JPH06291485A - Device for preventing radiation of electromagnetic wave noise - Google Patents

Abstract

PURPOSE:To reduce the electromagnetic wave noise radiated from the free end of a conductive plate-shaped member supporting an electromagnetic wave noise generating member. CONSTITUTION:An earthable member F is arranged along the free end 4a of a conductive plate-shaped member 4, and an elastic conductive member 14 for earthing is arranged for bringing the free end 4a in continuity with the earthable member F. By doing it this way, the radiation of the electromagnetic waves from the free end 4A can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing emission of radio wave noise for reducing the emission of radio wave noise radiated from a radio wave noise generating member to the outside of the device, and is particularly used for fax machines and copying machines. The present invention relates to a device for preventing radio wave noise radiation.

[0002]

2. Description of the Related Art The following techniques are known as this type of technique. (J01) (JP-A-1-214199, JP-A-63)
-43164, etc.) In the technologies described in these publications, in an electric device, in order to prevent the emission of radio noise to the outside of the device, a radio noise generating member that generates radio waves such as a printed circuit board. Also, a means for covering the conductive plate-shaped member and the like that supports it with a metal or a shield cover whose surface is conductively processed is used. (J03) (JP-A-56-66099, JP-A-60)
No. 169859, Japanese Utility Model Laid-Open No. 1-29896 (that is, the technology described in Japanese Utility Model Laid-Open No. 64-29896), and the like. In the technology described in these publications, a conductive member such as a shield cover is electrically connected to the frame ground. This helps stabilize against noise. Conventionally, various methods have been adopted as means for electrically connecting the conductive member to the frame ground. For example, a conductor for grounding is used, or as in the technique described in Japanese Utility Model Laid-Open No. 1-29896, an outer end portion of a shield cover is provided on an edge of a printed circuit board, and a guide member for guiding the edge of the printed circuit board is used. And is grounded.

[0003]

Although the emission of radio noise can be reduced by using the above-mentioned conventional technique, it was not sufficient. The reason why the reduction of the radio noise is not sufficient is that, when a conductive plate member having a free end portion (a portion which becomes an antenna for radiating radio noise) is used, conventionally, a reduction from the free end portion is caused. It is probable that no measures were taken to prevent the emission of radio noise. According to the research conducted by the present inventor, radio wave noise may be radiated not only by the radio wave generating member but also by a conductive plate-like member that supports or covers the radio wave generating member as an antenna. In particular, radio noise is likely to be radiated from the free end (edge portion) of the conductive plate-shaped member whose surface is made of metal or conductive.

Next, the research results will be described in detail with reference to FIGS. In FIG. 7, a radio noise generating member 01 such as a printed circuit board is supported by a noise generating member support base 02 made of a conductive plate member. The radio noise shield cover 03, which is made of metal or has a conductive process applied to the surface thereof, covers the radio noise generation member 01 so as to shield the radio noise emitted from the radio noise generation member 01.
Is fixed to the noise generating member support base 02 in a state of covering the. The noise generating member support base 02 is supported and grounded by a frame ground 04 as a groundable member by a support member (not shown). The radio noise shield cover 03 can prevent the emission of radio noise from the radio noise generation member 01. However, as described above, radio noise 06 is generated by using the free end portion 02a of the noise generating member support base 02 formed of the conductive plate member as an antenna.
Is emitted.

Therefore, as shown in FIG. 8, the inventor of the present invention, along with the free end portion 02a of the noise generating member supporting base 02, conducts a conductive spring (which connects the free end portion 02a and the frame ground 04). A grounding conductive member) 05 is arranged. This prevents the emission of radio noise using the free end 02a as an antenna.

In view of the above-mentioned circumstances and research results, the present invention has an object to be described in (O01) below. (O01) To reduce the radio noise radiated from the free end of the conductive plate member supporting the radio noise generating member.

