are formed at a constant pitch P1 in the longitudinal direction of the electrode member 10, and when the charging device 36 is mounted on a laser printer, the discharge direction thereof is aligned with the photoreceptor 35.
directed towards. This electrode member 10 has first and second support members 12 and 13 so that the sawtooth electrodes 11 are aligned in a straight line.
Supported by

The first support member 12 is formed integrally with the mold case 51 by extending and protruding a part of the mold case 51 forming the main body of the discharge device 36 in the discharge direction and in the axial direction of the photoreceptor 35. has been done. In this way, the first
The reason why the supporting member 12 is formed integrally and not as a separate member is to reduce the number of parts. Note that this embodiment naturally also includes a configuration in which the first support member 12 is a separate member.

The second support member 13 is formed by molding a mold material, and has a plurality of contact portions 52 that contact the non-discharge surface of the electrode member 10 at a predetermined pitch P2, and an opening of the mold case 51. 53 and a snap portion 54 that is engaged with and fastened by a snap stop. In this embodiment, the contact portion 52 is formed in a wave shape with a pitch P2, and contacts the non-discharge surface of the electrode member 10 by the top of the wave portion. The formation pitch P2 of the contact portions 52 is set to be the same as the formation pitch P1 of the sawtooth electrodes 11, or an integral multiple thereof. Then, the top of the wave portion of the contact portion 52 is removed from the extension line of the sawtooth electrode 11 and brought into contact with the non-discharge surface. This allows the snap portion 54 of the second support member 13 to be attached to the opening 5.
3, the contact portion 52 is connected to the serrated electrode 11.
It can be set without touching it. Furthermore, although not shown, if the contact portion 52 is tapered so that the upper portion of the contact portion 52 contacts the electrode member 10, the second support member 13 can be more safely assembled into the mold case 51. I can do it.

The charging device 36 of this embodiment is provided with a grid 55, a grid presser 56, and a grid terminal 57 to improve the discharge characteristics of the sawtooth electrode 11. Here, in the first embodiment, a plurality of contact portions 52 are formed at a predetermined pitch P2 on the second support member 13 of the two support members 12 and 13, and the contact portions 52
By contacting the non-discharge surface of the electrode member 10, the contact area between the electrode member 10 and the second support member 13 can be reduced, making it easier to protect the serrated electrode 11 during assembly, and preventing deformation of the electrode. assembly errors can be reduced. As a result,
It becomes possible to facilitate or automate the mass production assembly of corona discharge devices.

Furthermore, by setting the formation pitch P2 of the contact portions 52 to an integral multiple of the formation pitch P1 of the sawtooth electrodes 11, and arranging the contact portions 52 so as to avoid the extension line of the sawtooth electrodes 11, When assembling the second support member 13, the serrated electrode 11 can be completely protected and assembly errors can be eliminated. Furthermore, the second support member 13 on which the contact portion 52 is formed is engaged with the mold case 51 which becomes the main body of the discharge device by snap-fitting, and the first support member 12 is integrally formed with the mold case 51. The holding pins 16 and the like shown in the conventional example of FIG. 6 can be eliminated, and assembly efficiency can be improved.

FIG. 2 is an exploded perspective view showing the second embodiment. In this embodiment, the formation pitch P2 of the contact portions 52 is
is set to twice the formation pitch P1 of the sawtooth electrodes 11, and the contact area can be reduced compared to the above example. Figure 3 is the third
It is an exploded perspective view showing an example. In this example,
Contact portions 52a on both sides of the second support member 13
, 52b, the plurality of electrode members 10a, 1
0b can be incorporated into one charging device. In this case, the first support members 12a and 12b are the mold case 5.
1 and is integrally formed. Note that the plurality of electrode members 10a, 1
In a corona discharge device incorporating Ob, for example, one can be used as a transfer charging device and the other can be used as a pre-transfer charging device.

FIG. 4 is an exploded perspective view showing a fourth embodiment. In this embodiment, the opening 5 is provided in the second support member 13.
3 is provided, and the molded case 51 is provided with a snap portion 54. Note that the effects in the second to fourth embodiments described above are the same as those in the first embodiment, and will therefore be omitted.

[0021]

As described above, according to the invention as claimed in claim 1, a plurality of contact portions are formed at a predetermined pitch on one of the two support members, and the contact portions are By contacting the non-discharge surface of the electrode member,
The contact portion between the electrode member and the supporting member can be reduced, the sawtooth electrode can be easily protected during assembly, and assembly errors such as deformation of the electrode can be reduced. As a result, mass production and assembly of the corona discharge device can be facilitated or automated.

According to the second aspect of the invention, the pitch at which the contact portions are formed is set to an integral multiple of the pitch at which the sawtooth electrodes are formed, and the contact portions are arranged so as to avoid being on an extension line of the sawtooth electrodes. As a result, the serrated electrode can be completely protected during assembly of the support member having the contact portion, and assembly errors can be eliminated. Further, according to the third aspect of the invention, by engaging the support member on which the contact portion is formed with the discharge device main body by snap-fitting, assembly efficiency can be improved, and other support members can be connected to the discharge device main body. By forming it integrally with the main body, the number of parts can be reduced.

[Brief explanation of the drawing]

[Fig. 1] A first embodiment according to the invention according to any one of claims 1 to 3.
FIG. 2 is an exploded perspective view showing an example.

FIG. 2 is an exploded perspective view showing a second embodiment.

FIG. 3 is an exploded perspective view showing a third embodiment.

FIG. 4 is an exploded perspective view showing a fourth embodiment.

FIG. 5 is a schematic configuration diagram showing a laser printer to which this embodiment is applied.

FIG. 6 is an exploded perspective view showing an example of a conventional corona discharge device.

FIG. 7 is an exploded perspective view showing the main parts of FIG. 6;

FIG. 8 is a sectional view of FIG. 6 after assembly.

FIG. 9 is an exploded perspective view showing the main parts of another conventional example.

[Explanation of symbols]

10　　　Electrode member 11 Serrated electrode 12 First support member 13 Second support member 52 Contact area

Claims (3)

[Claims] Claims: 1. An electrode member formed in a thin flat plate shape, in which a plurality of electrodes having directivity in the discharge direction are formed in a sawtooth shape at a constant pitch in the longitudinal direction, and the sawtooth electrodes of the electrode member are arranged in a straight line. A corona discharge device comprising two supporting members that support the electrode member by contacting the non-discharging surface in the longitudinal direction of the electrode member from both sides so as to be lined up. A corona discharge device characterized in that a plurality of contact portions are formed at a predetermined pitch on a non-discharge surface of an electrode member. 2. The pitch of the contact portions formed on the support member is set to an integral multiple of the pitch of the sawtooth electrodes formed on the electrode member, and the contact portions are arranged avoiding an extension line of the sawtooth electrodes. The corona discharge device according to claim 1, characterized in that: 3. The electric discharge device according to claim 1, wherein one support member on which a contact portion is formed is engaged with the discharge device main body by a snap fastening, and the other support member is formed integrally with the discharge device main body. Corona discharge device.