JP3075970B2 - Electrostatic discharge structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Rotary members for feeding paper are provided in printers, paper feeders installed in printers, scanners, and the like, and these rotary members are charged with static electricity. When static electricity is charged on the rotating member, etc.,
This static electricity is discharged to an electric component such as a motor, for example, and the device may malfunction. Therefore, it is necessary to provide a means for discharging the static electricity. In recent years, resin is often used for a gear or the like for driving the rotating member, and static electricity charged to the rotating member or the like cannot be discharged through a mechanism such as the gear in many cases. Therefore, usually, 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 above-mentioned electrostatic discharge structure. In the figure, 1 is a conductive spring, 2 is a rotating member made of the above conductive member charged with static electricity, P
t 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,
The other end is in contact with the rotary member 2 rotating in the figure the direction of the arrow for example, static electricity charged to the rotary member 2 is conductive spring 1
Through the ground pattern GP.

[0004]

By the way, in the electrostatic discharge structure shown in FIG. 8, the conductive spring 1 connected to the ground pattern GP of the printed board Pt and the rotating member
2 are in electrical contact, and noise generated on the printed board Pt flows into the rotating member 2 via the conductive spring 1. For this reason, there has been a problem in that radiation noise is radiated to the outside via the rotating member and affects other devices. The present invention has been made in consideration of the above-described problems of the related art, and an object of the present invention is to discharge static electricity charged on a rotating member and to reduce noise generated on a printed board or the like. The purpose is to prevent the gas from flowing into the rotating member and being radiated to the outside.

[0005]

FIG. 1 is a diagram showing a basic configuration of the present invention. In the figure, 1 is a conductive spring, 2 is a rotating member charged with the above-mentioned static electricity, Pt is a printed board, and GP is a ground pattern of the printed board. FIG.
In the present invention, the above-mentioned problem is solved as in the following (1) or (2). (1) In part A of FIG. 1, the conductive spring 1 and the rotating member 2 are not in contact with each other, and an insulating member such as an insulating tape is provided therebetween (in this case, the conductive spring 1 and the ground pattern G).
P is electrically connected). And the conductive spring 1
Static electricity is discharged through a gap between the rotating member 2 and the rotating shaft 2 so that noise generated on a printed board or the like does not flow into the rotating member 2. (2) At the portion B in FIG. 1, the conductive spring 1 is mounted on the insulating portion near the portion where the ground pattern GP of the printed board Pt is exposed (in this case, the tip of the conductive spring 1 and the rotating member 2 Contact). Then, static electricity is discharged through a gap between the conductive spring 1 and the ground pattern GP, and noise generated on a printed board or the like is generated by the conductive member 2.
To prevent inflow.

The invention of claims 1 to 3 of the present invention provides the above (1)
With the configuration as described in (2), static electricity charged on the conductive member can be discharged by a simple mechanism, and noise generated on a printed board or the like having a low voltage level flows into the conductive member. Radiation to the outside can be prevented.

[0007]

FIG. 2 is a diagram showing a first embodiment in which the present invention is applied to a hopper unit for supplying sheets to a printer or the like. In FIG. 2A, reference numeral 10 denotes a hopper unit, 11 denotes a paper feed roller, 12 denotes a conductive shaft, and 13 denotes a motor for driving the paper feed roller 11. A gear mechanism formed of an insulating material such as resin is provided. When the motor 13 is driven, the paper feed roller 11 is driven in the direction of the arrow in FIG. Is sent to a printer device or the like.

The paper feed roller 11 is mounted movably up and down with the conductive shaft 12 as a fulcrum.
When the height of the sheets stacked on the hopper unit 14 decreases, the sheet feeding roller 11 moves downward accordingly. The shaft of the feed roller 11 is formed of a conductive member, and the feed roller shaft and the conductive shaft 12 are electrically connected at a bearing portion or the like. Pt is a printed board on which an electronic circuit or the like for controlling the hopper unit 10 is mounted, and as shown in FIG. And
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-described configuration, when static electricity is charged on the paper feed roller 11 by feeding a sheet, the static electricity is charged on the conductive shaft 12 via a bearing portion (not shown) or the like. The static electricity charged on the conductive shaft 12 is discharged to the conductive spring 1 via an 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, the noise generated on the printed board Pt has a low voltage level, and 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. For this reason, noise generated in the printed board Pt is radiated to the outside and does not affect other devices and the like.

In order to confirm the effect of the above 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 set to 1 as shown in FIG. ~
When the hopper unit was operated at about 3 mm, the static electricity charged on the paper feed roller 13 could be discharged via the conductive spring 1, and the effect of the present embodiment could be confirmed.