[0007]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. Note that the reference numerals of the elements of the embodiments are enclosed in parentheses. Further, the reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.

In order to solve the above problems, the first aspect of the present application
An apparatus for preventing emission of radio noise according to the present invention is an apparatus for preventing emission of radio noise from a conductive plate-like member (4), characterized by having the following requirements (Y01):
Arranging a groundable member (F) along the free end (4a) of the conductive plate member (4), (Y02) Along the free end (4a) of the conductive plate member (4) Elastic grounding members (14, 141, 142, 14) for electrically connecting the free end portion (4a) and the groundable member (F).
Place 3).

The radio noise emission prevention apparatus of the second invention of the present application is characterized in that the radio noise emission prevention apparatus of the first invention has the following requirements.
(Y03) The conductive plate member (4) is a noise generating member support base (4) for supporting the radio noise generating member (6a).
To be.

The radio noise emission prevention apparatus of the third invention of the present application is characterized in that the radio noise emission prevention apparatus of the first or second invention has the following requirements (Y04): The free end (4a) is surface-treated to reduce the electric resistance.

(Supplementary explanation of means for solving the problem)
The elastic conductive member (14, 141, 142, 143) for grounding which electrically connects the free end portion (4a) of the conductive plate member (4) and the groundable member (F) to the free end portion (4). The reason for placing along 4a) is to ground as much of the free end (4a) as possible. That is,
This is because if there is a free end portion (4a) that is not grounded, radio noise may occur from there, and this is to prevent it. Elastic conduction member (14, 141, 142, 14
By using 3), the elastic conducting members (14, 14)
1, 142, 143) can contact (multi-contact) many parts of the free end portion (4a). The "multi-contact" means contact at a large number of points for preventing emission of radio noise from the free end, and means contact at a large number of continuous lines, surfaces and points. In each invention of the present application, the “groundable member (F)” also has a grounding frame member of the device for preventing radio wave noise radiation, and also has a function of being grounded for another function. Means a member or the like. Further, in the third invention, the reason why the surface treatment for reducing the electric resistance is performed is to ensure conduction.
This is also for grounding as much of the free end (4a) as possible as described above.

[0012]

(Operation of First Invention) Next, the operation of the first invention of the present application having the above-mentioned features will be described. According to the radiation noise radiation preventing apparatus of the first invention of the present application having the above-mentioned characteristics, the grounding elastic conducting member (14, 141, 142, 143) conducting to the groundable member (F) is provided. Since the elastic plate 3 is elastically deformed to make many contacts with the free end portion (4a) of the conductive plate member (4), the emission of radio noise from the free end portion (4a) can be reduced.

(Operation of Second Invention) Next, the operation of the second invention of the present application having the above-mentioned features will be described. According to the radio wave noise radiation preventing apparatus of the second invention of the present application having the above-mentioned characteristics, the conductive plate member (4) is a noise generating member support base for supporting the radio noise generating member (6a). is there.
Since the free end portion (4a) of the noise generating member support base (4) is grounded by the elastic conducting member (14, 141, 142, 143), the noise generated by the radio noise generating member (6a) is based on the noise. Secondary noise from the free end portion (4a) of the noise generating member support base (4) is reduced.

(Operation of Third Invention) Next, the operation of the third invention of the present application having the above-mentioned features will be described. According to the radiation noise radiation preventing apparatus of the third invention of the present application having the above-mentioned characteristics, the free end portion (4a) of the conductive plate member (4) is surface-treated so as to reduce the electric resistance. Therefore, the elastic conducting member (14, 141, 142, 143) can be more reliably conducted to the free end portion (4a), and the effect of preventing radio noise of the first invention of the present application is improved.

[0015]

EXAMPLES Examples of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples.

