JPH09148088A - Static electricity discharging structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the noise generated from a printed board from emission to outside through an electric conductive part such as a rotary member by discharging the static electricity charged on the rotary member, etc. SOLUTION: A conductive spring 1 is installed upright on a ground pattern provided on a printed board and arranged contactlessly from a conductive member 2 connected electrically with a rotary member, etc., on which the static electricity is charged, and between them an insulative member such as insulative tape is interposed, or otherwise the space is left as a gap. The static electricity charged on the conductive member is released through this space between the spring 1 and member 2, and the noise generated from the printed board, etc., is precluded from flowing into the conductive member 2. It may also be accepted that the tip of the spring 1 is contacted with the conductive member 2, that the spring 1 is attached onto the insulation part near that part of board Pt where the ground pattern GP is exposed, and that the static electricity is released through the gap between the spring 1 and ground pattern GP.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static electricity discharge structure for discharging static electricity charged on a rotating member such as a printer or a paper feeding device to the ground.
When the above static electricity is discharged through the conductive member to the ground pattern of the printed board provided in the printer, the paper feeder, etc., noise generated in the printed board causes rotation of the printer, the paper feeder, etc. through the conductive member. Flowing into the members,
The present invention relates to an electrostatic discharge structure capable of preventing radiation to the outside.

[0002]

2. Description of the Related Art A printer or a paper feeding device installed in a printer or a scanner is provided with rotating members for feeding sheets, and these rotating members are charged with static electricity. When static electricity is charged on the rotating member,
This static electricity may be discharged to electric parts such as a motor and cause the device to malfunction, so that it is necessary to provide the static electricity discharging means. In recent years, resin is often used for gears and the like that drive the rotating member, and in many cases static electricity charged on the rotating member and the like cannot be discharged through a mechanical portion such as the gear. Therefore, in general, a conductive spring or the like that comes into contact with the conductive member such as the rotating member is provided, and the conductive spring or the like is grounded to discharge static electricity.

FIG. 8 is a diagram showing an example of the electrostatic discharge structure described above. In the figure, 1 is a conductive spring, 2 is a conductive member electrically connected to the above-mentioned rotating member or the like charged with static electricity, Pt is a printed board, and GP is a ground pattern on the printed board Pt. . As shown in the figure, one end of the conductive spring 1 is connected to the ground pattern GP of the printed board Pt, and the other end is in contact with, for example, the conductive member 2 rotating in the direction of the arrow in FIG. The charged static electricity is discharged to the ground pattern GP via the conductive spring 1.

[0004]

By the way, in the electrostatic discharge structure shown in FIG. 8, the conductive spring 1 and the conductive member 2 connected to the ground pattern GP of the printed board Pt are in electrical contact with each other. The noise generated in the printed board Pt flows into the conductive member 2 through the conductive spring 1. Therefore, there is a problem that radiation noise is radiated to the outside through the conductive member and affects other devices. The present invention has been made in consideration of the above-mentioned problems of the prior art, and an object of the present invention is to discharge static electricity charged in a conductive member such as a rotating member,
It is to prevent noise generated on a printed board or the like from flowing into the conductive member and being radiated to the outside.

[0005]

FIG. 1 is a diagram showing the basic configuration of the present invention. In the figure, 1 is a conductive spring, 2 is a conductive member that is electrically connected to the above-mentioned rotating member that is charged with static electricity, Pt is a printed board, and GP is a ground pattern of the printed board. In FIG. 1, the present invention solves the above-described problems in the following (1) or (2). (1) In the portion A of FIG. 1, the conductive spring 1 and the conductive member 2 are not in contact with each other, and an insulating member such as an insulating tape or a gap is provided between them (in this case, the conductive spring 1).
And the ground pattern GP are electrically connected).
Then, static electricity is discharged through the gap between the conductive spring 1 and the conductive member 2 so that noise generated on the printed board or the like does not flow into the conductive member 2. (2) In the portion B of FIG. 1, the conductive spring 1 is attached to the insulating portion in the vicinity of the exposed portion of the ground pattern GP of the printed board Pt (in this case, the tip end of the conductive spring 1 and the conductive member 2). Are in contact). Then, static electricity is discharged through the gap between the conductive spring 1 and the ground pattern GP so that noise generated on the printed board or the like does not flow into the conductive member 2.