FIG. 3 is a view showing a second embodiment of the present invention. In this embodiment, an insulating sheet St provided with a hole H acting as a discharge passage is provided between a conductive spring 1 and a 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 provided with the holes H as described above, as shown in FIG.
S may be wound around the conductive shaft 12.

[0012] FIG. 5 is conductive spring 1 and the conductive shaft 12
Are separated from each other by such a distance as to discharge static electricity . Even in such a configuration , the static electricity charged on the paper feed roller 13 and the like is passed through the gap between the conductive spring 1 and the conductive shaft 12. it is possible to discharge Te.

FIG. 6 is a diagram showing a third embodiment of the present invention. In the present embodiment, as shown in the figure, the conductive shaft 2 and the conductive spring 1 are brought into contact with each other so as to be electrically connected, and the insulating layer IP formed on the ground pattern GP is formed.
The conductive spring 1 is mounted thereon, and the ground pattern GP near the conductive spring 1 is exposed. In the present embodiment, the static electricity charged on the paper feed roller 13 and the like is transferred to the conductive spring 1.
And the ground pattern GP can be discharged through a gap between the exposed portions, and the same effect as in the first embodiment can be obtained.

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

[0015]

As described in the foregoing, in the present invention, a rotary member which conductive spring and static electricity is charged a non-contact, or provided insulation member such as an insulating tape therebetween, or, conductive spring And the rotating member, which is charged with static electricity, is brought into contact with the conductive spring, and the conductive spring is mounted on the insulating portion near the portion where the ground pattern of the printed board is exposed.
With a simple mechanism, static electricity charged on the rotating member can be discharged, and noise generated on a printed board or the like can be prevented from flowing into the rotating member. For this reason, malfunctions of various devices due to static electricity can be prevented, and noise generated in a printed board or the like can be prevented 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 shows a gap provided between a conductive spring and a conductive shaft.
It is a figure showing a case .

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

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

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 conductive spring 2 rotating member Pt printed board GP ground pattern 10 hopper unit 11 paper feed roller 12 conductive shaft 13 motor 14 hopper section T insulating tape IP insulating layer IS insulating member H hole

Continuation of the front page (56) References JP-A-7-181776 (JP, A) JP-A-7-241364 (JP, A) JP-A-4-325852 (JP, A) JP-A-1-92100 (JP) , U) Actually open 60-80700 (JP, U) Actually open 56-32477 (JP, U) Actually open 1541-1426 (JP, U) Actually open 61-21736 (JP, U) Actually open 63-175637 (JP, U) Japanese Utility Model Showa 57-10066 (JP, U) Japanese Utility Model Utility Model 55-114996 (JP, U) Japanese Utility Model 1-29799 (JP, Y2) Japanese Utility Model 6-17276 (JP, U) Y2) Jigyo Hei 3-11839 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05F 3/00-3/06 H01T 1/00-4/20 G03G 13/04- 21/00 B65H 1/00-3/68 B41J 29/00

Claims (3)

(57) [Claims] 1. Paper feeder installed in a printer, scanner, etc.
The static electricity charged in the mechanism section composed of the rotating members of the device causes the noise generated by the printed board to flow into the mechanism section.
A static electricity discharging structure for discharging without static electricity, a conductive spring for electrostatic discharge is erected on the ground pattern of the printed board that generates noise, and the tip of the conductive spring for electrostatic discharge is Between the above-mentioned rotating members where static electricity is charged
The insulating member is provided, by pressure with the insulating member to the rotating member direction by the conductive spring tip and the rotation of the conductive spring
The members are held at a distance at which static electricity can be discharged, and a mechanism portion constituted by the rotating member is charged through the gap between the tip of the conductive spring and the rotating member and the conductive spring. An electrostatic discharge structure characterized by discharging the generated static electricity to a ground pattern of a printed board. 2. An electrostatic discharge structure according to claim 1, wherein an insulating member having a passage for discharging static electricity is provided between the tip of the conductive spring and the rotating member . 3. A paper feeder installed in a printer, a scanner, etc.
The static electricity charged in the mechanism section composed of the rotating members of the device causes the noise generated by the printed board to flow into the mechanism section.
A discharge structure of static electricity for discharging, on the insulating part near the exposed portion of the ground pattern of the printed board on which noise is generated, it is possible to discharge static electricity to the ground pattern A conductive spring for electrostatic discharge is erected at a distance , and the conductive spring is
By applying pressure in the direction of the rotating member, the conductive spring
The tip and the rotating member charged with static electricity were brought into contact with each other, and the mechanism part constituted by the rotating member was charged through the conductive spring for electrostatic discharge and the gap between the conductive spring and the ground pattern. An electrostatic discharge structure characterized by discharging static electricity to a ground pattern on a printed circuit board.