In the description of the embodiments of the present invention,
“Front” means the arrow X1 direction in the figure, and “rear” means the arrow X2 (see FIG. 1) direction in the figure. “Left” means the arrow Y1 direction in the figure (see FIGS. 1 and 2), and “right”
Means the direction of arrow Y2 in the figure. further,
“Upper” means the Z1 direction in the figure, and “lower” means the Z2 direction in the figure. Furthermore, in the figure,
"○" in "○" means an arrow from the back of the paper to the front, and "X" in "○" means an arrow from the front to the back of the paper. Shall mean. The X1 direction is the X axis, the Y1 direction is the Y axis, and the Z axis is
The Z axis is taken in one direction, and the plane perpendicular to the Z axis is called the XY plane.

(Embodiment 1) FIG. 1 is a vertical cross-sectional view of an image forming apparatus of a copying machine to which the embodiment 1 of the radiation noise radiation preventing apparatus of the present invention is applied. FIG. 2 is a view as seen from the line II-II in FIG. 1, and FIG. 3 is an explanatory view of the main part of the first embodiment. In FIG. 1, the copier is an image input terminal IIT (hereinafter, simply referred to as "II
"T") and the image output terminal IOT located below it (hereinafter simply "IOT")
That is) and. IIT is a portion provided with a document image reading element such as an exposure optical system and an image sensor,
IOT is a part for outputting the document image read by the IIT. The IIT includes a frame (hereinafter, referred to as “IIT frame”) F that supports the document image reading element. The IIT frame F has a portion used for grounding. That is, the IIT frame F is a groundable member.

The full rate carriage 1 which reciprocates in the left-right direction (Y1-Y2 direction) along a guide rail (not shown) supported by the IIT frame F is a light source 1a.
An illuminating device including the first mirror 1b and the like is mounted. The full rate carriage 1 reciprocates in the left-right direction while scanning the surface to be read of the document along the lower surface of the platen glass 2 on which the document is placed. The half rate carriage 3 includes a second mirror 3a and a third mirror 3b.
And is reciprocated in the left-right direction in FIG. 3 at a speed (1/2) of the speed of the full-rate carriage 1.

The original image reading light reflected from the reading surface of the original illuminated by the illuminating device of the full-rate carriage 1 is reflected by the second and third mirrors 3a and 3b, and the lens base (conductive plate-like member). ) 4 is incident on the lens 5. The lens 5 forms an original image on the image sensor 6 a on the image sensor substrate 6. As shown in FIG. 2, the lens base 4 is supported by support bases 7 as support members provided at both ends in the front-rear direction (X1-X2 direction), and the horizontal plane (X-Y
It is installed so that it can be adjusted in the plane. The image sensor substrate 6 is mounted on the conductive lens base 4 via the image sensor adjusting mechanism 8. The image sensor adjusting mechanism 8 is a mechanism that adjusts the position and orientation of the image sensor substrate 6 in order to focus the original image reading light incident through the lens 5 on the image sensor 6a.

The image sensor 6a converts the formed image into an electric signal and reads it. The read image signal is a signal line 6b connected to the image sensor substrate 6.
And is supplied to a device for forming an electrostatic image below the copying machine, that is, an IOT (image output terminal). The reading timing of the image sensor 6a is set by the driving clock. The frequency of the drive clock and an integral multiple thereof are generated as radio noise from the image sensor 6a. A conductive charge-coupled device cover (hereinafter referred to as a CCD cover) 9 is attached to the IIT frame F to reduce the emission of this radio noise to the outside. The conductive light-shielding cover 10 is fixed to the lens base 4 by a plurality of bolts 11 (see FIG. 2). The light shielding cover 10 is formed with a through hole 10a through which the original image reading light incident on the lens 5 passes. The CCD cover 9 is arranged inside the light shielding cover 10, and the CCD cover 9 and the light shielding cover 1 are arranged.
0 is conducted through the joining member 12 having conductivity and elasticity. The grounding wire 13 is connected to the IIT frame F and the CCD cover 9, which are grounding parts of the copying machine, and electrically connects the two.