The inventions of claims 1 to 4 of the present invention are based on the above (1).
Since it is configured as in (2), the static electricity charged in the conductive member can be discharged by a simple mechanism, and noise generated in a printed board or the like having a low voltage level flows into the conductive member. It is possible to prevent radiation to the outside.

[0007]

FIG. 2 is a diagram showing a first embodiment in which the present invention is applied to a hopper unit for supplying a sheet to a printer or the like. In FIG. 2A, 10 is a hopper unit, 11 is a paper feeding roller, 12 is a conductive shaft, 13 is a motor for driving the paper feeding roller 11, and a rotary shaft of the motor 13 and the paper feeding roller 11 are provided. A gear mechanism formed of an insulating material such as resin is provided, and when the motor 13 is driven, the paper feed roller 11 is driven in the direction of the arrow in the figure and the paper (not shown) set in the hopper unit 14 is shown. Is sent to a printer or the like.

Further, the paper feed roller 11 is attached so as to be movable in the vertical direction with the conductive shaft 12 as a fulcrum.
When the height of the sheets stacked on the hopper unit 14 becomes lower, the sheet feeding roller 11 moves downward accordingly. The shaft of the paper feed roller 11 is formed of a conductive member, and the paper feed roller shaft and the conductive shaft 12 are electrically connected by a bearing portion or the like. Pt is a printed board on which an electronic circuit for controlling the hopper unit 10 is mounted. As shown in the figure, the ground pattern GP of the printed board Pt is exposed, and one end of the conductive spring 1 is attached thereto. The
The conductive spring 1 and the ground pattern GP are electrically connected. The other end of the conductive spring 1 is in contact with the conductive shaft 12 via the insulating tape T as shown in FIG.

In the above structure, when the paper is fed, the paper feed roller 11 is charged with static electricity, and the static electricity is charged on the conductive shaft 12 via a bearing portion (not shown). The static electricity charged on the conductive shaft 12 is discharged to the conductive spring 1 via the insulating portion between the conductive shaft 12 and the conductive spring 1, and flows to the ground pattern GP via the conductive spring 1. On the other hand, noise generated in the printed board Pt has a low voltage level, so it is blocked by the insulating portion between the conductive spring 1 and the conductive shaft 12, and does not flow into the conductive shaft 12. Therefore, noise generated in the printed board Pt is radiated to the outside and does not affect other devices or the like.

In order to confirm the effect of the above-described embodiment, an insulating tape having a thickness of 2 mm or less is used, and the distance between the conductive spring 1 and the end of the insulating tape T is 1 as shown in FIG. 2 (b). ~
When the hopper unit was operated with a thickness of about 3 mm, the static electricity charged on the paper feed roller 13 could be discharged through the conductive spring 1, and the effect of this embodiment could be confirmed.

FIG. 3 is a view showing a second embodiment of the present invention. In this embodiment, an insulating sheet St having a hole H acting as a discharge passage is provided between the conductive spring 1 and the conductive shaft 12. It is provided. Also in this embodiment, the static electricity charged on the paper feed roller 13 and the like can be discharged through the hole H, and the same effect as that of the first embodiment can be obtained. Further, instead of using the insulating sheet St having the holes H as described above, two insulating members I as shown in FIG. 4 are used.
S may be wound around the conductive shaft 12.

FIG. 5 is a diagram showing a third embodiment of the present invention. In this embodiment, as shown in FIG. 5, the conductive spring 1 and the conductive shaft 12 are separated by a distance such that static electricity can be discharged. , They are facing each other. Also in this embodiment, the paper feed roller 1
The static electricity charged to 3 etc., the conductive spring 1 and the conductive shaft 12
It can be discharged through a gap between the first
The same effect as that of the embodiment can be obtained.

FIG. 6 is a diagram showing a fourth embodiment of the present invention. In this embodiment, as shown in the figure, the conductive shaft 2 and the conductive spring 1 are brought into contact with each other to be electrically connected to each other, and the insulating layer IP formed on the ground pattern GP is formed.
The conductive spring 1 is attached on the top of the ground pattern GP to expose the ground pattern GP in the vicinity thereof. In this embodiment, static electricity charged on the paper feed roller 13 and the like is applied to the conductive spring 1.
The discharge can be performed through the gap between the exposed portions of the ground pattern GP and the ground pattern GP, and the same effect as in the first embodiment can be obtained.