Then, along the free end 4a of the lens base 4, a conductive leaf spring 14 as an elastic conductive member having a small surface electric resistance is arranged in the gap between the free end 4a and the IIT frame F. Has been done. As you can see from Figure 2,
In this embodiment, the conductive leaf spring 14 is divided into two pieces, but it is also possible to form one long piece, and it is also possible to divide it into three pieces or more. Is. Due to the elastic force of the conductive leaf spring 14, the conductive leaf spring 14 is in multiple contact with the free end portion 4a (point contact, line contact, and surface contact at many points). The free end portion 4a of the lens base 4 is surface-treated to reduce the electric resistance in the range where the free end portion 4a is in many contact with the conductive leaf spring 14.
That is, the cut surface of the sheet metal member forming the lens base 4 is exposed to reduce the surface electrical resistance and facilitate conduction.

As shown in FIG. 3, the lower portion of the conductive leaf spring 14 is U-shaped so that the conductive leaf spring mounting sheet metal 15 can be held. The upper part of the conductive leaf spring 14 extends obliquely upward from the upper end of the U-shape, and is divided into a large number in the X-axis direction by the slit 14a in the Y-axis direction so as to be easily deformed. The conductive leaf spring 14 is formed with a half punching hole 14b, and the conductive leaf spring mounting sheet metal 15 is fitted with the half punching hole 14b into a half blank (stop the punching process midway. The formed protrusion) is formed. The lower part of the conductive leaf spring 14 is pushed so as to be sandwiched by the conductive leaf spring mounting metal plate 15, and the half punch hole 14b and the half punch 15a are engaged with each other to move the conductive leaf spring 14 to the conductive leaf spring. It is attached to the mounting metal plate 15. The conductive plate spring mounting sheet metal 15 having a crank-shaped cross section is conductive and is fixed to the IIT frame F by a bolt (not shown) penetrating the bolt through hole 15b.

(Method of Attaching Conductive Leaf Spring 14) Next, a method of attaching the aforementioned conductive leaf spring (elastic conductive member) 14 will be described. Normally, the lens base 4 is an image sensor 6
The position can be adjusted in the XY plane in order to adjust the position and orientation of the optical system such as a and the lens 5. After the adjustment of the optical system is completed, the IIT frame F and the lens base 4 are fastened and the lens base 4 is fixed.

By the way, if the conductive leaf spring 14 is inserted between the lens base free end portion 4a and the IIT frame F before the adjustment of the optical system, the lens base 4 is moved upward (Z1 by the restoring force of the conductive leaf spring 14). Direction). After that, when the optical system is adjusted and the lens base 4 is fastened to the IIT frame F, the conductive leaf spring 14 contracts due to this fastening, and the lens base 4 moves down after fastening, which may cause an optical system misalignment. is there. In order to prevent this, the conductive leaf spring mounting sheet metal 15 is attached to the IIT frame F in advance before adjusting the optical system, and the conductive leaf spring 14 is attached to the conductive leaf spring after the adjustment of the optical system of the lens base 4 is completed. Attach to sheet metal 15. If the weight of the lens base 4 overcomes the restoring force of the conductive plate spring 14 and the lens base 4 cannot be pushed up in the Z direction, the conductive plate spring 14 is preliminarily connected to the lens base free ends 4a and I.
There is no problem even if it is inserted between it and the IT frame F.

(Operation of First Embodiment) Next, the operation of the first embodiment having the above-described structure will be described. Conductive leaf spring 14
Is elastically deformed along the lens base free end 4a to make multiple contact with the free end 4a, and the conductive plate spring mounting plate 15 held by the conductive plate spring 14 is an IIT as a groundable member. Since it is fixed to the frame F, the lens base free end 4a is electrically connected to the IIT frame F. As a result, radiation of radio noise from the free end 4a as an antenna is prevented.