In the above embodiment, the conductive spring 1 is provided on the circumferential portion of the conductive shaft 12, but as shown in FIG. 7, the conductive spring 1 is provided on the shaft end portion of the conductive shaft 12. May be provided. Further, in the above-mentioned embodiment, the case where the static electricity charged in the paper feed roller of the hopper unit is discharged has been described, but the present invention is not limited to the above-mentioned embodiment, and a printer device, a scanner, a fax machine, a copying machine. It can be applied to various devices that are charged with static electricity such as.

[0015]

As described above, in the present invention, the conductive spring and the conductive member charged with static electricity are not in contact with each other, and an insulating member such as an insulating tape or a gap is provided between them. Alternatively, the conductive spring and a conductive member that is charged with static electricity are brought into contact with each other, and the conductive spring is mounted on the insulating portion in the vicinity of the exposed portion of the ground pattern of the printed board. It is possible to discharge static electricity charged on the member and prevent noise generated on the printed board or the like from flowing into the conductive member. Therefore, it is possible to prevent malfunction of various devices due to static electricity, and also to prevent noise generated on the printed board or the like from being radiated to the surroundings.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram showing a first embodiment in which the present invention is applied to a hopper unit.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a modification of the second embodiment.

FIG. 5 is a diagram showing a third embodiment of the present invention.

FIG. 6 is a diagram showing a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a case where a conductive spring is provided at the end of the conductive shaft.

FIG. 8 is a diagram showing a conventional electrostatic discharge structure.

[Explanation of symbols]

 1 Conductive Spring 2 Conductive Member Pt Printed Board GP Ground Pattern 10 Hopper Unit 11 Paper Feed Roller 12 Conductive Shaft 13 Motor 14 Hopper Part T Insulation Tape IP Insulation Layer IS Insulation Member H Hole

Claims (4)

[Claims] 1. In a static electricity discharge structure for discharging static electricity charged in a mechanism portion composed of a rotating member and the like to a ground pattern of a printed board, a conductive spring for electrostatic discharge is erected on the ground pattern of the printed board. An insulating member is provided between the tip of the conductive spring for electrostatic discharge and a conductive member electrically connected to a mechanism portion charged with static electricity, and the insulating member is connected to the conductive member by the conductive spring. By pressing in the direction, the distance between the tip of the conductive spring and the conductive member is maintained at a distance at which static electricity can be discharged, and the gap between the tip of the conductive spring and the conductive member and A static electricity discharging structure characterized in that static electricity charged in a mechanical portion composed of the rotating member and the like is discharged to a ground pattern of a printed board through a conductive spring. 2. The electrostatic discharge structure according to claim 2, wherein an insulating member having a passage for discharging static electricity is provided between the tip of the conductive spring and the conductive member charged with static electricity. 3. In a static electricity discharge structure for discharging static electricity charged in a mechanism portion composed of a rotating member and the like to a ground pattern of a printed board, a conductive member for electrostatic discharge is erected on the ground pattern of the printed board. A gap capable of discharging static electricity is provided between the tip of the conductive member for electrostatic discharge and the conductive member electrically connected to the mechanism portion charged with static electricity. A static electricity discharging structure characterized in that static electricity charged in a mechanical portion composed of the rotating member and the like is discharged to a ground pattern of a printed board through the conductive member. 4. A static electricity discharging structure for discharging static electricity charged in a mechanism portion composed of a rotating member or the like to a ground pattern of a printed board, wherein the ground pattern of the printed board is on an insulating portion near the exposed portion. And a conductive member for electrostatic discharge is erected at a position separated from the ground pattern by which static electricity can be discharged, and the tip end of the conductive member for electrostatic discharge and a mechanism part for charging static electricity. A conductive member electrically connected to is contacted with the conductive member for electrostatic discharge and a gap between the conductive member and the ground pattern is charged to the mechanism portion including the rotating member and the like. A static electricity discharge structure characterized by discharging static electricity to the ground pattern of the printed board.