(Embodiment 2) Next, Embodiment 2 of the radiation noise radiation preventing apparatus of the present invention will be described with reference to FIG.
In the second embodiment, instead of the conductive leaf spring 14 of the first embodiment,
A conductive leaf spring 141 is used. This conductive leaf spring 1
41 is a horizontal portion 141a facing the IIT frame F.
And an inclined portion 141b extending obliquely upward from the insertion side end portion (the left end portion in FIG. 4) of the horizontal portion 141a, and the inclined portion 141.
and a ground portion 141c extending downward from the upper end portion of b. Then, the horizontal portion 141a of the conductive leaf spring 141
Is fixed to the IIT frame F with the double-sided adhesive tape 16. The other configuration is the same as that of the first embodiment.

(Operation of Embodiment 2) The inclined portion 141b can make multiple contact with the lens base free end portion 4a, and the ground portion 141c.
Can be grounded to the IIT frame F, so that the lens base free end 4a is electrically connected to the IIT frame F. This allows
As in the first embodiment, the radiation of radio noise from the free end 4a as an antenna is prevented. Further, the conductive leaf spring 141 is directly connected to the IIT without using the metal leaf 15 for mounting the conductive leaf spring.
Since it can be fixed to the frame F, the assembly process can be simplified.

(Embodiment 3) Next, referring to FIG. 5, Embodiment 3 of the radiation noise radiation preventing apparatus of the present invention will be described.
In the third embodiment, instead of the conductive leaf spring 14 of the first embodiment,
A rectangular parallelepiped conductive urethane sponge 142 is used as the elastic conducting member. And this conductive sponge 14
Similarly, 2 is fixed to the IIT frame F with the double-sided adhesive tape 17. The other configuration is the same as that of the first embodiment.

(Operation of Example 3) This conductive sponge 1
The upper end surface of 42 makes many contact with the free end 4a of the lens base, and the protruding portions of the conductive sponge 142 on both sides of the double-sided adhesive tape 17 are grounded to the IIT frame F. Therefore, as in the first embodiment, the lens base free end portion 4a is II.
The T frame F is electrically connected to prevent the emission of radio noise from the free end 4a as an antenna. Further, since the conductive sponge 142 is used instead of the metal conductive leaf spring 14, an appropriate degree of elasticity can be easily obtained without processing such as providing the slit 14a.

(Embodiment 4) Further, FIGS. 6A to 6C.
A fourth embodiment of the radio wave noise radiation preventing apparatus according to the present invention will now be described. In the fourth embodiment, instead of the conductive leaf spring 14 of the first embodiment, a groove 143a is formed on the upper surface as an elastic conducting member.
A conductive sponge 143 having a substantially trapezoidal cross section is formed. The other configuration is the same as that of the first embodiment. When this conductive sponge 143 is inserted between the free end 4a of the lens base 4 and the upper surface of the IIT frame F, the protrusion at the left upper end is pushed downward and is bent (FIG. 6B). When the conductive sponge 143 is further inserted, the protrusion at the left upper end is in the original state of jumping up (FIG. 6C). In this way, the conductive sponge 143 is fixed to the lens base 4 by sandwiching the lens base 4 with the protrusion on the left upper end and the protrusion on the right upper end.

(Operation of Embodiment 4) Conductive sponge 143
The upper end surface of can make multiple contact with the free end 4a of the lens stand, and
The lower surface of the conductive sponge 143 is grounded to the IIT frame F. Therefore, as in the first embodiment, the free end 4a of the lens base is electrically connected to the IIT frame F, and the emission of radio noise from the free end 4a as an antenna is prevented. Also, no other member is required to fix the conductive sponge 143. When the elastic member is deteriorated due to aging or the like and is replaced, the conductive sponge 143 can be easily replaced.

(Modifications) The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and is within the scope of the gist of the present invention described in the claims. Thus, various changes can be made. A modified embodiment of the present invention is illustrated below.

(H01) In the above embodiment, as a surface treatment for reducing the electric resistance of the free end portion 4a, the cut surface of the sheet metal member forming the lens base 4 is exposed, and a plating treatment such as copper plating is applied to it. Is possible. (H02) In the first embodiment, the conductive leaf spring 14
It is also possible to adopt a conductive leaf spring having no slit 14a. (H03) The present invention can be applied not only to a fax machine and a copying machine, but also to electronic devices such as electronic computers, personal computers, and televisions that generate radio noise. (H04) In Example 3, the sponge was made of urethane, but various raw materials can be adopted as long as it has elasticity and conductivity. (H05) In each of the above embodiments, the support member 7 has a support function and a ground function, but it is also possible to employ a support member that does not have a ground function. (H06) Elastic conducting member 14, 141, 14 of the present invention
Examples of the structure of Nos. 2 and 143 are a single structure having a small surface electric resistance, a composite structure such as a multilayer structure in which only one part of the layer has conductivity, a conductive structure obtained by a post-treatment such as plating, and the like, and the lens base free end portion Various structures are possible as long as they have a function of electrically connecting the free end portion (4a) of the conductive plate member (4a) and the IIT frame (groundable member) F, and the material thereof is also metal, conductive plastics, conductive material. It is possible to use various materials such as a sponge. Further, the elastic conducting members 14, 141, 142, 143 used in each of the above-mentioned embodiments can be variously changed in shape, elastic value and the like.

[0034]

The device for preventing radio wave noise radiation according to the present invention described above can achieve the following effects (E01) and (E02). (E01) The radio noise radiated from the free end of the conductive plate member supporting the radio noise generating member can be reduced. In addition, the above-described radiation noise radiation preventing apparatus of the second invention of the present application can exert the following effects. (E02) The elastic conductive member can be more completely conductive with the free end portion, and the radio noise can be reliably reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of a radio noise radiation emission preventing apparatus according to the present invention, and is a diagram showing the present invention applied to an image forming apparatus of a copying machine.

FIG. 2 is a view seen from the line II-II in FIG.

FIG. 3 is an explanatory diagram of a mounting structure of a conductive leaf spring according to the first embodiment.

FIG. 4 is an explanatory diagram of a main part of a second embodiment of the radio noise emission prevention apparatus of the present invention.

FIG. 5 is an explanatory diagram of a main part of a third embodiment of the radio noise emission prevention apparatus of the present invention.

6A and 6B are explanatory views of the essential parts of Embodiment 4 of the device for preventing radio wave noise radiation according to the present invention. FIG. 6A is before insertion of the elastic sponge, FIG. 6B is during insertion of the elastic sponge, and FIG. 6C is insertion of the elastic sponge. It is a figure which shows the back.

FIG. 7 is an explanatory diagram of a main part of a conventional device for preventing radio wave noise radiation.

FIG. 8 is a cross-sectional view of a conventional radio noise emission prevention device.

[Explanation of symbols]

4 ... Conductive plate member (lens base), 4a ... Free end portion, 6a
... radio noise generating member (image sensor), 7 ... support member (support base), F ... groundable member (IIT frame),
14, 141, 142, 143 ... Elastic conductive member (conductive leaf spring, conductive sponge)

Claims (3)

[Claims] 1. A device for preventing the emission of radio wave noise from a conductive plate member, which is provided with the following requirements: (Y01) Freedom of the conductive plate member Arranging a groundable member along the end portion, (Y02) An elastic conductive member for grounding that connects the free end portion and the groundable member along the free end portion of the conductive plate member. Placed. 2. A device for preventing radio wave noise radiation according to claim 1, wherein the conductive plate member supports the radio noise generation member. Be a stand. 3. The device for preventing radio wave noise radiation according to claim 1 or 2, characterized by the following requirements: (Y04) The free end is surface-treated to reduce electrical resistance. thing.